Abstract:Food is a kind of multiphase and multicomponent complex system,and its component structure directly determines its quality function.With the in-depth understanding of the multi-scale structure changes of characteristic components in food processing and the in-depth intersection and integration of physics,chemistry,biology and material science,the multi-scale structure changes and quality function regulation of food also present a new direction and trend.In this paper,the basic concept,connotation and denotation of multi-scale structure of food were firstly proposed,and the research status and latest progress of multi-scale structure change and quality function of food were summarized,aiming to enrich the basic theoretical system of food structure-activity relationship and provide theoretical basis and technical approach for precise control of quality function in food processing.

Abstract:In this study,the trans-well co-culture system of Caco-2 monolayer cells and HaCaT cells was established,and the effects of resveratrol,kaempferol,punicalagin,fisetin and oenothein B on SIRT3 expression were evaluated by the SIRT3-EGFP reporter gene system in HaCaT cells,as well as the protective effect of the selected SIRT3-augmenting polyphenols on UVB-induced oxidative stress in HaCaT cells were further investigated.The result showed that resveratrol,kaempferol and oenothein B significantly enhanced the expression of exogenous and endogenous SIRT3 gene;among them,oenothein B significantly reduced the level of ROS in HaCaT cells;however,knockdown SIRT3 expression significantly reduced the inhibitory effect of oenothein B on UVB-induced oxidative stress.In conclusion,the inhibition effect of oenothein B on UVB-induced ROS generation depends on SIRT3 in the co-culture system of Caco-2 cells and HaCaT cells.

Abstract:Objective:Lactobacillus plantarum RX-8 was isolated from Chinese traditional pickles and shown to produce plantaricin EF,a genetically characterized inducible class IIb bacteriocin.It has broad spectrum antibacterial ability,good processing application characteristics and great potential application as a natural food biological preservative.However,plantaricin EF encounter various limits both in industrial fermentation and application because of its low synthesis.This work aimed at showing the effect of exogenous microorganisms act as an environmental stimulus activating plantaricin EF production by Lactobacillus plantarum RX-8.Method:Based on the existing conventional pure culture conditions and the main influencing factors of bacteriocin production by strain RX-8,two pure culture model systems with low and no bacteriocin production were established.Aliquots of the 16 strains from different fermented food sources were added to fresh MRS broth containing Ca.108 CFU/mL of an overnight culture of Lactobacillus plantarum RX-8.By comparing the bacteriocin antibacterial activity in co-culture and pure culture,the best co-culture induced strains and their conditions were screened and determined.To study the specific types of induction,the inducing activity of different treatments with living-cells and supernatants were tested.Results:When Bacillus subtilis BS-15 from grain vinegar was co-cultured with the strain RX-8,it showed significant induction ability (P<0.01).The best bacteriocin production was induced by co-cultivation as follows:the optimal inoculation ratio of Bacillus subtilis BS-15 and Lactobacillus plantarum RX-8 was 10:1,and the inoculation concentration was 108 CFU/mL and 107 CFU/mL respectively.It was speculated that the induction was caused by the protein substances secreted by Bacillus subtilis BS-15.Conclusion:Taken together,the results suggest that the presence of specific microorganisms act as environmental stimulus activating plantaricin EF production.Microbial co-cultivation can be used as an important technical means to increase the production of lactic acid bacteria.

Abstract:Ochratoxin A(OTA) is a fungal toxin widely distribute in food.Reducing or eliminating OTA in food and its raw materials is of great significance in improving food quality and ensuring national food safety.Previously,the amide hydrolase AF-OTd (Alcaligenes faecalis OTA degrading enzyme),which can degrade OTA,was identified from Alcaligenes faecalis in the laboratory.In this study,the protein AF-OTd was highly expressed through gene recombination,and the enzymatic properties of the purified AF-OTd protein were analyzed.The results showed that the degradation rate of the purified AF-OTd enzyme for OTA was over 90%,and the degradation activity was affected by temperature,pH,alcohol and metal ions.The optimal temperature and pH of the enzyme were 50 ℃ and 7.5,respectively.Increase of alcohol content lead to a decrease of enzyme activity.When the alcohol content increased to 8%,the remaining enzyme activity was almost zero.1 mmol/L of metal ions Ca2+,CO₂+,Cu2+,Mg2+,Mn2+,Zn2+,K+ and EDTA have different degrees of inhibition on the enzyme.At the same time,it was also found in this study that trace amounts of CO₂+ and Zn2+ could significantly promote the activity of AF-OTd.

Abstract:The objective of this study was to investigate the porcine pancreatic α-amylase(PPA) inhibitory activity of glutenin and gliadin.The half maximal inhibitory concentration (IC50) was determined,and the kinetics of inhibition were investigated using Dixon and Cornish-Bowden plots.The results showed glutenin was mixed inhibitors with competitive and uncompetitive inhibitory impacts on α-amylase,while gliadin showed competitive inhibitory effects on α-amylase.The competitive inhibition constants (Kic) of glutenin and gliadin were (20.533±3.582),(49.619±5.949) mg/mL,respectively,and the uncompetitive inhibition constants (Kiu) of glutenin was (49.358±9.779) mg/mL.The IC50 values of glutenin and gliadin were (14.014±1.089) mg/mL and (33.193±0.621) mg/mL,respectively.For glutenin,the lower Kic vs.Kiu suggested that glutenin bound more tightly to free PPA than the PPA-starch complex.Compared with gliadin,glutenin displayed a stronger inhibitory effect on α-amylase.These results indicated that glutenin and gliadin may delay the digestion of starchy foods by inhibiting starch hydrolytic enzymes.And these results will enrich the mechanism of protein regulation of starch digestion.The findings are also of important practical value for the development of carbohydrate-restricted diet and protein-based functional foods.

Abstract:This study aims to explore the potential utilization of sweet orange peels.In this paper,flavonoid compounds in the peels of blood orange,navel orange,egyptian orange,and sunkist orange were extracted,and the contents of 11 flavonoid compounds were analyzed by HPLC.Then the bioactive functions in four sweet orange peels were investigated in vitro.The results manifested that there were abundant flavanone compounds in the sweet orange peels,such as eriocitrin,narirutin,and hesperidin,and the contents of polymethoxyflavonoids were less than that of flavanone compounds.The comprehensive APC index of flavonoids in sweet orange peels ranged from 86.20% to 99.47%.The inhibitory ratio of α-glucosidase varying from 46.16% to 70.18%.Moreover,the bile acid salt binding experiment indicated that sweet orange peels flavonoids could bind bile acid sodium,sodium taurocholate,and sodium glycocholate.The adsorption capacity was within the range of 0.359 to 0.460 μmol/mg.Pearson correlation analysis showed positive correlations between the biological activity and the total content of 11 flavonoids.This study provided theoretical support for the development of antioxidative,hypoglycemic,and lipid-lowering functional products using sweet orange peels.

Abstract:Lactic acid bacteria exopolysaccharides have the characteristics of increasing the viscosity of fermented milk,preventing the precipitation of whey,and enhancing the strength of curd.It is currently one of the research hotspots in the field of food science.In this study,the basic medium M17 was used as a control,and the compound nitrogen source of M17 liquid medium was replaced with soy peptone,tryptone and casein peptone to explore the effect of different nitrogen sources on the yield,molecular weight and structure of the extracellular polysaccharide of Streptococcus thermophilus IMAU20561.The results showed that the yield of extracellular polysaccharide in M17 medium with soy peptone as the sole nitrogen source for Streptococcus thermophilus IMAU20539 reached 480.7 mg/L,which was much higher than the yield of polysaccharides obtained from the other three mediums.Among them,the M17 medium with soy peptone as the sole nitrogen source had the highest production of extracellular polysaccharides,reaching 480.7 mg/L.Much higher than the yield of polysaccharides from the other three media.The EPS fractions of the crude EPS obtained from different nitrogen sources were different after purification,and the molecular weight of each EPS fraction was also significantly different.The M17 medium with casein peptone as the sole nitrogen source had the highest EPS (5.964×105 u),followed by basic medium M17 (1.260×105 u),soybean peptone medium (6.635×104 u) and tryptone medium (1.192×104 u).There were significant differences in the structure of polysaccharides obtained from different nitrogen sources.The EPS obtained from soy peptone medium is mainly composed of galacturonic acid,galactose and arabinose;the EPS obtained from the tryptone medium mainly consists of glucuronic acid,glucose and galactose.The EPS obtained from casein peptone medium and basic medium M17 had similar monosaccharide composition,mainly composed of mannose,glucose and galactose,and the percentages were 10.46:1.62:87.37 and 20.37:2.77:74.91,respectively.

Abstract:In this study,with Lactobacillus rhamnosus GG (LGG) as control strain,probiotic probiotic Lactobacillus plantarum BF_15,isolated from breast milk infant,was used as the research object to evaluate its antioxidant activity in vitro,safety and alleviation of the DSS-induced oxidative damage in the colon of mice.The results show that the test strain Lactobacillus plantarum BF_15 could tolerate high concentrations of H2O₂ (3.5 mmol/L).In the fermentation supernatant,the scavenging ability of strain BF_15 on DPPH was lower than that of the control strain LGG (P＜0.01);the scavenging ability of oOH was higher than LGG (P＜0.05);the scavenging ability of ·O₂- was higher than LGG (P＞0.05);anti-lipid peroxidation ability was lower than LGG (P<0.01).In the bacterial suspension,the scavenging ability of strain BF_15 on DPPH and ·O₂- was higher than that of the control strain LGG (P>0.05);the scavenging ability on ·OH was higher than LGG (P＜0.01);the anti-lipid peroxidation ability was lower than LGG (P<0.01).Meanwhile,Neither the test strain BF_15 nor the control strain LGG produced harmful metabolites (bioamine,nitrite,indole),and had hemolytic properties.In animal experiments,the strain BF_15 could reduce the degree of intestinal mucosal damage and inflammatory cell infiltration,increase the activity of superoxide dismutase (SOD) (P<0.01),and reduce the level of malondialdehyde (MDA) content (P<0.01) through early intragastric administration,which effectively alleviated the symptoms of DSS-induced oxidative damage in the colon of mice;its effect was equivalent to that of the control strain LGG (P>0.05).This study provided a scientific basis for the development and application of probiotics derived from human breast milk infants and their early intervention to relieve intestinal diseases such as ulcerative colitis(UC).This study laid a solid foundation for probiotics in the prevention of intestinal diseases such as ulcerative colitis (UC),and provided a reference guide for oxidative stress as a new therapeutic target.

Abstract:Purpose:To explore the effect of camel milk on the diversity and structure of intestinal microflora in mice with chronic alcoholic liver injury.In this experiment,male C57BL/6NCr mice were randomly divided into 4 groups:control group (Con,n=6),model group (Et,n=6),camel milk dose group (EtCM,n=6) and cow milk dose group (EtNM,n=6);the experiment was conducted for 8 weeks,the first 4 weeks were fed with Lieber-DeCarli liquid feed (including control),and the following 4 weeks were fed with corresponding milk or saline on the basis of feeding Lieber-DeCarli liquid feed.After the gavage,the NIAAA model was established by gavage 31.5% alcohol solution at a dose of 5 g/kg.Serum LPS content was detected,and colonic feces of mice were collected under sterile conditions for 16S rRNA sequencing,and intestinal flora alpha diversity,beta diversity,and species structure based on genus and genus levels were analyzed.Serum index results showed that serum LPS of mice in EtCM group and EtNM group was significantly reduced (P < 0.01).16S rRNA sequencing results showed that camel milk and cow milk significantly increased the abundance and uniformity of the colonic intestinal flora of ALD mice,and better adjusted the structure of intestinal flora;among them,camel milk showed better alpha diversity than cow milk.At the phylum level,camel milk and cow milk significantly increased the abundance of Bacteroides phylum and decreased the abundance of thick-walled phylum.At the genus level,camel milk and cow milk significantly increased the abundance of Bacteroides,Bacteroides,and Ackermania,and reduced the abundance of the unknown genus Ruminococcaceae_UCG-013 under the Rumenaceae family.Among them,the beneficial bacteria abundance of camel milk is 9% higher than that of cow milk.Conclusion:Camel milk can adjust the intestinal flora structure by changing the intestinal flora environment of ALD mice.It shows that camel milk can be used as a functional dairy product to regulate intestinal flora,and can prevent intestinal barrier dysfunction caused by chronic ALD.

Abstract:Acaudina molpadioides is a low-value sea cucumber produced from the southeast coast.It is inexpensive and has hypoglycemic, hypolipidemic, and antioxidant activities.However, its effect on fracture healing has not been reported.In this study, Female C57BL/6 mice underwent right tibia open fracture surgery and were randomly divided into model control group, Apostichopus japonicus group (500 mg/kg BW) and Acaudina molpadioides group (500 mg/kg BW).The tests were performed on the 5th, 10th, and 21st days to explore the effect and mechanism of Acaudina molpadioides on the fracture healing process.Serum dynamic test results showed that on the 10th postoperative day, the serum Col10α concentration in the Acaudina molpadioides group was significantly reduced by 19.31% compared with the model group, and the serum MMP13 by 14.91%.It is suggested that compared with the model group, the chondrocytes in the Acaudina molpadioides group changed from proliferation to hypertrophy and differentiation in advance, which accelerated the healing process.H&E staining results show that compared with the model group, the intervention of Acaudina molpadioides and Apostichopus japonicus can promote the formation of fibrous callus on the 5th postoperative day, postoperative The formation of cartilage callus on day 10 and the formation of lamellar bone and the reconstruction of hard callus on day 21 suggest that the intervention of Acaudina molpadioides can accelerate the process of ossification in cartilage.Further q-PCR results showed that on the 10th day after surgery.The intervention of Acaudina molpadioides can activate Ihh and Smads/Runx2 signals, and down-regulate the transcription levels of key factors Ihh, Patched, Gli1, Gli2 and Smad1, Smad4, Smad5, and the transcription of Col10α is significantly down-regulated, suggesting that Acaudina molpadioides intervention can cross the cartilage faster.The hypertrophic stage of the cells enters the period of mineralization and osteogenesis.At this time, the significant increase in the transcription level of the bone growth factor ALP and Col1α also further proves the role of Acaudina molpadioides in accelerating the fracture healing process.Its effect is similar to that of Apostichopus japonicus.In summary, Acaudina molpadioides can regulate cartilage hypertrophy and accelerate the process of intra-cartilage ossification by mediating Ihh-PThrp and Smads/Runx2 signaling pathways to promote fracture healing, and its effect is equivalent to Apostichopus japonicus.This study provides a theoretical basis for the further development of Acaudina molpadioides and its application in fracture healing.

Abstract:In view of the current backward technical level of high-efficiency direct-injection starter in China and the widespread problem of yoghurt post-acidification in applications,it is imperative to develop a weak post-acidification high-efficiency direct-injection starter with independent intellectual property rights.In this paper,the self-selected weak post-acidification Lactobacillus bulgaricus Lb-s1 rp-1 was used as the starting strain,and the proliferation culture was carried out on an optimized carrot juice complex bacteria culture medium.Firstly,the effects of single factors such as culture temperature,culture method,initial pH value of medium and inoculation amount on the growth of weak post-acidification strains were studied,and then the fermentation conditions of batch culture in shake flasks were optimized by L9(33) orthogonal experiment.The effects of pH adjustment,glucose feed supplementation,both pH adjustment and glucose feed supplementation on the growth of weak post-acidification strains were studied through expansion culture experiment in 50 L fermenter with batch expansion culture as a control.The results showed that the optimal bacterial growth conditions for the weak post-acidification Lactobacillus bulgaricus Lb-s1 rp-1 in laboratory shake flask batch culture were:the culture temperature was 37 ℃,the initial pH of the medium was 6.5,and the amount of inoculation was 1.0%,static culture,under which process condition the strain was cultured,the time to reach the end of logarithmic growth was 6 h,and the number of live bacteria in the stationary phase was 2.28×1010 CFU/mL.The strains were cultured in three different feeding methods in 50 L fermenter.The time to reach the end of logarithmic growth was 8,6 h,and 8 h,respectively and the number of live bacteria in the stationary phase was 2.29×1010,2.39×1010,2.48×1010 CFU/mL,which was not significantly different from the number of live bacteria in batch expansion culture (P>0.05).Therefore,it is feasible to expand the cultivation of weak post-acidification Lactobacillus bulgaricus Lb-s1 rp-1 by batch fermentation in 50 L fermenter.This study provides a low-cost cell proliferation culture technology for industrialized production of weak post-acidification Lactobacillus bulgaricus direct-injection yogurt starter,and also provided a reference for the study of other cell culture techniques of weakly acidified probiotic bacteria.

Abstract:In order to solve the problem of incomplete deinsectization caused by uneven heating of radio frequency,this paper studied the role of pore dispersion structure in improving the radio frequency heating rate and the heating uniformity and its application in insecticidal application from the aspects of pore direction,hollow solid,pore number,pore diameter and distribution mode.Taking rice as an example,it was found that the vertical dispersed structure was superior to the horizontal structure and the hollow structure was superior to the solid core in promoting the heating rate.With the same pore size,the more holes,the better the effect.With the same number of holes,the larger the diameter,the better the effect.The equidistant distribution has the highest heating rate,but the concentrated distribution of the cold area has the best heating uniformity.After using the 12-pore 22 mm dispersed structure for radio frequency deinsectization,the death rate of adult rice weevils in the samples increased from 16.8% in the control group to 100% after heating for 7 min.For the red flour beetle,the death rate increased from 8.7% in the control group to 98.1% after radio frequency heating for 10 min.

Abstract:In the process of cider fermentation,Saccharomyces cerevisiae will make metabolic responses to various stresses and environmental changes.Chlorogenic acid is a relatively high content of apple polyphenols in apples and cider.This study selected chlorogenic acid as a representative apple polyphenol to investigate the effects of different concentrations on the physiological characteristic of Saccharomyces cerevisiae.The results showed that Saccharomyces cerevisiae CICC 31084 improved the resistance to stress by changing the activity of superoxide dismutase (SOD),catalase (CAT) and the content of intracellular malondialdehyde (MDA) under the stress of chlorogenic acid.Among them,SOD activity gradually increased with the increase of chlorogenic acid's concentration.The stress of low concentration of chlorogenic acid(0.01 g/L)promoted the increase of CAT activity of Saccharomyces cerevisiae.The content of MDA was reduced in the early fermentation stage,and increased in the late fermentation stage under the stress of chlorogenic acid.With the extension of the fermentation time,the concentration of key aroma substances in cider gradually increased,which reached the maximum in the middle of fermentation,and then gradually decreased and stabilized.Correlation analysis showed that the concentration of key aroma substances,such as phenylethyl alcohol,phenylethyl acetate,isoamyl acetate,and ethyl caprate were positively correlated with the concentration of chlorogenic acid,the correlation coefficients respectively were 0.133,0.253,0.026,0.114;ethyl caprylate and ethyl caproate were negatively correlated with the concentration of chlorogenic acid,the correlation coefficients were -0.012 and -0.248.

Abstract:Using the scraps such as the stalks of bisporus mushrooms and irregular mushrooms produced in the factory as raw materials,the protein of Agaricus bisporus is extracted by the alkaline solution and acid precipitation method,after ultrasonic treatment,trypsin,alkaline protease and composite protease were selected to hydrolyze the protein.By measuring the degree of protein hydrolysis and ACE inhibition rate,the best kind of protease was determined.In order to obtain the active peptide with higher ACE inhibition rate,the enzymatic hydrolysis conditions were optimized by using response surface methodology(RSM).The results showed that the ACE inhibition rate of A.bisporus protein hydrolyzed by alkaline protease was the highest.The optimal process parameters were as follows:the addition amount of alkaline protease was 6.25 mg/100 mL,the hydrolysis temperature was 40.47 ℃,the hydrolysis time was 92.97 min,and the hydrolysis pH was 8.04,the ACE inhibition rate can reach 43.75%.A verification test was performed under the condition,and the ACE inhibition rate of the hydrolyzed solution was 43.4%,which was close to the predicted value.After ultrafiltration and vacuum freeze-drying,the peptide sample with potential ACE inhibitory activity was prepared,and the yield was 24.36 mg/g.The industrial production prospect was good,which could provide a new way for the high value utilization of the industrial scraps of A.bisporus.

Abstract:The gelatinization characteristics,physicochemical indexes,dough rheological properties and sensory quality and texture characteristics of steamed bread were studied after adding different proportions of highland barley whole flour (QF) and highland barley peeled flour (TPF) in high gluten wheat flour.The results show that:the addition of QF and TPF had a negative effect on the gelatinization characteristics,which made the flour more difficult to gelatinize.The falling value of QF composite powder decreased from 370.5 s to 300.5 s,but the TPF composite powder decreased at first and then increased.The sedimentation value of QF and TPF composite powder were decreased by 21.94% and 20.28%,respectively.The addition of QF increased the damaged starch from 27.0% to 28.6%,but the TPF compound powder was not changed without the additive amount of 10%.With the increase of QF and TPF,the farinograph and tensile properties of highland barley dough were significantly affected.The structure of highland barley dough gradually became loose,not easy to form,hardness increased,elasticity became poor,and muscle strength became weak.Sensory score and texture characteristics of highland barley steamed bread also showed with the increase of barley powder downward trend.

Abstract:Cell wall polysaccharides are the main components of the dry matter of fruits and vegetables and material basis that determines the texture formation of dried fruits and vegetables.In order to explore the influence of cell wall polysaccharides on the textural quality of restructured apple chips produced by vacuum freeze drying,three polysaccharide components of apple cell walls,e.g.alcohol-insoluble residue (AIR),soluble dietary fiber (SDF) and insoluble dietary fiber (IDF) were extracted and then added to the restructured apple chips with various relative contents.The results showed that the hardness of the chips increased by 0.56%-214.13% and the brittleness decreased by 21.67%-65.14% after adding the cell wall polysaccharide components.Moreover,the hardness of chips was increased by 214.13% and the brittleness was reduced by 52.89% after simultaneously adding 2% IDF and 2% SDF.The addition of cell wall polysaccharides can significantly increase the Tg and reduce moisture absorption of chips,while reduce the broken rate of the product.The restructured apple chips with the addition of SDF exerted the porous microstructure as compared with other polysaccharides.Conclusion:The cell wall polysaccharide component is an important factor that regulates the texture formation of the vacuum freeze-dried restructured apple chips.

Abstract:The effect of phytosterol organogelators (β-sitosterol:γ-oryzanol=2:3,m:m) on the network structure and oxidation characteristics of soybean oil oleogels were studied.The results showed that when the addition amount of phytosterol organogelators was within the range of 2% to 10%,the storage modulus (G') of soybean oil oleogels of 6% was always higher than loss modulus (G''),which indicated that the system had formed a stable solid-like gel structure.Polarized light microscopy showed that 6% oleogels appeared a regular and compact aggregation state after stored at 45 ℃ for 10 days,with a peroxide value of 15.59 mmol/kg,a malondialdehyde content of 1.49 mg/kg,and a headspace oxygen consumption of 24.19%,showed the best oxidation stability.2% to 10% of β-sitosterol or γ-oryzanol was added to soybean oil respectively,the headspace oxygen consumption of the sample showed that β-sitosterol had an anti-oxidant effect,and γ-oryzanol had a pro-oxidant effect.After heated at 180 ℃ for 2.5 hours,the headspace oxygen consumption of 6% phytosterol oleogels was 5.00% lower than the control,showed a good thermal oxidation stability.Meanwhile,both Rao and Rad acquired from 1H NMR spectra had a good positive correlation with the total oxidation value of phytosterol oleogels during the thermal oxidation at 70 ℃.

Abstract:The foaming property of egg white protein is widely used in bakery food.In order to improve the foaming property of egg white liquid,high field intensity ultrasound (20 kHz) with different ultrasonic power (120,240 W) and ultrasonic time (1,5,10,20,30 min) was set to modify the egg white protein.It was found that the foaming ability of egg white was the best (266.7%) when treated with 120 W ultrasound for 20 min,which was 6.9 times of that of untreated egg white.Ultrasonic treatment significantly reduced the viscosity,surface tension and particle size of the egg white (P < 0.05),which made the protein molecules more easily adsorbed to the gas-liquid interface for unfolding and rearrangement.The results of zeta potential indicated that the negative charge on the protein surface was significantly decreased at 120 W for 20 min compared with untreated egg white (reduced from -14.47 to -8.16 mV,P < 0.05).The rheology results showed that the protein membrane of egg white at the interface was always dominated by elasticity,showing the properties of viscoelastic solid,and the ultrasonic treatment didn't change its fluid state,showing a pseudoplastic fluid state all the time.

Abstract:In this study,microfibril film was prepared by konjac glucomannan (KGM) combined with polyacrylamide (PAAM) via microfluidic spinning technology.The rheological properties of the obtained KGM/PAAM sol were measured,the microfibril film was characterized by FT-IR,GTA,SEM and XRD.The ofloxacin particles were further loaded into the microfiber for antibacterial experiments.The results revealed that:(1) The optimum ratio of KGM/PAAM sol was:KGM:PAAM (mass ratio) = 1:1;(2) The KGM/PAAM microfibril film prepared formed an ordered network structure,with the fiber diameter of 100 μm,and the thermal stability of the film was enhanced.(3) The antibacterial experiment results reveled that KGM/PAAM microfibril film had good antibacterial properties,it had obvious antibacterial effect on Vibrio parahaemolyticus,and the inhibition zone diameters for Escherichia coli and Staphylococcus aureus were 39.6 mm and 31.5 mm,respectively.The purpose of this work is to provide a theoretical basis for the development of new antibacterial materials.

Abstract:The effect of storage temperature on the quality indexes and total number of colonies of fresh-cut kiwifruit slices treated with low-temperature plasma were studied,and the shelf life prediction models of quality indexes and total number of colonies were established.The fresh-cut kiwifruit slices treated with low-temperature plasma were stored at 0,5,10,15,20,25 ℃,and the VC content,chlorophyll content,total phenol content,total colony count,brittleness,color aberrations and solid-acid ratio were measured regularly.The effect of different temperatures on the quality indexes and the total number of colonies were explored.The fitting equations of monitoring indexes were determined.The shelf life prediction models of the quality indexes and the total number of colonies of fresh-cut kiwifruit slices were established by combining the Arrhenius model and the Belehradck model.The results show that the storage temperature has no significant effect on the solid-acid ratio,total phenol content and chlorophyll content,while the storage temperature has significant effect on color aberration,brittleness,VC content and total colony count.The changes of VC content,brittleness,color aberration and total colony count of fresh-cut kiwifruit slices treated with low-temperature plasma follow the first-order reaction,first-order reaction,zero-order reaction and Logistics equation models respectively during storage.The shelf life prediction models (SLbrittleness,SLcolor aberration,SLVC,SLcolony) of fresh-cut kiwifruit slices quality index and total bacterial colonies was effective.The relative errors of the shelf life prediction models were 4.03%,3.41%,2.4% and 2.8% respectively under the storage condition of 3 ℃.The models can be used to predict the shelf life of fresh-cut kiwifruit slices treated with low-temperature plasma under 0-25 ℃ storage conditions.

Abstract:In order to explore the storage and preservation effect of atmospheric plasma on cold fresh pork,effect of air,nitrogen and argon discharge plasma treatment on the quality and sanitation levels of cold fresh pork was investigated,including variations of quality indicators such as sensory evaluation,Red value,total number of colonies,volatile base nitrogen (TVB-N).The results showed that different discharge gas treatment enhanced the sensory evaluation and red value of pork.The total number of bacterial colonies and TVB-N test showed that gliding arc discharge treatment could prolong the storage life of pork,among which argon treatment was the best,and nitrogen and air discharge treatment promoted the fat oxidation of cold fresh pork,as consistent with the morphology results of plasma treated samples.These results showed that effect of atmospheric plasma treatment depends on the type of discharge gas species.Based on the index situation of comprehensive fresh-keeping quality,argon discharge plasma showed its owning advantages in improving water retention and sensory performance while reducing microorganisms on the surface of cold fresh pork,which would provide a new treatment method for the storage and preservation of cold fresh pork.

Abstract:Brassica chinensis L.is a typical green leafy vegetable which is easy to senesce and yellow after harvest.The effects of different concentrations of melatonin (MT) (0.2,0.4,0.6,0.8 mmol/L) on the storage quality of Brassica chinensis L.were studied.The results showed that MT treatment could effectively delay the senescence,keep the good color,delay the increase of weight loss rate and yellowing rate,and keep the higher contents of chlorophyll,vitamin C,soluble solids and reduce sugar.In addition,MT treatment also significantly increased the activities of peroxidase and polyphenol oxidase.Among the four different melatonin concentrations,0.6 mmol/L melatonin was the most suitable for the storage and preservation of Brassica chinensis L.The results provided theoretical basis and technical support for the storage and preservation of Brassica chinensis L.

Abstract:In order to reveal the inhibitory effect of the extract of fermentation broth from Streptomyces lavendulae X33 (hereafter referred to as SLFE) on Penicillium digitatum (P.digitatum),a postharvest pathogen of citrus,the cellular integrity and related cell contents of P.digitatum treated with SLFE were determined.Scanning electron microscope,Raman spectrum,fluorescence probe,fluorescence spectrum and fluorescence quantitative PCR were used to observe the effects of SLFE treatment on mycelium morphology,cell response and DNA.The results showed that the hyphae of the strain Pd165 appeared withered,twisted and folded,and the conidiophores and conidia were abnormal by the treatment of 1.2 mg/mL SLFE,and moreover,the sporulation inhibition rate was as high as 94.86%.At the same time,the cell integrity of the strain was seriously damaged by SLFE,which acted as triggers for an increase in the characteristic peaks of fatty acids,nucleic acids and proteins in the extracellular supernatant (1 129,1 330,1 565 cm-1),and the massive exudation of intracellular sugars,nucleic acids and soluble proteins,and a decrease of the pyruvate content.In addition,SLFE treatment destroyed the conformation and structure of P.digitatum genomic DNA and upregulated the expression levels of genes related to cell integrity,sporulation,metabolism and oxidative stress (cej60377.1,oko99898.1,crl18986.1,kzn90160.1).The results suggested that SLFE treatment damaged the integrity of P.digitatum cells,disturbed the original homeostasis of cells,and seriously destroyed the conformation of DNA and the morphology of mycelium.

Abstract:In this study,non-target metabolomics methods were used to study the metabonomic differences between trimethoprim-sulfamethoxazole (SXT) -resistant and sensitive strains of Listeria monocytogenes.Ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) was used to obtain the intracellular metabolic profile information of the strains contained by SXT-resistant and sensitive strains.OPLS-DA discriminant models were established to illustrate the metabonomics differences,then the number and type of different compounds were qualitatived and their regulatory expression in metabolic pathways were analyzed.The results showed that there were significant differences in the metabolic characteristics of drug-resistant strains and sensitive strains.A total of 21 compounds that contributed significantly to the classification were identified,mainly amino acids and nucleotides.Differential metabolites are mainly involved in the pathways of amino acid metabolism,carbohydrate metabolism and nucleotide metabolism.The expression changes of adenosine,tryptophan and leucine in two significantly different metabolic pathways indicate that the synthesis of peptides and proteins in the cell has been blocked and the cell oxidative stress has increased after the strain is affected by the compound trimethoprim.The metabolism of glycerophospholipids indicated that the cell regulation of transport,protein function,and signal transduction were severely affected by the strains being affected by the SXT.The study clarified the reasons for the formation of the drug resistance of the strains affected by the SXT,and provided help for the search for drug targets and intervention in the prevention and control of strains.

Abstract:Acrolein is an endogenous food toxin produced during thermal processing of foods.To investigate the significantly reduced reasons of acrolein in fried potato chips,seven amino acids (glycine,asparagine,aspartic acid,glutamic acid,glutamine,valine,and threonine) with high level in potato were chosen to react with acrolein under different reaction temperature and time.The structures of reaction products were identified after purification,and the scavenging effect as well as the mechanism of amino acids on acrolein were correspondingly studied.The selected amino acids were found to effectively eliminate acrolein and eight new main reaction products were identified for the first time.The supposed reaction mechanism is:one molecule of amino acid reacts with two molecules of acrolein via Michael addition,and then forms a more stable ring (similar to the structure of pyridine) through aldol condensation.However,the simplest amino acid,glycine,generates another major product composed of 3 molecules of acrolein and 2 molecules of glycine.The reaction mechanism was speculated as follows:after one molecule of glycine undergoes Michael addition with two molecules of acrolein,one of the two aldehyde groups in the adduct reacts with another molecule of glycine to form a Schiff base,while another acrolein in the adduct undergoes aldol condensation with the third molecule of acrolein,resulting in a conjugated structure.In addition,an HPLC-MS/MS analysis method was developed and it was found that the reaction adducts exist in fried potato crisps,such as asparagine-acrolein,indicating that free amino acids in potato may play an important role in the reduction of acrolein in fried potato chips.

Abstract:Phytosterols have been widely concerned for their efficacy in lowering cholesterol,anti-tumor,anti-inflammatory and anti-oxidation.In order to find out the composition of phytosterols in cauliflower,both free and three kinds of conjugated phytosterols were separated by solid phase extraction,and then the species and structure of phytosterols in cauliflower were identified and analyzed by UPLC-Triple-TOF/MS.The results showed that the free phytosterol(FS) in cauliflower were stigmasterol,campesterol,lupeol and β-sitosterol. Campesterol linoleate,stigmasterol oleate and β-sitosterol oleate were identified as three phytosterol esters(SE).Campesterol glucoside and β-sitosterol glucoside were identified as phytosterol glycosides (SG).Acylated sterol glycosides (ASG) include campesterol glucoside palm oleyl ester,campesterol glucoside eicosapentaenoic acid ester,stigmasterol glucoside linolenic acid ester,β-sitosterol glucoside eicosapentaenoic acid ester and β-sitosterol glucoside linolenic acid ester.

Abstract:Through the research on the stability of infant nutritional rice noodles,it provides reference for the prediction and determination of the shelf life of infant nutritional rice noodles,product storage,and the improvement of product formula and processing technology.According to the chemodynamic principle,the samples were stored at the temperature (37±2) ℃ and humidity (75±5) % for 6 months to accelerate the rate of nutrient decay and deterioration,and the nutrient indicators were tested to investigate the stability of nutrients in nutritional rice noodles for infants.The results showed that the stability of VA,VC,VB1 and pantothenic acid in vitamins was poor,with an average attenuation rate of 47.60%,42.59%,26.70% and 28.30%,VD,VE,VB2,VB6,VB7,VB9,VB12 and niacin were stable.The stability of sodium in mineral nutrition was poor,with a maximum attenuation of 40.00%,while calcium,iron,zinc,potassium and phosphorus remain stable without significant changes.Although some nutrients showed a decay trend in the accelerated test,they were all within the qualified range.Some indicators can be adjusted in the later formulation design.

Abstract:To systematically investigate the thawing characteristics of beef in multiple needle-to-plate electrode systems,thawing experiment of frozen beef were carried out with different needle spacings,and the thawing characteristics of beef were analyzed by infrared spectroscopy.The thawing time of beef under high-voltage electric field was 47.11 min,which was 2.535 times shorter than that of the control group.The drip loss of beef was reduced by 7.16%,the cooking loss was reduced by 3.21%,and the centrifugal loss was reduced by 2.72%.These results indicated that the high voltage electric field could not only accelerate the thawing time of beef but also improve the water holding capacity of beef.Different needle spacing can change the superposition of electric fields.The results of color and infrared spectrum showed that the needle spacing was best at 8 cm.By analyzing the double index sequence and the secondary structures of protein,it was found that the high voltage electric field has a great influence on the microstructure of beef.

Abstract:Based on the hyperspectral imaging of bacon,the CNN-SVM model designed in this paper organically combines deep learning extraction features with traditional machine learning extraction features to design an accurate and reliable bacon nutrition and health risk four classifier.The three-dimensional convolutional neural network is used to extract the deep features of the hyperspectral image of bacon,and the spectral features of the hyperspectral are fused.Both input the support vector machine (SVM) to realize the classification and health risk assessment of bacon,which is comparable to the national bacon biochemical detection standard.Consistent hyperspectral nutrition quality detection and health risk assessment indicators have achieved the research purpose of reliable and rapid evaluation of its health and nutrition quality.Based on the two classifications of bacon,the accuracy of the four classifications achieved by this method reaches 92.5%.The experimental results prove the feasibility and effectiveness of this method.

Abstract:There were 1 000 single-grain rice samples collected from 10 origins and 4 varieties in Northeast and non-Northeast China.Near-infrared hyperspectral images were acquired within the wavelength range of 950 nm to 1 700 nm.The region of interest was selected according to the outline of single rice from the images to calculate average spectra.Firstly,principal component analysis was used to extract the first and second principal components with a cumulative contribution rate greater than 99%.According to the maximum value of the weight coefficient in the loading matrix,the characteristic wavelengths of the first and second principal components of 1 396.67 nm and 1 467.38 nm are screened respectively.The principal component analysis was performed on the two sets of characteristic wavelength images,and the first three-dimensional principal components were selected respectively,and a total of 2×3 sets of training sample sets can be obtained.Finally,there were 6 models established to discriminate Northeast/ Non-Northeast rice.Among them,the best performing model was built based on the 1 467.38 nm third principal component image,and its recognition accuracy can reach 99.5%.

Abstract:The whiteness of Agaricus bisporus is an important index to evaluate its freshness and quality.In order to accurately evaluate the whiteness of Agaricus bisporus,a method based on machine image analysis was proposed.The imaging system of D65 standard light source is built,and the nonlinear whiteness calibration model is constructed.The conversion from RGB value to CIE-XYZ tristimulus value is realized,and then CIE Ganz whiteness formula is used to realize the accurate measurement of whiteness.The image system was calibrated by using 8 color cards with different gray levels in combination with a colorimeter,and the Agaricus bisporus with different whiteness grades were measured.The results showed that there was a high correlation between the results of image analysis and colorimeter (r=0.99),and the color difference ΔE*ab<2.For the four groups of Agaricus bisporus with different whiteness levels,the measurement results of image analysis were significantly different (P<0.01).At the same time,the whiteness value of Agaricus bisporus under different storage conditions was measured by image analysis.It was found that there was a significant correlation between the storage time and the whiteness value of Agaricus bisporus,which indicated that the whiteness value determined by image analysis can be used to quantitatively evaluate the freshness of Agaricus bisporus.

Abstract:To investigate the penetration ability of near infrared diffuse light on different fruit pericarp based on chemometric methods.Pear,kiwi fruit,apple,Shatangju mandarin,fertile orange,mandarin,sweet orange,Hu You,and Shatian pomelo were analyzed and the original spectra of intact fruit,pericarp,pericarp with plastic,pericarp with metal plate were obtained.It was found that the pericarp spectra were almost the same as those of the intact fruit.The thicker the pericarp,the greater the similarity.The results showed that that the pericarp has great absorption of near infrared light.Furthermore,principal component analysis was used to cluster the four spectra. The spectral clustering results of pear,kiwi fruit and apple showed perfect differentiation,indicating that near infrared diffuse light could penetrate the pericarp of these thin-skinned fruits.According to the results of near infrared spectral clustering analysis of citrus fruits,the near infrared diffuse light could penetrate the pericarp of Shatangju mandarin,fertile orange,mandarin,sweet orange,and could not penetrate the pericarp of Hu You and Shatian pomelo.

Abstract:Olive pomace was used to prepare cellulose by alkaline solution extraction,then microcrystalline cellulose (MCC) was obtained by further hydrolysis of cellulose with 2 mol/L HCl and H2SO4.Water-holding capacity (WHC),oil-holding capacity (OHC) and swelling capacity were measured and analyzed.Differential scanning calorimeter (DSC),Fourier transform infrared spectra (FTIR),X-ray diffraction (XRD),scanning electron microscope (SEM) and confocal laser scanning microscope(CLSM) were used to evaluate the physicochemical properties of primary cellulose and MCC.The results showed that morphology changed from loose to ordered array with rod-shape after hydrolyzing with H2SO4 and HCl.Besides,WHC and swelling capacity were increased.The crystallinity and crystal size of H2SO4-MCC are 75.77% and 5.35 nm,and that of HCl-MCC are 64.92% and 4.96 nm,respectively.Compared with the primary cellulose,emulsification characteristics of MCCs were also improved.FTIR spectra proved the lignin and hemicellulose degraded after acid hydrolysis.DSC results showed MCC had higher water evaporation temperature but lower thermal degradation temperature.

Abstract:Objection:To explore the distribution of protein morphology and rheological characteristics from different fractions of wheat kernels,and to provide a theoretical basis for explaining the differences in the quality of flour products from different flour mill streams.Methods:The flour was prepared by pearling mill,experimental mill and industrial mill.On the basis of protein quality and quantity,the flour was used to detect the morphology of sodium dodecyl sulfate soluble protein and the dynamic rheological properties of gluten macropolymer.Results:The closer to the wheat endosperm center,the crude protein content decreased from 205.9 mg/g to 93.4 mg/g,the percentage of dry gluten in total protein increased from 0 mg/g to 1 210.2 mg/g,but the trend of gluten macropolymer in total protein is not obvious;the higher the water holding capacity of gluten,the lower the sodium dodecyl sulfate solvent retention.The density of sodium dodecyl sulfate soluble protein generally showed a gradual decrease,but the storage modulus and loss modulus plateau values of gluten macropolymer gel showed an opposite trend.They increased from 13.5 Pa to 141.6 Pa,5.3 Pa to 26.2 Pa separately.L*/ash can be used to quantitatively characterize the different fractions of wheat kernels from outside to inside effectively.Conclusions:The results showed the protein conformation structure near the endosperm center is loose.

Abstract:A method was developed for the detection of 5-hydroxymethylfurfural in roasting Coffea arabica by high performance liquid chromatography combined with liquid-liquid extraction and dispersive solid phase extraction (DSPE).After extracted with 1.0% acetic acid acetonitrile solution with ultrasound assistance,the samples were pretreated with QuEChERS method including extraction salting-out (3.0 g NaCl + 1.0 g NaAc),purification (50 mg C18 + 20 mg PSA + 200 mg MgSO4).The 5-hydroxymethylfurfural was then purified on a Shiseido CAPCELL PAK MG C18 column (150 mm×4.6 mm,5.0 μm),and gradient elution was conducted using methanol and water solution as the mobile phases.Under the optimum conditions,the calibration curves of the 5-hydroxymethylfurfural showed good linearity (r = 0.9991) within their respective linear ranges.The limits of quantification (LOQs) and limits of detection (LODs) was 0.01 mg/kg (S/N = 10) and 0.03 mg/kg (S/N = 3).The recoveries were in the range of 85.50%-105.5% at three spiked levels,with relative standard deviations of 4.28%-7.59% (n = 5).The results showed that roasting temperature,time and degree play an important role in the 5-HMF content of the final Coffea arabica product.

Abstract:The nutritional fortified milky green tea was developed by adding 15% ultrafine powder of artichoke stem and leaf by-products,and its composition and content of functional components were analyzed.The functional polyphenols and terpenoids in milky green tea were qualitatively and quantitatively analyzed by high performance liquid chromatography-triple quadrupole-tandem mass spectrometry (HPLC-QqQ-MS/MS) and gas chromatography-mass spectrometry (GC-MS),respectively.The results showed that the contents of 17 polyphenol compounds in milky green tea were significantly increased by adding ultrafine powder of artichoke stem and leaf(P﹤0.05),including 12 phenolic acids and 5 flavonoids.For terpenoids,the sesquiterpene lactones,sterols and pentacyclic triterpenes were enriched,and the contents of 10 terpenoids in milky green tea was significantly increased(P﹤0.05).The results suggested that the functional polyphenols and terpenoids in the stem and leaf of artichoke were abundant,and the artichoke by-products may be used as a potential source of natural functional ingredients for development of milky tea products.

Abstract:Traditional solid-phase extraction (SPE) and membrane filtration technology are complicated,and time and labor consuming.In this study,the PRiME and membrane filtration technology were integrated to realize the integration of operational steps before sample injection,and the relevant technical parameters were optimized.A quantitative method for the determination of berberine hydrochloride and robenidine hydrochloride in fish was established by liquid chromatography tandem mass spectrometry.The results showed that berberine hydrochloride and robenidine hydrochloride had good linearity in the range of 0.5-100 g/L,the detection limits (LOD) were 0.51 g/kg and 0.53 g/kg,the quantitative limits (LOQ) were 1.67 g/kg and 1.68 g/kg,the intraday relative standard deviation of precision was 4.09%-4.48% and 3.84%-3.90%,respectively,and the intraday relative standard deviation of precision was 5.17%-5.73% and 4.23%-5.29%,respectively.The recoveries of berberine hydrochloride and robenidine hydrochloride were 91.2%-93.2% and 91.3%-92.4%,respectively,at 5,10,50 g/kg concentrations.The RSD was 4.5%-4.6% and 1.8%-5.2%,respectively.The liquid chromatography-tandem mass spectrometry (LC-MS) was used to determine the residues of target compounds in fresh fish on the market,and no positive samples were detected,indicating that berberine hydrochloride and chlorophenguanidine hydrochloride were used well in aquaculture.

Abstract:In this study,in order to analyze the influence factors and sources of heavy metals in peanuts,the field experiment of geographical origin and variety was conducted.Peanut,soil,and precipitation samples were collected,and the concentrations of seven heavy metals were determined in all the samples.Combined with one-way analysis of variance (ANOVA),multi-way ANOVA,and Pearson correlation analysis,the influences of geographical origin,variety,and their interaction on the contents of heavy metals in peanut kernels were analyzed,and the relationships between the heavy metal contents in peanut and those in the provenance soil or precipitation were explored.The results indicated that the variations of Ni,Cd,and Tl contents in peanut were mainly affected by the region;the variation of As content was mainly affected by the interaction of origin and variety;while the variations of the contents of Cr,Sb,and Pb could be mainly affected by other factors.The contents of As,Sb,and Pb in peanut had no significant correlation with those in soil or precipitation;the contents of Cd and Ni in peanut had significant correlation with both soil and precipitation;and the contents of Cr and Tl in peanut were significantly related to those in soil.This study suggested that the contents of heavy metals in peanuts were affected by the origin and variety,and its sources include not only soil and precipitation,but also other sources such as pesticides and fertilizers.

Abstract:In order to compare from the environmental performance of starch and cellulose material,this thesis to popularize the use of the biological basis of takeout areas catering utensils (compound starch material coated fiber wiki) and biodegradable plastic tableware (total starch materials All fiber) as the research object,analysis of the product life cycle energy consumption and environmental emissions of various resources and evaluate its environmental impact Flow based on 1 000 take-out lunch box,environmental assessment software is used to establish the green environmental protection tableware of LCA in life cycle assessment model results show that the carbon emissions and energy consumption is the result of starch green boxes which focuses on raw material acquisition and the two stages of waste disposal,green boxes from the fiber carbon emissions and energy consumption is mainly in the products production stage The total starch degradable tableware has the lowest environmental impact index,in which the cumulative CO₂ release is 39.91 kg and the energy consumption is 332.04 MJ.Compared with the total fiber degradable meal box,the carbon emission is reduced by 69.5% and the energy saving is 416.23 MJ.

Abstract:The development of biodegradable materials as the substitute of plastics has been widely studied recent years due to the problem of plastic pollution.Starch,a common natural polysaccharide,has been considered as an ideal source of biodegradable materials because of its with low price and wide source.This paper reviewed the most advanced research progress of starch-based biodegradable materials,including the additives,preparation and characterization methods of starch-based biodegradable materials,as well as their applications in food industry.Finally,this article provides the perspectives on current challenges and share our outlook of starch-based biodegradable materials to provide reference and guidance for the future studies in this area.

Abstract:Aromatic plant essential oils generally have good antibacterial properties and are potential natural antibacterial agents.The article reviews the main chemical components,antibacterial objects and antibacterial mechanism of 24 essential oils including Litsea cubeba(Lour.) Pers,Cinnamomum cassia Presl,Syringa Linn,Moringa oleifera Lam,Thymus mongolicus Ronn,Salvia japonica Thunb,Cuminum cyminum L,Illicium verum,Origanum vulgare L.,Zanthoxylum bungeanum Maxim,Allium sativum L.,etc.Detailed analysis of the antibacterial mechanism of 6 essential oil monomer components including carvacrol,cinnamaldehyde,thymol,eugenol,citral,and limonene were carried out against different microorganisms.

Abstract:Surimi is an intermediate protein product gained from the raw fish,having high nutritional value,low price and high developing and utilization potential.Surimi is rich in protein (about 17%),and during processing the structure and gel properties of surimi protein are changed by the processing conditions such as pressure,temperature,shear force,ultrasound,microwave,etc.Then various surimi products such as fish cakes,fish balls,fish sausages,fish noodles,fish tofu and bionic products are manufactured.The bionic crab meat is high value-added and gains widespread concern.However,affected by the difference in the types,batches and gel characteristics of the raw material,the quality of surimi products is uneven,and during processing the structure-activity relationship between the gradual changes of surimi protein structure and the quality of surimi products is still unclear,which restricts the development of high value-added and high-quality surimi products.This study firstly investigated the market overview of the surimi products in China,and then described the characteristics of surimi protein gel change during processing and its relationship with product quality combined with ultra high pressure,extrusion,microwave,ultrasonic,electron beam irradiation and 3D printing,providing reference for the improvement of the quality of surimi products and the development of the "double protein" surimi products and other new nutritional and healthy surimi products.

Abstract:Although the formation of ice crystals is the most fundamental factor inducing the quality deterioration of frozen surimi,the only addition of antifreeze aiming at inhibition against the formation of ice crystals alone fails to maximize the quality of surimi during frozen,due to their limited effectiveness and economy.Different from antifreezes aiming to control the formation of ice crystals,freezing stabilizers show great potentials to inhibit the various biochemical reactions involving in freezing treatments by enhancing the stability of surimi components.Hence,the combination of antifreezes and stabilizers may be the effective ways to maximize food freezing protection.In this review,the quality deterioration of surimi during the freezing process were summarized.Meanwhile,several freezing stabilizers (sugars,protein hydrolysates,colloids and polyphenols) and their acting mechanism were emphasized.At last,the future development trend of cryopreservation strategy of surimi was prospected.The present review proposes the novel cryopreservation as the complementary to the inhibition of ice crystal growth in terms of components stabilization,to improve the frozen quality of surimi.

Abstract:The sheep milk is the 'special industry' of goat milk industry in China,and the breeding scale and milk production is rising rapidly.But,at present,the level of sheep milk industry in China is basically zero,and the field of sheep dairy product processing is still blank.Sheep milk has high nutritional value.The content of total solid is the highest among various milk sources.Sheep milk is characterized with high amounts of protein,fat,minerals and vitamins,and the composition and biological activity of sheep milk lactoferrin,active peptides,milk fat globule membranes and oligosaccharides are different with cow milk and goat milk.The development of functional dairy products based on the composition and nutritional characteristics of sheep milk has broad market prospects.In this article,the current research of sheep milk was reviewed,and its nutritional and bioactive composition were also focused on.This review can provide the scientific basis for the research and industrialization of sheep milk to guide and promote the development of sheep milk industry in China.

Abstract:Capsicum plants such as chili peppers not only have unique pungent flavor,but also have many pharmacological effects owing to their components such as capsaicinoids.In order to know the correct research progress and the main academic context in the field of pungent science,a total number of 13 389 papers from the Web of Science core databases were conducted as the data sources to analyze the global research on the pungent science from 2010 to 2020 by using the statistical analysis tools like VOSviewer software,CiteSpace software,MATLAB software and Origin software,with the help of bibliometrics methods,where the factors like the number of research papers,the influence of countries/ journals/ academic institutions/ authors,and the research hotspots were considered.The results showed that the pungent science study not only involves the traditional fields such as food science and pharmacology,but also includes the fields like plant science,neuroscience,toxicology,biochemistry and molecular biology,among which biochemistry and molecular biology,pharmacology and neuroscience are the main research hotspots in recent ten years.The United States has the largest number of papers published in the concerned field,followed by China and Japan.The annual number of papers published by Chinese scientists has increased rapidly,the proportion of Chinese scientists in the top 20 scientists in the field is quite high,and the overall H index of papers published by Chinese scientists is large,but the number of citations per paper is some what lower than that of some countries like United States and Germany.The cooperation between academic institutions or scientists in different countries has become a norm,which mainly include the above-mentioned hot fields.In addition,the Keywords with the strongest jump intensity and the longest jump duration were explored through related analysis,along with the main jump Keywords in recent years.This paper would guide the scholars in the fields of food science,chemistry,pharmacology and molecular biology to fast grasp the research direction,development trend and hot spots of pungent science study,and also provide the theoretical basis for the strategic decision of the pungent industry.