Abstract:The diverse composition and changes of carotenoids under low-temperature refrigeration conditions have gradually attracted widespread attention. However, there is still a lack of research on the effects of long-term low-temperature refrigeration on carotenoids in different parts of blood orange pulp. In this study, the blood orange was used as the experimental material, the influence of low-temperature storage at 9 ℃ for 0, 30, 60 d, and 90 d on the composition and content of carotenoids in the different parts of blood orange pulp was analyzed by UPLC-API-Q TRAP-MS/MS method. ①The results showed that 34 kinds of carotenoids were identified from blood orange pulp, among them, the contents of β-cryptoxanthin palmitate, rubixanthin palmitate and β-cryptoxanthin oleate were the highest in the pulp of different parts of blood orange, and the content of various carotenoid esters at the stem end pulp showed an upward trend with the prolongation of low-temperature storage time, while the equator and stylar end pulp did not change significantly under the condition of low temperature storage. ②The results of principal component analysis showed that the carotenoid esters at stem end, equator and stylar end pulp were significantly different, and most of the carotenoids such as the neochrome palmitate, rubixanthin palmitate, violaxanthin ester, zeaxanthin ester and β-cryptoxanthin ester in different parts of the blood orange pulp during storage periods had changes, and various carotene esters at the stem end pulp significantly increased during low temperature storage. In conclusion, a total of 34 carotenoid esters were identified in blood orange pulp, and of which the esters content in three parts of pulp were significantly different. In addition, the content of various carotenoid esters at stem end pulp significantly increased with the prolongation of low-temperature storage time, while the equator and stylar end pulp did not change significantly. In this study, the composition of carotenoid ester in blood orange was analyzed, and which provide a reference for exploring its change mechanism.