Abstract:
To investigate the effect of thermal sterilization on the quality of not from concentrated(NFC) orange juice,a NFC orange juice made from a mixture of orange varieties including Hamlin, Valencia and Pera were used as raw material, the freshly squeezed NFC orange juice sterilized at 80, 85, 90 and 95 ℃ for 30 s, respectively, were stored at 4 ℃ for 42 days, and the room temperature NFC orange juices sterilized at 100, 105 and 110 ℃ for 15 s and at100 ℃ for 30 s, respectively, were stored at 20 ℃ for 90 days. The differences in microbiological number and quality of the NFC juices with different thermal sterilization during storage were compared. The results showed that the freshly squeezed NFC orange juice sterilized at 85 ℃ for 30 s and stored at 4 ℃ had no microorganisms detected on the 21 th days of storage, and showed small change in browning index(BI). The room temperature NFC orange juice sterilized at 100 ℃ for 30 s and stored at 20 ℃ had 12.1 mg/100 g of vitamin C on the 90 th days of storage, and the total number of microbial colonies met the requirements of national sanitary standards and was lower than that in the other juices with different thermal treatments during the storage period of 0~75 days. Comprehensive comparison suggested that the 85 ℃ for 30 s and 100 ℃ for 30 s treatment could be used as a promised thermal sterilization for freshly squeezed NFC orange juice and room temperature NFC orange juices, respectively.