Changes of aroma compounds and qualities of freshly-squeezed orange juice during storage.

This study focused on the changes of physicochemical and microbiological properties and aroma compounds of freshly-squeezed orange juice during storage at different temperatures. Aroma compounds were analyzed by solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS). The results showed that the total aerobic plate counts of orange juice stored at room temperature and 37 °C was far more than 4 °C. Totally 33 aroma compounds were determined in these orange juices. Significant differences on the aroma compounds in orange juices stored at different temperatures were observed in the present study. Most of the terpenes decreased at 4 °C after 15 days' storage, while 10 and 8 terpenes increased during storage at room temperature and 37 °C. α-Terpineol and p-vinylguaiacol were the only off-flavor compounds found in juice stored at 4 °C and room temperature at late storage respectively. While terpinen-4-ol, 4-ethylguaiacol and p-vinylguaiacol were found in juice stored at 37 °C at late storage. α-Terpineol was the only off-flavor compound found in orange juice stored at 4 °C.