Studies on Off-Flavor Formed during Storage of Satsuma Mandarin Juice (Part III)

Quantitative changes in volatile compounds were investigated during storage at 20, 30 and 40°C. Terpene hydrocarbons recovery decreased by 20—30% during the early stage of storage, and then increased gradually with storage time. After reaching maxima at 13 days (40°C), 40 days (30°C) and 80 days (20°C), terpene hydrocarbons recovery again decreased. β-Pinene decreased rapidly and its recovery was only 13% after 40 days storage at 30°C. Citronellal decreased by about 50% during 40 days at 20°C, while by 90% during the same period at 30°C. The amount of linalool increased during the early stage of storage, and reached maxima at 40 days (30°C) and 80 days (20°C). The storage periods for furfural formation of 100 ppb were 8 days at 40°C, 24 days at 30°C and 75 days at 20°C. At furfural level of 100 ppb, the juice contained fenchyl alcohol (0. 07—0. 08 ppb), terpinen-4-ol (1. 0—1. 4 ppm), β-terpineol (0. 7—0. 8 ppm) and a-terpineol (4. 2—4. 4 ppm). It was concluded that furfural level was a useful indicator of off-flavor development in Satsuma Mandarin juice. (Received October 6, 1980).