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

Abstract

Fresh juice and reconstituted concentrate of Satsuma Mandarin were stored at 40°C. The volatile compounds were determined by an internal standard method after 0, 10, 20, 30, 50 and 75 days of storage. For low boiling compounds, the headspace gas of the juice was analyzed by GLC, while for higher boiling compounds, the extract recovered from the juice by low tempe rature distillation and ether extraction was analyzed by GC-MS. In low boiling compounds (acetaldehyde, dimethyl sulfide, acetone, methanol, ethanol), dime thyl sulfide increased remarkably during storage. Dimet'hyl sulfide was organoleptically the most detrimental compound in juice containing a little peel oil. In higher boiling compounds, the contents of furfural, terpinen-4-ol, a-terpineol, a-terpineol and fenchyl alcohol increased, whereas those of j3-pinene, citronellal, linalool, Q-elemene, geranyl acetate and several oxygenated terpenes decreased. Terpinen-4-ol, j-terpineol, e-terpineol and fenchyl alcohol imparted a musty or piney odor to the juice, and fenchyl alcohol was reported for the first time as a degradation product of the off-flavored juice. As furfural content increased linearly with storage time, it may be a useful indicator of the storage time of Satsuma Mandarin juice. (Received August 8, 1980)