Blanched samples of frozen vegetable soybeans using peroxidase (POD) and lipoxygcnase (LIP) as blanching indices were compared with unblanched samples during storage by sensory evaluation, vitamin C determination and remaining enzyme activity. Samples using LIP and POD as blanching indices showed no significant differences in sensory quality during 160-day frozen storage, while both treatments were significantly different from unblanched samples. Vitamin C in samplcs using LIP as blanching index was higher than that in unblanched ones but not significantly different from that in samples using POD as an index. Samples using LIP as blanching index had 11.5% POD activity but no LIP activity, while blanched samples using POD as blanching index had no LIP or POD activities during storage.

The identification and quantitation of major carotenoids in juices of Ponkan mandarin and Liucheng orange and their changes during harvesting were studied. Neoxanthin, violaxanthin, lutein, β‐cryptoxanthin, α‐carotene and β‐carotene are the major carotenoids for Ponkan mandarin. During the harvesting period, the contents of violaxanthin, β‐cryptoxanthin and β‐carotene increase significantly. For Liucheng orange, neoxanthin, violaxanthin, lutein, antheraxanthin, β‐cryptoxanthin, α‐carotene and β‐carotene are the major carotenoids. Among them, neoxanthin, violaxanthin, lutein, antheraxanthin and β‐cryptoxanthin increase significantly during the harvesting period. The β‐cryptoxanthin and β‐carotene are the major contributors to the color of Ponkan mandarin juice while neoxanthin, violaxanthin, lutein and antheraxanthin are the major ones for the color of Liucheng orange juice.

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