Kinetics of frozen stored green bean (Phaseolus vulgaris L.) quality changes: texture, vitamin C, reducing sugars, and starch

Texture, vitamin C, reducing sugars, and starch quality changes of frozen green beans (Phaseolus vulgaris L.) were studied for 250 d at storage temperatures of -7, -15, and -30°C. All studied parameters suffered significant changes during frozen storage. Texture loss was described by a fractional conversion model, while ascorbic acid and starch evolution were successfully modeled with first-order reaction kinetics. Dehydro-ascorbic acid (DHAA) degraded only 8% during storage time, and thus frozen storage well preserves total vitamin C. The low estimated Arrhenius activation energies of texture, starch, and ascorbic acid losses emphasize that low temperatures do not substantially reduce degradation rates.