| Enzymatic browning and its prevention in sweet potato and bamboo shoots in spring were studied in this research. First, the effect of different anti-browning agents such as ascorbic acid, citric acid, phytic acid and calcium chloride and time of treatment on the sweet potato which with 5mm thickness were studied. The results indicated that the effects of phytic acid, citric acid and calcium chloride were the best distinct. Second, microwave power, microwave treatment time, citric acid, calcium chloride and the sock time were studied to determine their influences to PPO activity and color parameters (A L,△a,△b) using L8(27) orthogonal method.' And a preferable microwave blanching method was obtained. Third, the effect of microwave blanching power the time of treatment on the inhibition of enzymatic browning in the sweet potato was compared by considering PPO value and color changes. The results showed 1.25kg/kg and 180s were the fittest processing parameters.Microwave drying test on bamboo shoots in spring has been studied in the thesis. This experiment was to study and model the microwave drying kinetics, using the Page model adapted. L9(34) orthogonal experiment was designed with three factors of former-power, latter-power and transform drying base, and five indexes of dehydration rate, rehydration rate and color parameters (L, a, b). The result indicated a preferable drying method when the former power was 375w/g, the latter power was 150w/g and the transform drying base was 600%, respectively.Preserved sweet potato samples (5 mm thick) were dried by hot air. Response Surface Methodology Design was applied to investigate variables such as air temperature and air velocity for drying rates △L,△a and Ab . 50℃ and 0.5m/s were the optimized processing parameters.
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