【作者】 杨金英；

【导师】 王剑平；

【作者基本信息】 浙江大学 ， 农业机械化工程， 2004， 硕士

【摘要】 本文在农产品加工抑制酶促褐变方面，进行了甘薯、春笋两种物料的护色试验研究，主要内容包括：1、考察了抗坏血酸、植酸、柠檬酸、氯化钙和护色时间等因素对5mm厚度的甘薯片的PPO进行抑制的护色效果。结果表明，植酸、柠檬酸和氯化钙对PPO活性抑制影响极显著。2、对春笋干燥中容易酶促褐变现象，以微波热烫功率、热烫时间、柠檬酸、氯化钙及其浸泡时间为试验因素，采用L₈（2⁷）正交试验，得出对PPO活性和色泽参数（ΔL，Δa，Δb）的影响较佳的护色工艺组合。3、采用二次通用旋转设计进行甘薯的进一步微波热烫灭酶试验，得出了甘薯微波护色对PPO与色泽参数（L、a、b）影响的较佳工艺参数为微波质量功率1.25kw／kg，灭酶时间180s，建立了模型拟和较好的甘薯微波预处理灭酶模型。 本文首次对春笋的微波干燥应用技术进行了研究，主要内容为：1、讨论了春笋在不同微波功率干燥过程中水分含量和颜色的变化规律，采用Page方程进行拟和，建立水分含量和颜色动力学变化模型，用于春笋微波干燥加工过程中品质变化的预测与监控。2、以前期发射功率、后期发射功率和前后期转换水分含量作为试验因素，单位失水率、复原率、色泽参数L、a和b为指标，研究了三因素三水平正交试验，得出较佳的工艺组合：前期功率375w，后期功率150w，转换干基含量为600％左右。 本文对甘薯果脯进行了热风干燥工艺研究。采用二次通用旋转组合设计的方法，研究了热风干燥温度与风速对失水速率和色泽参数变化（ΔL，Δa，Δb）的影响。进行加权综合优化计算，认为较好的工艺参数为干燥温度50℃、风速0.5m／s。利用SAS软件得出了失水速率和色泽各参数L、a和b变化的预测模型。更多还原

【Abstract】 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.更多还原