微波膨化处理对苹果脆片品质及营养素的影响研究

发布时间：2018-04-13 20:33

本文选题：微波膨化 + 苹果　；参考：《沈阳农业大学》2017年硕士论文

【摘要】：随着人们消费水平和健康意识的提高,对果蔬脆片类休闲食品的需求日益增加。切合消费者对产品口感好、营养健康的需要以及商家生产效益最大化的追求,从营养素较为全面且我国产量极高的水果:苹果着手,以效率高、更安全的微波技术对苹果片进行膨化。本文采用响应面法对预干燥时间、微波功率和微波时间三个参数通过感官鉴评评分和出品率进行优化以获得理想品质的脆片,并比较加工过程中的预干燥和微波膨化过程苹果中果胶和其他营养素与鲜果之间的差异,以期从营养方面对加工工艺进行评价,为苹果加工产业提供有力支持,主要研究结果如下:(1)随预干燥时间的延长,脆度600min后趋近于1s,硬度和色差值先增加至1000.67g和25.24后减小,糖酸比不断增加至24.23;微波功率和时间对产品品质的影响相似,随功率增加,脆度和糖酸比不断减小至0.7s和18,硬度在600w时达到最大值1060.33g后降低,色差值不断增加至49.98;随微波时间增加,硬度先升高后降低,在30s时达到最大值1066.67g,脆度降低到0.71s,糖酸比减小到18.32,色差增加至30.91。(2)a*、脆度和色差值与苹果脆片感官鉴评评分呈负相关,糖酸比、硬度、L*和b*与苹果脆片感官鉴评评分呈正相关关系,且感官鉴评评分与L*、糖酸比和色差值之间具有较强的相关性,认为感官鉴评评分能够准确表征苹果脆片的品质。(3)单因素实验确定预干燥时间60-100min、微波功率600-1000w、微波时间20-40s之间时产品品质最佳。经响应面优化,预干燥时间、微波功率和微波时间分别为89.09min、729w和28.89s时可以得到品质最佳的苹果脆片,此时苹果脆片感官品质评分94.18、出品率为0.9016,进行验证实验,拟合度良好。(4)预干燥过程对果胶的提取率、重均分子量、纯度及酯化度无明显影响,但乙酰化时,吡喃环构象可能发生变化。膨化后果胶提取率提高16.74%(P0.01),重均分子量显著减小,纯度无明显变化,酯化度稍有提高(P0.05)。通过红外光谱分析,微波对果胶半乳糖醛酸甲氧基上C-H键、羧酸盐上的酯键有一定影响。膨化后的苹果片中果胶溶液相同条件下粘度均小于预干燥、溶解度大于预干燥(P0.05)。(5)营养素的损失主要发生在预干燥过程中,苹果片中水分大量蒸发造成可溶性糖和有机酸分别损失25.9%和13.9%,糖酸比减小到21.91,且热效应使AA氧化、总VC含量下降到2.47mg/100g,黄酮类化合物损失5.7%(P0.01),微波处理使黄酮类分子间挤压、碰撞,导致细胞膜破碎,黄酮化合物溶出,提取率增加2.4%(P0.05)。
[Abstract]:The results are as follows : ( 1 ) The difference between pectin and other nutrients and fresh fruit in the process of pre - drying , microwave power and microwave time is reduced to 10.67 g and 25.24 , the difference between hardness and color is decreased to 18.32 , the color difference is increased to 30.91 . ( 2 ) a * , the ratio of crispness and color is decreased to 18.32 , the color difference is increased to 30.91 . ( 2 ) a * , the sugar acid ratio is decreased to 18.32 , the difference of color difference is increased to 30.91 . ( 2 ) a * , the ratio of sugar and acid is reduced to 18.32 , the color difference is increased to 30.91 . ( 2 ) a * , the sugar acid ratio is decreased to 18.32 , the color difference is increased to 30.91 . ( 2 ) a * , the sugar acid ratio is decreased to 18.32 , the color difference is increased to 30.91 . ( 2 ) a * , the sugar acid ratio is reduced to 18.32 , the color difference is increased to 30.91 . ( 2 ) a * , the sugar acid ratio is reduced to 18.32 , the color difference is increased to 30.91 . ( 2 ) a * , the sugar acid ratio is reduced to 18.32 , the color difference is increased to 30.91 . ( 2 ) a * , the sugar acid ratio is reduced to 18.32 , and the color difference is increased to 30.91 . ( 4 ) The yield of pectin was increased by 16.74 % ( P0.01 ) . The yield of pectin was increased by 16.74 % ( P0.01 ) . The yield of pectin was increased by 16.74 % ( P0.01 ) .

【学位授予单位】：沈阳农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TS255.4

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