摘要
通过分析测定-18、-25、-60℃冰箱冻结及液氮速冻处理后烤甘薯淀粉、脂肪、还原糖、Vc、胡萝卜素、L^*值、硬度、咀嚼性、最大剪切力等理化指标的变化,研究4种冻结方式处理对烤甘薯品质的影响,并描绘了4种冻结温度下的冻结曲线。利用相关性分析和主成分分析对不同冻结速率下烤甘薯的营养品质进行综合评价,结果表明,液氮冻结通过最大冰晶生成带的时间最短,质构特性与现烤甘薯最接近;-60℃冻结对烤甘薯理化品质和色泽的保存最好。相关性分析显示,多数品质指标间存在一定的相关性,其中咀嚼性的改变对烤甘薯食用品质的影响最大。主成分分析显示,11个检测指标可简化为3个主成分,累积方差贡献率达93.94%,可反映大部分烤甘薯品质的信息。该研究筛选出蛋白质、咀嚼性、弹性、还原糖、胡萝卜素作为评价烤甘薯综合品质的核心指标。综合来看,-60℃冰箱冻结对速冻烤甘薯的营养品质保存较好。该研究为速冻烤甘薯的综合评价及进一步的研发生产提供数据支持。
The effects of four freezing methods on the quality of baked sweet potatoes were studied.The baked sweet potatoes were treated by-18℃,-25℃,-60℃refrigerator freezing and liquid nitrogen quick-freezing,respectively.The changes of physical and chemical indicators,including starch,fat,reducing sugar,ascorbic acid,carotene,L^*,hardness,chewiness and maximum shearing force,were analyzed,and the freezing curves were described.Correlation analysis and principal component analysis were used to evaluate the nutritional quality of the baked sweet potatoes under different freezing rates.Results showed that the time of liquid nitrogen through the maximum ice-crystal formation zone was shortest,and its texture characteristics were closest to fresh-baked sweet potatoes.The preservation for major quality parameters and color was best after freezing at-60℃compared with other freezing methods.Correlation analysis approved that there was a certain correlation among most quality indexes,and the influence of chewiness on the baked sweet potatoes quality was greatest.Principal component analysis indicated that 11 quality characteristics were consolidated into three principal components,and the cumulative variance contribution rate was 93.94%,which reflected the most information of baked sweet potatoes.Protein,chewiness,elasticity and reducing sugar and carotene were selected as the core indexes to evaluate the comprehensive quality of baked sweet potatoes.In a word,-60℃refrigerator freezing is beneficial to maintain the nutritional quality of pre-frozen baked sweet potatoes.The present study provides data support for the comprehensive evaluation and further research and production of pre-frozen roasted sweet potatoes.
作者
徐茂
向敏
王子涵
蒋和体
XU Mao;XIANG Min;WANG Zihan;JIANG Heti(College of Food Science,Southwest University,Chongqing 400715,China)
出处
《食品与发酵工业》
CAS
CSCD
北大核心
2020年第13期217-224,共8页
Food and Fermentation Industries
关键词
冻结速率
甘薯
营养品质
相关性分析
主成分分析
freezing rates
sweet potato
nutrition quality
correlation analysis
principal component analysis
