摘要
【目的】探究脱水胡萝卜在不同水分活度下的品质变化与细菌菌群演替规律,为控制脱水胡萝卜贮藏过程中的食用品质劣变,延长其货架期提供理论依据。【方法】挑选大小均一的新制备脱水胡萝卜丁,置于水分活度(water activity,aw)分别为0.43、0.67、0.78和0.84的密闭干燥器中贮藏50 d,观测脱水胡萝卜贮藏过程中硬度、微观结构、β-胡萝卜素含量、风味等品质变化情况,分析脱水胡萝卜在不同贮藏条件下的细菌菌群丰度变化和演替规律。【结果】乳酸菌(Lactic acid bacteria)是存在于脱水胡萝卜中的主要外源细菌菌群。经50 d的贮藏后,在低aw贮藏条件下(aw=0.43),脱水胡萝卜中的芽孢杆菌属(Bacillus spp.)相对含量高于其他组,高aw环境能够促进片球菌属(Pediococcus spp.)、葡萄球菌属(Staphylococcus spp.)和乳酸杆菌属(Lactobacillus spp.)的生长,同时加剧脱水胡萝卜中典型营养物质β-胡萝卜素的损失,并使脱水胡萝卜的硬度降低,微观结构粘连褶皱。同时,电子鼻分析显示高aw引起脱水胡萝卜中烯烃类和酮类等特征风味物质下降,而乳酸菌生长代谢相关的胺类物质上升。【结论】高aw环境能够加速脱水胡萝卜中片球菌属、葡萄球菌属和乳酸杆菌属的生长,造成脱水胡萝卜硬度下降、β-胡萝卜素损失、特征风味的劣变以及微观结构的粘连。
【Objective】The aim of this study was to explore quality change and exogenous bacteria succession in dried carrots at different water activities(aw),so as to provide a theoretical basis for controlling quality deterioration and prolonging shelf life of dried carrots during storage.【Method】Dried carrots with uniform size at different aw levels of 0.43,0.67,0.78 and 0.84,respectively were stored for 50 d in sealed desiccators.Hardness,microstructure,content of β-carotene and flavor components were then determined,and the changes of exogenous bacteria abundance and succession were also analyzed.【Result】Results suggested that lactic acid bacteria were the dominant bacteria in dried carrots.After 50 d storage,the relative abundance of Bacillus spp.in dried carrots stored at aw=0.43 was significantly higher than that of other groups.However,higher aw levels promoted the growth of Pediococcus spp.,Staphylococcus spp.and Lactobacillus spp.Moreover,the higher aw levels reduced the hardness and adhesion of dried carrots microstructure and aggravated the loss of β-carotene,a typical nutrient in dried carrots.E-nose analysis showed that higher aw caused a decrease in olefins and ketones contents,indicating loss of characteristic flavors in dried carrots.On the other hand,the increase of amines content was attributed to growth of lactic acid bacteria.【Conclusion】Higher aw promoted the growth of Pediococcus spp.,Staphylococcus spp.and Lactobacillus spp.,caused a decline in hardness and microstructure adhesion of dried carrots,and accelerated the loss of β-carotene,as well as the deterioration of characteristic flavors.
作者
杨文建
浦浩亮
王柳清
胡秋辉
裴斐
YANG WenJian;PU HaoLiang;WANG LiuQing;HU QiuHui;PEI Fei(College of Food Science and Engineering,Nanjing University of Finance and Economics/Collaborative Innovation Center for Modern Grain Circulation and Safety/Key Laboratory of Grains and Oils Quality Control and Processing of Jiangsu Province,Nanjing 210023)
出处
《中国农业科学》
CAS
CSCD
北大核心
2019年第20期3661-3671,共11页
Scientia Agricultura Sinica
基金
“十三五”国家重点研发计划(2017YFD0400903)
江苏高校优势学科建设工程(KYCX18_1437)
关键词
脱水胡萝卜
水分活度
Β-胡萝卜素
硬度
微观结构
特征风味
细菌演替
dried carrot
water activity
β-carotene
hardness
microstructure
characteristic flavors
bacteria succession
