摘要
采用真空冷冻干燥技术制备草莓果粉,利用扫描电镜观察果粉的微观结构,并将草莓成品包装后分别贮藏在5,20,35℃条件下,研究其品质和微生物指标变化。结果表明,冷冻干燥草莓粉微观结构呈无定形态,表面疏松多孔;随贮藏时间的延长草莓果粉逐渐结块、褐变;不同温度下贮藏样品的水分含量、褐变指数在贮藏期间呈上升趋势,而可滴定酸、还原糖和Vc含量呈下降趋势;在整个贮藏期内,微生物指标均符合国家标准。对比各温度条件,以5℃贮藏效果最好,表明低温贮藏有利于维持草莓果粉品质。
In the present study,vacuum freeze-drying technology was used to produce strawberry powder,and SEM was used to observe the microstructure of the produced strawberry powder. The produced powder was packed and then stored at 5,20,35℃,respectively,and changes of its quality properties and microorganism indexes were investigated during the storage period regularly. It was shown that the microstructure of strawberry powder was amorphous and porous. The powder became lumping and browning with prolonged storage period. The moisture content and nonenzymatic browning index increased,whereas the content of titratable acid,reducing sugar and vitamin C decreased during storage. The microorganism indexes stayed within the limit of national standard. It was concluded that the best storage temperature for vacuum freeze-dried strawberry was 5℃,which indicated that the relatively low temperature was beneficial to maintain the quality of strawberry powder.
出处
《浙江农业学报》
CSCD
北大核心
2014年第6期1622-1628,共7页
Acta Agriculturae Zhejiangensis
基金
国家公益性行业(农业)科研专项(201303073)
浙江省公益技术研究农业项目(2013C32078)
关键词
温度
冷冻干燥
草莓果粉
贮藏品质
temperature
freeze-drying
strawberry powder
storage quality
