食品科学

• 基础研究 • 上一篇    下一篇

热烫处理苹果片真空冻结特性

王海鸥,扶庆权,陈守江,王蓉蓉,张 伟,杨 平   

  1. 南京晓庄学院食品科学学院,江苏 南京 211171
  • 出版日期:2016-12-15 发布日期:2016-12-21

Vacuum Freezing Properties of Blanched Apple Slices

WANG Haiou, FU Qingquan, CHEN Shoujiang, WANG Rongrong, ZHANG Wei, YANG Ping   

  1. School of Food Science, Nanjing Xiaozhuang University, Nanjing 211171, China
  • Online:2016-12-15 Published:2016-12-21

摘要: The vacuum freezing properties of blanched apple slices were investigated by comparing with traditional refrigerator freezing. Results showed that after 40 min vacuum freezing, a mass loss of 27.5% and the lowest frozen temperature of -27.6 ℃ were achieved in apple slices pretreated by blanching, while a mass loss of 22.9% and the lowest frozen temperature of -26.5 ℃ were obtained in non-blanched apple slices. The total process of vacuum freezing was divided into low pressure flash evaporation stage, ice crystal formation stage and deep freezing stage. Vacuum freezing caused less microstructural changes and less significant cell disruption and contributed to smaller thawing loss and weaker relative electrical conductivity in frozen-thawed apple slices in contrast to refrigerator freezing. Blanching pretreatment before freezing caused more severe damage to cell microstructure in apple slices than non-blanching pretreatment, resulting in a significant increase in thawing loss and relative electrical conductivity in frozen-thawed apple slices.

关键词: vacuum freezing, blanching pretreatment, apple slices, micro-structure

Abstract: 本研究与传统冰箱冷冻相比较,研究了热烫处理苹果片的真空冻结特性。真空冻结40 min后,经热烫处理的苹果片冻结最低温度达-27.6 ℃,质量损失为27.5%,而未经热烫处理的苹果片的冻结最低温度和质量损失分别为-26.5 ℃、22.9%。依据温度变化,苹果片真空冻结过程可分为:减压闪发段、冰晶形成段、深层冻结段。相对于冰箱冷冻而言,真空冻结苹果片对组织微观结构改变小,冻融后汁液流失率低,电导率低,另外,冷冻前热烫处理会引起更大的组织结构损坏,显著增加冻融后的汁液流失率和电导率。

Key words: 真空冻结, 热烫处理, 苹果片, 微观结构

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