食品科学 ›› 2020, Vol. 41 ›› Issue (7): 102-109.doi: 10.7506/spkx1002-6630-20190129-376

• 食品工程 • 上一篇    下一篇

苹果汁冷冻浓缩与真空蒸发浓缩效果的对比

秦贯丰,丁中祥,原姣姣,蒋润花,黄斯珉,邵友元   

  1. (1.东莞理工学院 广东省分布式能源系统重点实验室,广东 东莞 532808;2.广东工业大学化工与轻工学院,广东 广州 510000)
  • 出版日期:2020-04-15 发布日期:2020-04-20
  • 基金资助:
    “十三五”国家重点研发计划重点专项(2016YFD04003032);国家自然科学基金面上项目(21376052)

Comparative Experimental Study on Freeze Concentration and Vacuum Evaporation Concentration of Apple Juice

Frank G. F. QIN, DING Zhongxiang, YUAN Jiaojiao, JIANG Runhua, HUANG Simin, SHAO Youyuan   

  1. (1. Guangdong Provincial Key-Laboratory of Distributed Energy Systems, Dongguan University of Technology, Dongguan 532808, China; 2. School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510000, China)
  • Online:2020-04-15 Published:2020-04-20

摘要: 基于悬浮结晶式冷冻浓缩仪,将传统上相互分离的单元操作——刮面换热器、结晶器和洗涤柱整合,研发具有三位一体紧凑结构的多级智能化冷冻浓缩仪。采用该冷冻浓缩仪对苹果汁进行冷冻浓缩,并以真空蒸发浓缩作对比分析。结果表明:单级浓缩比约为1.8;经三级冷冻浓缩后苹果汁可溶性固形物含量由初始的10.5 °Brix增加至34.5 °Brix;VC和芳香物乙酸丁酯的保留率均在90%以上;同时对还原糖的破坏和果汁颜色的影响很小;此外,可溶性组分在冰晶和母液中的分配系数为0.008 1~0.067 0;三级冷冻浓缩后对应的可溶性固形物回收率约为98%。对比分析结果表明,当苹果浓缩汁可溶性固形物含量为33.6 °Brix时,真空蒸发浓缩苹果汁的VC保留率为84.5%,芳香物乙酸丁酯保留率为43.9%。就苹果汁营养及风味保存而言,冷冻浓缩远优于蒸发浓缩。

关键词: 苹果汁, 冷冻浓缩, 蒸发浓缩, VC, 芳香物质, 保留率, 对比研究

Abstract: In this study, the freezing concentration and vacuum evaporation concentration of apple juice were compared and analyzed by using a prototype of a multi-pass intelligent freeze concentrator and a rotary vacuum evaporator. The freeze concentrator works in suspension crystallization mode and integrates the traditional separated unit operations: scraper heat exchanger, crystallizer and washing column to form a trinity compact structure. Its concentration ratio in a single pass was about 1.8. After three-pass freeze concentration, the concentration of apple juice increased from 10.5 to 34.5 °Brix. The retention rates of vitamin C and butyl acetate as an aromatic component were above 90%. At the same time, it had little effect on reducing sugar damage and the color of the juice. In addition, the distribution coefficients of soluble solids in ice crystals and mother liquor ranged from 0.008 1 to 0.067 0. The recovery yield of soluble solids was 98% and the loss of soluble solids was about 2% after three-pass freeze concentration. Parallel comparative experiments of apple juice concentration by vacuum evaporation showed that when the concentration of apple juice was 33.6 °Brix, the retention rates of vitamin C and butyl acetate were 84.5% and 43.9%, respectively. Therefore, freeze condensation was much better than evaporation concentration in terms of nutrition and flavor preservation.

Key words: apple juice, freeze concentration, evaporating concentration, vitamin C, aromatic substance, retention rate, comparative study

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