食品科学 ›› 2020, Vol. 41 ›› Issue (13): 69-75.doi: 10.7506/spkx1002-6630-20190714-186

• 食品工程 • 上一篇    下一篇

不同方式干制龙眼果肉的粗多糖理化及生化特性比较

王诗琪,黄晓芸,易阳,黄菲,王丽梅,王宏勋   

  1. (1.武汉轻工大学食品科学与工程学院,湖北 武汉 430023;2.广东省农业科学院蚕业与农产品加工研究所,农业农村部功能食品重点实验室,广东 广州 510610;3.武汉轻工大学生物与制药工程学院,湖北 武汉 430023)
  • 出版日期:2020-07-15 发布日期:2020-07-29
  • 基金资助:
    国家自然科学基金面上项目(31771979)

Comparison of Physicochemical and Biochemical Characteristics of Crude Polysaccharides from Dimocarpus longan Pulp Dried by Different Methods

WANG Shiqi, HUANG Xiaoyun, YI Yang, HUANG Fei, WANG Limei, WANG Hongxun   

  1. (1. School of Food Science and Engineering, Wuhan Polytechnic University, Wuhan 430023, China;2. Key Laboratory of Functional Foods, Ministry of Agriculture and Rural Affairs, Sericultural and Agri-food Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510610, China;3. School of Biology and Pharmaceutical Engineering, Wuhan Polytechnic University, Wuhan 430023, China)
  • Online:2020-07-15 Published:2020-07-29

摘要: 目的:研究超声处理对谷氨酰胺转氨酶(glutamine transaminase,TG)诱导的大豆分离蛋白凝胶冻融稳定性的影响。方法:采用粒径、表面疏水性分析以及内源性荧光光谱和傅里叶变换红外光谱等分析大豆分离蛋白结构,同时研究了冻融循环过程中TG诱导大豆分离蛋白凝胶的持水性、质构、微观结构及可溶性蛋白含量变化。结果:未经超声处理的TG诱导大豆分离蛋白凝胶,随着冻融次数增加,凝胶持水性和可溶蛋白含量呈降低趋势,凝胶硬度和弹性呈增大趋势,凝胶微观结构呈明显的蜂窝状,说明凝胶品质发生劣变;经过超声处理的TG诱导大豆分离蛋白凝胶与未经超声处理凝胶相比,持水性、硬度和弹性都显著增加,且凝胶微观结构更加均匀致密,经冻融循环后,其凝胶持水性、硬度、弹性和可溶性蛋白含量变化幅度显著小于未经超声处理凝胶,5 次冻融循环后,当超声时间为40 min时,TG诱导大豆分离蛋白凝胶的持水性和可溶性蛋白含量较0 次冻融循环时分别降低了38.59%和3.65%,硬度和弹性分别增加了510.23 g和0.07 mm。说明超声处理是提高TG诱导的大豆分离蛋白凝胶冻融稳定性的有效方法。

关键词: 大豆分离蛋白, 超声处理, 谷氨酰胺转氨酶, 凝胶, 冻融稳定性

Abstract: The composition, Fourier transform infrared (FTIR) spectral characteristics and molecular mass distribution of crude polysaccharides extracted from fresh, hot air, vacuum, infrared and freeze-dried longan (Dimocarpus longan Lour.) pulp, named as FLP, HDLP, VDLP, IDLP and FDLP, respectively were analyzed, and their antioxidant activity and immune-stimulating activity were evaluated as well as their stability in simulated digestive system. The five crude polysaccharides mainly contained glucans and proteins at different mass fractions, and were distinct in amino acid composition. In addition, they exhibited significant differences in molecular mass distribution with average molecular mass ratio of 51.37:28.33:5.95:7.86:1.00, but not in the polysaccharide and protein (in the amide region) infrared absorption characteristics. Comprehensive comparison showed that FDLP had stronger scavenging capacity against 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radicals, while HDLP had a stronger ability to stimulate macrophages to generate NO and tumor necrosis factor-α. Longan polysaccharides were relatively stable in simulated intestinal juice, but degraded in simulated saliva and gastric juice, releasing a small amount of reducing sugar dominated by glucose, while the digestion performance of IDLP was different from the other four polysaccharides. From this study, we conclude that drying methods affect the physicochemical and biochemical properties of polysaccharides extracted from dried longan pulp. Selecting an appropriate drying method is vital for controlling the functional quality of dried longan pulp.

Key words: longan, polysaccharide, physicochemical characteristics, activity, digestion

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