食品科学 ›› 2020, Vol. 41 ›› Issue (1): 68-73.doi: 10.7506/spkx1002-6630-20181112-134

• 基础研究 • 上一篇    下一篇

谷物蛋白体外消化率测定方法的修正

刘艳美,周学永,付荣霞,Angadi Honnursab RAJASAB,肖建中   

  1. (1.天津市农副产品深加工技术工程中心,天津农学院食品科学与生物工程学院,天津 300384;2.古尔伯加大学科学技术学院,印度 古尔伯加 585308;3.天津市黑马工贸有限公司,天津 301711)
  • 出版日期:2020-01-15 发布日期:2020-01-19
  • 基金资助:
    天津市科技支撑重点项目(17YFZCNC00220;18YFZCNC01270); 国家外国专家局教科文卫高端外国专家项目(GDW20171200099);天津农学院研究生创新培育项目(2017YPY023)

Correction for the Determination of in Vitro Digestibility of Grain Proteins

LIU Yanmei, ZHOU Xueyong, FU Rongxia, Angadi Honnursab RAJASAB, XIAO Jianzhong   

  1. (1. Tianjin Engineering and Technology Research Center of Agricultural Products Processing, College of Food Science and Bioengineering, Tianjin Agriculture University, Tianjin 300384, China; 2. Faculty of Science & Technology, Gulbarga University, Gulbarga 585308, India; 3. Tianjin Heima Industry and Trade Limited Company, Tianjin 301711, China)
  • Online:2020-01-15 Published:2020-01-19

摘要: 关于谷物蛋白体外消化率的测定方法,已有文献中有加入与不加入三氯乙酸(trichloroacetic acid,TCA)两种操作,且背景值扣除不规范。为了验证加入TCA对谷物蛋白体外消化率测定的影响,采用胃-胰蛋白酶两步消化法对大米、玉米、小米、藜麦4?种谷物进行酶解,在酶解液过滤前分别进行加TCA与不加TCA的对比研究。结果表明,上述4?种谷物酶解液过滤前不加TCA将导致测定结果偏高,结果分别偏高2.85%、3.42%、15.97%和18.74%;4?种谷物酶解液加入TCA但不扣除胃-胰蛋白酶背景导致测定结果偏低,结果分别偏低3.39%、2.92%、2.15%和1.78%。以本实验结果为依据提出了TCA沉淀法测定谷物蛋白消化率的修正公式,可以保证计算结果的准确性。采用沉淀法测定谷物蛋白体外消化率时,以加入TCA沉淀剂为宜,但计算过程中必须正确扣除胃蛋白酶和胰蛋白酶的空白对照值。

关键词: 谷物蛋白, 蛋白沉淀剂, 三氯乙酸, 蛋白消化率

Abstract: The procedures with and without the addition of trichloroacetic acid (TCA) to determine the in vitro digestibility of cereal proteins are currently available in the literature, both of which feature unregulated deduction of background. The aim of this study was to verify the effect of TCA on the determination of the in vitro digestibility of grain proteins. Four kinds of grains (rice, corn, millet and quinoa) were hydrolyzed by pepsin and trypsin through a two-step procedure. Comparative experiments with and without TCA addition before filtration of the hydrolysates were carried out. Results showed that the protein digestibility values determined by direct filtration without TCA addition were 2.85%, 3.42%, 15.97% and 18.74% higher than those with TCA addition for the four hydrolysates, respectively. However, the values from the latter method decreased by 3.39%, 2.92%, 2.15% and 1.78%, respectively when the background values of pepsin and pepsin were not deducted. Based on these experimental results, a modified formula for the accurate determination of grain protein digestibility by TCA precipitation was proposed. Therefore, it is recommended to add TCA to the protein hydrolysates in the determination of grain protein digestibility in vitro and simultaneously to deduct correctly the blank control values of pepsin and trypsin.

Key words: grain protein, protein precipitator, trichloroacetic acid, digestibility of protein

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