Villanova Franciene Almeida, Vanier Nathan Levien, de Avila Madruga Nathalia, Pesek Joseph, Matyska-Pesek Maria, Elias Moacir Cardoso, de Oliveira Maurício
Department of Agroindustrial Science and Technology, Federal University of Pelotas, 96160-000 Capão do Leão, RS, Brazil.
Department of Agroindustrial Science and Technology, Federal University of Pelotas, 96160-000 Capão do Leão, RS, Brazil.
Food Chem. 2017 Nov 15;235:51-57. doi: 10.1016/j.foodchem.2017.05.053. Epub 2017 May 10.
Browning occurs in parboiled rice as a result of the Maillard reaction that negatively affects consumers' acceptability. The aim of this study was to evaluate the ability of gallic acid, glycine, reduced glutathione and l-cysteine at 0.1, 0.5, 1.0 and 2.0% levels to inhibit browning reactions during the parboiling of rice. Gallic acid and l-cysteine did not exhibit browning inhibition effect at the studied levels. On the other hand, glycine and the higher concentrations of reduced glutathione (1.0 and 2.0%) were able to promote a whiter color and a low free 5-hydroxymethyl-2-furaldehyde content (HMF). The highest level of 2.0% for glycine and reduced glutathione favored protein extractability and a weaker protein-starch matrix, roughly increasing the broken grains percentage. Cooking time changed just for reduced glutathione-treated rice, as a result of their weaker protein-starch matrix and the greater ability of the grains to soften during cooking.
由于美拉德反应，半熟米中会出现褐变，这会对消费者的接受度产生负面影响。本研究的目的是评估在0.1%、0.5%、1.0%和2.0%水平下，没食子酸、甘氨酸、还原型谷胱甘肽和L-半胱氨酸抑制大米半熟化过程中褐变反应的能力。在所研究的水平下，没食子酸和L-半胱氨酸未表现出褐变抑制作用。另一方面，甘氨酸和较高浓度的还原型谷胱甘肽（1.0%和2.0%）能够使大米颜色更白，且游离5-羟甲基-2-糠醛（HMF）含量较低。甘氨酸和还原型谷胱甘肽2.0%的最高水平有利于蛋白质的提取，并使蛋白质-淀粉基质变弱，大致增加了碎米率。由于还原型谷胱甘肽处理的大米其蛋白质-淀粉基质较弱，且在烹饪过程中谷物软化能力更强，因此仅其烹饪时间发生了变化。
