New function of antioxidants in foods

1.烹调模型中调味料对抗坏血酸稳定性的影响研究了在100 ℃下，在日本烹调中常用的各种调味料存在下，抗坏血酸（AA）水溶液的热不稳定性。本实验反应体系中AA的减少与AA损失浓度呈一级反应。当每种调味品添加到AA溶液中，盐稳定的AA和日本含酒精的混合物，如清酒和甜清酒（米林），没有显着的稳定性的影响。相反，酱料、味噌和鲣鱼肉汤粉以浓度依赖的方式加速AA的下降。在日本调味品的成分中，不仅铁，而且氨基酸也参与加速AA降解。2.抗氧化剂对肿瘤坏死因子（TNF）诱导的人单核细胞U937细胞凋亡的影响研究了抗氧化剂对TNF诱导的人单核细胞U937细胞凋亡的影响。N-乙酰半胱氨酸（NAC）、2-巯基乙醇（2-ME）、维生素E（VE）和丁基羟基甲苯（BHT）可抑制放线菌酮诱导的肿瘤坏死因子（TNF）诱导的U937细胞凋亡。细胞凋亡抑制率为40 - 60%，表明抗氧化剂对TNF诱导的细胞凋亡具有部分抑制作用。加入NAC或2-ME后，细胞内谷胱甘肽（GSH）水平维持在高于对照组（未加抗氧化剂）的水平。然而，当细胞用YE或BHT处理时，GSH水平保持不变。这些结果表明，抗氧化剂的所有抑制作用都不能用GSH水平来解释。

1.Effects of seasonings on the stability of ascorbic acid in a cooking modelThe thermolability of ascorbic acid (AA) in aqueous solution at 100□C was assessed in the presence of various seasonings commonly used in Japanese style cooking. The decrease of AA in the reaction system of this experiment was a first-order reaction with respect to the concentration of AA loss. When each seasoning was added to AA solution, salt stabilized AA and Japanese alcohol-containing admixtures, such as sake and sweet sake (mirin), did not have a significant effect on the stability. Conversely, soy sauce, miso and broth powder from skipjack accelerated the decrease of AA in a concentration-dependent manner. Of the constituents of Japanese seasonings, not only iron but also amino acids are involved in the acceleration of AA degradation.2.Effects of antioxidants on TNF-induced apoptosisThe effects of antioxidants on tumor necrosis factor (TNF) -induced apoptosis of human monocytic U937 cells were evaluated. Apoptosis of U937 cells induced by TNF in the presence of cycloheximide was attenuated by N-acetylcystein (NAC), 2-mercaptoethanol (2-ME), vitamin E (VE), or butylhydroxytoluene (BHT). The inhibition rate of apoptosis was 40 -60%, indicating that antioxidants could play a role as a partial inhibitor of TNF-induced apoptosis. When NAC or 2-ME was added to culture medium and cells were treated with TNF, the level of intracellular glutathione (GSH) was maintained higher than the control group (without antioxidant treatment). However, when cells were treated with YE or BHT, the level of GSH remained unchanged. These results suggested that all the inhibitory effects by antioxidants are not explicable by the level of GSH.