Degradation Kinetics of Catechin in Aqueous Solution in the Presence of Ascorbic Acid or Octanoyl Ascorbate
Degradation Kinetics of Catechin in Aqueous Solution in the Presence of Ascorbic Acid or Octanoyl Ascorbate
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DOI：
10.11301/jsfe.10.117
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发表时间：
2009-06
期刊：
影响因子：
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通讯作者：
Yoshiyuki Watanabe;Tatsunori Okayasu;Kana Idenoue;S. Adachi
中科院分区：
文献类型：
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作者：
Yoshiyuki Watanabe;Tatsunori Okayasu;Kana Idenoue;S. Adachi
L-抗坏血酸是一种水溶性维生素，被称为维生素C，由于其强大的还原能力，广泛用作食品和化妆品的添加剂。在有机溶剂中，抗坏血酸与脂肪酸缩合，脂肪酶催化合成6-O-酰基抗坏血酸酯已有报道[1，2]。酰基抗坏血酸酯的酶促合成由于其反应过程简单和高区域选择性而比化学方法更有利。酰基抗坏血酸酯是一种两亲性抗氧化剂，因为它由分别作为亲水性抗氧化剂和亲脂性基团的抗坏血酸和脂肪酸组成。据报道，抗坏血酸盐，如6-O-棕榈酰抗坏血酸盐，具有抗肿瘤活性和转移抑制作用[3，4]。因此，酰基抗坏血酸有望成为一种有用的食品添加剂。我们还使用固定化脂肪酶在分批或连续反应器中合成酰基抗坏血酸酯[5，6]，评估其表面活性剂性质[7]和其对亚油酸的抗氧化能力[8]，并将其用于脂质的微胶囊化[9]。然而，还没有关于酰基抗坏血酸盐对水溶性和不稳定的化合物在水溶液中的抗氧化性能的报道，尽管其在水溶液中的行为的知识是必要的，其有效使用。儿茶素被认为是绿色茶的成分，具有抗氧化活性[10]和抑制脂肪细胞分化的能力[11]。大多数含有儿茶素的茶饮料是低酸饮料，在寒冷的季节在自动售货系统中保持温暖。此外，需要在高温下进行热处理以使嗜热厌氧菌的孢子灭菌。因此，许多研究人员在各种条件下研究了茶儿茶素在水溶液中的稳定性[12，13]，并使用一级动力学[14，15]对降解进行了动力学检查。儿茶素在抗坏血酸或辛酰抗坏血酸存在下的降解动力学
L-Ascorbic acid is a water-soluble vitamin known as vitamin C, and widely used as an additive in foods and cosmetics due to its strong reducing ability. The lipasecatalyzed synthesis of 6-O-acyl ascorbate through the condensation of ascorbic acid and fatty acid in an organic solvent has been reported [1,2]. The enzymatic synthesis of the acyl ascorbates would be more advantageous than a chemical method due to the simplicity of its reaction process and its high regioselectivity. Acyl ascorbate is an amphilic antioxidant, as it consists of ascorbic acid and a fatty acid as the hydrophilic antioxidant and lipophilic group, respectively. It has been reported that the ascorbates, such as 6-O-palmitoyl ascorbate, have an antitumor activity and metastasis-inhibitory ef fects [3,4]. Therefore, acyl ascorbate would be expected to be a useful food additive. We have also synthesized acyl ascorbates using an immobilized lipase in a batch or continuous reactor [5,6], evaluated their surfactant properties [7] and their antioxidative ability against linoleic acid [8], and used them for the microencapsulation of lipids [9]. However, there has been no report about the antioxidative property of acyl ascorbate against a water-soluble and unstable compound in aqueous solution, though knowledge of its behavior in aqueous solution is required for its effective use. Catechins are recognized as constituents of green tea with an antioxidative activity [10] and suppressive ability against adipocyte differentiation [11]. Most tea drinks containing catechins are low acid beverages, and kept warm in the vending system during the cold season. Furthermore, heat processing at high temperature is required to sterilize the spores of thermophilic anaerobes. Thus, the stability of tea catechins in aqueous solution has been investigated under various conditions by many researchers [12,13], and the degradation is kinetically examined using first-order kinetics [14,15]. Degradation Kinetics of Catechin in Aqueous Solution in the Presence of Ascorbic Acid or Octanoyl Ascorbate