抗氧化剂在苹果多酚-牛奶模型体系中的稳定性。

Stability of antioxidants in an apple polyphenol-milk model system.

机构信息

Health and Food, The Horticulture and Food Institute of New Zealand Limited, Mt Albert Research Centre, Private Bag 92169, Auckland 1020, New Zealand.

出版信息

Food Chem. 2008 Jul 15;109(2):310-8. doi: 10.1016/j.foodchem.2007.12.034. Epub 2008 Feb 1.

DOI:10.1016/j.foodchem.2007.12.034

PMID:26003352

Abstract

The stability of antioxidants in an apple polyphenol-milk model system was examined. The model system consisted of skim milk fortified with pH-neutralised apple polyphenols (AP, 0-200mg per 100ml milk), with or without ascorbic acid (100mg per 100ml milk). Physical and chemical changes were evaluated after thermal treatment (120°C, 5min) and oxidative storage (20°C and 38°C, up to 12 weeks). Antioxidant capacity was determined using both oxygen radical absorbance capacity (ORAC) assay and ferric reducing antioxidant power (FRAP) assay. Significant antioxidant capacity was detected in the presence of milk. Antioxidant capacity was retained during thermal treatment but decreased slowly during storage. The concentration of ascorbic acid decreased rapidly, and was close to zero after 2-week storage at 38°C or 10-week storage at 20°C. The brownness of the polyphenol-milk system increased over storage duration of 0-12 weeks; this effect was retarded by the addition of ascorbic acid. This high polyphenol-milk has demonstrated good physical stability.

摘要

研究了抗氧化剂在苹果多酚-牛奶模型体系中的稳定性。该模型体系由脱脂牛奶组成，其中添加了 pH 中性化的苹果多酚（AP，每 100ml 牛奶中添加 0-200mg），并添加或不添加抗坏血酸（每 100ml 牛奶中添加 100mg）。在热处理（120°C，5min）和氧化储存（20°C 和 38°C，最长 12 周）后，评估了物理和化学变化。使用氧自由基吸收能力（ORAC）测定法和铁还原抗氧化能力（FRAP）测定法测定了抗氧化能力。在有牛奶存在的情况下，检测到了显著的抗氧化能力。在热处理过程中，抗氧化能力得以保留，但在储存过程中缓慢下降。抗坏血酸的浓度迅速下降，在 38°C 下储存 2 周或在 20°C 下储存 10 周后，接近零。多酚-牛奶体系的褐变程度随着储存时间的延长（0-12 周）而增加；添加抗坏血酸可减缓这种褐变。这种高多酚牛奶具有良好的物理稳定性。