The phenolic constituents usually exist in free and covalently bound forms in the plant materials. This study reports the impact of microwave heating on certain phenolic compounds and antioxidant potential assessed by free radical‐scavenging and reducing power of citrus peels. Different levels of microwave power (125, 250, 500 W) and heating times (5, 10, 15 min) were applied. The phenolic acids were fractionated into three forms namely; free, glycoside‐bound, and ester‐bound. Microwave power and heating time significantly increased the content of free phenolic fraction while the content of bound fractions decreased. Increasing microwave power significantly increased the antioxidant activity of heated samples. The microwave heating up to 10 min at 250 W increased the antioxidant activity of the samples but further heating to 15 min exerted an adverse effect. A moderate microwave power and heating time was helpful for improving the antioxidant potential of citrus peels.

中文翻译：

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微波加热可增强抗氧化活性并从Feutrell的早期柑橘类柑桔皮中释放可溶性结合物

酚类成分通常以游离和共价键形式存在于植物材料中。这项研究报告了微波加热对某些酚类化合物和抗氧化剂潜力的影响，该作用通过自由基清除和降低柑桔皮的能力来评估。应用了不同级别的微波功率（125、250、500 W）和加热时间（5、10、15分钟）。将酚酸分馏为三种形式：游离，糖苷键和酯键。微波功率和加热时间显着增加了游离酚类组分的含量，而结合组分的含量却降低了。微波功率的增加显着提高了加热样品的抗氧化活性。微波在250 W下加热至10分钟可提高样品的抗氧化活性，但进一步加热至15分钟则会产生不利影响。适度的微波功率和加热时间有助于提高柑桔皮的抗氧化能力。