Effect of oviposition by Bactrocera dorsalis on the antioxidant activity of orange juice

Abstract Among fruits and fruit products, oranges and orange juice are the most widely consumed worldwide. However, the effects of pest infestation of oranges on the quality of orange juice are not yet known. To evaluate the effect of the oriental fruit fly Bactrocera dorsalis on the antioxidant activity of orange juice, we measured changes in the vitamin C (Vc) concentration, total phenol content, and antioxidant activity of orange juice after the introduction of fruit fly eggs. Ten days after the eggs were introduced (larvae removed), the concentration of Vc in orange juice was 18.65 µg/mL, which was 9.16 µg/mL lower than that measured in healthy orange juice. In addition, the total phenol content decreased by 46.519 mg Gallic Acid Equivalents (GAE)/g to 9.748 mg GAE/g. Furthermore, the free-radical scavenging activity decreased from 22.297% to 5.393%. Correlation analysis indicated significant correlations between Vc concentration, total phenol content, and antioxidant activity of orange juice after B. dorsalis infestation. The decrease in Vc concentration, total phenol content and free-radical scavenging activity indicated that B. dorsalis changed the quality of orange juice by affecting the antioxidant activity of the juice after the oranges were infested.摘要 在各类水果及水果制品中，橙子与橙汁是全球消费量最高的品类。然而，橙类遭受虫害侵染后对橙汁品质的影响尚未明确。为评估东方果实蝇（Bactrocera dorsalis）对橙汁抗氧化活性的影响，本研究在接种实蝇虫卵后，对橙汁的维生素C（Vc）浓度、总酚含量及抗氧化活性的变化进行了测定。接种虫卵10日后（移除幼虫），橙汁中Vc浓度为18.65 μg/mL，较健康对照组橙汁降低了9.16 μg/mL。此外，总酚含量从46.519 mg没食子酸当量（GAE）/g降至9.748 mg GAE/g。进一步地，橙汁的自由基清除活性从22.297%降至5.393%。相关性分析结果显示，遭受东方果实蝇侵染后的橙汁，其Vc浓度、总酚含量与抗氧化活性之间存在显著相关性。Vc浓度、总酚含量及自由基清除活性的下降表明，橙类遭受东方果实蝇侵染后，该虫害可通过影响橙汁的抗氧化活性，进而改变橙汁的品质。