Evaluation of antioxidant activities, total phenolic content (TPC), and total catechin content (TCC) of 10 sugar apple (Annona squamosa L.) cultivar peels grown in Thailand

Abstract Antioxidant activities, total phenolic content (TPC), and total catechin content were analyzed in the ethanol extracts of 10 sugar apple (Annona squamosa L.) cultivar peels grown in Thailand. Antioxidant activity assays carried out in the this study were the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, ferric ion reducing antioxidant power (FRAP), 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation scavenging activity, and oxygen radical absorbance activity (ORAC). ‘Nhur Thong’, ‘Nung Keaw’, and ‘Fai Keaw’ showed high percentage fruit peel (over 38.0%). ‘Nhur Thong’, ‘Nung Keaw’, and ‘Fai Keaw’ ethanol extracts possessed high antioxidant capacities in the majority of methods used, and thus could be potential candidate of natural antioxidants. ‘Fai Keaw’ showed the best activity in the ABTS (1.57 mmol of trolox/g dry sample), FRAP (0.43 mmol of trolox/g dry sample), and ORAC assays (2.84 mmol of trolox/g dry sample), as well as the highest content of TPC (140.4 mg) per gram dry sugar apple peel among the 10 cultivars. TPC showed a positive correlation compared with all antioxidant activity assays. In conclusion, ‘Fai Keaw’ could be utilized as an excellent phenolic compound source for functional food products.

摘要：本研究对泰国种植的10个番荔枝（Annona squamosa L.）品种果皮的乙醇提取物开展了抗氧化活性、总酚含量（total phenolic content, TPC）以及总儿茶素含量的检测分析。本研究采用的抗氧化活性测定方法包括2,2-二苯基-1-苦基肼自由基清除活性（2,2-diphenyl-1-picrylhydrazyl, DPPH）、铁离子还原抗氧化能力（ferric ion reducing antioxidant power, FRAP）、2,2′-连氮基-双-(3-乙基苯并噻唑啉-6-磺酸)自由基阳离子清除活性（2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid), ABTS）以及氧自由基吸收活性（oxygen radical absorbance activity, ORAC）。‘Nhur Thong’、‘Nung Keaw’以及‘Fai Keaw’三个品种的果皮占比超过38.0%。‘Nhur Thong’、‘Nung Keaw’与‘Fai Keaw’的乙醇提取物在多数检测方法中均展现出优异的抗氧化能力，具备开发为天然抗氧化剂的潜在应用前景。其中，‘Fai Keaw’在ABTS（1.57 mmol Trolox/克干样品）、FRAP（0.43 mmol Trolox/克干样品）以及ORAC检测（2.84 mmol Trolox/克干样品）中表现出最优活性；同时在10个供试品种中，其每克干番荔枝果皮的总酚含量最高，达140.4 mg。总酚含量与所有抗氧化活性测定指标均呈正相关。综上，‘Fai Keaw’可作为优质酚类化合物来源，用于功能性食品的生产开发。