Characterization, Antioxidant Capacity, and Anti-Inflammatory Activity of Polyphenol-Enriched Extracts Obtained from Unripe, Mature, and Overripe Fruits of Red-Fleshed Kiwifruit Cultivars
Qian-Ni Yang,
Wen Deng,
Ding-Tao Wu,
Jie Li,
Hong-Yan Liu,
Hui-Ling Yan,
Kui Du,
Yi-Chen Hu,
Liang Zou,
Jing-Wei Huang
Affiliations
Qian-Ni Yang
Key Laboratory of Coarse Cereal Processing of Ministry of Agriculture and Rural Affairs, School of Food and Biological Engineering, Chengdu University, Chengdu 610106, China
Wen Deng
Key Laboratory of Coarse Cereal Processing of Ministry of Agriculture and Rural Affairs, School of Food and Biological Engineering, Chengdu University, Chengdu 610106, China
Ding-Tao Wu
Institute for Advanced Study, Chengdu University, Chengdu 610106, China
Jie Li
Research Center for Plants and Human Health, Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, National Agricultural Science and Technology Center, Chengdu 610213, China
Hong-Yan Liu
Research Center for Plants and Human Health, Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, National Agricultural Science and Technology Center, Chengdu 610213, China
Hui-Ling Yan
Key Laboratory of Coarse Cereal Processing of Ministry of Agriculture and Rural Affairs, School of Food and Biological Engineering, Chengdu University, Chengdu 610106, China
Kui Du
China-New Zealand Belt and Road Joint Laboratory on Kiwifruit, Kiwifruit Breeding and Utilization Key Laboratory of Sichuan Province, Sichuan Provincial Academy of Natural Resource Sciences, Chengdu 610015, China
Yi-Chen Hu
Key Laboratory of Coarse Cereal Processing of Ministry of Agriculture and Rural Affairs, School of Food and Biological Engineering, Chengdu University, Chengdu 610106, China
Liang Zou
Key Laboratory of Coarse Cereal Processing of Ministry of Agriculture and Rural Affairs, School of Food and Biological Engineering, Chengdu University, Chengdu 610106, China
Jing-Wei Huang
Key Laboratory of Coarse Cereal Processing of Ministry of Agriculture and Rural Affairs, School of Food and Biological Engineering, Chengdu University, Chengdu 610106, China
Discarded unripe kiwifruits (DUKs) are regarded as the major agro-byproducts in the production of kiwifruits, which have abundantly valuable secondary metabolites. Nevertheless, owing to the limited knowledge about the differences in phytochemicals and bioactivity between DUKs and mature kiwifruits, the utilization of DUKs in the food industry remains scarce. Hence, to promote their food applications, the phenolic compounds and bioactivity of discarded unripe, mature, and overripe fruits from three red-fleshed kiwifruit cultivars were studied and compared. The results revealed that the levels of total phenolics, total flavonoids, and total procyanidins in kiwifruits varied significantly by maturity stage. In addition, our findings demonstrated that DUKs possessed much higher contents of valuable phenolic compounds (e.g., chlorogenic acid (CHA), neochlorogenic acid (NCHA), gallic acid (GA), protocatechuic acid (PA), procyanidin B1 (ProcB1), procyanidin B2 (ProcB2), procyanidin C1 (ProcC1), quercetin 3-O-glucoside (QueG), and quercetin 3-O-rhamnoside (QueR)) than mature and overripe kiwifruits. Furthermore, DUKs exerted much stronger in vitro antioxidant capacity, inhibitory effects on α-glucosidase, and anti-inflammatory activity than mature and overripe kiwifruits, which were mainly attributed to their higher contents of total polyphenols and individual phenolic components, such as GA, CHA, NCHA, PA, ProcB1, ProcB2, ProcC1, and QueR. Overall, these findings provide sufficient evidence for the development and utilization of DUKs in the food/functional food industry.
