Bioactive compounds and antioxidant activity of papaya inoculated with Colletotrichum gloeosporioides as affected by hot water-calcium chloride

The application of technologies to reduce papaya (Carica papaya L.) anthracnose, a disease caused by the fungus Colletotrichum gloeosporioides, most of the time results in a loss of nutrients and other bioactive compounds. This study was performed to determine the effect of hot water (HW; 48 degrees C/20min), calcium chloride (Ca; 1%/20min), and their combination (HW-Ca) in bioactive compounds and antioxidant activity of papaya inoculated with Colletotrichum gloeosporioides stored during 20days at 12 degrees C. HW-Ca treated fruits showed higher ascorbic acid, phenolics content, and antioxidant activity than untreated and HW and Ca treated fruit, which correlated with the contents of ascorbic acid, phenolics, and -cryptoxanthin. Also, HW-Ca treatment resulted in fruits showing lower decay area, greater firmness and color retention. The results suggest that HW-Ca treatment could be used to reach higher antioxidant activity values and to preserve the postharvest quality parameters, whereas the development of anthracnose symptoms was delayed. Practical applications Papaya infected by Colletotrichum gloeosporioides and treated with hot water (HW) in combination with calcium chloride (Ca) had a good firmness, color retention, and higher antioxidant activity and content of ascorbic acid and phenolics, while the development of anthracnose symptoms was delayed. In this sense, the proposed HW-Ca treatment of papaya is a strategy to protect against Colletotrichum gloeosporioides and to obtain fruits with good quality, resulting in an interesting postharvest alternative to the application of fungicides.