Physicochemical, antioxidant changes and volatile compounds of ‘Kluai Namwa’ and ‘Kluai Leb Mue Nang’ banana fruits during ripening

Abstract

Bananas are nutritious and often consumed as desserts. Although Thailand is home to several banana varieties such as ‘Kluai Namwa’ (NW) and ‘Kluai Leb Mue Nang’ (LMN), there is limited information on their quality characteristics, especially bioactive and antioxidant properties as they ripen. This study determined the physicochemical changes (including bioactive compounds) and volatile compounds of these two varieties as they ripen. Banana fruits from the two varieties were ripened at 24.5-30.5°C and 79-85% humidity. At three different ripening stages (mature green, fully ripe and overripe), the peel and pulp color, pulp-to-peel ratio, firmness, total soluble solids, titratable acidity, pH, total starch, total sugar, total phenolic content (TPC), total flavonoid content (TFC), antioxidant activities (DPPH and FRAP), and volatile compounds were determined. Similar changes in the physicochemical parameters were observed in both varieties as ripening occurred. In addition, LMN had a more yellow, firmer pulp and more total sugar content than NW. NW had more acid, starch, total soluble solids and TPC, while LMN had a higher TFC. The antioxidant activities (DPPH, FRAP) changed in varieties as bananas ripened. Regarding the volatile compounds, LMN had more esters, alcohols, and ketones, while NW had more acids and alkanes. This difference in composition of volatile compounds will affect their flavor and aroma. These varied qualities observed are important in the fresh consumption, processing and development of food products from bananas.