Development of value added unripe papaya flour from waste product of fruit industry

Abstract

Papaya fruit (Carica papaya L.) belonging to Caricaceae family is recognized as a good source of dietary fiber and antioxidants. The objective of this study was to develop the unripe papaya flour (UPF) from waste fruit product. The study was also investigated physicochemical, functional properties of UPF and its addition of pancake. First, the small pieces of unripe papaya were heated by hot air oven, then ground by using a high-speed universal grinder and sieved through a 100-mesh sieve. The particle size of UPF was 140.8±2.1 µm with randomly irregular shape. The hydration properties of UPF was higher than wheat flour, whereas bulk density was not significant differences. Total polyphenol and ᵦ-carotene contents of UPF were 85.7±1.6 mg gallic acid equivalent/100 g dry weight and 39±3.3 µg/100 g dry weight, respectively. In addition, UPF had the ferric reducing antioxidant power (411.6±38 µmol FeSO4 per 100 g DW) and DPPH free radical scavenging activity (37.87±3.69 mg vitamin C equivalent per 100 g DW) higher than that of wheat flour. Moreover, UPF had the ability on bind bile acid and interfere the cholesterol micellization. Thereafter, the replacement of wheat flour with UPF into pancake (0%, 5%, 10%, and 20%) presented the darker shade of brown color on their surface. Hardness and cohesiveness of pancake were increased in a higher level of replacement. However, pancake with UPF (20%) could attenuate the glucose release under simulated digestion. Moreover, pancake with UPF had significantly lower predicted glycemic index when compared to the control pancake. Undigestible starch in pancake was also increased when the replacement of UPF was increased. Furthermore, pancake with UPF significantly increased total polyphenol content and antioxidant activity. In sensory evaluation, the taste and aftertaste parameters were significantly decreased in pancake with 20% UPF. However, the overall acceptance showed no significant difference among all groups. The results suggest that the unripe papaya flour can be regarded as a good ingredient for natural antioxidants for development of healthy products.