Production of Multi-enzymes from the Natural Fermentation of Fruit Peels

Background: Fruit peel waste constitutes a significant proportion in organic waste generated daily in our communities. Processing this waste into value-added products hold the potential to mitigate the environmental waste challenge. Objective: This study aimed to evaluate the potential of fermenting fruit peels for the production of industrial enzymes, focusing specifically on amylase, cellulase, pectinase, protease, and lipase. Methods: The fruit peels used include banana, papaya, and mango individually and in combination. The peels were subjected to a 90-days natural anaerobic fermentation in a mixture with brown sugar and water at a ratio of 3:10:1 (fruit peel: water: brown sugar). The fermented solutions were characterized on the basis of color appearance, aroma, pH, and biocatalytic attributes. Results: The color of the fermented solutions was ranges from yellowish-brown to dark brown after 90 days fermentation. The smell was fresh/sour and fresh, and all samples exhibited acidic pH between 2.7–3.4. Biocatalytic assays indicated that all the solutions possessed the tested enzymes with mango peels solution having highest amylase activity of 5.30 U/mL, mixed fruits peels solution showed highest cellulase activity of 5.75 U/mL. Banana peels solution exhibited the highest pectinase activity of 3.35 U/mL, while mango peels solution was found to have the highest activities of both protease and lipase at 7.17 U/mL and 6.67 U/mL respectively. Conclusion: The results revealed that fruit peels fermentation is a valuable process for repurposing organic waste such as fruit peels in to value added products. Through this, a vast amount of multi-enzyme can be obtained within a short period of time. This holds a promising potential as cost effective, environmentally friendly, and sustainable process in various industries including food, animal feed supplements, juice/pulp clarity, textiles, detergents, paper, and leather among others.