UTILIZATION OF POTATO PROCESSING WASTE AS NATURAL ANTIOXIDANTS SOURCE IN BEVERAGES.

Abstract

The majority of soft drinks are generally considered ready media for spoilage microbial growth. Deterioration of these products by undesirable microorganisms can alter the sensory quality of the product which also poses a major public health risk. The soft drink category with lemon made up 85% of all bacterial contamination and was considered microbiologically unsafe due to a lack of preservatives. Potato peel waste containing phenols and flavonoids give it advantages in high antioxidant activities and antimicrobial activities. Therefore, this study was designed to enhance a high category of soft drink most expose to microbial contamination with antioxidants and antimicrobial components extracted from potato peels waste, and then evaluate their physical, chemical, microbiological and sensory properties. Bioactive compounds (phenols and flavonoids) were extracted from potato peels by using different solvents such as methanol and ethanol (80 and 100%) as well as water. The results indicated that methanol extract at 80% of potato peels had higher yield extract; total phenols; total flavonoids and antioxidants activity than other solvent extracts such as methanol (100%), ethanol (80 & 100 %) and water. Antioxidant activity using Rancimat instrument illustrated that potato peels methanol extract (PPME) at 200 and 400 ppm exhibited induction period 10.9 and 11 hr, respectively comparing with 14 hr for BHT. Also, PPME at 200 and 400 ppm has antibacterial and antifungal activities. Addition of PPME to lemon soft drink formulation at 200 ppm let to improve its sensory properties and decreased bacterial, yeast and mold populations during stored for 6-months storage period at room temperature comparing with global lemon soft drink. Therefore, it can be recommended that potato peels methanol extract (PPME) be added as an antimicrobial and antioxidant ingredients in order to reduce microbial deterioration and improve sensory properties of lemon soft drink.