Epsilon-Polylysine: A Substitute for Pasteurization in Fruit and Vegetable-Based Beverages and Its Effects on Physicochemical, Microbiological, and Organoleptic Properties

Subject Areas :

Hamidreza Noori ¹ , Toktam Mostaghim ^{2 *} , Alireza Rahman ³

1 - Department of Food Science and Technology, Shahr-e-Qods Branch, Islamic Azad University, Tehran, Iran
2 - Department of Food Science and Technology, Shahr-e-Qods Branch, Islamic Azad University, Tehran, Iran
3 - Department of Food Science and Technology, Shahr-e-Qods Branch, Islamic Azad University, Tehran, Iran

Received: 2023-09-16 Accepted : 2023-11-13 Published : 2024-02-20

Keywords: Epsilon-Polylysine, / Pasteurization, / Microbiology, / Preservative, / Beverage,

Abstract :

This study aimed to investigate the potential of epsilon-polylysine as a substitute for pasteurization in beverages derived from a mixture of fruit and vegetable juices. Pasteurization is widely employed in the food industry as the primary method to inactivate microorganisms and enzymes in beverages. In contrast, epsilon-polylysine is known for its non-toxic, cationic properties and proven antimicrobial efficacy. To achieve this objective, different concentrations of epsilon-polylysine (0.025, 0.05, 0.075, and 0.1%) were added to the beverage formulation. Throughout a 28-day storage period at 4°C, a comprehensive evaluation was conducted on physicochemical properties (pH, titratable acidity, soluble solids, total sugar, formalin number, viscosity, vitamin C content, and color indices), microbiological parameters (total microbial count, mold, and yeast count), and sensory attributes (taste, color, aroma, and overall acceptance). Results indicate that pasteurization leads to decreased Brix value, formalin number, and vitamin C concentration compared to unpasteurized treatments (p<0.05). Pasteurized beverages also exhibit a darker and more reddish hue, indicating a decrease in yellow chromaticity. However, pH, acidity, total sugar, and viscosity values of the beverages remain unaffected by pasteurization. Microbiological evaluations indicate that formulations containing 0.075% and 0.1% epsilon-polylysine exhibit comparable outcomes to pasteurization, successfully inhibiting the proliferation of bacteria, molds, and yeasts during the storage period. Sensory evaluations show that incorporating varying levels of epsilon-polylysine has no negative impact on the sensory attributes of the beverages, maintaining their appeal throughout storage. In conclusion, the findings demonstrate that epsilon-polylysine, particularly at higher concentrations (0.075 and 0.1%), can effectively maintain the quality of fruit and vegetable-based beverages while showing promise as a viable substitute for the pasteurization method.