Isolation and Utilization of Anthocyanins from Syzygium cumini as Biocolorants in Food Products

Abstract

The isolation and utilization of anthocyanins have gained significant attention due to their antioxidant properties and associated health benefits, making them valuable across the food, pharmaceutical, and cosmetic industries. As consumers increasingly favor natural alternatives, anthocyanins are emerging as promising options. Syzygium cumini, despite being rich in anthocyanins, flavonoids, and phenolic compounds, remains underutilized. This research investigates the anthocyanin and phenolic profiles of S. cumini, focusing on extraction techniques for obtaining anthocyanin-rich extracts through methods such as ultrasoundassisted extraction (UAE), natural deep eutectic solvent-assisted UAE (NADES-UAE), and ultrasound-assisted enzyme extraction (UAEE). The study optimized UAEE for total anthocyanin content (TAC) yield, establishing optimal conditions of 0.01% enzyme concentration, pH 2, and 10 minutes of sonication. The UHPLC characterization of extracts identified major anthocyanins, specifically cyanidin and malvidin, alongside twenty-three additional compounds, including gallic acid and myricetin. A stability analysis of S. cumini anthocyanin extracts (SCAE) evaluated their resilience under varying temperatures (60, 80, and 100°C), pH levels (2 to 7), light exposure (dark, UV, sunlight), and different storage conditions. The results demonstrated that anthocyanins remained stable at an acidic pH of 2 with reduced degradation in a controlled light exposure (specifically dark) at refrigerated temperatures of 4°C of storage. Moreover, thermal treatments showed a slower degradation of SCAE at 60°C over 60 minutes. Additionally, anthocyanins were incorporated into a fermented whey beverage and a buttermilk yogurt. The incorporation of anthocyanins in a fermented whey beverage indicated freshness/ spoilage, revealing a change in pH from acidic to slightly alkaline, and significant visual color changes pre- and post-fermentation. Moreover, S. cumini anthocyanins were integrated into buttermilk yogurt as a functional food ingredient at concentrations of 0%, 0.25%, 0.5%, 0.75%, and 1% over a 15-day period at 4°C. The study measured total anthocyanin content, phenolic content, antioxidant activity (DPPH), pH, water activity, color, syneresis, and viable cell count. The findings highlight the cost-effective extraction of anthocyanins from S. cumini fruit and their potential as functional food ingredients in dairy products, supported by significant health benefits documented in existing literature.