Green ultrasound-assisted processing for extending the shelf-life of prebiotic-rich strawberry juices

Abstract

Adding value to conventional fruit juices by including prebiotic compounds into their formulation and preserving them using non-thermal, eco-friendly and safe technologies represents interesting and strategic approaches to diversify the healthy and innovative food products offer. In this context, the effect of ultrasound-assisted processing (for 15 and 30 min, 40 kHz, 180 W) on microbiological, physicochemical, nutritional and sensory quality of prebiotic-rich strawberry juices was investigated during storage (14 days, 5 ºC). Compared to untreated samples, the applied preservation treatments enhanced the microbiological and nutritional quality of samples by significantly reducing native microflora counts and increasing the total phenolic content (leading to a higher antioxidant capacity) of prebiotic-rich strawberry juices. Ultrasound processing and prebiotic enrichment had no negative effect on sensory attributes of enriched samples, suggesting that this non-thermal technique allowed to successfully retain the fresh-like attributes of strawberry juices during their shelf-life, contributing to the good sensory stability of juices. In addition, ultrasound treatments had no detrimental impact on physicochemical quality and ascorbic acid content of enriched samples, showing similar stability to control samples during storage. Based on our results, ultrasound processing appears to be a promising non-thermal technique to ensure a stable product from both microbiological and sensory points of view with improved antioxidant capacity and unaltered physicochemical quality while offering a healthier, nutritive and valuable food alternative.