Enhancing the Quality and Shelf-Life of a Fruit and Vegetable Smoothie Through an Optimized Combination of Ultrasound and Nisin Treatments

Abstract

This study aimed to optimize three factors of a non-thermal treatment for a fruit and vegetable (F&V) smoothie: ultrasonication (US) time, US amplitude as a percentage of the maximum one (%maxA), and nisin concentration. When the focus was on minimizing deterioration and maximizing quality immediately after treatment (day 0), the analysis suggested an optimal treatment of 2.4 min of US at 70%maxA and 11.83 mg kg−1 of nisin (opt1). However, when targeting minimal deterioration at advanced storage (day 9), a more intensive treatment of 7.4 min at 74%maxA and 12.5 mg kg−1 of nisin (opt2) was recommended. Both optimal treatments significantly reduced spoilage microorganisms and enzyme activity, increased total phenolic content and antioxidant capacity in the F&V smoothie, while maintaining its physicochemical properties and color. During storage, samples treated with both optimal conditions exhibited enhanced stability, extending the microbiological shelf-life by at least 14 days. Opt2 outperformed opt1, but cost-effectiveness must be weighed due to factors higher intensities. The obtained results lay the foundation for future research and demonstrate the great potential of these combined methods for preserving F&V beverages.