Development of new powdered smoothies agglomerated with polyphenol extracts

Abstract

Consuming fruits and vegetables through smoothies can contribute to improving current dietary imbalances in the population. Fruit and vegetables have high nutritional value, although they are not stable and can quickly lose their properties. Spray Drying can be used to stabilise these products although entails some loss of quality, involving antioxidants and other oxidizable compounds. By applying an appropriate addition technique, powdered smoothies can be enhanced with functional compounds, such as polyphenol antioxidants from plant extracts. This research explores the technological feasibility of developing fruit and vegetable-based powdered smoothies, enriched with a sustainable rosemary extract obtained from distillation by-products, which is rich in polyphenols (e.g., rosmarinic acid). The objective was to test a novel agglomeration method using a fluidised bed to obtain powdered smoothies enriched with rosemary polyphenols. Two formulations were assessed: a fruit-based (apple, banana, orange and whey protein) and a vegetable-based (apple, carrot, pumpkin and whey protein) to which aqueous rosemary extract (RE146) (145.6 mg polyphenols/g) was added at 800 mg/kg powder. The results showed that the agglomeration with RE has a little impact on the physical traits of powders (granulometry, colour, pH, sorption and solubility properties) and does not degrade rosemary polyphenols, maintaining the recovery level of rosmarinic acid around 100%. Addition of RE enhances the response of phenolic antioxidants 100% in these powdered smoothies, however, rosemary off-flavour is detected in the rehydrated smoothies, being needed reduce RE dose in preventing acceptability problems. The study concludes that agglomeration with RE represents a viable, innovative and sustainable technological strategy for the development of functional and value-added smoothies, contributing to reduced fruit and vegetable wastage and reaching their recommended daily intake.