Consumer perception and physicochemical characterization of a new product made from lactic acid fermented orange peels

A new product made from orange peels discarded from juice making has been characterized during the present study. In order to reduce its bitterness, orange peel was fermented during 10 days in two different sugary brines (2% or 5% NaCl content) using a Lactiplantibacillus plantarum strain. The lactic acid fermentation process was characterized by determining pH, sucrose, and the organic acids content. The original peel and the final products were characterized by instrumental texture and color determination, and total flavonoids content. In addition, consumers' expectations and perception of the new products were also studied using an online survey and a consumer study in which acceptance and perceived bitterness were assessed. Results suggested that the 2% NaClfermentation process allowed a greater bacteria development (with a higher lactic acid production and larger differences in color parameters with the original peel than the 5% NaCl-fermented samples) although both fermented samples were significantly different from the original peel in their physicochemical characteristics. Total flavonoids content, which has been related to bitterness perception, was significatively lower in the fermented samples than in the raw orange peel (50% reduction). Spanish consumers' expectations and perception of the new product were similar, and the snack made with the peel fermented in the 2% NaCl-brine was more liked than the same snack made with the original peel, or the 5% NaCl-fermented one. Using a lactic acid fermentation in a sugary brine was useful to decrease the bitterness perception and increase liking of the orange peel, meaning a potential valorization for this orange juice by-product. Implications for gastronomy. The present study includes the physico-chemical characterization and consumers' perception of a new product developed with one of the main citrus by-products: orange peels. A new ingredient for the Spanish gastronomy is proposed, showing a potential use for one of the main HORECA (HOtels REstaurants Catering sector) and juices industry by-products. A simple lactic-acid fermentation process, inspired in the North-African gastronomy culture, is described, and the consumer perception of the new product, presented as a freeze-dried snack is shown, proposing a new way of decreasing this food waste in Spain. In addition, some ideas about how to decrease bitterness perception on flavonoids-rich materials are shown, contributing to the knowledge on other new foods development.

Automated summary

This study characterized a new product made from discarded orange peels. The orange peel was fermented in sugary brines with different salt concentrations to reduce its bitterness. The fermentation process resulted in significant differences in physicochemical characteristics between the fermented samples and the original peel. The snack made with the orange peel fermented in a 2% salt brine was more liked by consumers, indicating potential value for this orange juice by-product.