Recent advances and perspectives for effective utilization of onion solid waste in food packaging: a critical review

Renewable resources have gained significant attention and are being evaluated as a base material for developing biodegradable packaging materials. A massive quantity of agricultural/food processing waste has been employed alone or in combination to make biodegradable packaging material with good barriers and functional capabilities. Onion is extensively used in dishes and condiments preparation. To meet consumer demand, the onion processing industry focuses on onion-based value-added products such as peeled onion, onion paste, onion powder, etc., that generate a considerable amount of solid waste (OSW). This OSW cannot be fit for animal fodder, landfill, and incineration due to their high carbon content and phytopathogens. OSW was found to be explored in the packaging sector because of high cellulose, lignin, and polyphenols. The biopolymers and pigments in OSW can be effectively used in active/smart packaging, which will aid in monitoring packaged food quality. The pigments and bioactive components in OSW can serve as indicators, maintaining the freshness of packaged foods in real-time by visual examination and reducing food loss and waste. The present review provides an approach of OSW for packaging material development and their potential application for food quality monitoring. Graphical Abstract