Bioconversion of horticultural waste into value-added products: A Review

Abstract

Horticultural crops are vital component of food diversity, human health, and agriculture, especially in India. These crops contribute greatly to the gross domestic product (GDP), provide employment, and support food and nutritional security. Fruit, vegetable and spice processing industries produce large volumes of solid by-products, including peels, pomace, seeds, cores, rinds, stones and spent residues, which constitute a significant proportion of the raw material processed. The magnitude of processing waste varies with commodity and technology, with fruit and vegetable processing generating approximately 30–60% solid residues, while spice oil and oleoresin industries produce exceptionally high waste fractions, reaching 80–90% of the processed material. At the global level, the fruit processing industry alone generates around 0.5 billion tonnes of processing waste annually, in addition to large volumes of wastewater, showing the resource-intensive nature of horticultural value addition. Improper management of these nutrient-rich but highly perishable processing residues leads to environmental problems like wastewater pollution, greenhouse gas emissions, odour formation and localized land and water contamination, while also imposing economic burdens on processors through disposal costs and inefficient resource utilization. These wastes could be gainfully utilized for production of animal feed, compost, biofertilizers, biofuels, essential oils, edible oils, food additives, pigments, nutraceuticals, preservatives, edible coatings, ethanol, and biodegradable plastics. Through appropriate bioconversion and value-addition technologies, horticultural residues can be transformed into a wide range of bio-based products, thereby minimizing environmental impacts and promoting resource efficiency. This review emphasizes the potential of utilizing horticultural waste to promote sustainable agricultural practices and support a circular economy.