Sustainable valorization of garlic byproducts: From waste to resource in the pursuit of carbon neutrality

Abstract

Large-scale garlic planting and processing activities generate considerable amounts of agro-food waste and pose serious environmental and economic challenges. These byproducts are rich in bioactive compounds with promising applications in the food, medicine, and agriculture sectors. This review provides a comprehensive overview of the generation, classification, chemical composition, and valorization of garlic byproducts. Garlic agricultural waste is derived from all stages of garlic harvesting and post-harvest processing and contain abundant soluble polysaccharides, polyphenols, proteins, insoluble dietary fiber, and organic sulfur compounds. The valorization of garlic waste can be achieved through tailoring processing technologies to extract and utilize individual components or applying the whole matter. Using traditional and emerging extraction and modification technologies, a variety of bioactive constituents can be transformed into functional foods, nutraceuticals, or other high-value products with exceptional functional properties and health benefits. Moreover, garlic waste can be converted into N/S/O self-doped carbon dots and biochar or be utilized directly in applications such as biocomposite films for food packaging, fluorescence sensors for food safety detection, biosorbents for food wastewater purification, agricultural quality enhancers, or nutritional supplements. Despite these opportunities, there are still several knowledge gaps regarding assessment and grading of materials, clean and low-cost production, efficient applications, long-term performance evaluation of products, and well-establishment of a robust industrial chain. Therefore, more research is required to advance the valorization of garlic agricultural waste, fostering a win–win scenario for the effective utilization of garlic byproducts and progress toward carbon neutrality.