AUTHOR=Li Chen , Liu Tong , Li Xiaohong , Gao Wenli , Lv Jiayin , Hu Gaojian , Li Chunjiang , Liu Fangfang , Liu Xianjun , Meng Xianglong TITLE=Review of quinoa fermentation: product diversity, process optimization, and nutritional enhancement JOURNAL=Frontiers in Nutrition VOLUME=Volume 12 - 2025 YEAR=2025 URL=https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2025.1605558 DOI=10.3389/fnut.2025.1605558 ISSN=2296-861X ABSTRACT=Fermented quinoa has emerged as a promising functional food owing to its enhanced nutritional profile, improved bioactive compound bioavailability, and favorable sensory attributes. Key fermentation parameters-microbial selection, process conditions, and substrate pretreatment-that govern the quality and functionality of fermented quinoa products. It highlights microbial-driven biotransformation of polyphenols and flavonoids, which enhances antioxidant activity and bioavailability. Fermentation also modulates sensory profiles and promotes gut health through enrichment of beneficial genera. These data provide a foundational framework for process standardization, scale-up, and industrial adaptation, particularly highlighting the versatility of lactic acid bacteria and the need for mechanized fermentation technologies to enhance commercial viability. Future research should focus on multi-omics approaches to decipher microbial consortia dynamics, in vivo validation of health benefits, development of clean-label formulations, and exploration of sustainable fermentation technologies. This review provides a scientific foundation for optimizing quinoa-based biotransformation processes and accelerating the development of next-generation fermented quinoa products with enhanced nutritional and health-promoting properties.