Role of Microbial Fermentation in the Bio-Production of Food Aroma Compounds from Vegetable Waste

Flavour is a key driver of consumer preferences and acceptability of foods, and the food industry has made food aroma compounds a crucial area of research. At present, about 80% of food aroma compounds are produced by chemical synthesis; however, alternative production approaches have been explored to meet consumers’ demand for “clean label” food products and “natural” aromas. Bio-production of food aroma compounds from vegetable wastes through fermentation has emerged as a promising alternative. This review showed that fungi and yeasts, and also lactic acid bacteria, can be used to produce aroma compounds through the fermentation of vegetable waste. The produced compounds were mostly responsible for sweet, fruity, and floral notes. Other molecules imparting cheesy/buttery, creamy, green, herbal, grass notes were also obtained through the fermentation of vegetable food waste. Substrates varied from agricultural waste such as rice bran to by-products and waste from the fruit supply chain, in particular pomace, peels, pods. During the study, challenges and limitations for the scale-up of the process emerged. The production of aromas is still strongly strain and waste dependent. Certain aspects thus still require attention to avoid that a joint occurrence of technical challenges may cause the failure of the process.