Improving nutritional, bioactivity, and sensory properties of cereal by-products by co-culture fermentation: A review

Cereal bran, brewers’ spent grains, and corn gluten meals, which are generated in greater quantities, are underutilized by-products of grain processing industries. Cereal by-products have nutritional and functional potential and can be incorporated into various food products. However, the insoluble cell wall fiber and proteins, bound phenolic compounds, and anti-nutritional factors limit their application. This review provides an in-depth look at co-culture fermentation of cereal by-products and its impact on nutrition, bioactivity, and sensory properties. The potential limitations and strategies to improve co-fermentation processes are also covered. The studies described indeed provide supporting evidence for co-fermentation being more effective than monoculture fermentation with respect to nutrient bioavailability, antioxidant capacity, and gut microbiota modulation. Co-fermentation can also improve the aroma and shelf-life characteristics of cereal-based foods. Currently, the specific mechanisms underlying the synergistic effects of co-cultures during fermentation remain not fully understood, along with the lack of standardization of co-fermentation conditions and clinical studies. Moreover, the biovalorization of cereal by-products using co-cultures not only enhances their functionality, but also provides an eco-friendly and sustainable approach to reduce agro-industrial food waste.