Solid-State Fermented Plant Foods as New Protein Sources.

The current animal-based production of protein-rich foods is unsustainable, especially in light of continued population growth. New alternative proteinaceous foods are therefore required. Solid-state fermented plant foods from Africa and Asia include several mold- and Bacillus-fermented foods such as tempeh, sufu, and natto. These fermentations improve the protein digestibility of the plant food materials while also creating unique textures, flavors, and taste sensations. Understanding the nature of these transformations is of crucial interest to inspire the development of new plant-protein foods. In this review, we describe the conversions taking place in the plant food matrix as a result of these solid-state fermentations. We also summarize how these (nonlactic) plant food fermentations can lead to desirable flavor properties, such as kokumi and umami sensations, and improve the protein quality by removing antinutritional factors and producing additional essential amino acids in these foods.

Application of apigeninidin-rich red sorghum biocolorant in a fermented food improves product quality.

BACKGROUND: The 'clean label' trend is pushing the food industry to replace synthetic colorants with plant-based colorants. However, technological efficacy and undesirable side effects restrict the use of plant-based colorants in industrial applications. This research studied the production of fermented maize dough coloured by apigeninidin-rich red sorghum biocolorant, as practised for centuries in West Africa, as a model to assess the impact of the biocolorant on nutritional and sensorial quality of foods. RESULTS: A 3-day fermentation of a dyed maize dough (containing 327 µg g-1 dry matter of apigeninidin) by Pichia kudriavzevii and Lactobacillus fermentum led to a degradation of 69% of the apigeninidin content, causing a clearly visible colour difference (ΔE*00 17.4). The antioxidant activity of fermented dyed dough (DD) increased by 51% compared to fermented non-dyed dough (NDD). However, the phytate dephosphorylation and volatile organic compound concentrations were lower in DD than in NDD. This suggests a lower mineral solubility and change in the sensory quality of fermented DD. CONCLUSION: Apigeninidin extract from sorghum leaf sheaths proved to be a bioactive red biocolorant with potential in fermented foods. The formation of new antioxidant compounds needs further investigation, as does the impact on the development of volatile compounds. © 2018 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.