Tempeh is a fermented soybean food with high nutritional value, culinary versatility, and palatability. Its popularity is rising because it aligns with the trend towards sustainable and healthy plant-based diets. However, consumers have exhibited a strong preference for local ingredients over soy. Faba bean is a promising raw material in Scandinavia due to its high protein, dietary fiber, and phytochemical content. In this study, we evaluated the effects of soaking media (vinegar, water and sodium bicarbonate with or without lactic acid bacteria (LAB)) on boiling time and physicochemical properties of faba bean-based tempeh. We demonstrated that sodium bicarbonate, with and without LAB, significantly reduces the boiling time of faba beans (7–8 min), while beans soaked in vinegar and water with and without LAB require longer boiling times for tempeh production (>16 min). Texture analysis has revealed notable variations among the samples, with statistically significant differences (p < 0.05) observed across the majority of the measured attributes. Our study has demonstrated that faba beans are suitable for tempeh production and expand the sources of possible raw materials. However, further studies are needed to investigate consumers’ preferences and expectations towards faba bean-based tempeh.

Soy (Glycine max) is used in a wide range of products and plays a major role in replacing animal-based products. Since the cultivation of soy is limited by cold climates, this review assessed the nutritional, sensory, and functional properties of three alternative cold-tolerant crops (faba bean (Vicia faba), yellow pea (Pisum sativum), and oat (Avena sativa)). Lower protein quality compared with soy and the presence of anti-nutrients are nutritional problems with all three crops, but different methods to adjust for these problems are available. Off-flavors in all pulses, including soy, and in cereals impair the sensory properties of the resulting food products, and few mitigation methods are successful. The functional properties of faba bean, pea, and oat are comparable to those of soy, which makes them usable for 3D printing, gelation, emulsification, and extrusion. Enzymatic treatment, fermentation, and fibrillation can be applied to improve the nutritional value, sensory attributes, and functional properties of all the three crops assessed, making them suitable for replacing soy in a broad range of products, although more research is needed on all attributes.

This study evaluates how processing methods, soaking/cooking, fermentation (e.g. tempeh), and protein coagulation (e.g. tofu), affect the nutritional profile, protein digestibility, and mineral bioavailability of faba beans, grey peas, yellow peas, and soybeans. Protein digestibility was assessed using in vitro digestion and o-phthalaldehyde (OPA) assay, whilst mineral bioavailability was estimated using phytate-to-mineral molar ratios and further evaluated using a Caco-2/HT29-MTX co-culture model measuring ferritin formation. Processing markedly influenced nutritional properties. Protein coagulation resulted in the highest protein content and degree of hydrolysis, indicating improved protein digestibility. Fermentation substantially reduced phytate levels across all crops, in some cases below detection limits, leading to lower phytate-to-mineral ratios compared with cooked and tofu products. Consistent with these estimates, higher ferritin formation was observed in cells exposed to digested fermented products than to tofu digesta. Processing also altered amino acid composition, reflecting structural modifications of proteins. Overall, the results demonstrate that processing modulates protein digestibility and mineral bioavailability of legumes. Fermentation shows potential to enhance mineral availability, whereas protein coagulation improves protein digestibility. These findings are based on in vitro and cell-based models and provide guidance for the development of nutritionally improved plant-based foods.