Quality attributes of legume-based tofu: a systematic review

Tofu is a commonly eaten food rich in plant-based proteins, traditionally produced from soybeans for many centuries. Soybean unavailability in some countries, along with growing interest in plant-based diets, has encouraged researchers to produce tofu from legumes other than soybeans. The main aim of this systematic review was to evaluate and synthesize existing data on the nutritional composition, physicochemical properties, sensory attributes, shelf life, and storability of tofu produced from legumes other than soybeans. Major scientific databases were used for conducting the systematic literature search. This search was conducted in accordance with the PRISMA 2020 guidelines. Only experimental studies that reported nutritional, physicochemical, and sensory results of non-soy legume-based tofu were included. Due to heterogeneity in the study designs and reporting, data were extracted and synthesized descriptively. A total of 19 studies were included. The legumes investigated by the studies included chickpea (4 studies), kenaf seed (3 studies), peanuts (2 studies), yellow field peas (2 studies), lupin (2 studies), peas, lentil, faba bean, cowpea, Bambara groundnut, and jack bean. The studies utilized 19 various coagulants that included calcium sulfate (CaSO₄) (8 studies), glucono-δ-lactone (GDL) (5 studies), magnesium chloride (MgCl₂) (5 studies), organic acids (5 studies), chitosan (2 studies), and sodium alginate (1 study). All studies carried out nutritional and physicochemical analyses, whereas sensory analysis was reported in only 7 of the 19 included studies, limiting conclusions about consumer acceptance. Higher protein contents (50–60%) were obtained with tofu made with lupin. For fat, the highest content (48–65%) was obtained with tofu made with kenaf seed. The highest values for fiber (9.16%) and ash (5–6%) were obtained from chickpea tofu. Regarding physicochemical properties, fava bean tofu reported the highest pH values (4.46–6.60) and water holding capacity (86–88%). The sensory quality of tofu formulations made from non-soy legumes depended both on the type of legume and the level of substitution. But they were generally accepted by sensory panels, with a hedonic rating of 6.0 to 8.0 on a 9-point scale. Non-soy legumes are a promising, sustainable alternative for tofu with high content of protein and fiber as soybean tofu. Current gaps include limited exploration of diverse legumes, lack of standardized processing, shelf-life data, and sensory comparisons with soybean tofu. Future studies should focus on more legume varieties and comprehensive analysis.