Title : Enhancing plant protein utility: Evaluating nutrient and sensory profiles of lemon-coagulated tofu with different cooking methods
Abstract:
This study investigated the nutrient and sensory profiles of lemon coagulated tofu with different cooking methods (steaming, frying, baking, and microwave cooking). Proximate composition, mineral content, anti-nutrient properties, and sensory attributes of the tofu samples were analyzed using standard laboratory methods. Proximate analysis revealed significant differences in moisture, protein, fat, crude fiber, ash, carbohydrates, and energy across treatments. Fresh tofu (FRC) had the highest moisture (64.84%), while baked tofu (TBC) exhibited the lowest moisture (18.43%), highest crude protein (18.13%), crude fiber (1.12%), ash (2.13%) and carbohydrate (57.96%) indicating baking significantly reduced moisture and enhanced nutrient value and shelf life of tofu. Fried tofu recorded the highest fat (12.83%) and energy (365.35 kcal) values which greatly increased the caloric value. Mineral analysis showed steamed tofu (TSC) had the highest calcium (187.13 mg/100g), potassium (64.21mg/100g) and sodium (4.83mg/100g). This indicate steamed tofu is a mineral-rich option, especially for bone and heart health. While microwaved tofu (TMC) contained the most iron (4.40mg/100g) and could be ideal for individuals needing iron, such as those prone to anemia. Anti-nutrients (phytate, tannin, oxalate, saponin) were significantly reduced by heat treatments, with frying yielding the lowest phytate (0.36 mg/100g) and tannin (0.46 mg/100g) levels, all of which were below the permissible limit. Although fried tofu (TFC) was liked slightly for color and texture as well as neither liked nor disliked for taste and flavor yet it was rated highly by the sensory panelist followed by baked tofu (TBC), while steamed tofu (TSC) was disliked moderately and scored lowest. The study demonstrates that the method of tofu preparation significantly influences its nutrient, anti-nutrient, and sensory qualities. Moreover, the findings provide valuable guidance for health-conscious consumers, nutritionists, and food manufacturers in selecting or recommending tofu processing methods based on nutritional goals, health conditions, and sensory preferences.
Fried tofu, although rated highest in taste, color, flavor, and texture, also recorded the highest fat and energy values, making it the most energy-dense. While this enhances palatability and consumer appeal making it suitable for individuals needing high-energy diets (e.g. underweight individuals, athletes, or people with high caloric need). It may be less desirable for individuals managing weight or cardiovascular health, particularly if fried in saturated or reused oils.
Steamed tofu proved to be mineral-rich, offering high levels of calcium, potassium, and sodium nutrients which are essential for bone, nerve, and cardiovascular health. Microwaved tofu recorded the highest iron content, making it potentially beneficial for individuals at risk of iron deficiency anemia. However, baked tofu (TBC) emerged as the most nutrient-dense, with high protein and carbohydrate content and the lowest moisture, contributing to longer shelf life. It stands out as a healthy option for protein-rich diets and snack formulations.
