Improvement of the production process and nutritional quality of Nigerian Tofu (Beske) through fermentation

Abstract

Tofu (Nigerian Beske) is a soybeans based food that is highly rich in protein. It is made from curdling of hot soymilk using a coagulant. The food has a short shelf life of about two to three days. This work is aimed at improving the nutritional quality and shelf life of tofu by using starter cultures of lactic acid bacteria (LAB) for fermentation of soy milk. A total of 52 LAB were isolated from spontaneously fermented soymilk and they were; Leuconostoc mesenteroides(11.5%),Pediococcus pentosaceus cremoris(9.6%),Lactobacillus casei (11.5%), (7.7%),Lactococcus Lactobacillus curvatus lactis (13.5%),Lactococcus (9.6%),Pediococcus acidilactic (7.7%),Lactobacillus delbrueckii (5.8%),Streptococcus sp (11.5%), Lactobacillus acidophilus (3.8%) and Enterococcus faecalis (7.7%). The fermenting soymilk recorded a pH of 6.5 and a total titratable acidity of 0.74% at 0hr and pH of 4.8 and a total titratable acidity of 1.96% at 18hrs. The soymilk fermented with Lactococcus lactis SO51 (SYL2) had the highest protein and ash content with a mean score of (4.06 ± 0.01) and (0.34±0.01) respectively while the unfermented soymilk had the highest carbohydrate content (1.99±0.00) and fat content (1.81±0.00). The fried fermented tofu with combined starters (FFTL1L2) recorded the highest mean score in protein (24.81±0.13), fat (11.02 ±0.05) and ash content (1.58±0.01). The fried fermented tofu using Lactobacillus casei SO36 (FFTL1) had the least phytate and lectin content with a mean score of (0.03±0.00) % and (11.24±0.02) HU/mg respectively. This study showed that fermentation process increased the nutritional quality and shelf life of tofu, reduced the anti-nutritional factors and also brought about a new variety of the food product.