A STUDY ON EFFECT OF LACTIC ACID BACTERIA STARTER CULTURE ON PHYSICOCHEMICAL, NUTRITIONAL AND ANTINUTRITIONAL PROPERTIES OF UGBA, A TRADITIONAL NIGERIAN FERMENTED FOOD

Ome, A.P. and Olaoye, O.A.

Food Science and Technology Department,

Michael Okpara University of Agriculture,  Abia State.

Email:talk2omepeter@gmail.com

ABSTRACT

The research was carried out with the aim of studying the effect of lactic acid bacteria on quality properties of ugba (fermented African oil bean seeds). The pure culture of lactic acid bacteria (Lactobacillus plantarum) isolated from ugba samples produced by traditional method, were successively screened and used (in single) to ferment African oil bean slices. The samples (ugba produced by spontaneous fermentation with that produced by LAB starter cultures) were subjected to physicochemical, proximate, anti nutritional and mineral analysis, and the mean values statistically analysed using a one-way Analysis of Variance at P < 0.05. The use of LAB starter culture in Sample B shortened the fermentation period from 72 h to 48 h with a significant reduction in pH (7.32 – 6.44) and increase in titratable acidity (0.068 – 0.097) as the fermentation time progressed, showing a favourable temperature (37^oC) for the activities of lactic acid bacteria.There were significant differences (P<0.05) among all the samples in the pH and titratable acidity. The proximate composition of all the ugbasamples had different levels of protein content (14.27%, 14.20%, 14.17%, 14.03%, 12.76%) respectively. Fat content (10.23% – 15.75%), moisture content (41.22% – 54.23%), ash content (0.67% – 2.89%), fibre content (7.07% – 9.03%) and carbohydrate content (10.79% – 25.73%), with Sample B (ugba produced by LAB starter culture) having the highest values in protein, fat and ash contents. There were significant differences (P<0.05) among all the samples in the proximate compositions. The anti nutritional factors of ugba produced by LAB starter culture had a significant reduction at the end of the fermentation process: tannins were reduced by >68%; oxalates were reduced by >90%; cyanide was reduced by >31% and phytic acid was reduced by >62% respectively. There were significant differences (P<0.05) among all the samples in the anti nutritional factors. The samples had different levels of mineral content: magnesium (162.05 – 189.06 mg/100g), calcium (270.10 – 298.19 mg/100g), sodium (11.35 – 20.65 mg/100g), potassium (16.80 – 24.73 mg/100g) and phosphorous (209.10 – 214.16 mg/100g), with Sample B (ugba produced by LAB starter culture) having the highest values in magnesium, calcium, potassium and phosphorous contents. There were significant differences (P<0.05) among all the samples in the mineral contents. It was concluded that pure cultures of Lactobacillus plantarum used as starter culture had good effect on the quality attributes of the fermented African oil bean slices.

Keywords: Lactic acid bacteria, ugba, starter cultures, fermentation.