Microbiological assessment of tigernut milk as a potential probiotic product

M.B Osho,O.E Sobande

doi:10.4314/njb.v36i1.24

Abstract

This study aimed at developing starter cultures as probiotic from spontaneous fermented tigernut milk (SFTM) by the natural flora. Fermented tiger nut milk (FTM) was produced from these varieties – small dried brown, big dried brown and fresh yellow tiger nuts. Microbiological analysis of SFTM and pasteurized fermented tiger nut milk (PFTM) were carried out using Nutrient agar, De Mann Rogosa and Sharp and Malt Extract Agar for isolation of aerobic bacteria, lactic acid bacteria and yeast respectively. The pH of SFTM and PFTM, and titratable acidity of the lactic acid produced were investigated. Lactic acid bacteria (LAB) Lactococcus lactis (LC) and two species of yeast Pichia sp. PM13 and Pichia Kudriazevii CBS 245 were obtained from FTM at different fermentation periods. LAB were found to predominate the microflora of the FTM with their count ranging between 2.2 x 10 4 - 6.5 x 10 4 (SFTM) and 4.6 x 10 5 - 7.9 x 10 6 (PFTM) and pH ranged 4.3- 6.5. The quantity of lactic acid produced by the LAB isolate ranged between 0.46 g/l - 1.92 g/l and hydrogen peroxide between 0.16 g/l – 0.51 g/l. Thus, the propagation and selection of known starter cultures as a probiotic microbes might bring about uniformity of product. Keywords: Tiger nut milk; Lactic acid bacteria, Spontaneous, Starter Culture; Probiotic Product

Highlights

Tiger nut (Cyperus esculenta), popularly referred as “Ofio” in Yoruba, “Akiausa” Igbo and “Ayaya” Hausa in Nigeria has three varieties which can be eaten raw, roasted, dried, baked or be made into milk (Oladele and Aina, 2007). Ukwuru and Ogbodo, (2011) and Roselló-Soto et al (2019) reported that four varieties of the milk product viz: pasteurized, natural, ultra-high temperature, and condensed tiger nut milk could be obtained when tigernut milk undergoes fermentation
Starter culture micro-flora in raw milk and fermented milks belong to a family of bacteria collectively known as the Lactic Acid Bacteria (LAB) which occur naturally as indigenous organisms and are widely distributed in nature (Olokun et al, 2018)
LAB have the ability to dominate other bacteria involved in natural fermentation of tigernut milk drink

Summary

Introduction

Tiger nut (Cyperus esculenta), popularly referred as “Ofio” in Yoruba, “Akiausa” Igbo and “Ayaya” Hausa in Nigeria has three varieties (brown, yellow and black) which can be eaten raw, roasted, dried, baked or be made into milk (Oladele and Aina, 2007). Ukwuru and Ogbodo, (2011) and Roselló-Soto et al (2019) reported that four varieties of the milk product viz: pasteurized, natural, ultra-high temperature, and condensed tiger nut milk could be obtained when tigernut milk undergoes fermentation. Tiger nut (Cyperus esculenta), popularly referred as “Ofio” in Yoruba, “Akiausa” Igbo and “Ayaya” Hausa in Nigeria has three varieties (brown, yellow and black) which can be eaten raw, roasted, dried, baked or be made into milk (Oladele and Aina, 2007). Ukwuru and Ogbodo, (2011) and Roselló-Soto et al (2019) reported that four varieties of the milk product viz: pasteurized, natural, ultra-high temperature, and condensed tiger nut milk could be obtained when tigernut milk undergoes fermentation. LAB have the ability to dominate other bacteria involved in natural fermentation of tigernut milk drink. They possess adhesional adaptation with ability to survive different environments such as diverse food matrices (Wakil et al, 2014). Tigernut can support the growth of lactic acid bacteria being slightly acidic pH 6.34. Maduka et al (2017) reported that tigernut is a substrate that can sustain microbial

Objectives

Methods

Results