ABSTRACT
Fruits and vegetable juices are proving to be promising carriers for
probiotics. The development of these plant-based probiotic beverages is owed to
the issues of lactose intolerance and cholesterol content associated with
fermented dairy foods. Thus, tigernut was exploited for the development of a
functional beverage. The starter cultures employed for this development of
functional tigernut milk beverage were Lactobacillus
fermentum CS19 and Lactococcus lactis
isolated from “Ogi” and Yoghurt
respectively. These starter cultures were characterized. They were subjected to
Gram Staining and biochemical tests. Their probiotic potentials were
determined. They were screened for their acid tolerance, salt tolerance, milk
fermentation capacity and antimicrobial activity. Then molecular
characterization of the starter cultures was done by DNA extraction and
quantification, 16S rRNA amplification, sequencing and phylogenetic analysis.
1.5 x 108 CFU/ml of each identified isolate were
encapsulated in gelatin matrix and used for fermentation of the pasteurized
milk extracted from the tigernut. There was a control sample which was left
uninoculated. The fermentation of the tigernut milk was carried out at 30oC
for 72 hours. The physicochemical and proximate compositions of the tigernut
milk samples were determined before and after fermentation. After 72hours of
fermentation, the viability counts of the starter cultures were determined and
the fermented tigernut milk samples were stored at different temperatures, 4,
28 and 40oC for 4 weeks. Samples were taken weekly to determine the
changes in the physicochemical and proximate compositions of the fermented
tigernut milk samples. Effects of storage temperature and storage time of the
fermented tigernut milk beverage on viability of the starter cultures: Lactobacillus fermentum CS19 and Lactococcus lactis were evaluated. The
sensory properties of the functional tigernut milk product was also evaluated.
There was decrease in pH and increase in TTA of the fermented tigernut milk
samples with increase in storage time. There was increase in the moisture and protein
contents of the fermented samples while decrease in fat and ash contents were
observed. However, no fibre was detected after fermentation. Lactobacillus fermentum CS19 had more
viability count with value of 1.7x 1010 CFU/ml than Lactococcus lactis which had 1.9 X 109
CFU/ml viable cells. There was significant reduction in the lactic acid
bacteria counts as storage period increased. At the end of the 4weeks, there
was reduction by 1.0 X 105 CFU/ml in all counts between
the first and fourth weeks, with exception of the samples stored at 40oC
as they had approximately 1.0 x 106CFU/ml reduction. At storage
temperature of 4oC, the samples fermented by Lactobacillus fermentum CS19 and Lactococcus lactis and had viability counts of 1.3 X 1010
and 1.3 X 1010 in the first week of storage and reduced to 1.3 X 105
and 1.7 X 105 respectively, in the fourth week. While at storage
temperature of 40oC, the samples fermented by Lactobacillus fermentum CS19 and Lactococcus lactis and had viability counts of 1.7 X 109
and 1.3 X 109 CFU/ml in the first week of storage and reduced to 7.0
X 103 and 6.7 X 103 CFU/ml. The tigernut milk sample
fermented by Lactobacillus fermentum CS19
had the best sensory acceptability. From
this study, despite the encapsulation of the starter cultures, the minimum
biovalue of 1.0 X 106 CFU/ml required for beverages to be considered
functional was not met at the end of the fourth week of storage. More studies
to achieve this are therefore recommended.
UCHENNA, N (2023). Fermentation Of Tigernut Milk By Lactobacillus fermentum CS19 And Lactococcus lactis As A Potential Probiotic Product. Mouau.afribary.org: Retrieved Nov 13, 2024, from https://repository.mouau.edu.ng/work/view/fermentation-of-tigernut-milk-by-lactobacillus-fermentum-cs19-and-lactococcus-lactis-as-a-potential-probiotic-product-7-2
NWADINMA, UCHENNA. "Fermentation Of Tigernut Milk By Lactobacillus fermentum CS19 And Lactococcus lactis As A Potential Probiotic Product" Mouau.afribary.org. Mouau.afribary.org, 22 Mar. 2023, https://repository.mouau.edu.ng/work/view/fermentation-of-tigernut-milk-by-lactobacillus-fermentum-cs19-and-lactococcus-lactis-as-a-potential-probiotic-product-7-2. Accessed 13 Nov. 2024.
NWADINMA, UCHENNA. "Fermentation Of Tigernut Milk By Lactobacillus fermentum CS19 And Lactococcus lactis As A Potential Probiotic Product". Mouau.afribary.org, Mouau.afribary.org, 22 Mar. 2023. Web. 13 Nov. 2024. < https://repository.mouau.edu.ng/work/view/fermentation-of-tigernut-milk-by-lactobacillus-fermentum-cs19-and-lactococcus-lactis-as-a-potential-probiotic-product-7-2 >.
NWADINMA, UCHENNA. "Fermentation Of Tigernut Milk By Lactobacillus fermentum CS19 And Lactococcus lactis As A Potential Probiotic Product" Mouau.afribary.org (2023). Accessed 13 Nov. 2024. https://repository.mouau.edu.ng/work/view/fermentation-of-tigernut-milk-by-lactobacillus-fermentum-cs19-and-lactococcus-lactis-as-a-potential-probiotic-product-7-2