ABSTRACT
The
phenotypic and molecular characterization of lactic acid bacteria (LAB) species
associated with ugba (fermented
African oil bean seeds) and evaluation of their fermentation capabilities and biopreservative
potentials were studied. A total of seven LAB isolates from ugba were presumptively identified using
phenotypic method while confirmations of their full identities were obtained using
randomly amplified polymorphic DNA (RAPD) and PCR-16S rDNA gene nucleotide
sequencing. Among the LAB isolates, three including Lactobacillus plantarum, Lactobacillus brevis and Lactobacillus fermentum were selected as
potential candidates of starter cultures as a result of their technological
properties for use in the production of ugba.
The ugba produced using
LAB starter cultures and uninoculated samples were subjected to chemical and microbiological analysis during storage. Results
show that the
LAB inoculated and uninoculated ugba samples
were significantly different (p<0.05) in hydrogen ion concentration (pH) and
total titratable acidity (TTA) during storage. The temperature range recorded
(28-36oC) favoured the growth of lactic acid bacteria. The pH of the
inoculated ugba samples decreased
towards acidity and the uninoculated counterpart increased slightly towards
alkalinity, ranging within 3.42 – 7.32, while the total titratable acidity
decreased, falling within the range of 0.033 – 0.085 as the storage days
progressed. Result of organic acid
content showed that; formic, acetic, lactic and butyric acids significantly (p<0.05)
increased as storage period progressed. The proximate composition of the ugba indicated that ugba sample inoculated with Lactobacillus
plantarum and Lactobacillus brevis had the highest values in
protein, fat, ash and carbohydrate contents during storage. The antinutritional
factors of ugba samples
inoculated with LAB starter culture were lower than their uninoculated
counterparts at the end of the fermentation process and storage
period. Ugba inoculated with L. plantarum and L.
brevis had the lowest values in all the antinutrients investigated during
storage. Ugba inoculated with L. plantarum and L. brevis
recorded the highest values in potassium, phosphorous and sodium, followed by ugba
inoculated with L. brevis and L. fermentum in calcium and
magnesium contents in the mineral contents. The water-soluble vitamins; vitamin C
(ascorbic acid), vitamins B1 (thiamine), B2 (riboflavin),
and B3 (niacin) screened showed that they
decreased as storage period progressed. The fatty acids identified in the
samples include four (4) saturated fatty acid (lauric, palmitic, myristic and
stearic), one (1) monounsaturated fatty acid (oleic) and two (2)
polyunsaturated fatty acids (linolenic and linoleic) respectively. Both
linolenic and linoleic acids showed a significant (p<0.05)
increase
throughout the storage period followed by oleic acid. The presence of essential amino acids such as threonine, lysine,
valine, leucine, phenylalanine, methionine, and isoleucine were indicated in
the ugba samples with significant differences (p<0.05) during
storage. GC-MS analyses of the ugba samples revealed twenty eight (28)
flavour volatile compounds during storage, consisting of nine compounds of hydrocarbons (32%), one aldehyde (4%), six
alcohols (21%) and three carbonyls (11%). Others include seven esters (25%) and
two unidentified compounds (7%) which could not be grouped into any of the
classes. The microbial quality of ugba samples
inoculated with LAB starter cultures showed
less microbial load with improved keeping qualities than their
uninoculated counterparts during storage. Results from this study have demonstrated the
usefulness of a polyphasic taxonomy approach for characterization of LAB
strains being proposed as potential candidates of
starter cultures for food biopreservation thereby improving process
control, and increase storage stability of the ugba products in Nigeria.
-- (2023). Phenotypic And Molecular Characterization Of Lactic Acid Bacteria Species Associated With Nigerian Traditional Food Product Ugba: Their Fermentation Capabilities And Biopreservative Potentials. Mouau.afribary.org: Retrieved Nov 24, 2024, from https://repository.mouau.edu.ng/work/view/phenotypic-and-molecular-characterization-of-lactic-acid-bacteria-species-associated-with-nigerian-traditional-food-product-ugba-their-fermentation-capabilities-and-biopreservative-potentials-7-2
--. "Phenotypic And Molecular Characterization Of Lactic Acid Bacteria Species Associated With Nigerian Traditional Food Product Ugba: Their Fermentation Capabilities And Biopreservative Potentials" Mouau.afribary.org. Mouau.afribary.org, 26 Jun. 2023, https://repository.mouau.edu.ng/work/view/phenotypic-and-molecular-characterization-of-lactic-acid-bacteria-species-associated-with-nigerian-traditional-food-product-ugba-their-fermentation-capabilities-and-biopreservative-potentials-7-2. Accessed 24 Nov. 2024.
--. "Phenotypic And Molecular Characterization Of Lactic Acid Bacteria Species Associated With Nigerian Traditional Food Product Ugba: Their Fermentation Capabilities And Biopreservative Potentials". Mouau.afribary.org, Mouau.afribary.org, 26 Jun. 2023. Web. 24 Nov. 2024. < https://repository.mouau.edu.ng/work/view/phenotypic-and-molecular-characterization-of-lactic-acid-bacteria-species-associated-with-nigerian-traditional-food-product-ugba-their-fermentation-capabilities-and-biopreservative-potentials-7-2 >.
--. "Phenotypic And Molecular Characterization Of Lactic Acid Bacteria Species Associated With Nigerian Traditional Food Product Ugba: Their Fermentation Capabilities And Biopreservative Potentials" Mouau.afribary.org (2023). Accessed 24 Nov. 2024. https://repository.mouau.edu.ng/work/view/phenotypic-and-molecular-characterization-of-lactic-acid-bacteria-species-associated-with-nigerian-traditional-food-product-ugba-their-fermentation-capabilities-and-biopreservative-potentials-7-2