The protective effect of Lactobacillus acidophilus and Lactobacillus casei, isolated from fresh cow milk, was studied in vivo. Toxicological data of rat serum revealed that the Lactobacillus isolates had liver improvement functions. Serum alanine aminotransferase (ALT) activities of the rats dosed with Lactobacillus isolates alone were lower (15.50 and 18.27 iu/l) than the control. There was a reduction in the count of enterobacteria in rats dosed with L. casei after 3 days of feeding trials. Protection of the gastrointestinal tract (GIT) by these isolates was also observed. Histopathological data confirmed partial protection of the GIT in rats dosed with Lactobacillus isolates and simultaneously infected with Escherichia coli. L. casei was generally observed to have a better effect than L. acidophilus in terms of liver function improvement, anticholesterolaemic effect, and reduction of enterobacteria in the GIT.

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The present study was conducted to determine the pro-biotic properties in vitro of the lactic acid bacteria isolated from spontaneously fermenting kunu-zaki. Kunu-zaki was processed using composite, non composite, germinated and ungerminated Digitaria exilis (Fonio), Sorghum bicolor (Sorghum) and Pennisetum americanum (Millet) cereals. A total of 150 LAB isolates were obtained from all the fermenting slurries. These 150 LAB isolates were screened for their ability to grow at pH 3.0, resistance against bile salt and ability to inhibit reference test pathogens. Out of these 150 LAB isolates; 21 exhibited good probiotic properties. All the 21 isolates were further identified to specie and subspecies level using standard API50CHL system with all 21 showing good survival (P < 0.05) in a pH 3.0 buffered medium and subsequent resistance to 0.3% bile. The LAB isolates which survived these conditions consisted of 18 Lactobacillus species, 2 Pediococcus species and 1 Lactococcus specie. These LAB species were further examined for antimicrobial activity against the growth of reference pathogens Staphylococcus aureus 25923, Escherichia coli 25922, Pseudomonas aeruginosa 27853 and Enterococcus faecalis 29212. All 21 LAB species exhibited good inhibition of all test reference pathogens except Lactobacillus fructivorans, Lactococcus lactis sp lactis and L. fermentum which however, showed no zone of inhibition against the growth of E. faecalis. Kunu-zaki made from composite un-germinated Sorghum bicolor (Sorghum) and Pennisetum americanum (Millet) cereal grains contained the highest percentage (52%) of LAB species which showed good probiotic criteria in vitro. Non composite ungerminated cereals accounted for 33% of the total probiotic LAB isolates whilst the germinated non composite and composite cereals recorded the lowest percentage (10%) and (5%) of probiotic LAB respectively. The results of this research study showed that the LAB species isolated from wild fermentation of kunu-zaki beverage fulfilled the criteria for in vitro screening of probiotic characteristics. These LAB species possed potential for further use as probiotic in human preparations and suggested the use of kunu-zaki made from ungerminated composite sorghum and millet grains as a natural probiotic drink.

The antagonistic properties of indigenous microflora from cassava starch, flour and grated cassava were investigated using the conventional streak, novel ring and well diffusion methods. Antagonism was measured by zone of inhibition between the fungal plug and bacterial streak/ring. Bacillus species were more effective to inhibit the growth of Aspergillus niger, A. fumigatus, Fusarium moniliforme and Rhizoctonia sp. Pseudomonas fluorescens, Escherichia coli and Saccharomyces sp. inhibited the growth of A. niger, A. flavus and F. moniliforme. There were considerable variations in inhibitory activity. The zone of inhibition was more apparent in the novel ring method. Percentage inhibition increased to 78% in the Ring method and 62% in streak method after 168 h of incubation. Lactobacillus brevis, L. acidophilus and Bacillus subtilis inhibited the growth of E. coli and Staphylococcus aureus. Inhibition of the pathogenic microorganisms was probably due to the production of organic acids and bacteriocins.

Five varieties of Nigerian long pepper (Capsicum frutescens) fruits (var. baccatum, chacoense, fingerh, maxima and minima) were studied for their antibacterial activities. Methods described by Association of Official Analytical Chemists (AOAC) were employed to determine the phytochemicals in the pepper fruits. The Capsicum frutescens fruits showed antibacterial activity (10.33 -32.66 mm zones of inhibition) against all the tested pathogenic bacteria. The minimum inhibitory concentrations for the peppers range between 7.8 and 37.5 mg/ml. Pepper var. minima had the highest MIC (37.5 mg/ml) while pepper var. fingerh exhibited the lowest MIC (7.8 mg/ml) against Pseudomonas aeruginosa and Salmonella typhi, respectively. The flavonoids, tannins, alkaloids and saponins found present in the extracts were quantified as 0. 0019-0.0043, 0.0084-0.0146, 6.57-15.78 and 15.67-26.29 mg/ml, respectively. From this study, it was concluded that the long peppers have antibacterial effect on the tested food borne pathogens; even the less pungent C. frutescens var. fingerh showed antibacterial activity. These peppers when consumed raw could prevent elaboration of infection that the test pathogenic bacteria could cause if consumed in foods.

This study evaluated the sensory properties, proximate composition, and overall consumer acceptability of kunu-zaki using germinated and ungerminated Sorghum bicolor (sorghum), Pennisetum americanum (millet), and Digitaria exilis (acha) cereal grains. The three cereal grains were used in nongerminated and germinated composite and noncomposite proportions coded A (Acha), S (Sorghum), M (Millet), AS (Acha–Sorghum), AM (Acha–Millet), SM (Sorghum–Millet), ASG (Acha–Sorghum Germinated), AMG (Acha–Millet Germinated), and SMG (Sorghum–Millet Germinated). Proximate analysis determined the moisture content, ash, crude fiber, fat, and crude protein content of the fermented grains. The 9-point hedonic scale was used to judge the sensory parameters of taste, color, and aroma. The paired comparison test was used to judge consumer preference between kunu-zaki made from germinated grains and the ungerminated counterpart. Scores were statistically analyzed using the Kruskal–Wallis test in the SPSS analytical software package. Panelists ranked the ASG-coded drink highest in terms of taste and aroma, the AMG-coded drink highest in terms of color. SM ranked least in terms of taste; SMG ranked least in terms of aroma; and AM ranked the least in terms of color. Preference for each parameter was significantly different (P < 0.001). Panelists ranked overall preference for the drinks from the most liked to the least liked in the order ASG>AMG>A>AS>S>M>SMG>AM>SM. The overall preference for the drinks was also significantly different (P < 0.001). Panelists pairing both ungerminated drinks with the germinated drinks ranked the ungerminated drink AS as most preferred in terms of taste, color, and aroma above its germinated counterpart ASG with preference not significantly dependent on the parameters (P = 0.065 > 0.05). Ungerminated AM was also preferred above the germinated counterpart AMG in terms of taste, color, and aroma with preference not significantly dependent on parameters (P = 0.055 > 0.05). However, panelists showed preference for the taste and aroma of the germinated drink SMG but more preference for the color of the ungerminated drink SM with preference significantly dependent on the parameters (P = 0.028 < 0.05). Crude fiber values were higher – 11.3%, 13.1%, and 17.37% for SMG, AMG and ASG, respectively. Germination increased %Fat values slightly but the %Ash was relatively stable in both germinated and ungerminated drinks. Addition of germinated acha cereal grains to either sorghum or millet prior to fermentation offers desirable sensory and nutritional quality attributes in kunu-zaki.

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