Roger TCHIKOUA

Improvement of the Nutritional Quality of Black Bean (<i>Phaseolus Vulgaris</i> I.) Powder During Fermentation: Use of Lactic Starters

Tchikoua Roger, Siappi Leugoue Kevine, Kotue Taptue Charles

International Journal of Microbiology and Biotechnology

The objective of this study was to investigate lactic acid starters able to improve the nutritional quality of black bean powder (BBP) during fermentation. For this purpose, raw and cooked BBP was fermented with <i>Lactobacillus acidophilus</i> and BLHN7 isolate. After 120 hours of fermentation, the pH of medium was measured by pH meter, tannins and phytates by spectrophotometry, total proteins by the Kdjedhal method. The minerals by atomic absorption spectrophotometry and the total sugars by the phenol method. From these analyses, it was found that the pH decrease was not significantly different in BBP fermented with <i>Lactobacillus acidophilus</i> and BLHN7 isolate. This decrease in pH varied between 4.0 and 4.3. Principal Component Analysis (PCA) of the results shows the variability of nutritional parameters depending on the microorganisms used and the type of treatment applied to the BBP. However, a better increase in protein, iron and microbial growth is observed in the raw BBP fermented with <i>Lactobacillus acidophilus</i>. We observed an increase of 267, 240 and 118% respectively. It is also in the raw BBP that we observe a reduction of tannins and a small reduction of sugar content by 76 and 20% respectively. On the other hand, it is in the cooked BBP fermented with <i>Lactobacillus acidophilus</i> that phytates were reduced by 3.4% and magnesium increased by 180%. Calcium increased by 165% in cooked BBP fermented with BLHN7 isolate. Considering the effect of <i>Lactobacillus acidophilus</i> on the majority of the nutritional parameters studied, it would be interesting to use it to improve the nutritional quality of BBP as a dietary supplement for malnourished children.

• #proteins in food systems
• #phytase and its applications
• #food composition and properties
• #lactobacillus acidophilus

Influence of selected lactic acid bacteria on the sensory characteristics of soft cheese with natural rind

Renaud Blanchard Okamba Elouti, Tchikoua Roger, Nardis Nkoudou Ze, Jean Justin Essia Ngang

International Food Research Journal

Cheese is obtained by the coagulation of milk, followed by maturation under the action of microorganisms which are responsible for the development of physicochemical and organoleptic characteristics of cheese. Among various microorganisms, lactic acid bacteria (LAB) play an essential role in establishing sensory characteristics of the cheese. In Cameroon, the effect of isolated LAB on the sensory characteristics of cheese produced from local cow milk has not yet been investigated. Therefore, the present work aimed to isolate LAB and evaluate their influence on the physicochemical and sensory characteristics of locally produced soft cheeses. Four strains of LAB were isolated and identified as Enterococcus sp.1, Enterococcus sp.2, Pediococcus sp., and Leuconostoc sp. These isolates were combined in batches for production of cheeses, including Frm 741 (Enterococcus sp.1 and Enterococcus sp.2), Frm 891 (Enterococcus sp.2 and Leuconostoc sp.), Frm 683 (Pediococcus sp. and Enterococcus sp.1), Frm 425 (Pediococcus sp. and Leuconostoc sp.), Frm 503 (Pediococcus sp. and Enterococcus sp.2), Frm 439 (Leuconostoc sp. and Enterococcus sp.1), and Frm 625 (Enterococcus sp.1, Enterococcus sp.2, Leuconostoc sp., and Pediococcus sp.). Cheese produced from the combination of Enterococcus sp.1 and Enterococcus sp.2 (Frm 741), unlike the others, did not drain properly throughout the production process. However, all products showed excellent microbiological quality in relation to biological contaminants, such as Salmonella, staphylococci, and coliforms. Moreover, cheese Frm 425 was most appreciated by consumers for its sweet taste, yellow colour, pleasant smell, and low acidity (51.7°D). On the other hand, cheese Frm 439 was least appreciated by consumers owing to its bad odour, bitter taste, and high acidity (144.9°D). Taken together, the present work demonstrated that the isolated LAB could be used to produce soft cheese with a natural rind and unique sensory characteristics that are appreciated by Cameroonian consumers.

• #probiotics and fermented foods
• #proteins in food systems
• #protein hydrolysis and bioactive peptides
• #pediococcus

Improvement of Sanitary Quality of the &lt;i&gt;Digue&lt;/i&gt; by Use of Lactic Starters

Tchikoua Roger, Ezo’o Ezo’o, Essia Ngang J.J

American journal of microbiological research

Digue is a traditional food obtained from the addition of the paste of roasted peanuts in pumpkin juice obtained by spontaneous fermentation. This spontaneous fermentation unfortunately contributes to its alteration by molds and certain pathogenic bacteria. The aim of this work is to use lactic starters to inhibit the growth of certain pathogenic germs during controlled fermentation. A total of 24 lactic acid bacteria were isolated from the samples of Digue collected in the locality of Gamboura in the Far North of Cameroon. The screening allowed to retaining 02 strains of lactic acid bacteria for their best antimicrobial activities. The molecular identification of these two strains showed that they belong to the species Lactobacillus casei and Pediococcus acidilactici. The use of these two 02 lactic acid bacteria during the controlled fermentation of the Digue contaminated by Aspergillus M2, Aspergillus M3, Escherichia coli ATCC 25922 and Salmonella enteritidis 155A showed that all the pathogen germs were totally inhibited by Lactobacillus casei after 21 days of fermentation. The same result was obtained with Pediococcus acidilactici on all molds and Escherichia coli ATCC 25922. At the end of this study, it appears that, the lactic acid bacteria Lactobacillus casei can be used to ensure the hygienic quality of the Digue after 21 days of fermentation.

• #probiotics and fermented foods
• #peanut plant research studies
• #viral gastroenteritis research and epidemiology
• #pediococcus acidilactici

Biopreservation against Fungi Contamination of Traditional Food ( Iassa ) Produce by Fermentation of Hibiscus sabdariffa Seeds

Tchikoua Roger, A T Edzili Awono, SANDRINE AIMÉE YOUTE FANCHE, Jean Justin Essia Ngang

Journal of Microbiology Research

Uncontrolled fermentation is a method of transformation which can expose food to risks of contamination by moulds and mycotoxins. Food contaminations represent a potential threat to the health of consumers. In the far North of Cameroun, Iassa obtained by spontaneous fermentation of Hibiscus sabdariffa grains belongs to this food category. This study was aimed at preserving the safety quality of Iassa against fungal growth during fermentation by using lactic acid bacteria (LAB). To carry out this work, moulds and LAB were first isolated from Iassa samples collected in the locality of Gamboura (Cameroon). This was followed by the production of Iassa at the laboratory which was inoculated with moulds and LAB, and the entire batch was left to ferment for 120 hours at 25°C. The antifungal activity of LAB and titratable acidity were evaluated during fermentation. The results showed that, Iassa is a favourable food to the development of moulds. High contamination of this product by moulds of the genus Aspergillus and Fusarium were observed. Generally, this contamination ranged from 2.9Log10CFU/g to 6.9Log10CFU/g. Among the isolated LAB, Lactobacillus brevis and Lactobacillus paracasei were identified as the best LAB with good antifungal activity. Lactobacillusbrevisinhibited completely the growth of Aspergillus in Iassa after 96 hours of fermentation. During this assay, a high growth of Lactobacillus brevis varying between 12.0 and 13.3 Log10CFU/g was also observed. Unlike Lactobacillus brevis, Lactobacillus paracasei produced a high quantity of acidity evaluated at 0.9%. From this work, these bacteria can be used as a LAB starter to ensure safety of the Iassa against moulds after 96 hours of fermentation.

• #african botany and ecology studies
• #hibiscus plant research studies
• #polysaccharides composition and applications
• #hibiscus sabdariffa

Use of the aqueous extract of Eucalyptus microcorys for the treatment in microcosm, of water containing Enterococcus faecalis: hierarchisation of cells' inhibition factors

Tamsa Arfao Antoine, Lontsi Djimeli Chretien, Noah Ewoti Olive Vivien, Moussa Djaouda, Aoudou Yaouba, Tchikoua Roger et 1 autre(s)

H2Open Journal

Abstract An experimental study in aquatic microcosm was carried out to determine the major factors involved in the inhibition of Enterococcus faecalis in the presence of aqueous extract of Eucalyptus microcorys. The planktonic bacterial cells remained in various concentrations of the aqueous solution at light intensities which fluctuated between 0 and 3,000 lx and incubation periods which ranged from 3 to 24 hours. A hierarchisation of studied factors revealed that the aqueous extract concentration, followed by experimental temperature, light intensity and incubation duration influence the inhibition of E. faecalis cells, respectively, with a rate of 86.82%, 7.03%, 5.25% and 0.90%. The cell abundances dropped significantly at 1.5% (λ = 0.491 and F = 5.518) and 2% (λ = 0.568 and F = 4.055) concentrations coupled with 1,000, 2,000 and 3,000 lx. The highest light intensities and extract concentration produce the highest log removal values. The disinfectant properties of E. microcorys were evaluated by the Chick–Watson model. This Chick–Watson model so obtained varied between log (N/No) = −0.09 Ct and log (N/No) = −0.17 Ct for extract concentrations of 1, 1.5 and 2%. Aqueous extract of E. microcorys could be used for water disinfection.

• #fecal contamination and water quality
• #water treatment and disinfection
• #wastewater treatment and reuse
• #microcosm

Quercus gambelii(ブナ科)の葉の内生菌の広範な栄養状態の新しい証拠【Powered by NICT】

Szink Ismaiel, L Davis Emily, D Ricks Kevin, Tchikoua Roger

Fungal ecology

• #wood and agarwood research
• #medical research and treatments
• #urban and spatial planning
• #biology

Nutritional Properties and Antinutritional Factors of Corn Paste ( Kutukutu ) Fermented by Different Strains of Lactic Acid Bacteria

Tchikoua Roger, Tatsadjieu Ngouné Léopold, Mbofung Carl Moses Funtong

International Journal of Food Science

The aim of this study is to reduce antinutritional factors and to improve the nutritional properties of Kutukutu during fermentation with Lactic Acid Bacteria (LAB). For that, Kutukutu (700 g) was prepared in the laboratory and inoculated with pure cultures of LAB (10(9) CFU/mL). Then, preparation was incubated for 120 h. Every 24 h, Kutukutu were collected, dried at 45°C for 24 h, and analyzed. The results showed that Lactobacillus brevis G25 increased reducing sugars content to 80.7% in Kutukutu after 96 h of fermentation. Lactobacillus fermentum N33 reduced the starch content to 73.2%, while Lactobacillus brevis G11, L. brevis G25, and Lactobacillus cellobiosus M41 rather increased the protein content to 18.9%. The bioavailability of Mg and Fe increased, respectively, to 50.5% and 70.6% in the Kutukutu fermented with L. brevis G25. L. plantarum A6 reduced the tannin content to 98.8% and L. buchneri M11 reduced the phytate content to 95.5%. The principal component analysis (PCA) shows that, for a best reduction of antinutrients factors and improvement of protein content and minerals, Kutukutu must be fermented by L. brevis G25 and L. fermentum N33, respectively. These starter cultures could be used to ameliorate nutritional proprieties of Kutukutu during the fermentation.

• #food composition and properties
• #phytase and its applications
• #probiotics and fermented foods
• #lactobacillus brevis