Nigerian Food Journal最新文献

Roselle calyces (Hibiscus sabdariffa) aqueous extracts were used in coagulating soymilk at four different concentrations (2.5%, 5%, 10% and 20%). The physical, chemical and sensory qualities of the tofu preparations were compared with fermented maize liquor and Calotropis procera extract coagulated tofus. pH of roselle extracts was acidic in nature (2.01 – 3.74) which was attributed to the ability to coagulate soy proteins. pH, titratable acidity of the roselle coagulated tofus ranged from 5.32 – 6.26 and 0.16 – 0.43% respectively and the yield and protein content ranged from 87.3 – 95.9 g and 42.6 – 46.3 g/100 g respectively. The yield of roselle coagulated tofu increased with increase in concentration of the roselle extracts. Roselle extract when utilized at 2.5% concentration will yield tofu that is acceptable and comparable to tofu coagulated with fermented maize steep water in terms of appearance, flavour and overall acceptability at p > 0.05. Roselle extract at 5% and 10% also yielded tofus that were acceptable in terms of all of the attributes tested.

The present study investigated the phytochemical analysis of Thaumatococcus daniellii leaves used as bean pudding wrapper in most part of Nigeria. The leaves were analysed before and after usage. The phytochemical components in the leaves were analysed qualitatively and quantitatively using standard methods. The toxicity of the leave extracts was determined by brine shrimp lethality assay and this recorded zero mortality. The TLC of the extracts was carried out and the chromatogram revealed differences in the number of components present in the fresh and used leaves. The amount of phytochemicals detected in the fresh leaves was higher than that of the used leaves e.g. 22.50% saponin was obtained in the methanol extract of the fresh leaf and 12.75% for used leaf. Tanin 8% in fresh leaf and 1.30% in used leaf of the methanol extracts. Some metabolites must have been absorbed by the bean pudding and some might have gone into the steam water.

The rice bran fermentation conditions for extraction of protein concentrate was enhanced by the use of baker’s yeast at optimized conditions using response surface methodology (RSM). A central composite design with three independent variables: fermentation temperature (25 to 35°C), yeast concentration (1 to 5%) and fermentation time (10 to 24 h) was used to study the response variable (protein yield). Results indicated that the generated regression model represented the relationship between the independent variables and the responses. Also, all linear terms, two quadratic terms (fermentation temperature and time) and all interactive terms had significant (p < 0.05) effect on the protein yield. The optimum conditions for yeast pretreatment of rice bran protein extraction were achieved at 30°C for 17 h using 3% yeast concentration to obtain a protein yield of 23.37%, which showed no significant difference (p > 0.05) from the response surface methodology predicted protein yield (23.02%). The use of baker’s yeast in the fermentation of rice bran for extraction of protein concentrate can be more effectively used to improve the extraction yield compared to natural fermented (15.43%) and untreated rice bran (10.16%).

Protein-rich extract (PRE) was made from okra (Abelmuscus esculentus) seeds. Three versions of feed A, B, and C were formulated using: as sources of protein, A – protein-rich extract from okra seed, B – dehulled and de-fatted okra seed flour (34% protein), C – casein. Each of the feeds was fed to a group of six rats (21 days old mice) for 21 days. The weights of the rats and their droppings were taken at 3-day intervals so were the weights of feed consumed. After 21 days, the rats were decapitated and blood samples harvested. The blood was used for the haematological tests. Liver and heart toxicity indicator including aspartate amino transferase (AST) and alanine amino transferase (ALT) were assayed. Ready-to-use therapeutic food (RUTF) prepared with PRE of okra seeds was formulated and organoleptically assessed in comparison to a standard product. The results showed protein efficiency ratio for A, B, C to be 0.33, 0.14 and 0.47 respectively. The mean weights of the droppings are 2.6, 1.9 and 1.5 respectively, showing significant difference (p ≤ 0.01). The serum AST was 56.5, 72 and 24 (IU/L) respectively. For ALT it was 16.5, 3.1 and 11 respectively. There was no significant difference between the RUTF as well as weaning foods formulated and the standards in terms of overall acceptability (p ≤ 0.01).

Acha (Digitaria exilis) and soybean (Glycine max) were processed into flours and used to substitute wheat flour (Titicum aestivm) as a composite flour at different proportions of 100:0:0 (Wheat); 75:25:25 (Wheat: Acha: Soybean); 75:25 (Wheat: Acha); 75:25 (Wheat: Soybean) and 50:50 (Acha: soybean). The formulated blends were used to produce noodles. The noodles were subjected to proximate analysis, functional properties and sensory evaluation using commercial instant noodles as control. The results revealed that the protein, moisture, ash and fat contents were higher in the formulated samples than in the control. Sample AS (50% Acha and 50% Soybean) had 26.47% protein and was significantly different (p < 0.05) from the control (8.97%). The protein and fat contents increased while carbohydrate decreased with increase in soybean addition to the blend. The functional properties showed that water absorption capacity increased with increase in wheat blend. There were no significant differences (p < 0.05) between the formulated samples in their swelling index and wettability. The result of the sensory evaluation based on a nine point hedonic scale showed that generally apart from the control, noodles from 100% wheat and wheat noodles supplemented with soybean up to 25% were acceptable to the panelists.

Knowledge of the true microbial diversity in cassava waste (CW) is fundamental to effective utilization of this waste. This paper reports, on the identification of bacteria species associated with CW, using molecular tools. The 16S rRNA gene of total bacteria community and bacterial isolates were amplified by Polymerase Chain Reaction (PCR) using 16S rRNA primers. Total microbial community DNA amplicons were spliced into the PCR-TRAP Cloning Vector, used to transform competent cells of Escherichia coli and sequenced. Sequences were identified by aligning with sequences in the GenBank. Twenty four bacterial species were detected in cassava peel (CP) belonging to Bacillus-Bacillales (7 species), Bacillus-Lactobacillales (12 species), Gamma-proteobacteria (3 species), Acinetobacteria-Actinomycetales (1 species) and uncultured bacteria (2 species). Bacillus licheniformis (11.3%) and B. substilis (11.3%) were the dominant species.

Azotobacter vinelandii, an uncultured bacterium clone ncd1462c07c1 and an uncultured compost bacteria clone PS2630 identified in this study, probably has not been reported in cassava fermentation. In cassava wastewater (CWW), 26 bacterial species were detected including Bacillus-Bacillales (5 species), Bacillus-Lactobacillales (18 species), Gamma-proteobacteria (2 species), Acinetobacteria-Actinomycetales (1 species), Beta-proteobacteria (1 species) and uncultured bacteria (1 species). Lactobacillus fermentum (11.1%) was the dominant species closely, followed by L. plantarum (10.7%). The potential of some of the species are highlighted. This study has shown that CW is an important microbial resource, considering its rich bacterial diversity.