Nigerian Food Journal最新文献

This study was conducted to determine effect of drying temperature and duration on selected physical properties of climbing black pepper (Piper nigrum) and alligator pepper (Aframomum melanguata) using response surface approach. Drying temperature (55.86, 60, 70, 80, 84.14 °C) and duration (2.59, 3, 4, 5, 5.414 hours) were variables while size (length, breadth, thickness), mass, sphericity, aspect ratio, moisture content, moisture loss, colour and bulk density were responses. Mass, density and moisture loss of climbing pepper were significantly affected by drying temperature and duration at 5% level of significance. Other climbing pepper physical properties under study were not influenced significantly. All alligator pepper properties considered were not significant (p > 0.05). Climbing pepper mass, density and moisture loss varied between 1.55 to 6.37 g, 0.17 to 0.59 g/ml and 31.1 to 84.0% respectively.

Five tropical leafy vegetables, Pterocarpus soyauxii (“oha”), Pterocarpus santalinodes (“nturukpa”), Gongronema latifolium (“utazi”), Corchorus olitorius (“ahihiara”) and Amaranthus hybridus (“green”) were held for four days at ambient condition using three different popular local methods used in the Southeastern states of Nigeria. Each leafy vegetable was divided into three lots. Lots I and II were unwrapped while lot III was wrapped with broad cocoyam leaves. The three lots were held under a shade. In addition, lot II was regularly taken outside to the open at nights where it was exposed to cool air and early morning dews. The vitamin contents of each leafy vegetable lot were analysed initially and on daily basis for four days. The beta carotene and ascorbic acid contents ranged respectively from 4.88 – 9.84 μg and 105.62 – 278.65 mg per 100 g of the leafy vegetable. The five leafy vegetables are fair sources of thiamin, riboflavin and niacin. There were losses in the vitamins as holding time increased, regardless of the holding method employed. The rate of loss of vitamins was highest in Lot I (the unwrapped leaves that were kept in a shade both day and night). The rate of loss of vitamins was lowest in Lot III (the wrapped leafy vegetables).

Soybean is rich in dietary protein but contains some anti-nutritional factors (ANFs), including phytates, tannins, trypsin inhibitors and oligosaccharides. It is used with cereals in weaning foods to improve the protein content and supply essential amino acids. The objective of this work, therefore, was to use microorganisms, specifically Lactobacillus plantarum and the enzymes it produces to reduce anti-nutritional factors and improve the nutritional composition of such food blends. Nine strains of Lactobacillus plantarum isolated from spontaneously fermenting cereals, identified and characterised, were selected based on the abundant production of alpha-galactosidase for the fermentation of the legume. Samples were subjected to fermentation for 5 days and the reduction of anti-nutritional factors was monitored. Anti-nutritional factors and alpha-galactosidase were determined by UV-spectrophotometry. Data were analysed using ANOVA at p = 0.05. Fermentation reduced the tannin content in the raw samples from 1.93 to 0.12 mg/g. Phytate content reduced from 1.16 to 0.04 mg/g. The trypsin inhibitor and protease inhibitor also reduced from 1.20 to 0.010 and 1.2 to 0.020 respectively. The production of alpha-galactosidase by L. plantarum (1.8 unit/ml) enhanced the reduction while the nutritional composition of the food blend in which the soybean was added improved significantly. The use of alpha-galactosidase enzyme by Lactobacillus plantarum from local food sources is thus shown to reduce anti-nutritional factors in soybeans, which can be of benefit in enhancing the nutritional quality of cereal-legume gruels.

“Ukpo” (Mucuna flagellipes) seed flour is one of the soup thickeners used in most rural Igbo-speaking communities of Southern Nigeria. Its preparation is usually associated with long cooking time which is required to soften the cotyledon before grinding as well as reduce the anti-nutritional components of the seed. This work was therefore aimed at determining the effect of boiling time on some functional properties and antinutritional properties of the ukpo seed flour. The result obtained showed that there were slight reductions in the protein, fat and ash content as boiling time increased probably due to leaching. All the functional properties analysed increased significantly (p ≤ 0.05) with increasing boiling time. The water absorption, oil absorption and emulsion capacities increased from values of 1.60 ml/g, 1.23 ml/g and 9.3 ml/g respectively at 0 minutes to 3.2 ml/g, 2.8 ml/g and 17.66 ml/g respectively at 60 minutes. The bulk density and swelling index also increased from 0.72 g/ml to 1.17 cm³/cm³ and from 1.02 g/ml to 1.36 cm³/cm³ respectively. The oxalate, tannin, saponin, phenol and phytate contents decreased significantly (p ≤ 0.05) with increasing boiling time. The values at 60 minutes boiling time were 0.14%, 0.182%, 0.434%, 0.146% and 0.719% respectively. These results suggest that heat treatment improves the performance of the Ukpo flour in soup thickening while reducing to a large extent the anti-nutritional properties.

Bacterial diversity and fermentation dynamics in palm wine, a traditional alcoholic fermented beverage, collected from upright palm trees from Idiaba community, Abeokuta, Ogun State, Nigeria were evaluated by DNA based method using the 16S rDNA of the microbial community to verify and complement previous reports, improve our understanding and document yet unreported, uncultured microbial diversity associated with palm wine. The 16S rRNA gene fragments were amplified from microbial community and genomic DNA of isolates, by Polymerase Chain Reaction (PCR) using universal primers; and sequenced. The partial sequences were identified by comparison with sequences deposited in the non-redundant nucleotide database of National Center for Biotechnology Information (NCBI). This analysis revealed that 32 community clones were identified as Lactobacillus sp, Lactobacillus casei strain zhang, Lactobacillusplantarum, Leuconostoc mesenteriodes ssp dextranicum, Leuconcostoc lactis, Pediococcusparvulus strain Bpe-299, Acetobacter pomorum, Acetobacter pasteurianus, Gluconobacter oxydans, Acinetobacter calcoaceticus, Enterobacterium bacterium, Acidovorax sp, Comamonas sp, Bacillus subtilis, Staphylococcuspiscifermentans and uncultured bacteria clone D1-78. The results showed that bacterial diversity in the palm wine sample is dominated by Lactobacillus and Leuconostoc species as reported by previous workers and uncultured bacteria clone D1-78 (1 clone) was detected for the first time in palm wine.

Fast foods consumption has been on the increase in Nigeria raising concerns about the nutritional and health implications. This study was carried out to determine the proximate composition and cholesterol contents of four commonly consumed fast foods (doughnut, chicken pie, roasted chicken, and Jollof rice) sold in Nigeria. Commonly consumed fast foods and most widely patronized fast food outlets were determined by a preliminary survey. There was a wide variation in the proximate composition and cholesterol contents of the food samples. Average dry matter ranged between 68.8 – 84.0 g while the range of values for ash, crude fibre, crude fat, crude protein and nitrogen free extract were 0.89 – 2.45%, 0.56 – 7.53%, 10.99 – 18.52%, 1.81 – 9.71% and 43.32 – 66.98% respectively. Energy content of the fast foods ranged between 304.9 and 400.8 Kcal/100 g. Cholesterol levels ranged between 10.40 – 117.80 (mg/100 g) in the food samples. This study has established the fact that fast foods are concentrated sources of energy, low fibre and high dietary cholesterol and could significantly contribute to dietary cholesterol intake with implications for cardiovascular health.

Based on previous research works, it was necessary to investigate the effects of varying steeping period on the quality of ogi powder. Sorghum grain steeped for 24, 36, 48, 60 and 72 h was processed into ogi making use of the traditional method and subsequently dried at 55 °C. The ogi powder obtained was analyzed for proximate composition, functional and pasting properties and consumer acceptability was also carried out. The results showed that the loose and pack bulk density ranged from 0.27 – 0.31 g/ml and 0.53 – 0.55 g/ml respectively from all the steeping periods. Water absorption capacity was from 178 – 199 g/100 g. Linear relationship described well the increase in water and oil absorption in this study and the coefficient of correlation (R²) was 0.988 and 0.814 respectively. Emulsion capacity increased from 19.40 – 21.25 g/100 g for all the steeping periods emulsion stability increased from 6.50 – 6.70%. Foaming capacity decreased from 15.05 – 13.10% for all the soaking periods. Swelling index was between 6.9 – 7.2 per cent for all the steeping periods 5.05 – 5.51 min respectively. There was significant difference (p < 0.05) in the peak viscosity, final, trough, and set back viscosities. These pasting properties decreased with increase in soaking period.

Bifidobacteria are categorized as health-promoting microorganisms (probiotics) in the gastrointestinal tracts of humans and animals. Antibiotic susceptibility is a key criterion for probiotic agent selection. Good survival of probiotics during storage at selected storage temperature(s) is highly desirable. Bifidobacteria isolated from human and chicken were thus characterized phenotypically by their ability to produce fructose-6-phosphoketolase enzyme. Eight selected isolates were then characterized on molecular basis employing genus-specific and species-specific 16S rRNA gene primers, and their antibiotic susceptibilities were also evaluated. Isolates were confirmed to be strains of B. catenulatum (4) and B. adolescentis (4). Studied strains were resistant to streptomycin, gentamycin, cloxacillin and cotrimoxazole but susceptible to chloramphenicol, augmentin, amoxicillin and erythromycin. Three strains (B. catenulatum HM2, B. catenulatum HM3 and B. catenulatum HM5) showed atypical tetracycline resistance. B. catenulatum HM2, B. adolescentis CH2 and B. adolescentis CH3 showed significant reduction in counts (p < 0.05) and survived in adequate amount in yoghurt stored at 4°C and -18°C for 4 weeks. In addition to presenting acceptable antibiotic susceptibility profile and exhibiting good survival in stored yoghurt, the bifidobacteria isolates inhibited Staphylococcus aureus ATCC 25925 and Escherichia coli ATCC 25922 in-vitro and demonstrated potential for application as probiotic agents for human and agricultural purposes.

The proximate and physicochemical properties of cassava leaf and peel meals were evaluated with a view to possible replacement of wheat offal which is the conventional source of fibre in animal feed, with these meals. The effect of feeds produced with cassava leaf and peel meals on the performance of growing snails was also investigated. Feeds (F1, F2 and F3) were formulated to contain 240, 235 and 230 g/kg cassava root meal each and 85, 85 and 90 g/kg cassava peel meal, wheat offal meal and cassava leaf meal respectively. The formulated feeds contain approximately 18.0% crude protein, 7.5% ash, 3% fat, 6.0% crude fibre 8%, calcium, 0.7% phosphorus, and energy level of 2400 kcal ME / kg. A total of 54 growing snails (Archachatina marginata) were used to investigate the nutritive potential of the formulated feeds on performance of growing snails for 15 weeks. Concentrations of the crude protein, crude fat, crude fibre, ash and calcium in cassava leaf meal were higher than those of wheat offal and cassava peel meal, with the exception of nitrogen free extract which was highest (70.01%) in cassava peel meal. Feed intake was 576 g 569 g and 581 g for snails fed with cassava leaf meal, cassava peel meal and wheat offal respectively but the corresponding weight gain ranged between 123.35 and 134.81 % being highest for F1. The feed conversion ratio shows that F1 > F3 > F2 indicating better conversion of feed to edible meat in F1. The results show that cassava leaves and peels have a strong potential to substitute the traditional wheat offal and can therefore be adapted as commercial feed ingredients.