Nigerian Food Journal最新文献

Study on isolation of bacterial species associated with ugba fermentation was carried out. Bacterial species including Bacillus licheniformis, Bacillus sphaericus, Bacillus subtilis, Bacillus pumilus, Bacillus firmus, Escherichia coli, Klebsiella and Staphylococcus were isolated from traditionally fermented ugba (TPU) obtained from the market, whereas laboratory produced ugba (LPU) indicated the presence of Bacillus licheniformis, Bacillus pumilus, Bacillus sphaericus, Bacillus subtilis and Staphylococcus before boiling and fermentation. The absence of Bacillus pumilus and Staphylococcus was evident in LPU during post fermentation assay. Quantitative estimation of pentose and hexose sugars which are product of hydrolysis of galacto-oligosaccharide content of the test legume reduced from 1158 ppm – 346.4 ppm and 588 ppm – 516 ppm respectively. Greater loss was observed after boiling of LPU (564 and 486 mg/l) on comparison to TPU (94 and 10 mg/l) for pentose and hexose respectively. Plasmid profile analysis carried out showed that Bacillus species from fermented and unfermented ugba had bands indicating the presence in the organism of the genes coding for enzymes responsible for hydrolysis of oligosaccharides in the substrate. This study elucidates the need for good manufacturing practices and adequate boiling before consumption of ugba with the view to prove that there are other Bacillus species aside B. subtilis which can ferment ugba (Pentaclethra macrophylla) to give it its characteristic flavour and taste. It also quantified the effect of fermentation process on some dietary carbohydrate content of the ugba.

Study on the assessment of bacteria load of some on-the-shelf canned food products bought from different shops in the open markets in Owerri, Imo State, Nigeria was undertaken. Eleven canned food products including 2 cans of tomato paste (TP), 2 of fish-in-tomato-sauce (FTS), 3 of sweet corn (SC), baked beans (BB), 1 of green peas (GP) and 2 kidney beans (KB) were collected randomly and used for the analysis. Culture-based identification depicts the presence of Bacillus sp., Staphylococcus sp., Vibrio parahaemolyticus, Salmonella sp., Klebsiella sp., Proteus sp., Pseudomonas sp. and Escherichia coli. Plasmid profiling of culture-dependent isolates showed visible bands except Staphylococcus sp., Klebsiella sp. and Bacillus sp. Randomly amplified polymorphism DNA [RAPD] profiling using varying oligonucleotide primers specific for identification of 16SrRNA genes of some organisms of public health concern, confirmed the presence of coliforms, Staphylococcus sp., Vibrio sp., S. typhi and S. enteritidis on gel electrophoresis field. In the context of possible risk of consuming contaminated canned food products, this study was designed to show that most on-the-shelf canned food products can possibly habour organisms of public health importance which can be ascertained through molecular characterization using PCR-based technique. There is also the possibility of these organisms posing food safety issues and pharmaceutical risks in case of possible out break, assayed through plasmid profiling of the culture-dependent isolates. A major concern in this study is the lack of adherence to food safety regulations. The products still been marketed on the shelves and analyzed in this study must have outlived the shelf stability period.

The study investigates the effect of seed sprouting on minerals, anti nutrients and pasting characteristics of flours produced from some tropical legume seeds. Samples were collected from cowpea (Vigna ungulculata); red kidney beans (Phaseolus vulgaris), and Pigeon pea (Cajanus cajan) and each sample was divided into two portions. A portion was sprouted while the other portion served as the control. The flours from sprouted and non-sprouted seeds were analyzed for the minerals, anti nutritional and pasting properties. The samples were found to differ significantly (p < 0.05) in the minerals, anti nutritional composition and pasting properties of the flours. Sprouting increased the mineral contents of the flours generally the calcium content of non-sprouted red kidney beans (13.8 mg/100 g) increased to 16.1 mg/100 g in the sprouted flour. The haemagglutinin decreased from 40.6 HU/mg in non sprouted red kidney to 6.4 HU/mg in the sprouted. The final viscosity of the non sprouted flours were higher than those of the sprouted, with non sprouted cowpea scoring the highest, 272 RVU, while sprouted red kidney beans had the least, 109.06 RVU, which implies that sprouting caused a reduction in the gel strength and elasticity of the samples. Seed sprouting effectively increased the mineral nutrients and lowered the anti nutrients, but produced steamed paste with poor gel strength.

Cocoyam tubers were processed into non-alcoholic beverage, flavoured with 0.5% and 1.0% extracts of ginger and alligator pepper respectively. Two varieties of cocoyam, namely Colocasia esculenta and Xanthosoma sagittifolium were used. The purpose of this study is to develop an acceptable flavoured non alcoholic beverage from cocoyam and thereby increase the utilization of this under-utilized crop. The proximate, vitamins C and A, mineral content, microbial and sensory evaluation were conducted on the products to assess the highest preference. Values for pH ranged from 3.00 to 3.86 and the total titratable acidity (TTA) from 0.50 – 0.82 with ginger flavoured samples rated higher than that of alligator pepper. Total solids varied significantly and ranged from 5.00 – 6.02% with alligator pepper samples being higher than ginger. Vitamin C content ranged from 1.02 – 1.98 × 10⁻⁴ mg/100 g while vitamin A content ranged from 6.04 to 14.41 μg/100 g with ginger flavoured samples having higher vitamin C and A than the alligator flavoured ones. The minerals evaluated showed a decreasing trends with increase in the concentration of each spice. The sensory results showed that significant differences (p < 0.05) existed between the different flavoured samples and not between varieties. The microbial analysis showed that the cocoyam non-alcoholic beverage is safe for human consumption. Generally, the beverage had good consumer preference with the 0.5% ginger flavoured being the most preferred.

This study was carried out to determine the effect of firm ripe plantain fruit flour addition on the chemical, sensory and microbial quality of fura powder. Millet flour was supplemented with plantain flour at substitution levels of 0, 10, 20, 30 and 40 to obtain fura powder. The chemical composition, sensory properties and microbial quality were determined using standard methods of analysis. Addition of firm ripe plantain fruit flour significantly (p < 0.05) increased vitamin A, vitamin C, potassium, fibre and soluble solids (°Brix) levels of plantain-fura with the increasing level of plantain flour substitution. Fat content decreased from 6.0% to 3.0% with increased levels of plantain fruit flour addition. Similar trend was observed in protein content as it decreased from 13.0% to 10.0%. Microbial analysis results during three months of storage showed significant (p > 0.05) decrease in the microbial population with the increasing level of plantain flour addition. The results showed that blending of firm ripe plantain flour with millet flour would produce fura that is shelf stable, rich in natural anti-oxidant vitamins and safe for consumption.

Powdered kunun-zaki (a beverage) was produced with 500 g of fermented sorghum residue and 200 g flavoured sweet potato paste. Blends were mixed with water, 10 g of granulated sugar and stuffed in a folded aluminum foil, steamed for 35 min. It was dried at 60 ± 1 °C for 12 h, milled and sieved. The reconstitution time in warm water (45 °C) and cold water (room temperature) were determined. The reconstituted sample was compared with freshly prepared kunun-zaki in terms of chemical and sensory properties. The pH values of the fresh kunun-zaki sample 2.03 was significantly different (p < 0.5) from that of the reconstituted kunun-zaki sample (3.61) indicating a higher hydrogen ion concentration in the freshly prepared kunun-zaki. There were no significant differences (p > 0.05) between the samples in their protein, ash, fibre and carbohydrate contents. The result of the sensory evaluation revealed significant difference (p < 0.05) in terms of taste of the sample, but there were no significant differences (p > 0.05) in other parameters tested.

Mung flours were fermented using spontaneous and backslopping methods for 72 h and microbial analysis over a period of 72 h fermentation was carried out. The samples were subjected to biochemical test, anti-nutrient and selected mineral and vitamin contents evaluation using standard methods. There was a gradual decline in pH from an initial value of 6.24 in unfermented flour to a pH of 3.68 in spontaneous fermentation and 3.87 in backslopping fermentation after 72 h. The total titratable acidity increased from 0.0085% to 0.0105% in fermented sample. The level of the increase did not differ significantly (p > 0.05) for the methods. Flours from back-slopping fermentation showed higher increase in protein and ash (17.59% and 18.25% respectively) than spontaneous fermentation with 16.70 % and 6.35% respectively. Similar increases were observed for calcium and iron. The decrease in zinc content was higher in spontaneous fermentation method than in back-slopping methods. Back-slopping fermentation sample had higher Vitamin A, lower phytate and tannin contents than spontaneous fermented sample. Samples from spontaneous fermentation showed significantly (p < 0.05) higher increases in microbial load (1.27 × 10⁵ − 4.08 × 10⁵ CFU/ml) than that from the back-slopping fermentation method (0.4 × 10⁵ − 2.9 × 10⁵ CFU /ml) within the same time interval. Back-slopping method improves the nutritional properties than spontaneous methods and could be encouraged at community levels.

The effect of soaking time on the proximate composition and functional properties of sprouted sesame seed flour were investigated. Sesame seed samples were cleaned and pretreated by soaking in clean water for 8, 10, 12, 14 and 16 h. One batch was sprouted for 36 h and another portion was sprouted and then boiled (100 °C for 20 min), dried, milled into flours and subjected to further analysis. The raw (unsprouted) sample was used as control. The proximate composition and the functional properties were determined for each of the samples and the result showed deviations in nutrient content from the raw seed flour. Moisture and protein content was increased by soaking and sprouting but reduced after boiling from a value of (4.99% and 47.64%) to (4.92% and 42.06%) respectively, for the 10 h soaked sample. Fat, crude fibre, ash and carbohydrate contents were reduced by soaking and sprouting while boiling of the sprouted seeds increased the fat and carbohydrate content. Soaking, sprouting and boiling significantly affected the functional properties of the flour (p < 0.05). Soaking and sprouting reduced the bulk density and dispersion of the samples from an initial value of (0.83% and 67.50%) for the unsprouted seed flour to a value of (0.71% and 59.00%) in 10 h soaked samples but increased slightly in most of the soaked sprouted-boiled samples. Thus, soaking of sesame seeds for 12–14 h before sprouting can be used to improve the proximate composition and functional properties of sesame seeds, hence, increase the utilization of the flour.