Nigerian Food Journal最新文献

Blends of sorghum and cowpea flour (10%, 20% and 30%) were extruded at 20%, 22.5% and 25% moisture and 120 °C, 140 °C and 160 °C barrel temperatures respectively, using a single-screw extruder. A central composite face-centered (CCF) design was used to model the specific power consumption (SPC), torque, mass flow rate (MFR) and apparent specific volume (ASV) of the sorghum–cowpea extrudates. The SPC, torque, MFR and ASV varied from 201.71 to 229.28 Kw h⁻¹ kg⁻¹, 85 to 97 Nm, 1.94 to 2.31 g s⁻¹ and 4.01 to 6.36 cm³, respectively. The SPC was significantly (p<0.05) influenced by the linear effect of feed composition and the interaction effects of feed moisture and extrusion temperature. The torque was however significantly (p<0.05) influenced by the linear effect of feed moisture and the interaction effects (p<0.01) of feed moisture and extrusion temperature. The ASV was significantly (p≤0.01) influenced by the linear effect of extrusion temperature and the quadratic effect of extrusion temperature as well as the interaction effects of feed composition and feed moisture. The coefficients of determination were 0.78, 0.79, 0.63 and 0.86 for SPC, torque, MFR and ASV, respectively. There was no significant lack of fit for the SPC, torque, and MFR of the extrudates. The correlation coefficients (r²) for the observed and predicted values were 0.88, 0.75, 0.78 and 0.93 for SPC, torque, MFR and ASV, respectively, indicating a good fit for the model. The CCF was found appropriate in predicting the SPC, torque, MFR and ASV of the extrudates.

The resistant starch (RS) content of some Nigerian cassava varieties and staples, “fufu”, “garri” and “abacha” processed from them were determined. Tubers of six varieties studied contained different concentrations of resistant starch, ranging from 5.70% in TMS 4(2)1425 to 7.07% in the TMS 30,572. Processing using traditional methods reduced the RS content in all cassava based foods compared with tubers from which they were processed. RS concentration was reduced by an average of 70.4% in “fufu”, 52.8% in “garri” and 35.85% in “abacha” for the four varieties of cassava tested. Cassava processing steps involving fermentation were responsible for the major reductions in concentration of RS. Steps involving cooking or frying, resulted in increase in concentrations of RS relative to other processing methods. Modifications of traditional methods of processing such as the addition of bitter leaf during retting or the addition of oil to mash during dewatering of “garri” affected RS concentrations in foods studied. Results of this work suggest that manipulation of processing methods and conditions employed during cassava processing can be used to improve RS concentration in cassava based foods, thus making them more functional.

This work studied the potential of four bacteria as starter cultures for the fermentation of cotton seeds (Gossypium hirsutum) to produce Owoh condiment. Cotton seed was fermented using spontaneous traditional method and starter cultures. Single cultures of Bacillus subtilis, Bacillus licheniformis, Bacillus pumillus, and Staphylococcus spp. and their combinations with and without Staphylococcus spp. were used as starters for the fermentation at 35 °C for 3 days. Chemical components of fermented and unfermented samples of cotton seeds were analysed for titratable acidity, pH, gossypol and proximate using standard methods. Sensory evaluation of the fermented products was carried out for colour, aroma, taste, stickiness and overall acceptability. Data were analysed using Analysis of Variance (ANOVA) and means separated by Duncan׳s multiple range test. Crude protein, crude fat, crude fibre, ash, moisture content, dry matter, carbohydrate, pH, titratable acidity and gossypol ranged from 22.40% to 13.62%, 28.25% to 15.29%, 11.29% to 2.51%, 3.65% to 1.25%, 39.26% to 55.85%, 60.74% to 44.15%, 34.41% to 67.33%, pH 6.67 to 8.24, 0.36% to 0.02% and 0.004900% to 0.000233%, respectively. Sensory evaluation of the fermented products showed that Owoh produced by the spontaneous or traditional fermentation of cotton seed was not significantly different from Owoh produced with combinations of starters. Although most of the single starter culture did not produce acceptable products in the controlled fermentation of cotton seeds, they played some roles in the product quality. Overall, the use of combinations of isolated Bacillus species with and without Staphylococcus spp. produced Owoh of good quality.

This study focused on the processing of breadfruit and cassava co-fermented into gari analogue. The microbial load was determined and the microbes associated with the fermentation were identified. The shelf life of the co-fermented gari analogue samples was also determined. A portion of both mature cassava tubers and matured but unripe breadfruit (Artocarpus altilis) was co-fermented (100:0, 0:100, 80:20, 70:30, and 60:40 Cassava: Breadfruit) to obtain gari analogue. The samples were evaluated for microbial loads (total viable, total yeast and mould count and total lactic acid bacteria counts). The products were subjected to sensory analyses using a 7-point hedonic scale. Data obtained were subjected to descriptive and inferential statistics. The results showed that six bacteria species were isolated from the fermenting mash, Corynebacterium manihot, Lactobacillus plantarum, Bacillus subtilis, Bacillus coagulans, Bacillus species and Corynebacterium species. Also isolated were Saccharomyces cerevisae, Saccharomyces fragilis, Saccharomyces rouxii and Geotricum candidum. Two moulds, Aspergillus niger and Rhizopus stolonifer, were found associated with co-fermented meals of cassava and breadfruit. The sensory attributes of 100% breadfruit gari and co-processed gari samples were significantly different (p>0.05) from the control; the co-processed gari samples were however rated higher than the 100% breadfruit in terms of overall acceptability. All the gari samples retain their quality attributes during storage for six weeks, except for the gari sample with 100% breadfruit, which deteriorated after three weeks. This study established that 20% of breadfruit co-fermented with cassava yields a novel food product that compares favourably with 100% cassava gari in terms of microbial and sensory characteristics.

Biscuits were produced from five broken rice and cocoyam flour blends which were: (1) 100% cocoyam flour, (2) 25% cocoyam flour:75% broken rice flour, (3) 50% cocoyam flour: 50% broken rice flour, (4) 75% cocoyam flour: 25% broken rice flour and (5) 100% broken rice flour. Biscuits made with 100% wheat served as the control. Functional properties of the flour blends were analysed while proximate composition, physical properties and sensory quality of the biscuits produced were also determined. Significant differences (p<0.05) in the functional properties existed among the flour blends. Proximate content ranged as follows: protein: 7.18–10.54%; ash: 1.46–1.75%; fat: 11.17–18.52%; moisture: 6.56–7.89%; fibre: 1.15–1.23% and carbohydrates: 58.71–65.97%. Biscuits made with wheat flour did not differ significantly (p>0.05) from those made with 50% cocoyam and 50% broken rice flour blend with respect to the physical properties and sensory quality.