Asian Food Science Journal

The effects of fermentation on the antinutrient composition of African walnut enriched with carrot and without carrot were carried out in this study. The submerged natural fermentation of non- enriched and carrot enriched (walnut 70%; carrot 30%)  African walnut was carried out and lasted for 5 days during which microorganisms were isolated and identified. Species of Lactobacillus and Bacillus that are most commonly used as probiotics in foods, drugs, and dietary supplements, which was isolated during the natural fermentation of African walnut, were then used singly and in consortium during inoculation fermentation. During the fermentation processes, the anti nutritional analysis was carried out on the fermented samples on a daily basis. Result revealed that the bacteria B. subtilis strain b17a and L. lactis SFL8 were the most predominant bacteria during the natural fermentation. Raw African walnut and carrot have tannin, saponins, Phytate and oxalate of  2.47± 0.10, 1.46 ± 0.10, 14.41 ± 0.10 , 3.29 ± .10  and 2.28 ± .08,  2.10 ± .10,11.50± .05, 0.37± .03 respectively. Raw walnut generally had a higher anti-nutrient composition than carrot except in saponins. Fermentation led to the reduction in antinutrient composition in the fermented sample. Natural fermented African walnut (NFW) and natural fermented African walnut enriched with carrot (NFWC) resulted in the highest reduction in antinutrient composition. NFW and NFWC had a reduction in tannin, saponins, Phytate and oxalate from (2.47±0.008^b, 1.46±0.010^a, 14.41±0.026^d, 3.29±0.05^c) to (0.98 ± 0.05^a, 0.61±0.05^a, 4.35±0.03^a, 0.27±0.05^a) and (0.91±0.005a, 0.45±0.005^a, 3.61±0.03^a, 0.17±0.005^a) respectively. Inoculation fermentation in which a monoculture of L. lactis or B. subtillis was used as starter culture resulted in the least reduction in the antinutrient content. Carrot enrichment of fermented African walnut had a reducing effect on the antinutrient composition of African walnut as the fermentation enriched with carrot all had a reduced tannin, Phytate and oxalate composition compared to those that were not enriched. Hence, fermentation and enrichment with carrot can be employed in improving the nutritional quality of African walnut thereby helping in effectively utilising their potential as human food.

Aim: To evaluate effect of carrot powder addition on the quality attributes of cookies produced from wheat and soy flour blends.

Study Design: Cookies were produced from wheat flour, soy flour and carrot powder composite blends. Functional (bulk density, foam capacity, oil absorption capacity, water absorption capacity and swelling index) properties, Proximate (crude protein, ash, moisture, crude fibre, crude fat, carbohydrate and energy value) composition, Physical (weight, diameter, thickness and spread ratio) and sensory (appearance, flavour, taste, texture and overall acceptability) attributes were determined.

Results: The functional properties showed that Bulk Density ranged from 0.82 – 0.92, Foam capacity ranged 3.92 – 5.00, Oil Absorption Capacity ranged from 0.60 – 0.97%, Water Absorption Capacity ranged from 1.05 – 1.45% and Swelling Index ranged from 2.37 – 2.75. Results of percentage proximate composition showed that moisture content ranged from 4.70 – 7.57, protein content ranged from 10.61 – 21.60, fat content ranged from 8.89 – 15.85, fibre content ranged from 1.39 – 4.30, ash content ranged from 0.70 – 1.23 and carbohydrate content ranged from 52.34 – 70.84. The physical properties showed that weight of the cookies ranged from 17.85 – 21.60, diameter ranged from 57.50 – 60.50, thickness ranged from 20.50 – 24.00 and spread ratio ranged from 2.40 – 2.91. The sensory attribute showed that cookies produced from wheat flour, soy flour and carrot powder compared well with cookies produced with wheat flour. The wheat flour cookie sample (A) was most preferred by the panellist.

Conclusion: The functional properties of the composite flour produced from wheat, soybean and carrot powder show potential quality that when properly harnessed could be used for the production of baked product like biscuits, pastry etc. The proximate composition shows that the composite flour cookies were the most preferred sample to the 100% wheat flour cookies. This is due to its high protein, fat, ash and fibre content to that of thee 100% wheat cookies. However, in terms of proximate composition, the composite cookies were most acceptable. The physical property of the cookies indicates that the composite flour cookies were most preferred to the 100% wheat cookie. This could be seen from the high values it’s had in weight, diameter and spread ratio. However, the sensory score of the overall acceptability shows that the 100% wheat cookies were most acceptable. Though, the composite flour cookies compete very closely with 100% wheat cookies.

This study was carried out to determine the effect of lemon grass marinade (sample A), bay leaf marinade (sample B) and a combination of both spices (sample C) on the microbial load of stored smoked-dried Clarias gariepinus. Comparative analysis of the microbial load of each treated fish samples during ambient storage was done biweekly for six (6) weeks and then samples of each treatment were taken to the laboratory periodically. The fish samples were analysed using Potato Dextrose Agar and Nutrient Agar for fungi and bacteria respectively. The initial microbial load before storage showed that the highest number of bacteria counts occurred in smoke-dried Clarias gariepinus treated with bay leaf marinade (4.7´10³) while the lowest was in smoke-dried C. gariepinus treated with lemon grass marinade (1.3´10³). The highest fungi count was observed in smoke-dried C. gariepinus treated with the combination of both spices (9.5´10²) while the least fungi count was in fresh fish sample (1.4´10³), although the fresh fish sample had the highest bacteria mean count (5.1´10³) when compared with the treated samples. After 6 weeks of ambient storage, the result of smoke-dried C. gariepinus treated with bay leaf marinade was also significantly different from the mean population of smoke-dried C. gariepinus treated with lemon grass marinade and smoke-dried C. gariepinus treated with the combination of both spices. Smoke-dried C. gariepinus treated with bay leaf marinade again had the highest bacteria and fungi mean count of 1.7´10⁵ and 2.3´10⁴ respectively. Smoke-dried C. gariepinus treated with lemon grass marinade and smoke-dried C. gariepinus treated with the combination of both spices had similar bacteria mean count of 1.5´10⁵ while smoke-dried C. gariepinus treated with lemon grass marinade had the lowest fungi mean count of 1.6´10⁴. The study revealed that all three smoked-dried fish sample treatment had a relatively low bacterial and fungal count below the 5 x 10⁵cfu/g recommended by the International Commission of Microbial Specification for Food and Food Products (ICMS, 2002).

The effect of pH and sugar levels on the microbiological properties of sweet orange juice was evaluated. Microbial analysis of the treated Orange juice (Citrus Sinensis) were determined using standard method. The standard method of Prescott [12] was used. The microbial load of the produce reduced as the concentration of the derived preservatives increased. Both pH and sugar level used had inhibitive effect on the test organism. The result revealed that the use of pH and sugar level as hurdles should be encouraged in processing food products.

The physicochemical and sensory evaluation of bread from the composite of wheat, water yam and soybean flours were determined. Five bread samples were produced from the proportion of wheat/water yam/soybean flours as 80%:10%:10% (B), 75%:15%:10% (C), 70%:20%:10% (D), 65%:25%10% (E) and 100% wheat was the control sample (A). The moisture, crude protein, fiber and ash increased (p≤0.05) significantly while the carbohydrate and fat content decreased (p≤0.05) significantly with corresponding increase in the percentage of the composite flour from 10-25% for water yam flour at constant 10% soybean level. The result of the physical properties showed that there was a significant difference in all the physical parameters except loaf weight which didn’t increased (p≥0.05) significantly with increased addition of water yam flour at constant soybean level. The result of the sensory analysis showed there were significant differences in all the sensory scores. However, consumers preferred the bread from the composite flours of 20% substitution for both water yam and soybean flours.