Micronutrients and anti-nutritional contents of selected tropical vegetables grown in SouthEast, Nigeria

Levels of some nutrients and antinutrients of six green leafy vegetables grown in SouthEast, Nigeria were determined using standard analytical methods Crude protein, fat, moisture, crude fiber carbohydrate and calorific values ranged from 1.20 to 2.20 g/100g, 0.80 to 1.30g/100g, 74 to 93%, 0.70 to 2.10 g/100g, 1.30 to 13.20g/100g and 21.00 to 97.00 kcal /100g. The vitamin C composition varied from 14.61 to 30.84mg. The elemental analysis of the six leaves in mg dry matter indicated that the leaves contained appreciable levels of iron (3.43 to 23.03), calcium (204.26 to 305.51 and magnesium (195.57 to 340.39). The antinutrient composition for phytic acid, tannins and oxalic acid are; 34.70 to 68.50mg/100g, 0.32to 0.83 g/100g and 24.65to 42.15 mg/g respectively. These results reveal that those leaves contain an appreciable amount of nutrient, vitamin, mineral elements and low level of toxicants and should be included in diets to supplement our daily allowance needed by the body

Micronutrients and anti-nutritional contents of selected tropical vegetables grown in South East, Nigeria

Levels of some nutrients and antinutrients of six green leafy vegetables grown in SouthEast, Nigeria were determined using standard analytical methods Crude protein, fat, moisture, crude fiber carbohydrate and calorific values ranged from 1.20 to 2.20 g/100g, 0.80 to 1.30g/100g, 74 to 93%, 0.70 to 2.10 g/100g, 1.30 to 13.20g/100g and 21.00 to 97.00 kcal /100g. The vitamin C composition varied from 14.61 to 30.84mg. The elemental analysis of the six leaves in mg dry matter indicated that the leaves contained appreciable levels of iron (3.43 to 23.03), calcium (204.26 to 305.51 and magnesium (195.57 to 340.39). The antinutrient composition for phytic acid, tannins and oxalic acid are; 34.70 to 68.50mg/100g, 0.32to 0.83 g/100g and 24.65to 42.15 mg/g respectively. These results reveal that those leaves contain an appreciable amount of nutrient, vitamin, mineral elements and low level of toxicants and should be included in diets to supplement our daily allowance needed by the body

Chemical, functional and pasting properties of starches from brown and yellow tigernuts (Cyperus esculentus)

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Shelf Life Extension of Toasted Groundnuts through the Application of Cassava Starch and Soy Protein-Based Edible Coating

The use of cassava starch and soy protein concentrate edible coatings containing 20% glycerol in extending the shelf life of toasted groundnut during ambient (27 ± 1oC) storage for 14 days was studied. Chemical indices of oxidative rancidity and sensory parameters were evaluated using standard procedures. Moisture uptake, peroxide and thiobarbituric acid values of uncoated groundnuts were higher than 100% cassava starch coated groundnuts while toasted groundnuts coated with 50:50 (cassava starch:soy protein concentrate) had the lowest values. Toasted groundnuts coated with 50:50 (Cassava starch:soy protein concentrate) film had higher colour, taste, texture and overall acceptability scores than toasted groundnuts coated with 100% cassava starch film and control. The use of 50:50 (cassava starch:soy protein concentrate) edible coatings on toasted groundnut extended the shelf life of toasted groundnuts for 14 days compared to uncoated toasted groundnuts which developed objectionable taste after second day of storage at ambient (27 ± 1oC) condition.Keywords: Cassava starch, soy protein concentrate, edible film, toasted groundnuts, shelf life extension

Shelf Life Extension of Toasted Groundnuts through the Application of Cassava Starch and Soy Protein-Based Edible Coating

ABSTRACTThe use of cassava starch and soy protein concentrate edible coatings containing 20% glycerol in extending the shelf life of toasted groundnut during ambient (27±1°C) storage for 14 days was studied. Chemical indices of oxidative rancidity and sensory parameters were evaluated using standard procedures. Moisture uptake, peroxide and thiobarbituric acid values of uncoated groundnuts were higher than 100% cassava starch coated groundnuts while toasted groundnuts coated with 50:50 (cassava starch:soy protein concentrate) had the lowest values. Toasted groundnuts coated with 50:50 (Cassava starch:soy protein concentrate) film had higher colour, taste, texture and overall acceptability scores than toasted groundnuts coated with 100% cassava starch film and control. The use of 50:50 (cassava starch:soy protein concentrate) edible coatings on toasted groundnut extended the shelf life of toasted groundnuts for 14 days compared to uncoated toasted groundnuts which developed objectionable taste after second day of storage at ambient (27±1°C) condition

Optimization of Rice Bran Fermentation Conditions Enhanced by Baker’s Yeast for Extraction of Protein Concentrate

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 35oC), 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 30oC 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%).Keywords: Rice bran, fermentation, baker’s yeast, protein extraction, response surface methodology

Application of Response Surface Methodology and Central Composite Design for the Optimization of Tiger Nut (Cyperus esculentus L.) Flour Production

The Response Surface Methodology (RSM) involving three factors five level central composite design (CCD) was employed at design constrains of 46.590C ≤ X1 ≤ 63.410C; 11.32 hours ≤ X2 ≤ 14.59 hours and 31.91 hours ≤ X3 ≤ 52.09 hours, to optimize the selected process variables for the production of tiger nut flour. The objective of this study was to locate the best combination of drying temperature (X1), drying time (X2) and post-sprouting sampling time (X3) that will give optimum quality tiger nut flour. Regression models and response surface plots were developed and their adequacy tested by examining the coefficient of determination (R2, R2 adjusted) analysis of variance (ANOVA), lack-of-fit test and analysis of residual. The result showed models with 80.30% to 96.07% R2,76.75% to 95.36% R2 adjusted, 7.38 to 228 F calculated and insignificant lack-of-fit, as proof of model adequacy. The result of the composite desirability function showed the optimum  levels for the production of tiger nut flour to be 56.440C drying temperature, 12.03 hours drying time and 43.53 hours post-sprouting  sampling time with resultant of 2.75% moisture content, 21.75% protein, 2.66 x 10-3kg/s flowrate and 496mg/100g vitamin C content.Keyword: Response surface, central composite design, optimization, tiger nut flour

Physical, sensory and chemical properties of bread prepared from wheat and vitamin A enriched cassava flour blends containing cissus gum

Objective: The study investigated the effect of cissus gum addition on the physical, sensory and chemical properties of bread prepared from wheat and vitamin A enriched cassava flour blends.Materials and Methods: Cissus gum was extracted from cissus stem and prepared into powder while vitamin A enriched cassava tubers were prepared into flour using standard methods. Different levels (0, 1, 2 and 3% w/w) of cissus gum powder was added to different proportions (100:0, 90:10, 80: 20, 70: 30 and 60:40%) of wheat and vitamin A enriched cassava flours for bread making where 100% wheat bread without cissus gum served as control. Bread specific volume, loaf height was determined using standard procedures while sensory evaluation was carried out using twenty- member trained panelist on a 9-point Hedonic scale. The optimized composite bread was subjected to chemical analysis using standard procedures.Results: It was found that addition of cissus gum improved specific volume and loaf height of composite bread with an increased crumb colour, texture, taste and overall acceptability scores. The specific volume, loaf height, crumb colour, texture, taste and overall acceptability of composite bread containing 30% vitamin A enriched cassava flour with added 2% cissus gum were not significantly (p<0.05) different from control while other samples differed from the control. Substitution of vitamin A enriched cassava flour up to 30% in wheat flour containing 2% cissus gum improved β- carotene content (by 44.24%) with reduced carbohydrate content compared to 100% wheat bread.Conclusion: The inclusion of 2% cissus gum powder could serve as a gluten substitute in preparing acceptable wheat bread substituted with vitamin A enriched cassava flour in order to provide a low-cost way of combating vitamin A deficiency in Nigeria.Keywords: Physical and sensory properties, vitamin A, vitamin A enriched cassava flour, cissus gu

Functional Properties of Flours from Five Nigerian Rice Cultivars

In this study, the functional properties of five Nigerian rice cultivars (Bisalachi, Ebagichi, Lamiyatu, Majalisa and Walue) were determined. Functional properties such as hydration, pasting and thermal parameters, and vibrational spectroscopy of the flours were determined using standard methods. Bulk density, water binding capacity, water holding capacity, water absorption index, water solubility index, oil absorption capacity and swelling power ranged from 0.32 to 0.41 g/cm3, 1.21 to 1.40 g/g, 1.33 to 1.92 g/g, 5.81 to 7.53 g/g, 1.49 to 1.74 g/g, 1.26 to 1.35 g/g, and 10.35 g/g to 12.80 g/g, respectively. Peak viscosity, trough viscosity,  breakdown viscosity, final viscosity, pasting temperature and peak time ranged from 158.04 to 187.30 RVU, 107.59 to 124.76 RVU, 50.45 to 62.54 RVU, 222.86 to275.27 RVU, 115.27 to 151.89 RVU, 87.65 to 88.53 oC and 5.29 to 5.96 min, respectively. Onset, peak and conclusion temperatures, and enthalpy of  gelatinization ranged from 65.02 to 68.41 oC, 68.73 to 72.05 oC, 74.59 to 79.26 oC, and 11.62 to 14.88 J/g, respectively. Raman spectroscopy revealed that the bands in the spectra of the rice flours originated mainly from the vibrational modes of amylose and amylopectin. The results obtained are useful in determining theapplication of the rice flours in food systems.Keywords: Rice cultivars, flour, functional properties