Influence of pH and sodium chloride on selected functional and physical properties of African breadfruit (Treculia africana Decne) kernel flour

African breadfruit seeds were cleaned, parboiled (98 ^°C) for 15min, drained and dehulled. The kernels were sun-dried, then milled andsieved into flour. Nitrogen solubility (NS), water absorption capacity(WAC), emulsion activity (EA), viscosity, foaming and emulsifyingproperties of the flour were determined as functions of pH and NaClconcentration. The NS was pH dependent with a minimum at pH 4 andmaximum at pH 10. The flour also exhibited minimum and maximum foamcapacity at pH 4 and 10, respectively. The minimum emulsion activity wasat pH 4, a value which increased from 7–16% at pH 12. The addition ofNaCl at concentrations of 0.2 to 0.4 M improved WAC, NS, foamingand emulsion properties of the flour. Sodium chloride enhanced NS of theflour at pH 4–6 and EA at pH 2–8.The EA at pH 2, 10 and 12 correlated negatively (r = –0.30) with NaClconcentration levels; however, the correlation was not significant (p> 0.05). The flour dispersions had lower viscosities at acid pH and in thepresence of NaCl than at neutral and alkaline pH values. Results indicatedthe flour could be used in food product supplementation.     

Proximate composition and selected functional properties of African Breadfruit and sweet potato flour blends

Full-fat African breadfruit flour was used to replace 30, 40, 50, 60 and 70% of sweet potato flour. The chemical composition and functional properties of composite flours showed that they contains more protein, fat, and ash and less carbohydrate than sweet potato flour. With increasing level of supplementation of breadfruit, ash, protein and fat contents increased while carbohydrate decreased. The composite flours possessed higher water absorption than sweet potato flour. The water absorption capacity increased from 20% for sweet potato flour to the range of 85–120% for composite flours. The oil absorption capacities for some composite flours were higher than that for sweet potato but less than that of breadfruit. Composite flours had good foaming capacity but lacked foaming stability. The bulk density of the composite flours was found to be low which will be an advantage in the preparation of weaning food formulations.     

Influence of storage on chemical,microbial and consumer acceptability of a milk-like product made from melon seeds

The storage stability of melon milk at room (30 ± 2 ^°C)and refrigeration (10 ± 2 ^°C) temperatures was determined by analyzing changes in the chemical, microbial andsensory properties of the milk stored for 7 days. Theresults showed that at both storage temperatures, solublesolids and pH of the milk decreased while titratableacidity increased with storage. The standard plate countsincreased appreciably while coliforms were absent in themilk with storage at both storage temperatures. The overallacceptability score of the melon milk dropped duringstorage, the drop being faster at 30 ± 2 ^°C than at 10 ± 2 ^°C. The milk samples stored at 30 ± 2 ^°C and 10 ± 2 ^°C were acceptable only within one and three days, respectively; thereafter, theywere unacceptable.     

Proximate composition and selected functional properties of fermented and unfermented African oil bean (Pentaclethra macrophylla) seed flour

Flour samples were prepared from fermented and unfermentedAfrican oil bean (Pentaclethra macrophylla) seeds (AOBS). The flour samples were evaluated for proximate composition and certain functional properties. The influenceof defatting on these properties was also determined. Fermentation significantly increased (p<0.05) the proteinand decreased the crude fiber, ash, fat and carbohydrate contents of the AOBS flours. The nitrogen solubility of both fermented and unfermented flours was pH dependent withminimum and maximum solubility at pH 4.0 and pH 8.0, respectively, and with increased nitrogen solubility in the fermented sample. The fermented and unfermented flour sampleshad least gelation concentrations of 14 and 16% (w/v), respectively. The water absorption capacity and foam capacitiesof the fermented flour were 36 and 34%, respectively, over the unfermented seed flour. On the other hand, fermentation decreased the fat absorption capacity, emulsion activity and emulsion and foam stabilities. Fermentation decreased (p<0.05) the bulk density of AOBS flour by 15%. Defattingimproved all the functional properties evaluated except emulsion activity. These results indicate potential food usesof fermented and unfermented AOBS flour samples as protein supplements in diets and as functional ingredients in formulated foods.     

Chemical composition and selected functional properties of sweet orange (Citrus sinensis) seed flour

Flour samples were prepared from dehulled and undehulledsweet orange (Citrus sinensis) seeds. The flour samples were evaluated for proximate composition, mineralcontent and selected functional properties. Proximate analysis showed a composition of 54.2% fat, 28.5% carbohydrate, 5.5% crude fiber, 3.1% crude protein and 2.5% ash for the dehulled orange seed flour (dry weight).Mineral analyses showed high levels of calcium and potassium in flour samples. Partially defatted and undefatted flour samples prepared from dehulled orangeseeds had least gelation concentrations of 10 and 12%(w/v), respectively. Water absorption capacity for thedefatted and undefatted dehulled flour samples were 240and 220%, respectively. Defatting improved oil absorptioncapacity of the orange seed flour by 84%. Emulsion activity, emulsion stability and foaming capacity decreasedfollowing defatting of flour. Foam prepared from defattedflour was less stable than that from full-fat flour.Incorporation of NaCl up to 0.2 M improved the foamingcapacity of orange seed flour.     

Effects of processing methods on the quality and acceptability of melon milk

Physicochemical and sensory characteristics of melon milksamples prepared from toasted, autoclaved, boiled andgerminated melon seeds were determined. The germinated melonmilk (GMM) had higher protein and ash contents butlower pH and viscosity than the other treated milk samples.Toasting the melon seeds improved the ash, protein, totalsolids and soluble solids of melon milk more than theboiling and autoclaving processes. The mean sensoryscores showed that the GMM was rated lower than the othertypes of processed milk samples for all the sensoryattributes evaluated. The toasted melon milk (TMM) hadhigher sensory ratings for color, mouthfeel and flavorand was generally preferred to the other treated melonmilk samples.     

The suitability of African bush mango juice for wine production

A good quality wine was produced from African bush mango (Irvingia var.gabonensis). Analysis of the African bush mango juice showed that it contained 3.6% total sugar, 1.09% protein, 4.2° Brix soluble solids (SS) 0.5% ash, 50.24% total solids (TS), 66.7 mg/100 ml ascorbic acid and pH 5.12. The juice ameliorated to 23° Brix was inoculated with 3% (w/v) Baker's yeast (Saccharomyces cerevisiae) and held at 30±2°C for 28 days. SS and pH decreased while titratable acidity (TA) increased with increasing period of fermentation. Fermentation was 110% efficient. The wine produced had 8.12% (v/v) alcohol, 0.78% protein, 6.5% Brix SS, 0.64 g/100 ml TA, and a pH 3.10. Sensory evaluation results showed that there was no significant difference (p=0.05) in colour, mouthfeel, sweetness, flavour and general acceptability, between African Bush mango wine and a reference wine. The wine was generally accepted.     

Physicochemical,microbiological and sensory changes in stored plantain chips

Plantain chips were produced from unripe plantain fruits.The chips were packed in polyethylene bags and stored at30 ± 2 ^°C for 1, 2 and 3 months, respectively.The storage stability of the chips was evaluated by analyzing periodically for changes in the physicochemical,microbiological and sensory characteristics. Protein andash contents of the chips did not change (p > 0.05) overtime. Fat decreased slightly (p > 0.05) over time. VitaminC decreased and was negatively correlated with storagetime (r = –95; p < 0.05). Peroxide value and microbialcount increased with storage (p < 0.05). Sensory scoresfor chips did not change (p > 0.05) at 2 months storage,but, thereafter, decreased (p < 0.05).