Solubility, Emulsion And Foaming Properties Of Coconut (Cocos Nucifera) Protein Concentrates

Full-fat and defatted coconut protein concentrates containing 27.80% and 30.20% proteins (on a dry weight basis), respectively, were prepared from freeze-dried coconut meal samples. Selected functional properties such as: nitrogen solubility, emulsion and foaming properties were determined. Nitrogen solubility was measured in the range of PH 2.0-12.0 in three dispersion media including water, 0.1M NaCl (low salt) and 1.0M NaCl (high salt). The emulsion properties of the protein concentrates were measured at varying PH values (2.0-10.0) and sample concentrations. Foaming properties were determined using same parameters including the use of additives (NaCl solutions and carbohydrates). Below and above the isoelectric PH (4.0-5.0) the nitrogen solubility increased. The coconut protein samples showed a fairly high solubility (more than 54.0% and 53.0%) for full-fat coconut protein concentrate (FFC-PC) and defatted coconut protein concentrate (DFC-PC), respectively at pH 2.0. FFC-PC sample had maximum solubility (more than 73%) at 10.5 and minimum solubility (13.2%) at PH 4.0. On the alkaline PH scale, FFC-PC sample had maximum solubility of more than 43% at PH 10.5 in high salt (1.0M NaCl) solution while DFC-PC sample had maximum solubility of 50.2% in 1.0M NaCl solution and more than 80% in low salt (0.1M NaCl) dispersion medium. The emulsions prepared had good stability. A maximum of 92.5ml/g protein of emulsification capacity, at PH 10.0 and minimum of 45.3ml/g protein at PH 4.0 were obtained for FFC-PC while DFC-PC had a maximum EC of 86.4ml/g protein. FFC-PC samples produced significantly (P≤0.05) higher emulsion capacities than DFC-PC samples at all the dispersion PH and sample concentrations investigated. The FFC-PC samples had a significantly low foaming capacity than the DFC-PC samples at all the tested PH values. Similarly, the foaming capacities of FFC-PC and DFC-PC decreased with increasing PH of the sample medium. Both FFC-PC and DFC-PC foams collapsed completely, after 3hr standing at ambient temperature. Foaming was concentration dependent. The FFC-PC and DFC-PC foams increased sharply at 0.2% NaCl content of the sample slurries and progressed steadily to a peak of 92.0% and 113% in FFC-PC and DFC-PC samples respectively in 0.8% NaCl solution and then declined gradually with increased salt concentration. Addition of polymeric carbohydrates (sucrose, corn starch, gum acacia and pectins) significantly improved foaming properties of the protein concentrates but the foam stabilities were not significantly affected

Functional properties of cassava tapioca grits

Published online: 13 May 2010This study investigated the functional properties of tapioca grits produced from wet starches from 39 different cassava varieties (36 cassava mosaic disease resistant varieties CMD clones and 3 checks TMS 30572, 4(2) 1425 and 82/00058). There were significant differences (p < 0.05) for functional properties of tapioca grits from different cassava varieties. Dispersibility of tapioca ranged from 6–29%, water absorption capacity (WAC) ranged from 415.13–595.26%, swelling power ranged from 20.76–26.92%, solubility index ranged from 4.04–20.42%, color intensity ranged from 87.79–92.09%. Granule size of pre-gelatinized tapioca ranged from 12.50–22.50 mm. Significant differences (p < 0.05) were obtained on the effect of cassava varieties, viscometer speeds and temperature of tapioca meal. The viscosity of the tapioca meal decreased (37.90–0.72 Pa.s) with increasing shear rates at both 30 and 40o C, but higher for lower temperature respectively. Tapioca meal produced from cassava variety M98/0028 had the highest viscosity 37.90 Pa.s at 13.66 (s-1)

Chemical, pasting and sensory properties of tapioca grits from cassava mosaic diseaseresistant cassava varieties

The study investigated the chemical, pasting and sensory properties of tapioca grits produced from wet starches from 39 different cassava varieties (36 varieties resistant to cassava mosaic disease [CMD] and three checks TMS 30572, 4(2) 1425 and 82/00058) planted in June 2004/2005 at the experimental farm of the International Institute of Tropical Agriculture, highrainfall Onne (Lat 4.4°N, Long 7.1°E, mean annual rainfall of 2,600 mm.), Rivers State, Nigeria. There were significant differences (P < 0.05) for chemical and functional properties of tapioca grits from different cassava varieties. Amylose content ranged from 18.30 to 22.95%, amylopectin content ranged from 77.05 to 81.70%, protein content ranged from 0.16 to 0.42%, sugar content ranged from 0.10 to 1.20%, starch damage ranged from 1.22 to 1.49%, pH values ranged from 4.25 to 6.15, moisture content ranged from 5.75% to 10.12%, ash content ranged from 0.19 to 0.67%, starch content ranged from 67.34 to 81.86%. There were significant differences (P < 0.05) in all the pasting properties of the tapioca grits from different CMD starches. The peak viscosity of pregelatinized tapioca ranged from 110.79 to 545.17 RVU, final viscosities for tapioca ranged from 87.00 to 281.38 RVU. Setback values an

Effects Of Extracts From Three Indigenous Spices On The Chemical Stability Of Smoke-Dried Catfish ( Clarias Lezera ) During Storage

Fishes are the cheapest source of animal protein and it plays an important role in the diet of many people in both developed and developing countries. It is an important ingredient in the Nigerian traditional cuisine, cat fish being one of the most valued and very diverse groups of bony fish. The catfishes are a monophyletic group, belonging to the super-order called the Ostariophysi. Freshly caught fish spoil easily and therefore requires adequate preservation and storage. Of all flesh foods, fish is the most susceptible to tissue decomposition, development of rancidity, and microbial spoilage. Fish begin to deteriorate as soon as they leave the water. The preservation of fish is therefore considered to be a major hindrance to its production and utilisation especially in the tropical countries in Africa. The four most popular methods of fish preservation are freezing, canning, smoking and pickling, the major preservation method being pickling or salting, which has been used for centuries. In this present study, the effect of extracts from three indigenous spices; Piper guinensis (uziza), Xylopia aethiopicum (okada) and Myrustica monodora (ehuru) on the preservation of smoked-dried catfish stored for six weeks were evaluated using brine solution as control. Samples treated with uziza showed the lowest moisture content of 6.5% and lowest mean FFA formation of 0.55%, which was significantly different (p<0.5) from the other spices. The mean peroxide value range of 5.8-15.1 meq/kg was observed throughout the storage period for all the spices used. Thiobarbituric acid values ranged from 0.6mg/kg-1.4mg/kg with the lowest mean value of 0.37 mg/kg recorded in fish samples treated with uzizawhile the highest mean TBAvalue of 1.14mg was obtained in ehuru treated samples. This new research reveals that the three indigenous spices used, including Piper guinensis, Myristica monodora and Xylophia aethiopicum had chemical preservative and antioxidant properties. Among the three spices, Piper guinensis (uziza) was found to have the most effective preservation potential of smoked-dried fish during storage. This new result is anticipated to provide a simple, cheaper, healthier and safer method of fish preservation in developing countries

Seasonal variations in the chemical and functional properties of starches from local and improved cassava varieties in high rainfall region of Nigeria

The aim was to investigate the chemical and functional properties of starches produced from 39 different cassava varieties (36 varieties resistant to cassava mosaic disease and three checks TMS 30572, 4(2) 1425 and 8200058) in two planting seasons at the experimental farm of the International Institute of Tropical Agriculture, Onne, Rivers State, Nigeria. Varieties screened showed significant seasonal and varietal differences (p<0.05) in all the properties over two harvesting seasons. Amylose content ranged from 19.25 to 25.08% in Year 1 and from 16.19 to 20.29% in Year 2; amylopectin ranged from 77.88 to 79.71% in Year 1 and from 80.75 to 83.71% in Year 2. Protein content ranged from 0.7 to 1.06% in Year 1 and from 0.06 to 0.34% in Year 2. Sugar content ranged from 0.39 to 1.45% in Year 1 and from 0.52 to 1.13 % in Year 2. Starch damage ranged from 0.81 to 1.67% in Year 1 and from 0.58 to 0.89% in Year 2. pH ranged from 3.73 to 6.88 in Year 1 and from 5.25 to 9.30 in Year 2. Moisture content ranged from 7.47 to 14.55% in Year 1 and from 7.51 to 15.52% in Year 2. Ash content ranged from 0.05 to 0.36% in Year 1and from 0.03 to 0.77% in Year 2. Starch content ranged from 61.36 to 91.78% in Year 1 and from 64.67 to 84.21% for Year 2. Dispersibility ranged from 79.50 to 87% in Year 1 and from 79.50 to 85.50% in Year 2. Swelling power ranged from 10.91 to 17.47% in Year 1 and 8.57 to 14.28% in Year 2. Solubility index ranged from 4.68 to 26.36% in Year 1 and from 2.07 to 14.36% in Year 2. Colour ranged from 85.05 to 94.49% in Year 1 and from 90.27 to 92.96% in Year 2. The study therefore showed significant genotypic and seasonal variations in the chemical and functional properties of native starches from cassava