Aladesanmi A. Oshodi

Functional properties of pigeon pea (Cajanus cajan) flour

Abstract The functional properties of the seed flour of pigeon pea (Cajanus cajan) were studied. Results showed that the flour had a good gelation propensity and that the least gelation concentration was 12%. The foaming capacity was found to be 68% while the foam stability was 20%. This foam stability was found to be comparably higher than those of soy flour and sunflower. The emulsion capacity was determined to be 49·4% while the oil and water absorption capacities were 80·7 and 138%, respectively. Protein solubility of the flour was also determined and found to be pH-dependent with minimum solubility at about pH 5.

Effects of NaCl, ionic strength and pH on the foaming and gelation of pigeon pea (Cajanus cajan) protein concentrates

Abstract Studies were carried out on the effects of pH, ionic strength, sample concentration and added salt (NaCl) concentration on two hydrodynamic properties — gelation capacity and foaming properties of pigeon pea protein concentrates. Results indicate that the protein concentrate has a good gelation capacity with a least gelation concentration of 6% (w/v). Using the least concentration endpoint (LCE) as an index of gelating ability, the gelation capacity of the flour improved in the presence of moderate NaCl concentration and low ionic strength. Acidic and neutral pH also enhanced gelation while alkaline pH decreased it. The foaming capacity of the flour could be improved in a medium of low ionic strength and by increasing the concentration of protein sample as well as by a moderate concentration (0.25% w/v) of NaCl. Better foaming capacity was observed in the acidic region than in the alkaline region. Foams were also observed to be more stable as concentration of NaCl, concentration of protein concentrate and ionic strength increased.

Proximate composition, nutritionally valuable minerals and functional properties of Adenopus breviflorus benth seed flour and protein concentrate

Abstract The proximate analysis of Adenopus breviflorus benth seeds showed that the whole seed flour, dehulled full-fat seed flour and protein concentrate had crude protein contents of 28.6, 30.2 and 76.5% while fat contents were 47.7, 54.2 and 1.4%, respectively. The ash content ranged from 3.49% in samples with hull to 2.06% for the protein concentrate. The results also showed that potassium and calcium are evenly distributed in the seed while sodium, magnesium, iron, phosphorus and manganese are more concentrated in the cotyledon. The water absorption capacity of the flours varied from 112.5% for sample without hull to 201.5% for the protein concentrate while the oil absorption capacity varied from 125.9% to 206.7% depending on the sample under consideration. The least gelation concentrations and emulsion capacity were relatively good. The foaming capacity was low but relatively stable. Protein solubility studies showed that the protein of the protein concentrate was soluble at both acidic and basic pH.

Effect of salts on some of the functional properties of bovine plasma protein concentrate

Abstract The effects of salts, NaCl, Na2SO4, KCl and CH3CO2Na on some of the functional properties of bovine plasma protein concentrate (BPPC) were investigated. Results showed that the least gelation concentration of 6.0% observed in distilled deionized water was improved to between 2% and 4% in the presence of the salts used. The foaming capacity of about 36.0% in water considerably increased to between 52.0% to 158.0% depending on the type and concentration of the salts. The water absorption capacity decreased at low salt concentrations compared with values in distilled water and increased with increase in salt concentration while the emulsion capacity decreased with an increase in salt concentration. The variation of protein solubility with pH was found to depend on salt type and concentration.

Chemical composition of bitter cola (Garcinia kola) seed and hulls.

The chemical composition of Garcinia kola seed and hull was determined using standard methods. Results show that crude protein, lipid extract, ash, and crude fibre ratios are: 39.52 and 99.92 g/kg, 43.25 and 42.91 g/kg, 11.42 and 18.62 g/kg, 114.02 and 153.44 g/kg respectively. Carbon : nitrogen ratios for the seed and hull are 57.88 and 29.01, respectively. Garcinia kola hull had significantly higher (p<0.05) protein and fibre but has comparable values for lipid and ash. Potassium and phosphorus were the most abundant mineral elements in Garcinia kola seed (334.82 and 242.61 mg/kg, respectively) while phosphorus predominates in the hull (288.61 mg/kg). The seed had significantly higher values for sodium, potassium, copper and cobalt while chromium, molybdenum, manganese, nickel, selenium, lead and mercury were not detected. The dominant saturated, monosaturated, and polyunsaturated fatty acid, in the seed and hull are palmitic (31.55 and 276.01 mg/kg), oleic (38.36 and 52.77 mg/kg) and linoleic acids (36.16 and 235.83 mg/kg) respectively. The hull has significantly higher (p<0.05) a-linolenic acid content. Glutamic acid is the dominant non-essential amino acid in seed and hull (6.80 and 8.10 g/kg, respectively) while lysine and valine (2.40 and 7.10 g/kg, respectively) are the dominant essential amino acids. The proportion of essential amino acid in the total amino acid is 44.52% in the hull and 35.81% in the seed. Garcinia kola seeds and hulls may find use in food and feed formulations by virtue of their chemical composition.

Functional, thermal and molecular behaviours of ozone-oxidised cocoyam and yam starches.

Ozone-oxidised starches were prepared from the native starches isolated from white and red cocoyam, and white and yellow yam cultivars. The native and oxidised starches were evaluated for functional, thermal and molecular properties. The correlations between the amount of reacted ozone and carbonyl and carboxyl contents of the starches were positive, as ozone generation time (OGT) increased. Significant differences were obtained in terms of swelling power, solubility, pasting properties and textural properties of the native starches upon oxidation. The DSC data showed lower transition temperatures and enthalpies for retrograded gels compared to the gelatinized gels of the same starch types. The native starches showed CB-type XRD patterns while the oxidised starches resembled the CA-type pattern. As amylose content increased, amylopectin contents of the starches decreased upon oxidation. Similarly, an increase in Mw values were observed with a corresponding decrease in Mn values upon oxidation.

Sequestration of Aqueous Lead(II) Using Modified and Unmodified Red Onion Skin

ABSTRACT The efficacy of onion skins, both unmodified and chemically modified with thioglycolic acid, was investigated as alternative low-cost adsorbents for the sequestration of aqueous lead(II) ions from aqueous solution. The adsorbents were characterised using Fourier transform infrared spectroscopy and scanning electron microscopy – energy dispersive X-ray spectroscopy. Adsorption experiments were performed using batch sorption processes. The effects of contact time, pH, initial Pb(II) concentration, adsorbent dose, and temperature were investigated. Optimum sorption conditions were found at pH 4 and a 150 min equilibrium time for the modified onion skin and unmodified onion skin. The Langmuir, Freundlich, Dubinin-Radushkevich and Temkin models were used to characterize the equilibrium experimental results. The equilibrium process was best described by the Freundlich isotherm. The maximum adsorption capacities of 4.878 and 6.173 mg/g were obtained for modified and unmodified adsorbents, respectively, using the Langmuir model. Kinetic studies indicated that the sorption of Pb(II) ions followed a pseudo-second-order model. Thermodynamic parameters such as standard enthalpy change (ΔH°), entropy change (ΔS°), and free energy change (ΔG°) were evaluated from the sorption experimental measurements. The results showed that the sorption process of Pb(II) ions on unmodified and modified onion skins was feasible and exothermic under the conditions used in this study. The sorption process followed the mechanism of physisorption.