Effects of increasing acylation and enzymatic hydrolysis on functional properties of bambara bean (<i>Vigna subterranea</i>) protein concentrate

Journal of Food Processing and Preservation

Sogi

2015

The effect of different drying methods used in the preparation of protein concentrates from different cultivars of cowpea and bambara bean was investigated. Protein was extracted by the isoelectric precipitation method and subsequently dried by cabinet drying (CD), vacuum drying (VD) and freeze drying (FD). The protein extraction yield and protein content were high. The subunit composition of protein concentrates was characterized by electrophoresis. The drying methods affected water-holding capacity, oil absorption capacity and solubility of protein concentrates depending on cultivars. Water-holding capacity was adequate for its utilization in viscous foods. The protein concentrates prepared by FD showed higher oil absorption capacity than those by CD and VD. The protein concentrates prepared by FD showed lower solubility at pH 2-6, and above pH 6 the concentrates prepared by VD presented higher solubility compared with those by CD and FD. This study provided useful information to optimize utilization of legume protein concentrates in the food industry. PRACTICAL APPLICATIONSCowpea and bambara bean cultivars could be used in the preparation of protein concentrates due to their good nutritional quality and low cost. Techniques used during the preparation of protein concentrates usually involve the conversion into a dry powder form that facilitates stable and long-term storage, enabling their use as ingredient in food applications. In this regard, the effect of cabinet drying, vacuum drying and freeze drying in the functional properties of cowpea and bambara bean protein concentrates was investigated. The freeze-drying technique was adequate for utilization of concentrates in viscous foods, bakery products and in the cold meat industry as these concentrates presented high water-holding and oil absorption capacities. The vacuum-drying technique produced concentrates with high solubility at pH 2 and above pH 6, and was adequate for concentrates that could find utilization in the fortification of beverages. Choosing appropriate drying technique and cultivar could determine utilization of protein concentrates in the food industry.

“…The protein solutions were then centrifuged at 6,000× g for 20 min (Mune Mune et al . ). Protein concentration in each supernatant was determined by the Lowry method (Lowry et al .…”

Section: Methodsmentioning

confidence: 97%

Functional Properties of Protein Concentrates of Cowpea and Bambara Bean Involving Different Drying Techniques

Journal of Food Processing and Preservation

Sogi

2015

“…Generally, solubility, surface hydrophobicity and molecular flexibility influenced the emulsifying behavior of globular proteins. Surface hydrophobicity was probably determinant for EA of cowpea and Bambara bean protein concentrates, since there was a positive correlation (r= 0.80; p< 0.00) between these two variables.Panyam & Kilara (24) and Mune Mune et al(25) reported that increase in surface hydrophobicity facilitated adsorption of proteins at the oil-water interface, then reduced the surface tension and increased emulsifying properties. In addition, the partial unfolding of protein molecules could increase their molecular flexibility, which facilitated their rearrangement at the oil-water interface to form an elastic layer around the fat droplets and then retarded coalescence.…”

mentioning

confidence: 99%

Emulsifying and Foaming Properties of Protein Concentrates Prepared from Cowpea and Bambara Bean Using Different Drying Methods

International Journal of Food Properties

Sogi

2015

Effect of cabinet-drying (CD), vacuum-drying (VD) and freeze-drying (FD) methods on the surface hydrophobicity (H0), secondary structure, emulsifying and foaming properties of protein concentrates prepared from different cultivars of cowpea and Bambara bean was investigated.The VD method reduced H0, while freeze-dried concentrates presented high H0. The concentrates prepared by FD presented more β-sheet (40-43%) and less β-turn (19-24%) structures. Bambara bean protein concentrates prepared by FD presented higher emulsifying activity (56-59%) compared to those by VD and CD, while emulsifying activity varied significantly among cultivars of cowpea (46-61%). Protein concentrates prepared by CD showed the highest foaming ability.

“…Previous studies showed that solubility of BBPC followed a U‐shaped trend at different pH levels, with the lowest solubility around pH 4.5 (Mune Mune et al . ). Nitrogen solubility of BPH was then followed at neutral and isoelectric pH and the results are presented in Fig.…”

Section: Resultsmentioning

confidence: 97%

“…In a previous work, we reported that functional properties of BBPC could be effectively modified by enzymatic hydrolysis using pancreatin (Mune Mune et al . ).…”

Section: Introductionmentioning

confidence: 97%

Optimizing Functional Properties of Bambara Bean Protein Concentrate by Enzymatic Hydrolysis Using Pancreatin

Journal of Food Processing and Preservation

2015

Enzymatic hydrolysis of Bambara bean protein concentrate was investigated with the view to produce hydrolysates with desirable functional properties. A Box-Behnken design was used for experiments and models capable of predicting functional properties depending on hydrolysis conditions were developed. These models were then used to determine optimum hydrolysis conditions. It was found that hydrolysis parameters had significant influence on the functional properties. Nitrogen solubility and oil-holding capacity of Bambara bean protein hydrolysates were improved, while a slight increase in foaming capacity and decrease in emulsifying activity were observed. The optimum hydrolysis conditions were: time 97.5 min, solid-to-liquid ratio 6/75 (w/v) and enzyme substrate ratio 1.90% (w/w). The properties obtained were: nitrogen solubility at pH 7 of ≥75%, nitrogen solubility at pH 4.5 of ≥33% and oil-absorption capacity of ≥4.1 g/g. Finally, it was shown by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis that protein breakdown was selective. PRACTICAL APPLICATIONSBambara bean grain legume is a source of cheap, accessible and good nutritional quality protein which could be used in various food formulations as ingredient. However, utilization of the protein concentrate is limited by low functionality. Therefore, it is necessary to improve the functional properties and to adapt these properties to the specific needs in the food industry. Functional properties of Bambara bean protein hydrolysates, as a function of hydrolysis parameters (time, solid-to-liquid ratio, enzyme-to-substrate ratio), were adequately modeled in this study. In addition, optimum conditions where hydrolysates presented higher functional properties were determined. This hydrolysate could find application in the fortification of acid beverages for increasing the nutritional quality, as well as in meat products such as sausages where high oil-absorption capacity is required.