Physicochemical, functional and digestibility analyses were done of dehydrated quail egg white to determine its possible practical applications. Quail egg white was dehydrated by air convection using one of two temper...Physicochemical, functional and digestibility analyses were done of dehydrated quail egg white to determine its possible practical applications. Quail egg white was dehydrated by air convection using one of two temperatures and times: M1 (65℃, 3.5 h), M2 (65℃, 5.0 h), M3 (70℃, 3.5 h) and M4 (70℃, 5.0 h). Lyophilized quail egg white was used as a standard. All four air-dried treatments had good protein levels (92.56% to 93.96%), with electrophoresis showing the predominant proteins to be lysozyme, ovalbumin and ovotransferin. Denaturation temperatures ranged from 81.16℃ to 83.85℃ and denaturation enthalpy values from 5.51 to 9.08 J/g. Treatments M1-4 had lower water-holding (0.90 - 2.95 g/g) and oil-holding (0.92 - 1.01 g/g) capacities than the lyophilized treatment (4.5 g/g, 1.95 g/g, respectively). Foaming capacity was pH-dependent in all five treatments, with the lowest values at alkaline pH and the highest (153% to 222%) at acid pH (pH 2). Foam stability was lowest at acid pH and highest at alkaline pH. Emulsifying activity in the air-dried treatments was highest at pH 8 (41% - 46%). Emulsion stability was pH-dependent and highest in M3 between pH 2 and 4 (96.16% to 95.74%, respectively). In the air-dried treatments, in vitro protein digestibility was as high as 83.02% (M3).展开更多
With increased demand for plant based proteins by the consumers, the food manufacturers appeal for the new plant proteins with predetermined characteristics. This study aims at isolating the protein fraction from jack...With increased demand for plant based proteins by the consumers, the food manufacturers appeal for the new plant proteins with predetermined characteristics. This study aims at isolating the protein fraction from jackfruit seeds and characterizing the protein powder for functional and physicochemical properties. The protein part of the seeds was separated through pH treatments and centrifugation process and finally, the concentrate was converted into powder by spray drying method. The functional properties such as solubility, gelling capacity and emulsion properties and the physicochemical properties such as crystallinity, morphology and particle size distribution of the jackfruit seeds protein isolate (JSPI) were studied. The secondary structural elements of JSPI were also determined by Fourier-transform infrared (FTIR) spectroscopy. About 76.89% protein was estimated in the prepared JSPI with 78.44% solubility in an aquatic solvent. The least gelation concentration of JSPI was 12% in a salt solution. The pH of the solvent significantly affected the emulsifying and foaming properties. The protein isolate possessed amorphous structure, moderate bulk density and almost 75% of the particles fell in a similar size distribution range. The conformational study reported that the β-sheet is the dominant secondary structural element with the highest content of 50.28%. The observed features suggest that the JSPI holds satisfactory functional and physicochemical characteristics for being used in protein-enriched foods.展开更多
Starch is a very important biopolymer in the food industry. The velvet bean (M. pruriens) is an excellent potential starch source containing approximately 520 g starch per kg. The objective of this study was to evalua...Starch is a very important biopolymer in the food industry. The velvet bean (M. pruriens) is an excellent potential starch source containing approximately 520 g starch per kg. The objective of this study was to evaluate the physicochemical and functional properties of velvet bean depigmented starch. The starch granules appear oval and spherical shaped. The colour registered L*, a*, b* values of 44.9, 0.324 and 0.341 respectively. The chemical composition registered values of moisture, ash, fat, protein, fibre and NFE of 110.5, 5.8, 5.7, 0.0, 34 and 954.5 g/kg respectively, as well as amylose levels of 215.3 g/kg. Gelatinization onset (To), peak (Tp) and final (Tf) temperatures were of 74.23°C, 80.57°C and 86.39°C. The solubility (3.1% - 16.2%), swelling power (SP) (2.86% - 16.17%) and water absorption capacity (WAC) (2.67 - 15.95 g water/g starch) were directly correlated to temperature (60°C - 90°C). The enthalpy values (4.10 - 13.47 j/g) were directly correlated to the time (1 - 21 days). The retrogradation increased as time increased. The viscosity of M. pruriens depigmented starch decreased slightly during the heating stages and then increased during cooling and the refrigeration and freezing stability registered syneresis ranges from 17.65 to 23.18 mL/50mL and from 16.4 to 22.6 mL/50mL respectively, indicating that the depigmented starch was unstable in heating-cooling processes.展开更多
文摘Physicochemical, functional and digestibility analyses were done of dehydrated quail egg white to determine its possible practical applications. Quail egg white was dehydrated by air convection using one of two temperatures and times: M1 (65℃, 3.5 h), M2 (65℃, 5.0 h), M3 (70℃, 3.5 h) and M4 (70℃, 5.0 h). Lyophilized quail egg white was used as a standard. All four air-dried treatments had good protein levels (92.56% to 93.96%), with electrophoresis showing the predominant proteins to be lysozyme, ovalbumin and ovotransferin. Denaturation temperatures ranged from 81.16℃ to 83.85℃ and denaturation enthalpy values from 5.51 to 9.08 J/g. Treatments M1-4 had lower water-holding (0.90 - 2.95 g/g) and oil-holding (0.92 - 1.01 g/g) capacities than the lyophilized treatment (4.5 g/g, 1.95 g/g, respectively). Foaming capacity was pH-dependent in all five treatments, with the lowest values at alkaline pH and the highest (153% to 222%) at acid pH (pH 2). Foam stability was lowest at acid pH and highest at alkaline pH. Emulsifying activity in the air-dried treatments was highest at pH 8 (41% - 46%). Emulsion stability was pH-dependent and highest in M3 between pH 2 and 4 (96.16% to 95.74%, respectively). In the air-dried treatments, in vitro protein digestibility was as high as 83.02% (M3).
文摘With increased demand for plant based proteins by the consumers, the food manufacturers appeal for the new plant proteins with predetermined characteristics. This study aims at isolating the protein fraction from jackfruit seeds and characterizing the protein powder for functional and physicochemical properties. The protein part of the seeds was separated through pH treatments and centrifugation process and finally, the concentrate was converted into powder by spray drying method. The functional properties such as solubility, gelling capacity and emulsion properties and the physicochemical properties such as crystallinity, morphology and particle size distribution of the jackfruit seeds protein isolate (JSPI) were studied. The secondary structural elements of JSPI were also determined by Fourier-transform infrared (FTIR) spectroscopy. About 76.89% protein was estimated in the prepared JSPI with 78.44% solubility in an aquatic solvent. The least gelation concentration of JSPI was 12% in a salt solution. The pH of the solvent significantly affected the emulsifying and foaming properties. The protein isolate possessed amorphous structure, moderate bulk density and almost 75% of the particles fell in a similar size distribution range. The conformational study reported that the β-sheet is the dominant secondary structural element with the highest content of 50.28%. The observed features suggest that the JSPI holds satisfactory functional and physicochemical characteristics for being used in protein-enriched foods.
文摘Starch is a very important biopolymer in the food industry. The velvet bean (M. pruriens) is an excellent potential starch source containing approximately 520 g starch per kg. The objective of this study was to evaluate the physicochemical and functional properties of velvet bean depigmented starch. The starch granules appear oval and spherical shaped. The colour registered L*, a*, b* values of 44.9, 0.324 and 0.341 respectively. The chemical composition registered values of moisture, ash, fat, protein, fibre and NFE of 110.5, 5.8, 5.7, 0.0, 34 and 954.5 g/kg respectively, as well as amylose levels of 215.3 g/kg. Gelatinization onset (To), peak (Tp) and final (Tf) temperatures were of 74.23°C, 80.57°C and 86.39°C. The solubility (3.1% - 16.2%), swelling power (SP) (2.86% - 16.17%) and water absorption capacity (WAC) (2.67 - 15.95 g water/g starch) were directly correlated to temperature (60°C - 90°C). The enthalpy values (4.10 - 13.47 j/g) were directly correlated to the time (1 - 21 days). The retrogradation increased as time increased. The viscosity of M. pruriens depigmented starch decreased slightly during the heating stages and then increased during cooling and the refrigeration and freezing stability registered syneresis ranges from 17.65 to 23.18 mL/50mL and from 16.4 to 22.6 mL/50mL respectively, indicating that the depigmented starch was unstable in heating-cooling processes.
