A comparative study on the foaming properties and behavior at the air-water interface of soy and whey protein isolates were made, Foams were obtained by the method of gas bubbling. The initial rate of passage of liqui...A comparative study on the foaming properties and behavior at the air-water interface of soy and whey protein isolates were made, Foams were obtained by the method of gas bubbling. The initial rate of passage of liquid to the foam （vi） and the maximum volume of liquid incorporated to the foam （VLEmax） were determined. The destabilization process of the formed foams was analyzed by a biphasic second order equation. Measurements of equilibrium surface tension （water/air） and surface rheological properties were carried out in a dynamic drop tensiometer. The foaming capacity （vi and VLEmax） and the stability of foams prepared with the whey protein isolates （WPI） were better than those formulated with the soy protein isolates （SPI）. WPI foams were more stable showing the lower values of rate constants of gravity drainage and disproportion. There were significant differences （P 〈 0.05） in the dilatational modulus in the surface rheology measurements, which were higher at the interface with WPI, implying greater resistance of the film formed to collapse and disproportion. In conclusion, WPI formed better and more stable foams than the SPI.展开更多
A study was conducted for the development of value added dahi by incorporating fruit pulps, cereal flour and whey proteins concentrate （WHC） to increase the nutritional and sensory quality. Value added dahi （VAD） ...A study was conducted for the development of value added dahi by incorporating fruit pulps, cereal flour and whey proteins concentrate （WHC） to increase the nutritional and sensory quality. Value added dahi （VAD） was prepared by using skim milk, oat flour and WPC. VAD with 1% oat flour, 1% whey protein concentrate was found to be highly acceptable by sensory evaluation and curd tension study. Statistically there was a highly significant difference （P 〈 0.05） between skim milk dahi （control） and VAD VAD scored highest sensory score for all the sensory parameters studied. Curd tension found to be markedly increased in value added dahi with increased firmness of the product. Value added stirred dahi was prepared with oat flour, whey protein concentrate, papaya, fig pulps and sugar with different combination in order to assess the suitable level of addition with maximum acceptability. Value added stirred dahi （VADl） with 1% oat flour, 1% WPC, 5% papaya pulp, 4% sugar combination was found to be acceptable among the other combinations. Storage studies evaluated by sensory score revealed that the value added dahi can be stored up to 7 days at 5 ^（2. A significant increase in acidity and decrease in pH were noticed in the VAD1 during the storage period but within the permissible limit. Statistical analysis revealed no significance difference （P 〉 0.05） in total count and yeast and mould count between VAD0 （control） and VADl during storage 5 ~C. Total yield of value added dahi increased along with cost of production due to increased cost of ingredients （fruits and whey protein concentrate） used for value addition.展开更多
文摘A comparative study on the foaming properties and behavior at the air-water interface of soy and whey protein isolates were made, Foams were obtained by the method of gas bubbling. The initial rate of passage of liquid to the foam （vi） and the maximum volume of liquid incorporated to the foam （VLEmax） were determined. The destabilization process of the formed foams was analyzed by a biphasic second order equation. Measurements of equilibrium surface tension （water/air） and surface rheological properties were carried out in a dynamic drop tensiometer. The foaming capacity （vi and VLEmax） and the stability of foams prepared with the whey protein isolates （WPI） were better than those formulated with the soy protein isolates （SPI）. WPI foams were more stable showing the lower values of rate constants of gravity drainage and disproportion. There were significant differences （P 〈 0.05） in the dilatational modulus in the surface rheology measurements, which were higher at the interface with WPI, implying greater resistance of the film formed to collapse and disproportion. In conclusion, WPI formed better and more stable foams than the SPI.
文摘A study was conducted for the development of value added dahi by incorporating fruit pulps, cereal flour and whey proteins concentrate （WHC） to increase the nutritional and sensory quality. Value added dahi （VAD） was prepared by using skim milk, oat flour and WPC. VAD with 1% oat flour, 1% whey protein concentrate was found to be highly acceptable by sensory evaluation and curd tension study. Statistically there was a highly significant difference （P 〈 0.05） between skim milk dahi （control） and VAD VAD scored highest sensory score for all the sensory parameters studied. Curd tension found to be markedly increased in value added dahi with increased firmness of the product. Value added stirred dahi was prepared with oat flour, whey protein concentrate, papaya, fig pulps and sugar with different combination in order to assess the suitable level of addition with maximum acceptability. Value added stirred dahi （VADl） with 1% oat flour, 1% WPC, 5% papaya pulp, 4% sugar combination was found to be acceptable among the other combinations. Storage studies evaluated by sensory score revealed that the value added dahi can be stored up to 7 days at 5 ^（2. A significant increase in acidity and decrease in pH were noticed in the VAD1 during the storage period but within the permissible limit. Statistical analysis revealed no significance difference （P 〉 0.05） in total count and yeast and mould count between VAD0 （control） and VADl during storage 5 ~C. Total yield of value added dahi increased along with cost of production due to increased cost of ingredients （fruits and whey protein concentrate） used for value addition.
