Research On Physical And Chemical Properties And Functional Properties Of Bamboo Bean Albumin

The bamboo bean has a variety of resources and its planting land is spread all over the country.And it has the characteristics of fast growth,strong resistance and high yield.Currently,it has been used as fodder,but its seed resources have not been fully utilized and developed.Bamboo bean protein is rich in content and has good amino acid ratio.Therefore,It has great potential in food processing.However,there are few studies on bamboo bean protein,limiting the development and utilization of bamboo bean protein resources.In this paper,four aspects of extraction technology,physical and chemical properties,functional properties and application in cake were systematically studied,which laid the foundation for the development and utilization of bamboo bean protein in the field of food.The main conclusions are as follows:?1?The optimum extraction process for bamboo bean albumin was:stirring speed:356r/min,extraction temperature:44°C,extraction time 1.5 h,ratio of material to liquid 1:11.20g/mL,under this condition,the extraction rate was 27.56%.The relative error was 1.14%compared with the predicted value.The single factor affecting the extraction rate of bamboo bean albumin was:material liquid ratio>extraction time>extraction temperature>stirring rate.The bamboo bean protein is rich in glutamic acid,aspartate,leucine and lysine,and the essential amino acids are rich and proportions are relatively balanced.Therefore,bamboo bean albumin was a kind of high quality protein.?2?SDS-PAGE electrophoresis showed that bamboo bean albumin contained nine subunits,and main subunits were distributed in 49.6 ku and 27.6 ku.It had large surface hydrophobicity under the acid condition and different ultraviolet and fluorescence spectra characteristics under different pH.Thermal analysis showed that the bamboo bean albumin had the highest denaturation temperature?Td?of 100.6°C in pH=7.And it had the highest degeneration enthalpy??H?of 3.40 J/g in pH=5.The fourier transform infrared spectroscopy showed its secondary structure as follows:the proportion of beta angle was the highest?33.59%?,followed by beta folding?31.38%?,alpha helix?17.97%?and random coil?17.07%??3?The bamboo bean albumin had better foam ability and foam stability under alkaline conditions.And the emulsifying property and stability increased gradually under the alkaline condition.Within 40-60°C,the foam ability and stability of temperature change was consistent:first decreased and then increased.The highest emulsification is at 60°C and the best emulsifying stability is at 40°C.When the concentration of NaCl was within the 0.6-0.8 mol/L,the foaming property and stability were both good.When the NaCl concentration was 0.4 mol/L,it had the best emulsifying property and stability.?4?The bamboo bean albumin solution was a pseudoplastic fluid.Different pH protein solutions affected its gel performance,and far away from isoelectric point seemed better.The bamboo bean albumin always had weak gel solids with the changed temperature.The optimum additions of Na⁺,K⁺,Mg²⁺and Ca²⁺were as follows:0.8%,0.4%,0.4%and 0.8%.At the same time,the addition of metal ions can make the protein gel point appears to rise in varying degrees.?5?With the increase of the amount of albumin,the specific volume,elasticity and viscosity of cake decreased,and the hardness and chewiness increased.The 6%addition of bamboo bean albumin in cake is similar to pure egg cake in taste and appearance,which is the best addition.During the 5 day storage period,the moisture content of cake with different proportions decreased significantly,the viscosity decreased,the hardness increased,and the elasticity increased first,then decreased and then increased,and the recovery finally stabilized.