Studies On Extraction Of Protein From Tussah Pupa And Preparation Of Solid Beverage

The production of tussah is very large in China.Tussah pupa protein is a pure natural animal protein with high nutritional value and has significant medicinal benefits.Its reasonable amino acid ratio is very suitable for human to absorp and use.However,tussah pupae have their own special odor and the extraction process is not mature enough.These have led to the low production efficiency and poor processing characteristics of T.pupa protein,which is difficult to apply in food production and cannot exert its own high quality value of nutritional function.Therefore,This study aims to expand the utilization pathway,refine the extraction process,isolate active ingredients with special efficacy and produce applications of T.pupa proteins,thus achieving the purpose of improving the added value and increasing economic efficiency in the silkworm raising region.In this paper,the contents of T.pupa were defatted.T.pupa proteins were extracted by water extraction,alkaline extraction and ultrasonic assisted alkaline extraction,and optimization of extraction process to purify proteins.Protein structure and physicochemical processing characteristics were determined,and biological activities were investigated to develop T.pupa protein solid beverage products and expand the application range of T.pupa proteins.The specific findings were as follows:1.In this study,ultrasonic soaking ethanol extraction was used to maximize the removal of T.pupa oil.The purity and yield of T.pupa proteins were determined using three extraction methods based on orthogonal experiments to optimize the extraction of water-soluble and alkaline soluble proteins.The protein purity obtained by the best extraction process can reach 88.08±1.01%,and the extraction yield was64.26±4.50% by the alkaline method with ultrasonication for 20 min at a temperature of 50? and a power of 400 W.The effect of the extraction method on protein structure was further investigated by measuring the content of sulfhydryl and disulfide bonds,SDS-PAGE gel electrophoresis,Fourier infrared scanning analysis,and UV scanning analysis.2.In this study,the properties of T.pupa proteins obtained by different extraction methods were determined.The basic physicochemical characteristics were studied as follows: solubility,hydrophobicity,blistering,emulsification,stability,etc.It was proved that ultrasonic assisted extraction improved the processing characteristics of T.pupa protein.The biological activities including antioxidant activity,in vitro digestion activity,bacteriostatic and hypolipidemic activities of T.pupa protein were determined and confirmed to be suitable as a natural raw material for the manufacture of functional foods.3.In this study,T.pupa protein extracted by ultrasonic assisted alkaline method was used to prepare solid beverage products.Sucrose fatty acid esters and ?-Dextrin were used to improve the solubility of T.pupa protein and reduce peculiar smell.Through the observation and determination of solubility by optical microscope,the results of spray drying and vacuum freeze-drying were compared,and the spray drying method was more suitable for producing T.pupa protein solid beverage.By compounding vitamin C and xylitol,the solid protein beverage product with rich nutrition,unique flavor and stable preparation is finally prepared.The related product indexes were determined and compared with the commercial protein solid beverage.In summary,this study aims at the problem that the production and processing efficiency of T.pupa protein is low and fails to give full play to its real function.The preparation technology of T.pupa proteins were optimized,the effects of different extraction methods on protein characteristics were compared,and a new functional product was developed based on the protein obtained by the best extraction method.Not only improved the extraction efficiency of T.pupa proteins and clarified the effect of extraction method on their processing function,but also increased the application value of T.pupa protein,which is an incompletely exploited insect protein.The studies have a certain economic benefit and research value.