The Extraction Of Water-Soluble Protein From Peanut Meal And The Study Of Peanut Protein Beverage

Peanuts,also called groundnuts,longevity fruit,or the Fig,and their biological nomenclature was Arachis hypogaea Linn..They belong to rosales leguminosae,and they are annual herb,which are widely distributed in all parts of the world,and grown in most areas of China.The production of peanuts in our country is higher than before,these years the average annual output can reach 16 million tons.Peanuts can be edible and can be as oil crops,the peanut meals are byproducts after squeezing oil.According to the national bureau of statistics data,the annual output of peanuts are up to 4 million tons.However,high yield of peanut meal has not been fully used,which is mainly used as fodder,so the peanut meal’s application value is greatly reduced.Peanut meal contains rich protein,and the distribution of amino acid is balanced,which is a good source of protein.In this paper,protein was extracted from peanut meal through water extraction(Water-soluble Protein from Peanut Meal,later in this paper is referred to as WSPP),and the extraction technology conditions were studied,moreover,the peanut protein beverage recipe was determined by the stability and enhancing the stability test.This laid the foundation of industrial production of peanut protein beverage.The research contents of this experiment were as follows:1.The WSPP extraction and the analysis of protein molecular weight.Used extraction rate of protein as the index,the optimum technological conditions of protein extraction were determined through single factor and orthogonal test:at 55℃,ratio of solid to water was 1:20,water extraction 2h+ ultrasonic assisted extraction 1 h,twice repeated this,extraction rate reached 52.36%.Among them,the extracting time and the method had the greatest influence,followed by extraction times,and the impact of ratio of solid to water was minimal.Electrophoresis analysis showed that the WSPP molecular weight was within the range of 12.06～63.39 kD,the composition was mainly 2 s albumin;Besides it contained a small amount of arachin and conarrachin.2.The study of its stability and enhancing the stability.Through determinating isoelectric point,when the pH was 4.5,its protein content was minimum.Its stability study showed that WSPP at pH7,70℃,the stability is the best.In the enhancing stability study,sweetening agent added was isomaltose hypgather(content was 6%～10%),erythrose(8%)and fructose(6%),the stability of the WSPP was best;Stabilizer was CA composite stabilizer(0.12%),peruvian carob(0.2%)and 791avice(0.2%),the stability of the WSPP is best.3.The determination of optimal formula and sterilizing condition.Formula was determined by the stability studies for adding isomaltose hypgather.And the best sterilizing condition was boiling water bath sterilizing 40 minutes,the total bacterial count of peanut protein beverage<100 cfu/mL,peroxide value<0.15g/100 g,stability factor was above 0.95,and it got the highest scores in the sensory evaluation,because it was milk-white homogeneous emulsion,no precipitation and flocculation,which had full-bodied peanut fragrance.