Researches On The Extraction And Properties Of Mung Bean Protein

Mung bean（Vigna radiata）has a long planting history and a variety of resources in ourcountry. Mung bean has a high protein content and all kinds of amino acids.The proteinefficiency ratio of mung bean is high and it is proved to be the top of the beans. Mung beanhas very important developing value. At present, mung bean processing is mainly aboutstarch’s production, mung bean protein has not been fully exploited. This experiment usedmung bean as the raw material. The combination of the alkaline extraction and acidprecipitation methord and ultrasonication-assisted extraction were adopted to extract themung bean protein isolate, and its application in meat products and quick-frozen foodproducts were studied. A classical method of Osborne was chosen to separate mung beanprotein to four protein fractions and its functional properties were evaluated.At last, theeffect of high pressure processing on the characters of four protein isolates from mung beanwere studied The main work in this paper was concluded as follows:1. The process and condition of extracting protein isolate from mung bean werestudied. Through single factor and orthogonal experiments, the best extracting conditionwas as follows: raw material and water ratio was1：15, pH value was10.0,extractingtemperature was40℃,Under this condition, the extracting rate could reach to22.0769%.on this basis，ultrasonication-assisted extraction method and some other assisted extractionmethods were analysed and compared in order to improve the yield rate of mung beanprotein isolate. The ultrasonication-assisted extraction was proved the best one and it couldshorten the extraction time and improve the yield rate of mung bean protein isolate.2. Four protein isolates including albumin, globulin, gliadin and glutenin wereextracted from mung bean using the Osbron method and their functional properties wereevaluated. Comparative evaluation of functional properties showed that the order ofsolubility of mung bean protein fractions was as follows: albumin> globulin> glutenin>gliadin. The protein possessed the highest water-holding and oil-holding capacities wasglutenin. The protein possessed the highest foaming capacity was albumin. The color andsensory acceptance of gliadin were proved to be the best. The mung bean protein fractionsall had better emulsifying activity at basic conditions and the maximum absorption peaks at270-280nm.3. The effect of high pressure processing (from200to800MPa for10and20min) onUV-vis spectra and thermal stability of four protein isolates from mung bean were studied.The results indicated that the UV absorption peaks of albumin under different pressuretreatments were proved to be at265nm. Ten minutes’ UHP treatment could enhance the UVabsorption of globulin. However, UHP treatment could reduce the UV absorption of gliadin and glutenin. The effects of different pressure treatments on thermal stability of four proteinisolates from mung bean were proved to be different.4. Adding mung bean protein decreased cracking rate, water loss rate and cooking lossrate. The sensory and texture quality of dumplings were both improved. The color andsmell of dumplings were not affected when the addition of mung bean protein was within4%.The optimal dosage of mung bean protein was proved to be4%. Water addition, frozentime and different processing methods had an effect on the quality of dumplings. Theoptimum condation was that: water addition was55%, frozen time was30min, processingmethod was microwave reheating.5. The study on investigating the effect of mung bean protein isolate on qualitycharacteristics of emulsion-type sausage showed that: the addition of proper amount mungbean protein isolate could increase the production rate of emulsion-type sausage; The besttexture properties of emulsion-type sausage was got when the the addition of mung beanprotein isolate was6%.Adding mung bean protein isolate could reduce the degree ofbrigntness and red of emulsion-type sausage; The contribution rate of the first and secondcomponents were proved to be96.45%and2.8727%. The addition of proper amount mungbean protein isolate could improve the thermal stability of emulsion-type sausage.