Enzymatic Extraction Of Bovine Skin Gelatin And Its Application Of Compound

Gelatin could be produced by either thermal denaturation or partial hydrolysis of animal collagen.The paper focus on the optimization of enzymatic extraction of gelatin instead of traditional acid and alkali method.The properties and rheological properties of bovine gelatin gels treated with low methoxyl pectin(LMP)and transglutaminase(TGase)were herein investigated,and their synergistic interaction in set yogurt was tested.The research provided instructive guidance for the applications of gelatin in dairy products.First of all,using enzymatic method for extracting gelatin from bovine skin,explores the influence on yield and gel strength of gelatin on the enzymolysis pH,enzymolysis time,enzymolysis concentration and temperature.And the condition of enzymatic method was optimized using response surface methodology(RSM).The best condition of enzymatic method for extracting gelatin was that enzymolysis pH was 2.6,enzymolysis time was 35h,enzymolysis concentration was 0.3%,and temperature was 59?.Secondly,in the presence of TGase,the gel strength,texture and rheological properties of bovine gelatin gels treated with LMP were herein investigated,and the microstructures of gelatin were observed by scanning electron microscopy.The results showed that gelatin,LMP and TGase had a synergistic effect within a certain range,and for adding 0.4%(w/v)concentrate of LMP and 0.1%concentration of TGase,the gel strength,hardness,gumminess,and chewiness of gelatin was highest,it demonstrated the synergistic effect between gelatin and LMP or TGase could be superimposed.In the test of frequency rheology,gelatin modified by LMP and TGase simultaneously showed the highest storage modulus(G'),loss modulus(G"),and the complex viscosity(?*).In the test of temperature rheology,The viscoelasticity of gelatin which was dual modified was greater than that of monomer.The synergistic effect in rheology was consistent with gel strength and texture properties exhibited.Finally,the effects of gelatin,LMP,and TGase on sensory,hardness,gumminess,adhesiveness,and water-holding capacity(WHC)of set yogurt were studied and their ratio was optimized by RSM.The optimum acceptability of sensory properties,hardness,gumminess,adhesiveness and WHC could obtained in this condition:gelatin 0.5%,pectin 0.081%,TGaseO.0681%.