Study On The Influences Of Cooking And Enzymic Hydrolysis On The Properties Of Porcine Bone Soup As Well As Its Dibittering Methods

Porcine ossein maintained the intrinsic flavor and taste of the fresh materials,having strong ability of improving flavors as a kind of natural sauce.It is always the objective for the scholars to research.In order to supply a theory basis for the pre-treatement of porcine bone when developing porcine ossein,the influences of cooking methods on the characteristics of porcine soup,as well as its enzymic hydrolysis and debittering methods were researched.The main results could be showed as follows:1.the influences of cooking time,different parts of bone,cooking temperature as well as the bone-water proportion on the characteristics of porcine soup were studied with the concentration of soluble solid,the content of fat,the content of protein,POV level, the yield of extracts,F.E.A and sensory evaluation as measuring index.The main results showed as follows:With the longer of cooking time,the content of crude fat,the content of protein,the concentration of soluble solid,the yield of extracts and POV level got higher gradually, the increasing tends become slow when the cooking time was 3h above;while F.E.A dropped continiously and fast.Contrast between the influences of porcine shank on the quality of soup and porcine shoulder blade was significant in the concentration of soluble solid,the content of fat,the content of protein,POV level,the yield of extracts as well as F.E.A,with the former one higher than the latter one determined by physical chemical index but having less points than the latter one determined by sensory evaluation;With the continious increasing of cooking temperature,the overall charactereristics of porcine soup had little changes except POV level,which grew faster and faster.with the continious decreasing of bone-water proportion,the overall characteristics of porcine soup got better at first,then began to drop,with 1:2.0 as its reversing piont. bone-water proportion placed few influences on POV level.The optimized conditions for cooking porcine soup were,measured by the content of protein,cooking with porcine shank as its raw material,1:2.0 as its bone-water ratio,at 105℃for 4h2.With DH and TCA-NSI as measuring index,the separate effects of hydrolysis on porcine bone soup of the four kinds of enzymes(Papain,Flavourenzyme,Typsin,and mixed enzyme) at their separate optimal condition for hydrolysis were measured,the results showed that,the best single enzyme for the hydrolysis of porcine bone soup was Papain,whose DH was 1.0168%with TCA-NSI of its hydrolysates 0.5836%.The best enzymatic mixture for the hydrolysis of porcine bone soup was the conglomeration of Papain and Flavourenzyme;the optimizing condition for the hydrolysis of porcine bone soup with the enzymatic mixture mentioned above were as follows:The proportion of Papain and Flavourenzyme was 0.6:1.4,the systematic acidity was adjusted to pH 7.6,the amount of the whole mixture used was 800u/g,temperature for hydrolysis was maintained at 45℃,when determined by its DH.The proportion of Papain and Flavourenzyme was 1.2:0.8,the systematic acidity was adjusted to pH7.6,the amount of the whole mixture used was 800u/g,temperature for hydrolysis was maintained at 45℃,when determined by TCA-NSI of its hydrolysates.DH 0.8203%,as well as TCA-NSI 2.9213%was tested when the hydrolysis was managed for 4 hours under their optimizing condition seperately.3.the separate best conditions for the three debitterring methods—the extraction by azeotropic Isobuty lalcohol,azeotropic Isobuty lalcohol and hydrolysis with glutin and former substrate as its new substrate for reaction,were studied.Meanwhile,the comprehensive dibittering effects were compared together by Tricine-SDS-PAGE electrophoresis.The results showed just as follows:The optimal ratio by volume between azeotropic Isobuty lalcohol and hydrolysates was 1:1.0;The optimal albuminoid reaction condition was that hydrolysis were carried when the former substrate and glutin(1:1) for 3 hours;The albuminoid reaction shuld be carried with Flavourenzyme as its albuminoid enzyme for 2 hours.Among the three kinds of debittering methods——the extraction of azeotropic Isobuty lalcohol,hydrolysis were carried when the former substrate and glutin(1:1) were compound as the new subtrate,albuminoid reaction,the extraction of azeotropic Isobuty lalcohol was the one that had the best effect of eliminating the bitter peptide in hydrolysates,determined by Tricine-SDS-PAGE.