Study On The Enzymatichydrolysis Of Paphia Undulata And Its Products Development

Paphia undulata is widely distributed in the coastal areas of China,which is a kind of marine shellfish resources with high protein and low fat content.The production is Paphia is increasing as the continuous expansion of the area of farming,however,it is still based on fresh sales,and lack of intensive processing technology,resulting in low economic efficiency.In order to improve its added value of processing and utilization level,in this paper,based on the preparation of protein by enzymatic hydrolysis after screening enzyme types,enzymatic methods and determination of enzymatic hydrolysis conditions.The hydrolysate was decolorized and deodorized by adsorption method after determination of the decoloration and deodorization method;then,the enzymatic hydrolysate was separated into different peptides components by ultrafiltration.The enzymatic hydrolysate after decolorization and deodorization treatment was collected and spray-dried and the enzyme protein powder base was obtained.The enzyme hydrolysate after ultrafiltration use 5 K ultrafiltration membrane was collected and freeze-dried.Finally,a kind of nutritious and healthy clam protein product was developed by the enzymatic protein powder as main material,mixed with other excipients and prilled.The main results are as follows:1.According to the degree of hydrolysis,protein recovery rate and sensory evaluation as the index,the neutral protease,flavor protease,hydrolyzed animal protease and papain as hydrolyzed protease were selected and enzymatic hydrolysis of paphia undulate muscle by single enzyme and complex enzymes(adding enzymes step by step or simultaneously),finally the best type of enzyme and enzymatic hydrolysis method was obtained by comprehensive index.The results showed that after 3 hours of enzymatic hydrolysis simultaneously addition with the ratio of 1:1 of animal protease and flavor protease,the degree of comprehensive index was the best.Based on the results of the single factor and response surface optimization experiment,the optimized conditions were got as follows: the quantity of enzyme was 1700 U/g,enzymolysis time 3.5 h,liquid-solid ratio of 3.4:1.Under this condition,the degree of hydrolysis was 30.04±0.64%,protein recovery rate of hydrolysis was 81.46 ±0.70%,the comprehensive score of sensory evaluation was 15.8,with a better flavor.2.In order to determine the best method for decoloration and deodorization of theenzymatic hydrolysate.According to the sensory evaluation and protein recovery rate as the index,the powder activated carbon(Zinc Oxide carbon,phosphate carbon),granular activated carbon,diatomite(10#,300#),resin(LX-32,LSA-821)were selected and the best stactic decolorization and deodorization conditions was obtained by the single factor test.The results showed that the sensory value of LX-32 resin after static adsorption was 6.4,which was the highest value among the all adsorbents and the recovery rate was81.14±1.02 %.Then with the volume and mass ratio of the enzyme solution and the resin and flow rate as a single factor to optimize the dynamic adsorption decolorization and deodorization test of the best adsorbent.The optimized conditions were got as following:the ratio of enzymatic hydrolysate to resin was 2.5:1,flow rate was 5 BV/h,under this condition,the sensory value was 7.8,and protein recovery rate was 78.70±0.47%.3.The effects of membrane separation on the molecular weight distribution and recovery of protein components were studied.The results showed that the molecular weight of the component separated by the ceramic membrane,the ultrafiltration components(3~5 kDa,1~3 kDa,< 1 kDa)after separating by the ceramic membrane and the <5 kDa components separated by ultrafiltration directly were all below 5 kDa.The recovery rate of the protein was lower after the separation of the ceramic membrane.The component separated by 5 K ultrafiltration membrane have the content of 96.15±0.54 % peptides.Therefore,the best ultrafiltration component was obtained using the membrane of 5 kDa directly without the initial filtration of ceramic membrane.Then the optimum ultrafiltration component was collected and freeze-dried.The basic components and amino acid composition of two intermediates were analyzed,the results showed that the protein content was high and the fat content was low,and a wide range of amino acids with the content of essential amino acids balanced,the content of flavor amino acid was higher,the content of hydrophobic amino acids in enzymatic protein powder was 60.77%,which was higher than that of protein peptide,while the ratio of branched chain amino acids in protein peptide was higher.Therefore,the enzymatic protein powder base material can be used for the development of nutrition and health products,and the protein peptide based materials can be used to develop functional products.4.For the development of nutrition and health of clam essence protein products,mixed with pineapple powder,maltodextrin and microcrystalline cellulose,according to the degree of sensory value and L values,using the D-optimal mixture design to optimize the formula of clam essence protein powder.The L value and sensory value of clam essence protein powder were evaluated by different combinations of 4 ingredients in the recipe to determine the optimal formula.The results showed that the enzyme hydrolyzedprotein powder was 60~65%,the pineapple powder was 5~10%,maltodextrin was from 4~8%,microcrystalline cellulose was from 23~28%,and the content of sucrose was 0.10%.It was easy to granulation,and the sensory value and L value were better.By the mix design,the optimized formula were get as following: the hydrolyzed protein powder 62.08%,pineapple powder 7.08%,maltodextrin 5.66%,and microcrystalline cellulose 25.08%,sucrose 0.10%.Under this condition,the sensory value was 3.98,L value was 66.18,and there was no significant difference(P>0.05)compared with the predicted value.The made of clam essence protein were loose particles,uniform color and good taste.The results of physical and chemical indexes of the products showed that the content of protein(39.25%)was high,the amino acid composition was balanced,the content of delicious amino acid(DAA)was 54.53%,high content of branched chain amino acids and hydrophobic amino acids,the contents of trace elements were rich,and the contents of heavy metal and microbial were conformed to the national standards.