Study On Preparation And ACE Inhibitory Activity Of Peptides From Swine Blood Meal By Fermentation

The blood of swine was very abundant in our country.About 1.5 billion kilograms swine blood were produced by slaughter every year.The study on comprehensive utilization & deep processing of swine blood makes slow progress, low resource utilization rate,etc.Not only wasted the sources,but also severe contamination surroundings.At present,the exploiture of functional peptide has been a research focus.It was studied in this paper that the swine blood meal was used to get peptides.At the same time,it was studied that the inhibition of Angiotensin I-Converting Enzyme by peptides.In this paper,the transparent circle method and enzyme activity of their Protease were used for Bacillus subtilis.The stain B₃ was selected to ferment swine blood meal which has a larger DC value and high-yielding enzyme capacity.The result was that the protein of power from swine blood decreased 24.05%,the nitrogen of free amino acids increased 4.44 times and dissolving protein increased 53.77%,All these demonstrated that B3 was a fine strain to ferment swine blood meal.The fermentation conditions of B3 were studied by using single factor experiment and orthogonal method.After the cross experiment to ferment swine blood meal by B3,the optimal condition to produce peptide from swine blood meal with the highest degree of 32.3%was under conditions of 30℃fermentation temperature,160rpm rotation speed,7.5 pH value,4%inoculums size,60h fermentation time.The micro-filtration membrane and dialysis bags with different MWCO were used to classify the swine blood meal broth fermented by B3.After that the peptide was obtained by vacuum freeze-drying.The Tricine-SDS-PAGE showed that the untreated fermentation broth and peptide powder dealt with 0.22μm micro-filtration membrane with a broad molecular weight distribution,the classification by dialysis bags was apparently and the molecular mass of small molecular weight peptides was obviously less than globins from swine blood.The analysis of automatic amino acid showed that amino acid compositions of peptides from swine blood meal changed.Thirteen amino acids and 4 unknown oligopeptides were detected in swine blood meal.The compositions of amino acid of different MWCO peptides(＞10kDa,lkDa-10kDa,＜lkDa) were 13 amino acids and 4 unknown oligopeptides,12 amino acids and 6 unknown oligopeptides,8 amino acids and 7 unknown oligopeptides,respectively.Met was measured,but it did not measured in swine blood meal.What's more,Phe did not measured in peptides. Meanwhile,Arg did not measured in peptide which molecular weight between lkDa and l0kDa,and Asp,Thr,Ser,Arg did not measured in peptide which molecular weight＜lkDa,also.The ACE inhibitory activity of peptides from swine blood meal was determined by HPLC.The results showed that the ACE inhibition rate of different MWCO peptides(＞10kDa,lkDa-10kDa,＜lkDa) were increased with the increase of their concentrations.At the same time,the IC50 was 4.99 mg/ml,3.28 mg/ml and 1.83 mg/ml,respectively.