Preparation And Microencapsulation Of Heme Iron Peptides

The slaughter of livestock and poultry produces huge livestock and poultry blood resources.Making full use of livestock and poultry blood not only avoids pollution of the environment,but also has significant economic benefits.Livestock and poultry blood is rich in protein resources,most of which is hemoglobin.The hemoglobin ferrous iron in hemoglobin is an ideal iron-supplying substance,and its absorption rate by the human body is higher than that of non-heme iron,but hemoglobin is present in blood cells,and hemoglobin is difficult to be absorbed by the body,heme iron is easily oxidized.This experiment studied the method of wall breaking of blood cells,optimized the enzymolysis process of hemoglobin,protected the state of heme iron,concentrated the heme peptide by ultrafiltration,and finally microencapsulated it.The experimental results are as follows:1.The physicochemical indexes of raw chicken blood were determined.Among them,the blood protein content was 11.19%,the total iron content was 0.29 mg/mL,the heme level was 3.17 mg/mL;the blood cell protein content was 31.50%,and the total iron content was 1.21 mg/mL.The heme iron level was 13.61 mg/mL.The raw chicken blood has high protein content and rich iron content,and is a good source of extracted heme iron peptides.2.The effects of water swelling,freezing,and ultrasound on blood cell wall breaking rate were compared.Chicken blood was centrifuged at 4000 r/min for 10 min to obtain blood cells.The optimal blood cell wall-breaking parameter of the water swelling method was the ratio of material to liquid 1:3,stirring for 30 minutes,and the blood cell wall-breaking rate reached 96.59%±0.68%.The rate of cell wall breaking was 94.59%±1.06%after freezing at-18°C for 4 hours.The parameters of the ultrasonic method for optimizing wall breakage after orthogonal experiment are:material-liquid ratio 1:4,ultrasonic time 9 min,ultrasonic power 240 W,and the rate of cell wall breaking is 91.26%±2.26%.The optimized water-swelling method and freezing method have higher wall-broken rate than the ultrasonic method and have significant differences?P<0.05?.Among them,the freezing method is easier to control the heme,which is not easy to be oxidized and is suitable for the laboratory operation.Therefore,the blood cells are broken by freezing at-18°C for 4 hours.3.Research on enzymatic hydrolysis of heme peptides,and alkaline protease is preferably used for enzymatic hydrolysis of hemoglobin from neutral protease,alkaline protease,papain,and trypsin.Using the degree of hydrolysis as an index,the single factor experiments determined the best single factor conditions:ratio of material to solution 1/9,pH 8.0,amount of enzyme added 10 kU/g?the alkaline protease activity is 172.18 kU/g?,reaction temperature 45°C,and hydrolysis time 4 h.After centrifugation at 5000 r/min for10 min,the yield of total iron in the supernatant can reach 99.16%.The optimized enzymolysis process in orthogonal experiment was as follows:the ratio of solid to liquid was 1:10,the pH was adjusted to 8.5,the amount of enzyme was 10 kU/g,and it was hydrolyzed in a water bath at 45°C for 6 h;followed by two-step enzymatic hydrolysis,Flavour protease,enzyme dosage 10 kU/g?the flavor protease enzyme activity is 14.27kU/g?,enzymolysis temperature 50°C,enzymatic hydrolysis time 4 h.After hydrolysis,the degree of hydrolysis reached 55.06%and the ferrous yield was 41.26%.4.The time and type of the addition of the heme-iron protective agent was studied,and the effects of the heme-iron protective agent of the single-,complex-,and hemoglobin-based formulations were determined.The results show that there was no significant change in heme content before and after blood cell disruption?P>0.05?,and there was a significant change in heme content before and after hemoglobin digestion.?P<0.05?,the content of heme was reduced by 60%after enzymatic hydrolysis,so heme iron was protected in the hemolysis process.Compare the effects of ferrous iron protection methods for single,complex,and hemoglobin formulations.In the single type of ferrous ion protection method,the yield of heme iron of carbon dioxide-filled and oxygen-insulation was 61.29%,which was 22.65%higher than that of the blank group,and the effect was stable.The natural antioxidant,ascorbic acid was better than niacinamide.The yield of heme iron of adding 0.02%ascorbic acid was 67.42%,which was 33.85 higher than that of blank group,but the effect was unstable.The addition of reducing agent sodium nitrite was better than sodium sulfite,and the yield of heme iron of adding 0.015%sodium nitrite was48.78%,which was 15.21%higher than that of blank group,and the effect was stable.In the composite ferrous iron protection method,the effects of CO₂+0.015%NaNO₂ group and CO₂+0.02%ascorbic acid+0.015%NaNO₂ group were all worse than the single ferrous iron protection method,and only 0.02%ascorbic acid+0.015%NaNO₂ group effect was better than a single type,and the heme iron yield reached 102.89%,which was significantly increased?P<0.01?,an increase of 69.32%compared to the blank,but the effect is not stable.The hemoglobin composite ferrous iron protection method is better than nitroso-hemoglobin in histamine-hemoglobin protection method,and histidine-hemoglobin hemolysin heme yield is 85.97%,52.4%higher than the blank,and the effect is stable.The yield of heme iron after 48 h of hydrolysis was equal to that of 0.02%ascorbic acid+0.015%NaNO₂.Considering comprehensively,the heme ferrous iron protection method that first prepares histidine-hemoglobin to form a stable heme ferrous state and then undergoes enzymolysis is selected,and the effect is good and stable.5.The enzymatic hydrolysate was successively passed through 10 KD and 3 KD filters.The enzymatic hydrolysate was divided into three molecular weight segments:>10 KD,3to 10 KD,<3 KD,and the heme iron/short peptides of<3 KD segments was the highest,which was 21.70%,and the ultrafiltration product was a heme-rich peptide.The heme iron yield was 83.89%6.The effects of porous starch content,core/wall ratio,and wall material concentration on the encapsulation efficiency of microencapsulated heme peptides in vacuum freeze-drying were studied,and the microencapsulation process was optimized.The optimized results of microencapsulation were:the amount of porous starch added was 1.5/1,the core wall ratio was 1/1.6,the wall material concentration was 4%,and the embedding rate could reach 100%.The resulting product heme iron peptide microcapsules are gray-brown,uniform color,no bloody smell,powder,uniform size,of which heme content was 13.73mg/g.Thermal stability is stronger than the ultrafiltration product.When heated to 80?at the temperature,the significant change in the content of heme was observed?P<0.05?.The yield of heme iron from the raw material was 78.45%?calculated from the content of heme in raw blood cells?.