Studies On Preparation Of Calcium Tablets Containing Lactic Acid Bacteria From Pacific Cod Bone Fermented By Lactobacillus Reuteri

Calcium plays an important role in the growth and development of the human body,and people of all ages need to supplement calcium as a nutrient.At present,Ca CO₃ is mainly used as a calcium supplement,but the absorption rate of Ca CO₃ by the human body is not very high.Fish bones are rich in nitrogen and calcium resources,and fish bone calcium belongs to Ca₃（PO₄）₂,which has little side effect on the human body and is a cost-effective natural calcium source.However,the calcium in fish bones is usually composed of Ca HPO₄ and hydroxyapatite.It exists in crystalline form,making it ineffective for efficient use.LAB is a general term for a class of Gram-positive bacteria,named for their ability to ferment carbohydrates to produce lactic acid.Studies have shown that LAB have physiological functions such as regulating intestinal flora,enhancing human immunity,and anti-oxidation,and are widely used in various food processing.Their fermented foods are considered functional foods.However,for LAB to play their role,they need to reach the intestinal tract smoothly and reach a certain number.In this paper,L.reuteri BMBL 0612 was selected as the research object and its properties were determined.Gadus macrocephalus is rich in resources and has a large fishing volume.It is one of the main large-scale marine economic fish species in China.During its processing,it will produce leftovers such as fish skin,fish bones and fish heads.In order to realize the effective utilization of calcium in fish bone,first,fish bones were degreasing at high temperature,beating and enzymatically hydrolyzed,and then BMBL 0612 was used to ferment the enzymatic hydrolysate of fish bones.The fermentation broth and fermented fish bone were freeze-dried into powder,sieved through 60 mesh sieve,added with auxiliary materials magnesium stearate,microcrystalline cellulose and crosslinked polyvinylpyrrolidone,and granulated with dry powder to make calcium tablets containing lactic acid bacteria.The optimum technological conditions for tablet forming were determined through single factor and response surface experimental analysis.The results were as follows:（1）BMBL 0612 has certain hydrophobicity,self coagulation rate and copolymerization ability.It has varying degrees of sensitivity to five antibiotics,medium sensitivity to penicillin and tetracycline,low sensitivity to ceftriaxone,and no sensitivity to gentamicin and streptomycin.BMBL 0612 has certain tolerance to low acid environment;In MRS medium with mass fraction of 0.3%bile salt,the survival rate was 78.64%at 6 h,and it could grow and reproduce under 8%high osmotic pressure.BMBL 0612 has no hemolysis and no pathogenicity with hemolytic characteristics.The growth curve showed that the fermentation could reach a stable period in about 13 h,and the p H value of fermentation broth decreased rapidly in 0～12h,and then the p H value stabilized at about 4.（2）The results showed that the crude protein content of Pacific cod bone was23.98±1.12%,and the calcium content was 22.41±1.49%.Taking the total number of colonies and the content of free calcium in the fermentation broth as indicators,the optimum enzymatic hydrolysis conditions were determined as follows:enzymolysis with flavor protease,temperature was 50℃,p H was 6.0,enzymatic hydrolysis time was2.5 h.Taking the soluble calcium content in the fermentation broth as the index,the optimal fermentation process was obtained through single factor and orthogonal experiments.The addition amount of fish bone mud was 42 g/L,the inoculation amount of bacteria was 4%,the addition amount of glucose was 25 g/L,and the initial p H value of fermentation was 6.0.Under these conditions,the content of soluble calcium was970.95±57.51 mg/L,and the calcium conversion rate was 10.32±0.01%.（3）Taking the hardness and weight difference of tablets as the index,through single factor and response surface experimental analysis,the optimal process conditions for tablet molding were determined to maximize the hardness value of tablets.When the weight difference was the smallest,the addition amount of magnesium stearate was1.4%,microcrystalline cellulose was 1.0%,and the addition amount of cross-linked povidone was 1.0%.The validation test was carried out under these conditions.The difference of tablet weight was 4.3%and the hardness of tablet was 7.01±0.34 kg.Under the optimum conditions of tablet forming,the content of calcium and lactic acid bacteria in calcium tablets were determined.The content of calcium in calcium tablets was 50±1.03 mg/g and the content of lactic acid bacteria in calcium tablets was8.01±0.15 lg CFU/g.In conclusion,through the determination of the properties and growth curve of BMBL 0612,it is convenient to understand the characteristics of the strain for subsequent use.The fish bones were treated by high-temperature degreasing,beating and enzymatic hydrolysis for the preparation of culture medium.The fermentation of LAB can convert part of calcium in fish bones into soluble calcium and promote the absorption of calcium by the body.In addition to being used as calcium supplement,the calcium tablets containing lactic acid bacteria developed in this study can also regulate the balance of intestinal flora,enhance immunity and promote good digestion.At the same time,it also helps to improve the comprehensive benefits and economic added value of fish bone waste processing.