Calcium Binding Properties Of Deamidated Sunflower Seed Peptides And Peanut Peptides And Their Biological Effects On Calcium Absorption

This paper deals with the deamidation of sunflower proteolytic peptides,peanut proteolytic peptides(hereinafter referred to as sunflower peptides,peanut peptides),and studies the changes of calcium binding and digestive stability of sunflower peptides and peanut peptides before and after deamidation and analyzes them.Calcium binding properties.In addition,a growth mouse model was used to study the biological effects of sunflower seed peptides and peanut peanut calcium complexes on promoting calcium absorption and bone quality in mice,and to clarify the effects of calcium supplementation on growing mice.Firstly,the sunflower peptide and peanut peptide were deamidated with glutaminase.After deamidation,the calcium binding of sunflower peptide was increased from 83.5 mg/g to 98.20 mg/g,and the calcium binding of peanut peptide was 110.8 mg/g.g increased to 135.26 mg/g,indicating that deamidation treatment can significantly increase the calcium binding of sunflower seed peptides and peanut peptides,and that deamidated peanut peptides have higher calcium binding capacity than sunflower seed peptides;pepsin and trypsin were used.The deamidated sunflower peptides and peanut peptides were digested in vitro to investigate their digestion stability.The results showed that the retention ratio of calcium bound peptides after deamidation was increased from 62.40% to 86.29%,and the calcium binding capacity of peanut peptides was maintained by The increase of 74.05% to 84.15% indicates that deamidation treatment can significantly improve the digestion stability of sunflower peptides and peanut peptides and that deamidated peanut peptides have higher digestive stability than sunflower peptides.The calcium binding properties of deamidated sunflower peptides and peanut peptides were further analyzed by scanning electron microscopy,Fourier transform infrared spectroscopy,and ultraviolet spectroscopy.The results of scanning electron microscopy showed that the deamidated sunflower peptides and peanut peptides microstructure were all determined by the addition of calcium.The lamellar structure is aggregated into a granular structure;Fourier transform infrared spectroscopy results show that the characteristic absorption peaks of carboxyl groups and amino groups are changed after the combination of sunflower seed and peanut proteolytic peptides with calcium,and the deamidation treatment causes the characteristic absorption of carboxyl groups and amino groups.The shift of peaks to high frequencies indicates that the major calcium binding sites of deamidated sunflower seeds and peanut peptides are carboxyl and amino groups.Ultraviolet spectrum analysis showed that the characteristic groups containing oxygen atoms in sunflower seeds and peanut peptides coordinated with calcium.After deamidation treatment,the peak area further increased,and the maximum absorption peak was red-shifted,indicating that proteolysis of sunflower seeds after deamidation The coordination between the O atom of the peptide and the calcium ion is further enhanced.Further use of a growing mouse model to study the biological efficacy of deamidated sunflower seeds,peanut peanut calcium composites(hereinafter abbreviated as sunflower seeds,peanut peptide calcium composite)on promoting calcium absorption and bone quality in mice.The results showed that the apparent calcium absorption rate of the sunflower seed and peanut calcium peptide complex group was significantly higher than that of the blank group and the calcium carbonate group,which was similar to the CPP group.The femoral bone density of the mice was measured by a double shot bone density meter and the sunflower seeds were found.The bone mineral density in the low,middle,and high doses of Peanut Peptide-Calcium Complex was significantly higher than that of the blank and calcium carbonate groups and similar to that of the CPP group.The effect on bone mineral density was dose-dependent;the mouse femur was treated with a texture analyzer.Measured by mechanical parameters,it was found that the maximum fracture force of the femur in the low-,medium-,and high-dose groups of sunflower seeds and peanut peptide calcium composites was significantly higher than that of the calcium carbonate group and the blank group,and the bending toughness of the bone was also significantly increased.The enhancement of flexural toughness presented a dose-dependent effect.The microstructure of the femur surface of mice was analyzed by scanning electron microscopy.It was found that the sunflower seeds and peanut peptide calcium complexes can significantly enhance the microscopic structure of the bone surface and reduce the flaky structure and fracture of the bone surface.The structure forms a closely-aligned skeleton surface structure.Using a microplate reader to measure serum biochemical parameters in mice,it was found that serum calcium levels in the low,medium,and high doses of sunflower seeds and peanut peptide calcium complexes were significantly higher than those in the calcium carbonate group and the blank group,and serum phosphatase levels were also measured.Significantly lower than the blank group and calcium carbonate group.The above results indicate that deamidated sunflower seed peptide and peanut peptide calcium complex can promote calcium absorption in mice and enhance bone mass accumulation,effectively increase bone density,improve the surface structure of bone,increase serum calcium content and decrease serum phosphatase content,which promotes calcium Absorption is better than calcium carbonate,similar to the effect of CPP on calcium absorption.