Preparation Of Palm-based Instant Edible Mushroom And Vitamin D Calcium Soft Capsules And Study On The Interaction Between VD₃ And BSA

This article mainly studies the development and storage stability of palm-based instant edible mushroom and vitamin D calcium soft capsules,as well as the interaction between vitamin D₃and bovine serum albumin（BSA）to understand the metabolic process of vitamin D₃in animals.The main research contents and experimental results are as follows:1.Lentinus edodes and Boletus were used to produce a palm-based instant edible mushroom product.Optimize the formula and process conditions of instant edible mushroom through single factor test and response surface methodology,and then conduct the comparative analysis of the physical and chemical properties,composition and storage stability between palm-based instant edible mushroom and commercially available instant edible mushroom（Red soil garden and Lanye）.The results showed that the optimal formula and processing parameters of instant edible mushroom would require palm olein with a melting point of 5℃as a frying oil,a mass ratio of palm olein to mushroom of 6.3:1,a frying time of 5.0 min and a frying temperature of 138℃;Compared with the commercially available instant edible mushroom,the palm-based instant edible mushroom had the largest protein content（8.3 g/100g）and crude polysaccharide content（1.81 g/100g）,and had the lowest acid value.The water content is much greater than that of the instant edible fungus in the red soil garden.and the acid value of palm-based instant edible mushroom was the lowest.The water content of the instant edible mushroom and the Lanye was much greater than that of the Red soil garden.In addition,the crude polysaccharide content of the three instant edible mushroom was not much different and was negatively correlated with the protein content.The experimental results of the storage stability showed that the palm-based instant edible mushroom had a good flavor after accelerating storage at a constant temperature of 40℃for 90 days,and sensory quality was better than that of the two commercially available instant edible mushroom.Good storage stability can provide a certain theoretical and technical basis for the industrial production of instant edible mushroom.2.Calcium carbonate and Vitamin D₃were used to produce a palm-based vitamin D calcium soft capsules product.Optimize the composition ratio of the content of the vitamin D calcium soft capsules through single factor test and response surface methodology,as well as conduct the comparative analysis of the physical and chemical properties,functional component and storage stability between palm-based vitamin D soft capsule and commercially available vitamin D soft capsule（Unica）.The results suggested that the optimized formula of palm-based vitamin D calcium soft capsules was:58%5℃palm oil and 42%（w/w）soybean oil was used as a matrix.The ratio of the calcium powder（400 mesh）to the oil was 2:1（g/g）,and the amount of suspended beeswax accounted for 3%（w/w）of the matrix.And its physical and chemical indicators were consistent with the National standard of China,and the calcium content（293 mg/capsule）and vitamin D₃content（2.89μg/capsule）were within the allowable dosage range for adults;Results obtained from storage stability experiment showed that the sensory properties,disintegration time limit,total number of colonies,peroxide value,calcium and vitamin D₃content of palm-based vitamin D calcium soft capsule and commercial sample remained basically stable during storage.And the acid value increased slightly,but still met national standards.The peroxide value and acid value of palm-based vitamin D calcium soft capsules both were lower than those of commercially available product.3.With bovine serum albumin as the model protein,the binding mechanism of vitamin D₃with BSA and the structural changes of BSA in the environment under simulated physiological condition（pH 7.4）were investigated by fluorescence and ultraviolet-visible absorption spectroscopy combined with molecular simulation.The results suggested that VD₃could quench the endogenous fluorescence of BSA in a static quenching manner.ΔH°<0 andΔS°>0 indicated that the combination between VD₃and BSA was mainly through hydrogen bonding and hydrophobic force and there was only one binding site（n≈1）,and the binding constant was 2.55×10⁵L mol^-1（298 K）;The results of ultraviolet and synchronous fluorescence experiments showed that the binding of VD₃to BSA resulted in the conformation changing of BSA,the hydrophobicity decreasing and the polarity increasing around the tyrosine residues of BSA.Molecular docking results intuitively showed that VD₃binds to the calyx of BSA molecule and forms a hydrogen bond with BSA.It further verified the force type between VD₃and BSA.