Effects Of Glycosylation Modification On The Structure And Emulsifying Properties Of Gelatin

Gelatin(Gelatin,G)is a natural macromolecular polypeptide polymer obtained by breaking the hydrogen bond and electrostatic bond in macromolecular collagen under certain conditions and hydrolyzing to a certain degree of complexity.Gelatin is widely used in food industry production,medical drug manufacturing and cosmetic chemical products due to its rich and excellent functional properties.In the past actual production and life applications,its excellent commerciality and unique market value have been generally recognized by everyone,but its wide application in the field of food and medicine is limited by the content of its own proline and hydroxyproline.Low,low fracture strain,easy to be eroded by bacteria,weak emulsion stability and other shortcomings.How to solve this short board defect has become a research hotspot in the field of gelatin.Maillard reaction is one of the glycosylation modification methods,which can occur widely and naturally in food.Its principle is the reaction between the carbonyl compound of reducing sugar and the amino compound of protein.It can be carried out spontaneously,has the advantages of reliable safety,no chemical reagents,simple reaction conditions,and rapid reaction.The safety of carbonyl ammonia reaction provides a strong safety support for its application in improving the thermodynamic instability of gelatin in food emulsion systems,enhancing the functional properties of gelatin emulsification and expanding the application market.In this paper,sugar-gelatin complexes will be prepared by glycosylation,using pure B-type bovine bone gelatin as the main material.Specifically,the following work has been done:(1)The effects of monosaccharides with different carbon chain lengths on the structure and emulsifying properties of pure B-type bovine bone gelatin were investigated.Using the carbonyl ammonia chemical reaction between reducing sugar and gelatin,monosaccharides with different carbon chain lengths are used as single material variables,two p H values are selected,and the glycosylation modification with monosaccharides under the conditions of p H 3 and p H 9 is used.Gelatin was used as the base to load fish oil,and the monosaccharide-modified gelatin emulsion was prepared by homogenization.The structure and morphology of the modified gelatin were analyzed by digital camera,upright optical microscope,ultraviolet spectrophotometer,8% gel electrophoresis,ATRFTIR.The emulsification performance of the droplet size distribution,emulsion change,storage stability,solid-liquid phase change and other indicators were measured and analyzed.The results showed that the more carbon number of monosaccharides,the weaker the degree of glycosylation modification on gelatin.The degree of glycosylation of three-carbon monosaccharides was the highest at 55.97±0.15%,followed by fourcarbon monosaccharides at 20.53±0.21%.Glycosylation modification of gelatins did not obviously change the emulsion creaming index values(5.1%–8.4% at p H 9.0 and 25.8%–33.1% at p H 3.0).This work demonstrates that monosaccharide glycosylation can effectively modify the molecular structure of gelatin and improve the solid-liquid transition emulsification properties of gelatin.Provides useful information for understanding the effect of monosaccharide carbon number on gelatin.(2)The effects of different charged polysaccharides on the emulsification properties of pure B-type bovine bone gelatin were studied.Cationic polysaccharide(chitosan),neutral polysaccharide(locust bean gum),anionic polysaccharide(xanthan gum)and gelatin are selected for glycosylation reaction,and fish oil is loaded on the basis of polysaccharide-modified gelatin under the conditions of p H3 and p H9.Homogenize into emulsion.The structure and structure of the modified gelatin were characterized by digital camera,upright optical microscope,ultraviolet spectrophotometer,8% sodium dodecyl sulfate-polyacrylamide gel electrophoresis,ATR-FTIR and other characterization methods.Morphology analysis,by measuring the emulsion storage stability,droplet size distribution,emulsion change,droplet stability and other indicators,compared with pure gelatin emulsion,pure sugar emulsion.The results show that the p H of the gelatin solution after polysaccharide modification decreased from 9.0 to 8.26±0.25-8.63±0.18.Anionic polysaccharide had the best emulsification modification effect on gelatin,and the emulsification index was 1.09%±0.89% after 28 days storage at room temperature under p H9 condition.This work proves that polysaccharides can effectively modify the molecular structure of gelatin and improve the emulsification stability of gelatin through glycosylation modification.(3)The application of sugar-modified gelatin in milk beverage(milk tea)was studied.The sugar-modified gelatin was applied and used with different kinds of sugars,different additive ratios and different p H values,and compared its emulsification stability in milk beverages.The ordinary emulsion was prepared by the homogenization method and mixed with milk tea,and then homogenized again.And observe the difference of its emulsion stability and storage stability.The appearance of the milk beverage was observed by a digital camera,the microscopic morphology of the emulsion droplets was observed with an upright 40 x microscope,and the droplet particle size was measured and analyzed,and the droplet size was analyzed by Gaussian fitting.The results showed that the sugar-modified gelatin milk beverage had better storage stability and smaller droplet size than the unmodified gelatin milk beverage,and slowed down the aggregation of emulsion droplets.In summary,by studying the influence of the changes of each single factor on the structure and emulsifying properties of gelatin,the effects of monosaccharides with different carbon chain lengths and polysaccharides with different charges on the properties and structures of gelatin were clarified.By studying the storage stability of the emulsion,the change of the emulsion droplet size and the degree of emulsification,the influence of the type of sugar on the solid-liquid phase transition and the aggregation speed of the modified gelatin was clarified.It is proved that glycosylation is an effective method to improve gelatin emulsifying ability and emulsifying stability.An effective molecular modification method is provided for the modification and modification of gelatin,and the application prospect of the sugar-modified gelatin-stabilized fish oilloaded emulsifier in the food and pharmaceutical industries is expanded.