The Preparation And Application Of Artificial Casing Based On Gelatin

Sausage is the material for shaping and packaging sausage products.The quality of sausage affects the quality of meat products and consumers eating experience directly.Developed countries such as the European Union have stipulated that production is not allowed due to the insecurity and environmental pollution of plastic casings.The production of natural casings is time-consuming and labor-intensive.The production of natural sausage clothes is time-consuming and laborious,with high rate of defective products,serious waste and shortage of resources.Artificial sausage is a safe and environmentally friendly edible product with uniform thickness,adjustable size according to demand,small storage and transportation space and high technology content.There are many problems in artificial casings produced in China,such as complicated production process,immature technology,difficult condition control and low strength.The price is higher compared with imported casings.In this paper,protein,polysaccharide and other substances are used as matrix to make casing film by adding additives.The formula is continuously optimized to improve the production process and reduce the cost while ensuring the performance of the product and the market.The research results of the project are as follows:(1)The gelatin was used as a matrix to cast film.The mechanical properties,barrier properties,cooking resistance,grease barrier ability and light transmission performance of the film were determined by single factor test.The effects of gelatin and chitosan ratio,glycerin content,cinnamaldehyde content and Tween 80 on the properties of the film were investigated.According to the single factor test results,orthogonal test and performance weighted scoring method were used to obtain the optimal formula ratio,and the film was characterized by infrared spectroscopy,thermal stability and microstructure analysis.The study found that the overall score was 81.5 points.The tensile strength reached 48.9 MPa and the elongation at break was 16.7%,which basically met the strength requirements of the casing,which was comparable to the commercial collagen casing.The barrier performance is good,especially the grease barrier coefficient is extremely low and the water resistance can also meet the cooking requirements of the sausage.(2)The food additive vanillin was chosen as cross-linking agent.After determining the optimal ratio of other adjuvants,the influence of vanillin addition on the main properties of the film was investigated.According to various indexes,it is concluded that when the added amount of vanillin is 12% of the film matrix,the comprehensive performance is the best.At this time,the tensile strength of the film reaches 24 MPa and the elongation at break is 25.31%.The single factor experiment explored the effect of microcrystalline cellulose oxidation process parameters on the yield and aldehyde content after oxidation.The cellulose before and after oxidation were characterized.And the most oxidant solution pH and concentration,reaction temperature,reaction time,highest yield and aldehyde group content were obtained.The oxidized cellulose was prepared by using the optimal oxidation process parameters and was added into the gelatin-vanillin membrane to discuss the effect of the added amount on the properties of the film.It was found that the addition of an appropriate amount of oxidized cellulose significantly enhance the mechanical properties of the film.The maximum tensile strength reaches 42.3 MPa,which is nearly double that of the unadded one.The other properties are not affected by the large negative correlation.The performance of the item meet the requirements of the casing.(3)The gelatin-vanillin film with the optimum amount of oxidized cellulose and the collagen casing purchased by the mall were selected for the filling and storage of sausages.The preservation effect of the two casings under specific environmental conditions was studied.The freshness of the sausage is judged by periodically measuring the sensory quality,microbial index,water activity,texture and peroxide value of the sausage.Comparison of the two sausages found that the gelatin casing wrapped sausage index was significantly better than the collagen casing during the same storage time.After storage for 60 days,the indexes of sausages wrapped in collagen casings changed significantly and occurred rancidity.The indicators of gelatin-based casing sausages are still good which were all within the national standard or standard range.The sensory score is above 10 points,which is acceptable to consumers.