| As a by-product of sheep,sheep liver has rich yield and high nutritional value,but the current processing and utilization and value-added potential have not been fully utilized.In this study,sheep liver was used as the main raw material,and after seasoning,homogenization,canning,steaming,degassing,capping,sterilization,etc.,a sheep liver paste that can be eaten directly or accompany meals,and the process was further optimized through experiments and quality analysis.Sheep liver sauce has liver odor,loose texture,rough taste and graininess.In this experiment,ultra-high pressure technology was used to improve its quality and flavor.The experimental results are as follows:Through single factor experiment and orthogonal experiment,the basic seasoning and quality improver formula is optimized: Through sensory evaluation,it is concluded that when the salt content is 2.5%,white sugar is 2.0%,black pepper is0.8%,and white pepper is 0.6%,the liver sauce is moderately salty,the flavors of various seasonings are fused with each other,and it has the unique flavor of sheep liver,and has the highest score.When the amount of olive oil is added at 3%,linseed gum 0.3%,sodium caseinate 1%,the sheep liver paste is bright in color,uniform in texture and delicate in taste.Analysis of the nutritional components of the sheep liver paste made with the best technology shows that the protein content is 16.36%,the fat content is 10.38%,and it contains unsaturated fatty acids such as linolenic acid,arachidonic acid,and DHA.The value is similar to that of commercially available foie gras.In this experiment,the sheep liver paste was treated with different ultra-high pressures(0MPa,200 MPa,300MPa,400 MPa,500MPa),and the results showed:Different ultra-high pressure pressure has a significant effect on the total amino acid content of sheep liver sauce(p<0.05),and the free amino acid content of the200 MPa treatment group is the highest.As far as individual amino acids are concerned,except for glycine,methionine,tyrosine,and phenylalanine,the content of most amino acids has undergone significant changes.The content of glutamic acid in many free amino acids has changed significantly(p<0.01),and glutamic acid is the most important umami-flavored amino acid.Ultra-high pressure treatment has an effect on some fatty acids.Among them,palmitic acid,palmitoleic acid,oleic acid and DHA have significant changes(p<0.05),and stearic acid and linoleic acid have extremely significant changes(p<0.01).When the ultra-high pressure is 200 MPa,the PUFA/SFA content of sheep liver paste is the highest(0.8470),that is,the nutritional value is the highest.When the pressure condition is 300 MPa,the content of SFA+MUFA is the highest(67.61)and the flavor is the best.Therefore,from the perspective of fatty acids,UHP pressure does improve the nutrition and flavor of sheep liver paste.Electronic tongue analysis revealed that there was no significant difference in the taste of the non-UHP treatment group and the UHP treatment group.The sensory evaluation results showed that the UHP pressure had an effect on the flavor of the sheep liver sauce.When the high pressure pressure is 500 MPa,the sensory score of sheep liver paste is the highest,followed by 300,400,200 and 0 MPa.Compared with the group without UHP treatment,the UHP treatment group has improved aroma,finer texture and better taste.Based on the above experiments,it can be seen that the nutrition and flavor of sheep liver paste have been improved after ultra-high pressure treatment,and the overall acceptability is better.This research strengthens the promotion of sheep liver products with similar nutritional value to foie gras,provide experimental data for the development of green and pollution-free,high-safety,nutritious and easy-to-eat sheep liver products,and provide technology for the factory production and product promotion of liver products in the later period. |
