Analysis Of Quality Changes Of Chicken Soup During Storage Based On LF-NMR Technology And Research On The Differentiation And Identification Of Different Chicken Soups

Chicken soup processed by traditional methods contains high levels of nutrients such as protein,fat,vitamins and trace elements..However,long-term storage of chicken soup is susceptible to spoilage due to the influence of storage temperature and surrounding environmental factors,resulting in nutrient loss and flavor decline.With the increasing demand for chicken soup in the catering market,industrially produced concentrated chicken soup products are also increasing,but the quality and brand are mixed;and some merchants use concentrated chicken juice to blend to pretend to be chicken soup,and use chemical additives to imitate chicken soup.The phenomenon of flavor products is serious.Affect consumers' health and reduce consumers' trust in food safety.Low-field nuclear magnetic resonance(LF-NMR)technology is an emerging detection technology in recent years.It has the advantages of rapidity,accuracy,stability and safety.Combined with multivariate mathematical analysis technology,it has been widely used in food quality detection,food blending False identification and food storage analysis.This topic aims to explore the application of LF-NMR technology in the detection of broth(chicken soup),using LF-NMR technology,combined with traditional physical and chemical detection and multivariate data analysis methods,to explore the quality change law of chicken soup during storage,identify and distinguish different varieties of chicken soup and Adulterated Chicken Soup.The main research contents and conclusions are as follows:1.Use LF-NMR technology to detect the quality change of chicken soup during storage in refrigeration(6?)and freezing(-20?),and analyze physical and chemical indicators and sensory evaluations such as chicken soup color difference,pH,TBARS value and TVB-N value.Correlation of indicators with LF-NMR relaxation characteristic data and sensory evaluations.The results showed that the color difference(L*value and b*value)and pH of refrigerated chicken soup during storage showed a significant downward trend,while the TBARS value and TVB-N value showed a significant upward trend;the color difference and pH of frozen chicken soup did not change significantly during storage.,TBARS value and TVB-N value showed a slow upward trend;the sensory score of refrigerated chicken soup decreased more significantly than that of frozen chicken soup.The relaxation time T2 and peak area S of both refrigerated and frozen chicken soup showed a downward trend,and the relaxation data of refrigerated chicken soup decreased more significantly than that of frozen chicken soup.Through correlation analysis,it was found that there was a strong correlation between the physicochemical parameters of chicken soup,NMR parameters and food sensory evaluation,indicating that it is feasible to use LF-NMR relaxation data to characterize changes in chicken soup storage quality.2.Taking original chicken soup,concentrated chicken soup(Wu Tai Po brand and Shi Yunsheng brand)and blended chicken soup(Nong Tang Bao and Totole chicken juice)as the research objects,the general nutritional components(crude fat,crude protein,solids)of different chicken soups were analyzed.The content,free amino acid content and composition,and sensory evaluation were analyzed and compared,and different chicken soups were detected and distinguished by using LF-NMR technology combined with principal component analysis.The results showed that the nutritional properties and sensory scores of the original chicken soup were higher than those of other chicken soup products.Different chicken soup products contained 17 kinds of free amino acids,and the types were the same,but the content and composition of free fatty acids were significantly different;the nutritional properties of different chicken soups were similar to LF-There is a strong correlation between NMR relaxation data and food sensory scores;LF-NMR technology combined with principal component analysis can clearly distinguish different types of chicken soup products.3.In order to further explore the ability of LF-NMR technology to distinguish and identify chicken soup,different proportions of blended chicken soup were mixed into original chicken soup,and LF-NMR technology was used to detect different proportions of mixed chicken soup,and the principal components of relaxation characteristic parameters were calculated.Analysis and cluster analysis showed that the mixed chicken soup with different proportions could be clearly identified and distinguished on the principal component score map and cluster analysis dendrogram,and had good consistency with traditional sensory evaluation.It shows that it is feasible to apply low-field nuclear magnetic resonance technology to adulteration identification of chicken soup.