| Red Sour Soup,As one of the most representative “Sour food” in Guizhou province,red sour soup is mainly made by natural fermentation of fresh wild small tomato and red pepper with traditional techniques,because of its bright color,acid taste mellow,fragrant and palatable characteristics,by the local people and domestic and foreign diners favor.At present,the development of red sour soup industry has made some achievements,but the rapid and healthy development still faces many problems.The production quality control of red sour soup is still not perfect,the main problem is the lack of quality control of the production process and batch differences of raw materials.Fermentation is the key step in the production of red sour soup,and the quality control in each stage of production is still the traditional evaluation method.For example,according to the p H value of the fermentation process and the product phase,the production quality difference caused by the change of production conditions between batches is completely ignored,and the active ingredient in the system is only detected at the end of the process,lack of real-time monitoring and feedback on quality control indicators.This experiment provides some data support for the quality control of red sour soup by the rapid and non-destructive real-time monitoring of red sour soup decoction with near-infrared technology.Near Infrared Spectrometry(NIRS)is a high-tech Near-Infrared spectroscopy technique that is fast,real-time,low-cost and does not damage samples.This paper discusses the application of NIRS and Chemometrics in the quality control of red sour soup production process to ensure the uniformity and stability of the quality of red sour soup production process.Organic acids are the key to predict and evaluate the maturity,production and quality control of food.In this study,the analysis method of effective components was established by analyzing the content of organic acids and other index components in the production process of red sour soup,to establish an accurate and reliable Quantitative analysis model in conjunction with NIRS to provide a methodological basis for rapid analysis and on-line quality monitoring of the process,the contents and results of this study are as follows:1、Establish a determination method of organic acid content in red sour soupTaking red sour soup as the research object,eight kinds of organic acids were derivatized by methyl ester method,a Gas chromatography was established for the simultaneous determination of eight organic acids in red sour soup decoction with naphthalene as internal standard.The results show that the method has good precision,repeatability and stability.2、Determination of different brands of red sour soup physical and chemical indicatorsThe established organic acid Gas chromatography was used to determine the content of organic acids in all major brands of red sour soup,and the p H and total acids were determined by conventional methods.The results showed that the p H of red sour soup decoction ranged from 3.19 to 3.88,and the total acid ranged from 14.04 to 30.97.Lactic acid,acetic acid and citric acid accounted for 88.8% ～ 98.8% of the total organic acids in red sour soup decoction.Lactic acid accounted for 63.8% ～ 23.5% of the total organic acids.Different brands of red sour soup organic acid types and their contents vary greatly.This research has laid a foundation for further study of red sour soup and provided reliable data support.3、study on the fermentation process of red sour soupnatural fermentation and constant temperature fermentation were used to ferment red sour soup,and physical and chemical indexes(organic acid,total acidity,reducing sugar,PH)were detected periodically.The results showed that the p H and reducing sugar decreased gradually,and the total acid increased.After 5 days,a lot of sugar compounds were consumed and converted into organic acid.The content of organic acids increased gradually during the fermentation process,and there were some differences in the types and contents of organic acids between the two groups.The sour taste of red sour soup before fermentation mainly came from citric acid and malic acid.With the process of fermentation,the lactic acid and acetic acid in two groups of red sour soup gradually increased,the content of citric acid decreased first and then increased,this study can provide data support for the establishment of near infrared quantitative model of red sour soup decoction,and lay a foundation for further research on quality control of red sour soup decoction.4 、 Establish near-infrared spectroscopy for the analysis and identification of different brands of red sour soupUse TQ Analyst software to study the NIR of different brands of red sour soup.A rapid,simple and non-destructive method for the identification of red sour soup by near-infrared spectroscopy was established through a series of parameter optimization.The results showed that the samples of 5 brands could be identified effectively with an accuracy rate of 96.67%.5、To establish a quantitative model of the physical and chemical indexes of near-infrared spectroscopy acid soupThe quantitative models of acetic acid,lactic acid,succinic acid,total acid and reducing sugar were established by spectral pretreatment,selection of spectral range and different regression methods.The final results show that the optimal parameters are as follows: MSC+ S,D +S,G(5,5),MSC+F,D+N,D(5,5),MSC+F,D+N,D(5,5),MSC+S,D+N,D(5,5),MSC+F,D + N,D(5,5);RMSEC and RMC-r were0.9537、0.315;0.9116、0.454;0.9055、0.0552;0.8956、1.78;0.9080、0.276,respectively.The established 5 quantitative models of acetic acid,lactic acid,succinic acid,total acid and reducing sugar can be well applied in practice,and provide some theoretical support for the content prediction of red sour soup. |
