Physicochemical Assessment Of Msalais And Changing Law During Msalais Production

A Raman scaning method for Msalais was first constructed, with the following parameters: l75 m A laser energy, 50 um sliting aperture, focusing 1730, Side to side:165, up/down:20, 1s acquisition exposure time,0.5s preview acquisition time, 50 sample exposure times, moderate cosmic ray threshold, intelligent background. Method to detect total sugar was improved to be suitable for determination of total sugar in Msalais samples.23 Msalais samples from ten workshops and factories were scanned by Raman and UV-Vis spectroscopy,their physicochemical parameters of total sugar, total acid, total phenols, browing degree as well as color value, and sensory characters were measured. Compareing to cluster of physicochemical values, the data of optical spectrum of Ranma and UV-Vis and sensory value, Raman spectroscopy and UV-Vis spectra can be used in combination to differentiate different sample. The physicochemical cluster was better to classfy and slecte samples than the spectral cluster that can be a supplementary to quickly discriminate sample.The results of physicochemical assessment show the following: the samples from same workshops or factories had similar physicochemical values, but there were significant difference between samples from different workshops or factories. The total sugar content of samples from HB, ZF3(ZF2-3 fermented with adding of sugar) and M was higher than others. The total acid content of samples from HB and ZF1 was higher than others, and the content of samples from ZF4, ZF5 and M was lower than others. The total phenols content of samples from ZF1 and M was lower than that of samples from other workshops and manufacturers. The alcohol content of samples from ZF4 and M was below 10%, however, the alcohol content in the rest of samples was over 10%. The browning degree of samples from HB, ZF3 and ZF4 was stronger than others; the turbidity of samples from ZF4 was the highest, and that of M was the lowest; the color value of samples ZF4 was shown dark, the color of samples from HB, ZF2 and ZF4 red, the yellow of samples from ZF5 was lighter than other samples. The sensory analyses to 23 samples show that: samples from ZF2-3, HB and M(except M5 and M6) had higher sensory values than others, samples from ZF1, ZF3 and ZF4 in the middle, samples of ZF1-1 and from ZF5 low, 5 samples of Msalais in 2012 were lower than others because of long storage period. The total sugar was significantly correlated to appearance traits, and b* was significantly correlated to appearance and color.The representative samples during Msalais production screened by the analyses of Raman and UV-Vis spectral classification of all samples were used to physicochemical changing raw during Msalais production.The results showed that: total sugar, total acid, total phenols, browning degree and turbidity, glucose,fructose and chromaticity of the a* and b* significantly increased, the volatile acid was changed as "S" type,L* decreased significantly. Total sugar, glucose, fructose, total phenols, browning degree and a* value were a downward trend in alcohol fermentation and ripening process, alcohol content, volatile acid and L* value were on the rise, total acid and b* value were changed as "S" type. Total sugar, total acid, volatile acid,alcohol content, L* and b* had slightly change, total phenols and browning degree decreased, turbidity increased, a* value showed an increasing trend storage period. There was a significant difference in the concentration of the total acid, and there was no significant difference among the other indexes. There was no significant difference between different fermentation jars among the total sugar and alcohol, while other indicators showed significant differences. The browning degree, total phenol, turbidity, L* and a* hadsignificant difference between the ripening jars. There was no significant difference in the after-store jars and the after-store stage, while the other indicators had significant differences between the after-store jars.The prominent inflection points of T5(grape juice was concentrated for 2.5h after boiling) and T9(grape juice was concentrated for 4.5h after boiling) divided concentration process into three stages, the early strange(0h to 2.5h), middle stage(2.5h to 4.5h) and, late stage(4.5h to the end of concentration). Total acid,total phenols and browning degree could be used as main control index in early stage, total phenols could be used as a main control index in middle stage, total acid could be used as a main control index in lat stage.Total sugar could be used as an essential control index at the start and end of the concentration process. The prominent inflection points were 1d, 3d, 5d and 7d in fermentation process. Alcohol could be used as a judgment for end of fermentation process. Others could be used as control index to detection and control production of Msalais.The Raman characteristic peaks representing total sugar, alcohol and L* were 420cm-1, 876cm-1 and1084cm-1 respectively. The UV-Vis spectra characteristic peaks representing total phenol and a* were 217.5nm and 241.5nm. There were significant linear regression between these physicochemical indext and the characteristic peaks. The R2 of the regression model of alcohol content was 0.9143, the R2 of the regression model of total sugar, total phenols, browning degree and chromaticity were between 0.7 and 0.9, and that of total acid and volatile acid were below 0.5.