The Effects Of Processing Methods On Functional Characteristics Of Traditional Tartary Buckwheat Products

The contents and variations of main chemical elements in tartary buckwheat flour and its products, which were water, crude protein, amino acid, minerals, rutin, and quercetin, were determined. In our experiment, five traditional process methods were collected to comparing and studying the change of function elements contents and effect on function characteristics of traditional buckwheat products. The process methods were steamed, boiled, baked, fried and fermentation. During the course of vinegar fermented, the anti-oxidation ability of each stage was analyzed. Experiment on white mice was also the important part of our research to studied on the effect of tartary buckwheat vinegar on the weight reducing and antilipemic function. Its results were as follows:1. Liquid reflow fermentation was determined as optimum process of tartary buckwheat vinegar. This process was simple and the acidity reached 48.9g/L after 24h～30h of acetic.2. The content of water, crude protein, amino acids and minerals of tartary buckwheat residue were all higher than that of flour. Analysis amino acids contents of flour and residue, the maximum content was glutamate and the minimum was cystine and methionine. Though the amino acids content of residue was higher than that of flour, the composition did not change notably. For minerals content of flour and residue, K was the highest as to macro element and Mg the lowest as to micro elements.3. Rutin and quercetin content of traditional buckwheat products were determined by HPLC. Under the chromatography conditions we had selected, the characteristic peak of rutin and quercetin achieved a good separation effect. The HPLC graph indicated that rutin was the main form of flavonoids in buckwheat flour but it was quercetin in dough and traditional products. It was showed that mostly rutin was changed into quercetin in the process of buckwheat flour dough because of water participation. Comparison of the effect on rutin and quercetin content of different traditional products, boiled had a small influence while baked and fried had a significant effect.4. Rutin and quercetin content all declined in every stage of vinegar fermentation, especially in incipient period (liquefacient), the loss of rutin was great and partial of rutin transformed to quercetin.5. Flour, residue and traditional products all had anti-oxidation ability, and residue had highest the scavenging DPPH free radical ability and anti-oxidation ability among the three. Analysis and compared function characteristics of different traditional buckwheat products, the potency of scavenging DPPH free radical and anti-oxidation ability was extruded noodle > steam bread > pancake > crispy fried food. This results indicted that process methods were influenced the scavenging and anti-oxidation ability, and boiled process had the smallest influence.6. In the process of tartary buckwheat vinegar fermentation, the scavenging DPPH free radical ability of each stage product was vinegar > sugar decomposition > liquefaction liquid > yeast hydrolyzate. And the total anti-oxidation ability was sugar decomposition > vinegar > yeast hydrolyzate > liquefaction liquid.7. In the experiment on white mice, some indexes, including the weight growth velocity, total fat, fat coefficient, cholesterol level, triglyceride, low density lipoprotein cholesterol (LDL-C)and atherogenic index, were determined. All indexes of nutrition group had increased significant than that of normal group(P<0.01), indicated that animal weight-reduce model and antilipidemic model we used was feasible and successful. Compared the results of weight growth velocity, total fat and fat coefficient between nutrition group and vinegar-feed group, the vinegar-feed group had lower level, showed that tartary buckwheat vinegar would help to restrain the weight growth and adipose tissue formation. The content of cholesterol level, triglyceride and atherogenic index of vinegar group were also lower than that of nutrition group, indicated that buckwheat vinegar could prevent arteriosclerosis, helpful in reducing blood-fat content in the serum.