| According to the optical activity,there are L-lactic acid, D-lactic acid and DL-lactic acid.There is only L-lactic acid dehydrogenase in human body,and L-lactic acid may be metabolized. L-lactic acid may promoted the absorption of protein and tantalum,and plays a vital role in enhancing the intelligence and growth of child,strengthening the immunity of organism and the disease-resiStant ability.However,the accumulation of D-or DL-lactic acid in human body,the acidic nosohemia,acidosis and high uric acid value may be caused. However,the FAO and WHO prescript clearly:The D-lactic acid mean intake of a man one day was confined to less than 100mg/kg..Currently,our country market's fermentated beverage is much of DL-lactic acid.Therefore,using high-produced lactobacillus to ferment the enzymolysis fluid of grain,produce enriched L-lactic acid fermented grain beverage, and develop function lactic acid products, have an important meaning for raising people's food quality.With rice,millet,black rice,maize as raw material,Lactobacillus bulgaric,Streptococcus thermophilus,St-UNs9,Lactobacillus casei,Lactobacillus acidophilus was taken as starter culture,to study the processing technology of enriched L-lactic acid fermented grain beverage.Through screening of high producted L-lactic acid starter culture,ingredient analysis around the fermented enzymolysis fluid of grain,the fermentation condition of enriched L-lactic acid fermented grain beverage was optimized by four-factor second order rotation combination experiment, the result of study was as follows:1,The optimal experiment on different high producted L-lactic acid starter culture of fermented grain beverage. Take the total acidity and the L- lactic acid output as standardization,. four kind of grain enzymolysis fluid separately selected four kind of different lactobacillus starter culture to carry on the fermentation experiment.Obtained the conclusion: In the 0~21h fermentative process, (1) The black rice the maize enzymolysis fluid selected Lactobacillus bulgaric and Streptococcus thermophilus (1:1) for the best starter culture, the total acidity maximum respectively was 90°T, 95°T, the L- lactic acid output maximum respectively was 17.21mg/mL, 18.56mg/mL. (2) The millet enzymolysis fluid selected Lactobacillus acidophilus for the best starter culture, the total acidity maximum was 75°T, the L- lactic acid output maximum was 14.89mg/mL. (3) The rice enzymolysis fluid selected Lactobacillus bulgaric and mutafacient Streptococcus thermophilus St-UNs9 (1:1) for the best starter culture,the total acidity maximum was 108°T, the L-lactic acid output maximum was 21.41mg/mL.2,The oligosaccharide content determination and analysis around the fermentation of four kind of grain enzymolysis fluid.Through determinated and analyzed oligosaccharide around the fermentation of four kind of grain enzymolysis fluid,the finding was: After the fermentation of black rice enzymolysis fluid by Lactobacillus bulgaric and Streptococcus thermophilus,the glucose content changed to be the biggest, reduced 1.27mg/mL, the malt sugar reduces 1.46mg/mL.After the fermentation of millet enzymolysis fluid by Lactobacillus acidophilus,the glucose content reduced 0.14mg/mL, the malt sugar reduced 1.67mg/mL. After the fermentation of rice enzymolysis fluid by Lactobacillus bulgaric and mutafacient Streptococcus thermophilus St-UNs9, the glucose and the malt sugar changed to be the smallest, reduces 0.08mg/mL. After the fermentation of the maize enzymolysis fluid by Lactobacillus bulgaric and Streptococcus thermophilus, the glucose and the malt sugar change was smaller, separately reduces 0.14mg/mL and 0.66mg/mL. After four enzymolysis fluids fermentation, the oligosaccharide content change was small.3,The determination of fermentation process parameter on enriched L-lactic acid fermented grain beverage. Took four kind of grain respectively as raw materials, added high producted L-lactic acid grain starter culture. In the foundation of fermentation time, fermentation temperature, soybean isolate protein dosage,starter culture dosage four single factors experiments, L- lactic acid content and sense organ quality of fermented grain beverage was synthesis evaluation standard. Through four-factor second order rotation combination experiment the fermentation condition was optimized as follows: The rice enzymolysis fluid added 6% soybean isolate protein, added 2.6% starter culture , 43.9℃fermented for 9h, the L- lactic acid content was 12.15mg/mL,the sensory Score was 91. The millet enzymolysis fluid added 4.2% soybean isolate protein, added 3.1% starter culture , 39.6℃fermented for 9h, the L- lactic acid content was 11.91mg/mL,the sensory Score was 79.The black rice enzymolysis fluid added 6% soybean isolate protein, added 3% starter culture , 43.5℃fermented for 9h, the L- lactic acid content was 9.0mg/mL,the sensory Score was 85. The maize enzymolysis fluid added 2.8% soybean isolate protein, added 4.2% starter culture , 41.2℃fermented for 9h, the L- lactic acid content was 8.17mg/mL,the sensory Score was 88. |
