| Lotus root is a kind of aquatic vegetable that people eat more in daily life,people love it because of its crisp taste and rich nutrition value.However,the time to market of lotus root is concentrated,and it is easy to lose the value of commodity and nutrition because of the phenomenon of discoloration and mildew,this has led to the time limitation of fresh lotus root materials on the market.At present,the lotus root products are mainly salted lotus root slices,lotus root flour,lotus root juice drinks and so on,which limits the variety of lotus root products.In order to improve the diversity of lotus root products and promote the industrialization process of lotus root,developing a new type of lotus root product was the key point in this research.In this experiment,fresh lotus root was used as the experimental material,after several treatments such as protecting lotus root color,extracting juice and saccharifying starch,the optimum technological parameters of lotus root juice fermented by lactic acid bacteria were obtained by Lactic acid bacteria fermentation treatment and allocating fermentation broth of lotus root juice.The nutritional function of lotus root lactic acid beverage was studied by antioxidant test in vitro and animal experiment in rats and mice.Finally,according to the research results,the product standard of "lactic acid bacteria fermented lotus root juice beverage" was established in combination with the relevant regulations and standards of our country,which provided the basis for the industrial producting of the lotus root lactic acid beverage.The main findings are as follows:(1)Study on the making process of Lotus Root Juice:the results of using different concentrations of citric acid and ascorbic acid EDTA-2Na combined with scalding process for color protection of lotus root slices showed that blanching treatment with 0.2%citric acid for 20 s could effectively prevent the browning of lotus root,and the optimum technological conditions of amylase hydrolysis in lotus root juice were determined by single factor and orthogonal experiment of temperature and pH value,amount of enzyme added,enzymatic hydrolysis time and orthogonal test.The results show that the temperature is 75 ? and pH is 6.5,adding amylase is 140U/mL,the content of reducing sugar in lotus root juice reached the highest level and tended to be stable after 120 mins of enzymatic hydrolysis.(2)Studies on fermentation and blending of lotus root juice fermentation broth:In the process of lactic acid bacteria fermenting lotus root juice,it was found that lactic acid bacteria fermentation of lotus root juice with 112:V3:Y41=4%:5%:3%lactic acid bacteria had the best effect.,after comparing the effects of measuret of mixed lactic acid bacteria,nitrogen source,fermentation temperature and fermentation time on the content of lactic acid in lotus root juice.The results showed that the mixed lactic acid bacteria added 0.8%of soybean protein when the proportion of mixed lactic acid bacteria was 5%,the fermentation temperature was 39 ? and the fermentation time was 16 hours,the content of lactic acid in lotus root juice was the highest and the taste was the best.Using the xylitol,citric acid and cyclamate to treat lotus root juice,the results showed that when 2.2%xylitol 0.28%Lemonine 0.028%cyclamate was added,the sensory score of Lactic acid beverage lactic acid bacteria fermentation broth was the highest(92 points).By comparing the flavor substances of fermentation broth of lotus root juice and clear juice of lotus root juice(enzymatic hydrolysis)by GC-MS,the results showed that the aroma components of Lotus root juice fermentation broth increased from 20 to 42,the contents of lipids,hydrocarbons,ketones and ethers in flavor substances increased,which indicated that lactic acid bacteria could give lotus root juice better sensory value after fermentation.(3)Study on the stability of Lactic acid bacteria fermented lotus root juice beverage:the precipitation rate of the fermented lotus root juice could be reduced,and the sensory quality of drinks could be ensured by adding stabilizer and homogenization.,the results showed that when 0.07%sodium alginate,0.03%CMC-2Na,0.07%xanthan gum was added,the precipitation rate of live bacteria type lactic acid bacteria fermented lotus root juice beverage was the lowest.The microbial content and sensory quality of lactic acid beverage in lotus root juice were compared under different conditions.The results showed that the shelf life of the beverage could reach to 8 days at low temperature(0-4?),the number of live lactic acid bacteria remains above 106CFU/mL.When 0.07%sodium alginate 0.03%CMC-2Na,0.07%xanthan gum was added,the precipitation rate of non-live Lactobacillus lactic acid bacteria fermented lotus root juice beverage was the lowest,beverage structure remains stable and no significant precipitation;and the preservation effect of two kinds of non-live bacteria fermentation lotus root juice beverage was compared under different temperature.The results showed that the treatment of 5min at 90 ? could make the low temperature preservation time of the lactic acid beverage of the non-living lotus root juice reach 35 days,and better guarantee the lotus.Lotus root juice lactic acid beverage color,flavor,taste and other sensory qualities.(4)Functional study on the fermentation of Lotus Root Juice by Non-living Lactobacillus:after fermented by Lactobacillus,the antioxidation ability of lotus root juice was enhanced under 90 ? condition,and the antioxidant ability of non-living beverage could be effectively preserved by sterilizing 5min at 90 ?.Compared the effects of the fermented lotus root juice by non-live lactic acid bacteria on lotus root juice,lotus root juice and running lactic acid bacteria drink,the results showed that lactic acid beverage with lotus root juice had better effect on the recovery of intestinal flora in mice.To increase the food utilization rate to 14.07%,to reduce the intake of fat in food,to reduce the content of blood lipid and AI,and to maintain the blood glucose content in rats,.At the same time,the lactic acid beverage in lotus root juice had a certain protective effect on the liver of rats,and could reduce the liver injury,and there was significant difference between the lactic acid beverage and other beverages(P<0.05).(5)Formulation of product standard of "lactic acid bacteria fermented lotus root juice beverage"... |
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