Application Of Lactic Acid Bacteria Starter In Burger Buns Anticorrosion

Hamburg is a modern fast food that is popular with the public.Due to its fast meals and convenient eating,its current sales are increasing year by year.Due to its high content,rich in nutrients and other inherent characteristics,the burger bun is also easily contaminated by spoilage bacteria,which shortens the shelf life,causes food safety issues and economic losses.Therefore,in order to reduce the security problems and economic losses caused by bread spoilage,it is very important to choose an appropriate preservative method.At present,the preservative methods used in bread mainly include physical method,chemical method and biological method.Physical anticorrosion is usually used in combination with chemical anticorrosion and biological anticorrosion.Chemical anticorrosion will harm human health for a long time.Therefore,efficient and healthy microbial anticorrosion has become the current research hotspot.As a food-grade microorganism with probiotic and antiseptic effects,lactic acid bacteria is usually used in products in the form of starter cultures.It has been found that Lactobacillus added to bread as a starter can promote the dough fermentation.The fermentation products can not only prolong the shelf life of bread,but also improve the flavor and texture of bread.The main purpose of this study is that burger bun is made by sponge-dough fermentation,and it is fermented twice in total.The dough fermented for the first time is seed dough,and the dough fermented for the second time is main flour.The shelf life of hamburger bread can be prolonged by adding Lactobacillus fermenting agent to the bread.Firstly,the lactic acid bacteria starter and sugar added to the seed dough were determined.Then the fermentation process of seed dough was optimized,including the addition amount of skim milk,sucrose,fermentation time and fermentation temperature.Then,the amount of yeast added to the seed dough after optimization was determined.Finally,making the bread and evaluating the physical and chemical properties,microbial indicators,texture,sensory and shelf life of bread.As to see whether the lactic acid bacteria starter has the effect of extending the shelf life of bread.The results of this study are as follows:(1)The preparation of two different lactic acid bacteria starters.Lactobacillus plantarum KLDS1.0391 and Lactobacillus plantarum KLDS1.0315 are the strains that can produce bacteriocin,which are screened and optimized in the early stage of the laboratory.The two strains are used to prepare lactic acid bacteria starter.The two strains were cultured in MRS medium at 37? for 20 h and 21 h respectively until the number of viable strains reached the maximum value.The fermentation was stopped and the bacteria were collected.The above-mentioned bacteria were suspended in 11.3% skim milk,9.8% sucrose,5.1% sodium glutamate and 0.2% Tween-80 as freezedrying protectors,and then freeze-dried in vacuum.Finally,the lactic acid bacteria starter powder was prepared.The number of viable strains of Lactobacillus plantarum KLDS1.0391 and Lactobacillus plantarum KLDS1.0315 was 11.05 log CFU / g and 10.44 log CFU / g,The addition amount of the two kinds of starter was 0.05 g / 100 g flour and 0.053 g / 100 g flour.(2)Comparison of effect of different lactic acid bacteria starter and sugar on seed dough fermentation.Single factor experiment method was used,with lactic acid bacteria starter and sugar as independent variables,and the inhibition rate of Penicillium species as indicators.The results showed that when lactic acid bacteria starter B and sucrose were added to the seed su seed dough rface,the lactic acid and acetic acid contents and the bacteriostatic rate were highest,the p H value was the lowest,and the TTA value was the highest.Therefore,it was chosen to add commercial lactic acid bacteria starter B and sucrose to the seed dough.(3)Optimization of seed dough fermentation process.Add the above identified lactic acid bacteria starter B and sucrose to the seed dough.Firstly,a single factor experiment was used to determine the amount of skim milk,sucrose,fermentation time and fermentation temperature.Then,taking sucrose addition,fermentation time and fermentation temperature as independent variables,and the bactericidal rate as the response value,the fermentation process of the species was optimized by response surface test design.Finally,the optimal fermentation process parameters were obtained: the added amount of sucrose was 4.11%,the fermentation time was 19.90 h,and the fermentation temperature was 29.99?.Under this condition,after 20 h fermentation,the bacteriostatic rate of seed dough was 31.23%,and the relative error with the theoretical predicted value is 4.41%,no significant difference,shows that the established model can better reflect the actual fermentation conditions.(4)Determination of yeast addition in seed dough.0%,0.3%,0.6%,0.9% and 1.2% yeast were added to the optimized seed doughs.The results showed that adding 0.9% of active dry yeast to the seed dough had the highest inhibition rate,and compared with the dough only with lactic acid bacteria starter.When yeast is added to the seed dough,the viscosity and the loss of dough were reduced.(5)The making of burger bun.According to the above optimized process parameters to make burger bun.Bread with lactic acid bacteria starter B and highly active dry yeast as the experimental group,and bread with only highly active dry yeast as the control group.Measuring the physical and chemical indicators of bread,the number of microorganisms,the senses,and the shelf life.The results showed that the shelf life of the control group was 12 days,while the bread of the experimental group was more fluffy,slightly larger in volume,better flavor,better texture parameters,and had a shelf life of 15 days.Conclusion: The burger bun was made by the optimized fermentation process.The bread of the experimental group was added with lactic acid bacteria starter B,and its sensory evaluation and texture characteristics were better than those of the control group without lactic acid bacteria starter B.Meanwhile,the shelf life of bread in the control group was 12 days,and the shelf life of bread in the experimental group was 15 days,and the shelf life was extended by 3 days.The results show that it is feasible to add lactic acid bacteria starter B to the seed dough of hamburger bread,which can not only prolong the shelf life of bread,but also improve its flavor and texture.In addition,the addition of lactic acid bacteria fermentation agent B to bread can correspondingly reduce the addition of chemical preservatives such as calcium propionate which is in line with the concept of healthy eating for modern people,and does not need to improve the original production equipment.produce.so it is suitable for industrial production.