The Technology About Fermented Carrot Original Sauce By Lactic Acid Bacteria And The Study On Properties Of Its Products

Our country is a large state where the resources in fruit and vegetable are abundant and various. The fruit-vegetable production field has grown relatively mature with much stricter demands in resource, research, manufacture, sale, and so on.What’s more,with people’s growing living level, the common procedure can’t satisfy the consumer’s requirements in food nutriment and health protection. Recently, probiotics not only have great nutritive value and good property of health care, but also improve the flavor in common fruits and vegetables. In this study, as raw material, carrot was pulped to original sauce and fermented by Lactobacillus plantarum NCU166, finally, the main nutritional ingredients and properties were detected when the Lactobacillus fermented carrot original sauce is prepared well. The experimental results indicated that, the fermented original sauce has excellent property in the texture and bacteriostat aspects, improves the medicine smell in carrot, remains and enhances carrot’s nutritive value, therefore, it is a kind of new green probiotics with a large consumer market. The main research contents and results were as follows:(1) Screening strengthening bacteria which were high acid-resisting and high suger-resisting:The existing Lactobacillus plantarum in laboratory was screened respectively from culture mediums with high-concentration acid and high-concentration sugar. The final strengthening bacteria can resist the degree of pH=2and50%sugar content. Through the morphological and physiological and biochemical identification, the above strengthening bacteria was proved Lactobacillus plantarum, so it could be used in fermenting carrot original sauce. With high-density culture, the bacteria was made special fruit-vegetable lactobacillus preparation.(2) Study of processing of fermented carrot original sauce:In the process, whether peeling or not and different adding glucose contents are the factors considered for optimization. By detecting the product’s acidity and viable count to determine the processing of product, the results indicated that the method peeling and adding10% glucose in fermentation is the best choice; Through consumer test, carrot original sauces with different ferment times was evaluated in sensory from seven parameters, such as colour, sweetness, acidity, aroma, raw flavor, taste and total acceptance, summarizing that the fermented carrot original sauce with36h was the favorite for consumer.(3) Detection on TPA texture analysis of fermented carrot original sauce:The fermented original sauces before and after sterilization were determined by texture analyer and compared in following parameters:hardness, viscosity, springiness, cohesiveness, chewiness, gumminess. The results indicated that after sterilization, its hardness, viscosity, cohesiveness and chewiness would increase while springiness and gumminess would discrease.(4) Study of inhibitory effect of fermented carrot original sauce:With the method of oxford cup and the indicator bacteria, the inhibitory effect of fermented original sauces before and after sterilization was compared by determining the diameter of inhibition zone. The results indicated that fermented original sauce could restrain the pathogenic bacteria and Bacillus subtilis and without inhibitional effect on other probiotics before sterilization; fermented original sauce just restrain Escherichia coli and Salmonella and without inhibitional effect on others.(5) Study of changes in main composition in carrot original sauce before and after fermention:The viscosity of carrot original sauces before and after fermention was detected by rotary rheometer and the comparision indicated that the viscosity would discrease after fermentation.The soluble solid content was detected by abbe refractometer and the comparision indicated that there was no obvious difference between before and after fermentation.The water hold capacity was detected by vacuum absorption and the comparision indicated that the WHC would increase after fermentation.The flavor composition in original sauces before and after fermentation was detected by Gas Chromatography and Mass spectrometer. Through comparing and analysing the varieties and concentration of mineral salts which were added in original sauce to improve flavor’s extraction effect, the results indicated that fermented original sauce can produce more new compositions and some had higher relative amount;20%NaHCO3is the best choice for extracting flavor composition.The concentrations of β-carotene in carrot original sauces before and after fermentation were detected by high performance liquid chromatography with the concents of4.79mg/100g and4.28mg/100g. The comparision indicated that the concentration of β-carotene would discrease with the preserving rate of89.35%, and this change in content had close relationship with the metabolic mechanism of L. plantarum.The concentrations of malic acid and lactic acid in carrot original sauces which were sampled every four hours were detected by high performance liquid chromatography. The comparision indicated that the concentration of malic acid would discrease as the fermentation time lengthens while that of lactic acid would increase as the time lengthens. This change in content had close relationship with the metabolic mechanism of L. plantarum.