Studies On The Growth Rule And Its Control Of The Dominant Spoilage Bacteria In The Sprouts

Isolation and identification the major bacterium and researching the effect of different temperatures, washing agents, concentrations and kinds of plant essential oil, gas proportion were studied in this paper, with soybean sprouts as the research object. On the basis of appropriate temperatures, washing agents, plant essential oil concentration and gas component, the effects of Modified Atmosphere Packaging (MAP) treatment, temperatures treament, washing agents treament and plant essential oil treatment on quality and polluting microorganism of soybean sprouts during the storage period were studied. The results were as follows:1. The bacteria of soybean sprouts was mainly pseudomonas, enterobacter, yeast and mould. Pseudomonas, enterobacter and yeasts was the main pollution microorganism of soybean sprouts, the number of pseudomenas were close to the number of bacteria, and pseudomonas was the dominant spoilage bacteria in soybean sprouts.2. Low temperature could play a significant role in sterilization, and significantly inhibit the decrease of the soluble solids content, Vc content, sensory quality, and slow the degree of browning. Treatment with 0-4℃ had the best effect for soybean sprouts storage and 22-25℃treatment caused damage to it, due to the high temperature.3. The mass fraction of 0.02%NaClO could play a significant role in sterilization, and significantly inhibit the decrease of the soluble solids content, Vc content, sensory quality, and slow the degree of browning.4. When oxygen content was 5% and carbon dioxide concentration was 6%, it could effectively inhibit the increase of the bacteria of soybean sprouts, and it was better to maintain the soluble solids content, Vc content, sensory quality, and slow the degree of browing. When the soybean sprouts were stored at this condition for two days, the sensory evaluation of soybean sprouts was still as high as 33 score, it could meet the supermarket demand for the soybean sprouts’ shelf life.5. Through testing the inhibition zone, the Minimun Inhibitory Concentration (MIC) of artemisia vulgaris oil, lemongrass oil and clove oil, artemisia vulgaris oil could significantly inhibit and minimize bacteria growth. Artemisia vulgaris oil showed broad spectrum bacteriostasis, the MIC of yeasts and enterobacter was 1.25μL/mL, to pseudomonas was 2.5μL/mL.6. Identified the processes of plant essential oil antistaling agents:plant essential oil、 shellac、porous starch、 amount of 80% ethanl、magnesium stearate and gelantinize starch; The parameters of presser process:press10kn、speed 1000r/min、filling depth 8mm. The artemisia vulgaris oil tablets of 20% could inhibit the bacteria growth. When the soybean sprouts were stored for 4 days, the total number of colonies was only 8.9×109 CFU/g,35% of artemisia vulgaris oil tablets caused damage to it, due to the high concentration.