| Summary: | 碩士 === 國立屏東科技大學 === 食品科學系所 === 104 === Fresh vegetables and fruits after the treatment of selecting, cutting, washing and disinfecting are called processed vegetables and fruits, also called half-processed vegetables and fruits and minimally processed vegetables. Sodium hypochlorite is usually used to reduce bacteria on the surface of vegetables and fruits industry. Although high concentration of sodium hypochlorite has better antimicrobial ability, it is easy to cause off-odor and the corrosion of metal equipment, and it will result in forming halogenide with food components, and increase the hazard to customer health. Many foreign researches of oyster shell powder revealed that it has powerful antimicrobial ability. There are oyster shell powder products have been on the market, but the poor solubility and dispersion ability of these products limit them application on washing of vegetables and fruits. The objectives of this study are to investigate the application of microencapsulated of incinerated oyster shell powder (mIOSP) and other cleaners of vegetables and fruits including sodium hypochlorite, acetic acid, salty water and potassium sorbate. The result revealed the growth of Escherichia coli BCRC10675, 11509 and Kloeckera apiculata treated with 1.25% mIOSP or 50 ppm NaOCl for 1 min are totally inhibited. Bacillus cereus was totally inhibited after treating with 1.25% mIOSP and 50 ppm NaOCl for 1 and 5 min, respectively. Staphylococcus aureus treated with 50 ppm NaOCl for 5 min was totally inhibited. But it was reduced by 4.83 Log CFU/mL after treating with 1.25% mIOSP for 30 min treatment. Compared to other bactericidal solution, 1.25% mIOSP has better bactericidal effect to Listeria welshimeri, the colony number reduced by 5.06 Log CFU/mL after 30 min. The inhibition of total plate count and coliform were more effective at cucumber, green pepper and tomato treated with 1.25% mIOSP than 50 ppm NaOCl during storage. No significant difference of change of pH value on cucumber, green pepper and tomato after different solution washing during storage. Cucumber treated with 1.25% mIOSP increased green color in the period of storage. Green pepper treated with 1.25% mIOSP keeped higher L* value and postponed the reducing of green color among storage. The changes of color (L*a*b*) values were similar in 1.25% mIOSP treated tomato during storage. No significant of sensory evaluation difference between sample treated with 1.25% mIOSP, 50 ppm NaOCl and control.
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