ascorbic-acid and chlorine-dioxide

The objectives of this study were to optimize the condition of ultrasonic treatment combined with aqueous chlorine dioxide (ClO

Topics: Ascorbic Acid; Chlorine Compounds; Chlorophyll; Food Preservation; Food Preservatives; Food Storage; Nitrates; Oxides; Plant Leaves; Spinacia oleracea; Ultrasonics; Vegetables

Effects of aqueous chlorine dioxide (ClO(2)) treatment on nutritional components and shelf-life of mulberry fruit (Morus alba L.) were investigated. Mulberry fruit were immersed into 20, 60, and 80 mg/l ClO(2) solutions for 5, 10, and 15 min, respectively. Mulberries were then rinsed with potable tap water for 1 min and stored at -1°C for 14 d. ClO(2) treatment was effective in retention of flavonoid, ascorbic acid, reducing sugar, and titratable acid. ClO(2) concentration and treatment time were significant factors affecting ClO(2) treatment. The shelf-life of the samples treated by 60 mg/l ClO(2) for 15 min was extended to 14 d compared to 8 d for the control. No ClO(2), ClO(2)(-), or ClO(3)(-) residues were detected in samples treated by 60 mg/l ClO(2) for 15 min. These results indicated that ClO(2) treatment was a promising approach to preserve mulberry fruit with no significant risks of chemical residues.

Topics: Ascorbic Acid; Carbohydrates; Chlorates; Chlorides; Chlorine Compounds; Colony Count, Microbial; Consumer Product Safety; Disinfectants; Flavonoids; Food Contamination; Food Handling; Food Microbiology; Food Preservation; Fruit; Morus; Oxides

The main objective of this study was to determine survivability of a cocktail of three strains of Salmonella enterica (Montevideo, Javiana, and Baildon) and two strains of Listeria monocytogenes (LCDC 81-861 and F4244) on hydroponic tomatoes after treatment with chlorine dioxide (ClO(2)) gas. An initial concentration of 8-9 log cfu/mL of Salmonella and Listeria cocktails was inoculated individually, in separate experiments, on tomato skin to obtain a population of 7-8 log cfu/cm(2) after drying of the inoculums on the tomato skin. The aim was to achieve a 5 log reduction consistent with the recommendations of the National Advisory Committee on Microbiological Criteria for Foods. The tomato skins were treated with 0.1, 0.3, and 0.5 mg/L ClO(2) gas for 12 min at 22 degrees C and at the relative humidity of 90%. Untreated skin samples were processed under the same conditions. ClO(2)-gas-treated and untreated samples were recovered by an overlay method. The bottom layer contains tryptic soy agar, and the top layer consists of xylose-lysine-desoxycholate agar or modified Oxford antimicrobial supplement agar for Salmonella and Listeria, respectively. More than a 5 log reduction in Salmonella and Listeria was observed on the tomato skin surfaces after treatment with 0.5 mg/L ClO(2) gas for 12 min. Treatment with 0.5 mg/L ClO(2) gas for 12 min also delayed the growth of natural microflora on tomato surfaces and extended the shelf life of tomatoes by 7 days during storage at 22 degrees C, compared with the untreated control. These results revealed that ClO(2) gas is a promising antimicrobial technology for fresh tomato skin surfaces.

Topics: Anti-Bacterial Agents; Ascorbic Acid; Chlorine Compounds; Colony Count, Microbial; Disinfectants; Disinfection; Food Handling; Food Microbiology; Food Preservation; Foodborne Diseases; Fruit; Fungi; Hydroponics; Kinetics; Listeria monocytogenes; Microbial Viability; Oxides; Pigmentation; Quality Control; Salmonella enterica; Solanum lycopersicum; Time Factors