Characterization of Native Microbial Population of Swiss Chard (Beta vulgaris, type cicla)

The native microflora of fresh Swiss chard (Beta vulgaris, type cicla) was quantified and characterized. The populations concentration of the different microorganism groups presented great variability among different lots, that was attributed to their separated histories. The mean populations of the native microflora were: 3.0×106 cfu/g for mesophilic, 3.25×105 cfu/g for psycrotrophic microorganisms, 9.23×103 cfu/g for lactic acid bacteria, 2.95×103 cfu/g for total coliforms, 1.21×104 cfu/g for yeasts, 4.75×103 cfu/g for molds and 4.2×103 cfu/g for staphylococci. The following species were identified: Micrococcus roseus, Micrococcus sedentarius, Lactobacillus paracasei subsp. paracasei, Bacillus subtilis, Bacillus pumilus, Alternaria spp., Botrytis spp.,Aspergillus spp., Microsporium spp., Fusarium spp. and Trychophyton spp. Neither fecal nor pathogens were found. Immersion of Swiss chard leaves in tap water at 18 °C for 4 min reduced microbial populations but did not accomplish more than 70 percent removal in any of the populations under study.

[1]  C. Willemot,et al.  Microbial Changes in Shredded Iceberg Lettuce Stored under Controlled Atmospheres , 1991 .

[2]  A. E. Watada,et al.  Microbial populations of fresh-cut spinach leaves affected by controlled atmospheres , 1996 .

[3]  J. N. Sørensen,et al.  Influence of growth conditions on the value of crisphead lettuce , 1995, Plant foods for human nutrition.

[4]  M. Raccach,et al.  The Effect of Lactic Acid Bacteria on Some Properties of Mechanically Deboned Poultry Meat , 1979 .

[5]  F. A. Skinner,et al.  Identification methods for microbiologists , 1979 .

[6]  Octavio Giovanniello,et al.  Pruebas Bioquímicas para la Identificación de Bacterias de Importancia Clínica , 2003 .

[7]  L. Vuyst,et al.  Bacteriocins of Lactic Acid Bacteria , 1994 .

[8]  P. Franz,et al.  Efficacy of chlorine for inactivation of Escherichia coli on vegetables. , 2000 .

[9]  A. King,et al.  Microbial Flora and Storage Quality of Partially Processed Lettuce , 1991 .

[10]  Carl E. Sams,et al.  Preharvest factors affecting postharvest texture , 1999 .

[11]  R. Wiley.  Frutas y hortalizas mínimamente procesadas y refrigeradas , 1997 .

[12]  O. B. Williams.  TRYPTONE MEDIUM FOR THE DETECTION OF FLAT‐SOUR SPORES , 1936 .

[13]  M. Moss,et al.  Bacterial agents of foodborne illness , 2000 .

[14]  D. Zagory.  Effects of post-processing handling and packaging on microbial populations , 1999 .

[15]  J. Piard,et al.  Inhibiting factors produced by lactic acid bacteria. 2. Bacteriocins and other antibacterial substances , 1992 .

[16]  R. B. Maxcy.  Fate of Microbial Contaminants in Lettuce Juice 1. , 1982, Journal of food protection.

[17]  C. T. Butterfield.  The Selection of a Dilution Water for Bacteriological Examinations , 1932 .

[18]  Refrigerating.  ASHRAE handbook and product directory /published by the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc , 1977 .

[19]  Robert E. Brackett,et al.  Incidence, contributing factors, and control of bacterial pathogens in produce , 1999 .

[20]  J. N. Sørensen,et al.  Influence on growth conditions on the value of crisphead lettuce , 1994, Plant foods for human nutrition.

[21]  Adel A. Kader,et al.  Post Harvest Technology of Horticultural Crops , 1991 .

[22]  D. Pszczola.  20 ways to market the concept of food irradiation , 1997 .

[23]  C. Nguyen-the,et al.  The microbiology of minimally processed fresh fruits and vegetables. , 1994, Critical reviews in food science and nutrition.

[24]  T. Brocklehurst,et al.  A note on the microbiology of retail packs of prepared salad vegetables. , 1987, The Journal of applied bacteriology.

[25]  M. Daeschel,et al.  Antimicrobial Activity of Lactic Acid Bacteria Against Listeria monocytogene s. , 1989, Journal of food protection.

[26]  H. P. Fleming,et al.  Controlling cabbage fermentations with nisin and nisin-resistant Leuconostoc mesenteroides , 1995 .

[27]  T. Deák,et al.  Simplified identification of aerobic spore-formers in the investigation of foods. , 1988, International journal of food microbiology.

[28]  R. Brackett.  Antimicrobial Effect of Chlorine on Listeria monocytogenes. , 1987, Journal of food protection.

[29]  D. O'beirne,et al.  The microbiological safety of minimally processed vegetables , 1999 .

[30]  M. Rogosa,et al.  A MEDIUM FOR THE CULTIVATION OF LACTOBACILLI , 1960 .

[31]  K. L. Smiley,et al.  The Hydrolysis of Arginine by Streptococci , 1942, Journal of bacteriology.

[32]  A. E. Watada.  Quality Maintenance of Fresh-cut Fruits and Vegetables , 1997 .

[33]  J. S. Lee,et al.  INHIBITION OF PSEUDOMONAS SPECIES BY HYDROGEN PEROXIDE PRODUCING LACTOBACILLI1 , 1970 .

[34]  K. Pääkkönen,et al.  Equilibrium water content and the state of water in dehydrated white cabbage , 1991 .

[35]  J. N. Sørensen,et al.  Influence of growth conditions on the value of crisphead lettuce , 1994, Plant foods for human nutrition.

[36]  J. Iandolo,et al.  Repression of Staphylococcus aureus in associative culture. , 1965, Applied microbiology.

[37]  H. P. Fleming,et al.  Using lactic acid bacteria to improve the safety of minimally processed fruits and vegetables , 1997 .