Quality of Swiss chard produced by conventional and organic methods

The storage lives of Swiss chard produced by conventional and organic methods was investigated. No significant differences were found in the initial populations of yeast, molds (1-3 x 10(4) CFU/g) and psychrotrophic (1 x 10(4)-1.5 x 10(5) CFU/g), mesophilic (4 x 10(3)-5 x 10(4) CFU/g) and lactic acid bacteria (2 x 10(2) and 1.5 x 10(3) CFU/g). The evolutions of the population of those microorganisms during storage were also similar for both chards. First-order kinetics after an induction period were found for the degradation of ascorbic acid. Although the rate constant (0.057 days(-1)) was similar for both chard, the induction period for organic chard (similar to 10 days) was longer than for conventional chard (similar to 3 days). No significant differences were found between the water and chlorophyll contents and in pH and titratable acidity of both chards. Sensorial analysis showed that organically produced chard retained turgidity, color and brightness longer than the conventionally produced chard. (C) 2003 Published by Elsevier Science Ltd. on behalf of Swiss Society of Food Science and Technology.