Proceedings Volume 2010 (format .pdf) - SimpBTH

determined in order to establish the shelf life of apple slices treated with trans-2-hexenal.COLOR MEASUREMENTA HunterLab MiniScan XE Plus Spectrocolorimeter was used formeasuring the remission (reflectance/transmittance ratio) for the full spectrumbetween 400 and 700 nm as well as at one wavelength. The tristimulus values ofcolor CIE 1976 L * a * b * , in terms of hue, saturation and brightness were computedfrom remission spectra. The L*a*b* color system is one of the uniform colorspaces recommended by CIE in 1976 as a way of more closely representingperceived color and color differences. In this system, L* is the lightness factor; a*and b* are the chromaticity co-ordinates:• L* (lightness) axis – 0 is black; 100 is white.• a* (red-green) axis – positive values are red; negative values are green; 0 isneutral.• b* (yellow-blue) axis – positive values are yellow; negative values are blue; 0 isneutral.The degree of browning was analysed in terms of changes in L∗ and a∗ values[5].RESULTS AND DISCUSSIONSThe effects of trans-2-hexenal treatments by different application methodson the microbial population and on color retention of fresh sliced apples wereevaluated.Microbiological analysis results showed that the most efficient method ofessential oil application on apple slices surface was electrostatic field spraying,which inhibited all microbial populations tested.Essential oil application in slow release system or by spraying withoutelectrostatic field leads to a significant reduction of microbial load for both totalaerobic count and number of yeasts and moulds.Initial number of total aerobic count was reduced, for electrostatic fieldspraying samples, with 1,5 log unit compared to the control, respectively with 4 logunits after 7 days of storage at refrigeration temperature (fig. 1). Also the yeastsand mould number was initially reduced with 1 log, respectively with 3 log unitsafter 7 days of storage at refrigeration temperature (fig. 2).277