Detection of bruising of ‘Szampion Arno’ apple at visible light

Abstract

During transport, reloading and handling, apples are often damaged, among which bruises are the most common cause of permanent, visible changes in colour on the surface of the fruit. Discoloration of the apple skin affects the consumer assessment. The aim of the research was a parametric assessment of bruises colour on apple skin at shelf life, after impact loading at 0,74 J; 1,32 J, and 2,06 J. The tests were carried out on ‘Szampion Arno’ apples specifying lightness parameter L* and chromaticity parameters a* and b* in accordance with the CIE L*a* b* standard. It was observed that the brighter side of the base colour of fruit blended to a greater degree the changes of colour during the shelf life. In that period, the lightness parameter L * of the base colour decreased from 74.47 to 39.21, proving darkening of fruit, similarly to the yellow colour which decreased over the entire surface of the fruit, while the chromatic parameter a *, representing the red colour, rose from 6.8 to 29.68, so that darkening of flesh was visible on the opposite side. The darkening of bruises described by the lightness parameter L* on the blush of fruits was reduced to a lesser extent, from 41.28 to 27.82, and after 6 days of shelf life the differences between blush and bruises were invisible. The chromaticity parameter a* was also confirmed by the reduction of the red colour on the surface of the blush, in the range from 47.32 to 34.79, however, bruising was more visible on the base colour of fruit, as this parameter a * increased from 7.86 to 27.38. Generally, the colour of bruised apple on the surface of the blush was more even, however, after 2 days of shelf life, the base colour of apples evoked a negative quality assessment.

Keywords

• apples
• bruising
• shelf-life
• color
• lightness
• chromaticity
• cie l*a*b*