Vibration during transport induces reversion in blackberry fruit

Mexico provides 95% of the export market of blackberry worldwide. The quality of this fruit is defined by its characteristic black color. However, within 3-5% of the fruit can be rejected due to presenting color reversion (return of the black color to the red in the fruits). The origin of the problem involves varietal aspects and post-harvest handling not yet well determined. The objective of this study was to determine the effect of vibration during transportation on the color reversion. Exporting boxes with 12 clampshells of 6 oz with blackberry (Rubus fruticosus) cv ?Tupy? were put under vibration patterns of 5-30 Hz to determine the frequency that generates the damage. Different boxes of the same fruit were put at 10 Hz and 0.5 g?s of amplitude for 10 min identifying the color reversion; later, the fruits were stored at 3 ?C and 85% RH for 2 days. The black and red drupelets were separated from each fruit; samples of each one were prepared for observation by transmission electron microscopy (TEM) and others were frozen at -70?C and lyophilized for quantification of monomeric and polymeric anthocyanin. The cells of not reverted drupelets (black) showed a higher integrity and cellular order compared to reverted drupelets cells (red). The monomeric anthocyanin content was lower on reverted drupelets (4.912 mg C3G/g lyophilized sample) respect to non-reverted (8.389 mg C3G/g lyophilized sample), likewise the index of degradation and formation of anthocyanin-tannin complex or color polymeric percentage was lower in black drupelets (28%) in comparison with the red drupelets (36%). A frequency of 10 Hz and 0.5 g?s of amplitude generated internal cellular damage and molecular changes in the anthocyanin structure provoking the color reversion; this vibration pattern should be avoided during the transport of this fruit. ? SourcesEffect of the transport vibration on the color reversion in blackberry fruitEdmundo Mercado-Silva1, Dulce M. Rivera-Pastrana1, M. Estela V?zquez-Barrios1, Manuel Fabela3, Georgina P?rez1, V?ctor H. Escalona31Posgrado de Alimentos, Facultad Qu?mica,Cerro de las Campanas s/n, Quer?taro 76010, Mexico2Instituto Mexicano del Transporte, km. 12 Carretera Estatal 431, Quer?taro 76703, Mexico3Centro Estudios Poscosecha CEPOC, Universidad de Chile, Santiago, ChileVIII International Postharvest Symposium, Cartagena, Spain, 21-24 June 2016 Source of the image:?The health journals