These dates where selected after comparing the physico-chemical results (Fig. 2) with the PCA score plots (Figs. 9 and 10). The samples were first transferred into the microcentrifuge tubes containing 0.5 g of 0.5 mm zirconia beads and supplemented with 300 ll of sterile water, 300 ll of L 1.4 buffer and 20 ll of proteinase K. Next, the samples were placed in a Beadbeater for 60 s