2.2. Sample preparation
Tomatoes were washed, cut into pieces and blended using a household
blender. The seeds and skin of the tomato were removed by passing
the resulting juice through a cheese cloth. The juicewas divided into
three aliquots and the pH of one aliquot of tomato juice was altered to
pH 3.93 by adding citric acid. The pH of the other two aliquots was left
unaltered, at the original pH of 4.3. Samples of juice (50ml)were transferred
into polyethylene/polyamide pouches (15 × 10 cm), heat sealed
and kept under refrigeration (4 °C) until processing.