Tomato tissue (0.5g) derived from 4 fruits, free of placental tissue and seeds, was homogenized with 25ml 95% ethanol, and boiled for exactly 30min. After cooling at RT, the reaction was centrifuged at 8000g for 15min, the supernatant was removed, and the pellet suspended in 25ml 95% ethanol and boiled for 30min. After repeating 3–5 times, the pellet was suspended in 20ml distilled water, and incubated in a 50 °C water bath for 30min. The mixture was then centrifuged at 8000g for 15min, and the supernatant containing the water-soluble pectin was transferred to a 100ml volumetric flask. The pellet was dissolved with 25ml 0.5mol l–1 H2SO4 and boiled for 1h. Following centrifugation at 8000g for 15min, the supernatant containing the proto-pectin was transferred to a 100ml volumetric flask.
The pectin content was determined by mixing 1ml of collected pectin with 6ml of concentrated hydrochloric acid. The reaction was boiled for 20min, cooled in tap water, followed by the addition of 0.2ml 1.5g l–1 carbazole and a 30min incubation in the dark at RT. The absorbance at 530nm was measured against reagent blanks and pectin content was calculated based on a galacturonic acid standard curve.
The pectin content was determined by mixing 1ml of collected pectin with 6ml of concentrated hydrochloric acid. The reaction was boiled for 20min, cooled in tap water, followed by the addition of 0.2ml 1.5g l–1 carbazole and a 30min incubation in the dark at RT. The absorbance at 530nm was measured against reagent blanks and pectin content was calculated based on a galacturonic acid standard curve.
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