CHARACTERIZATION OF STRAWBERRY PECTIN EXTRACTED BY CHEMICAL MEANS

Alcohol Insoluble Residue was obtained from fresh strawberry fruit (37 g/kg). Pectic material was successively extracted from the residue by trans 1,2-Diamino Cyclohexane - N,N,N',N'- Tetra Acetic acid (CD TA), hot succinic acid in succinate buffer hot dilute HCl and cold dilute NaOH. The extracts were analysed for uronic acids, neutral sugars and proteins contents using colorimetric and GC methods and were subjected to ion exchange chromatography. A large portion of the strawberry pec tin (474 g/kg) was extracted by a calcium sequestrant (CD TA). The pro portion of arabinogalactans present as side-chains of the rhamnogalact uronan increased with the progress of the extractions. Ion exchange of chromatography revealed that soluble pectin (calcium-linked) and prot opectin (cell wall-linked) were accompanied by proteins and other neut ral sugars such as xylose and glucose. However, the presence of xylogl ucans was suspected because of the high proportions of glucose and xyl ose in the CD TA fractions purified by ion exchange chromatography. (C ) 1995 Academic Press Limited