Profiling of the different cell wall polysaccharides in orange (citrus reticulata) and bomali (Citrus grandis) fruit

Abstract

Citrus fruits are very popular and economically important agricultural crops in the Mediterranean. The composition of pectin varies with the source from which it is isolated. Cell wall materials from Orange (Citrus reticulata) and Bomali (Citrus grandis) were analyzed for sugar composition by different immunochemical and chromatography techniques to determine the variation of pectin content and its chemical composition in the two different citrus species. The extraction of pectic polysaccharides from various parts of the fruits (peel and pulp) was carried out using a sequence of aqueous solvents comprising water, buffers, calcium-ion chelators, and bases at different conditions (pH, temperature and time). The results revealed the diversity of pectic family with the presence of both unbranched (homogalacturonan) and branched (rhamnogalacturonan) pectin components in Citrus grandis (Bomali) and Citrus reticulata (Orange) peel and pulp. This reflects different pectic structure and probably different linkages with other cell wall components. This study demonstrates that there may be significant variation in the levels and compositions of pectic polysaccharides between different citrus species.