The Size And Localisation Of Yellow Pigmented Lipid Cells 6–Gingerol In Two Varieties Of Nigerian Ginger (<i>Zingiberis Officinale Roscoe</i>) At Various Maturity Stages

Abstract

The size and distribution of the main pungent principle (6-gingerol) in two ginger varieties “ Tafin giwa” (the yellow variety) and “Yatsum biri” (the dark variety) at 4, 5, 6, and 8 months stages of maturity at harvest were studied empirically by the determination of the mean number of yellow pigmented lipid cells per unit area (Cell Density = D) and their sizes (diameter = d) mainly in the Cortex and Central “pith” regions of the transverse sections (150 – 200 nm thickness) using the light microscopy. It was observed that the transverse sections of fresh ginger rhizomes contain spherical yellow-pigmented lipid cells (the spot of aroma and pungency mediating compounds), which were distributed more in the central than in the cortex regions of the rhizomes. The mean cell distribution showed that the proportion of these yellow lipid cells varied with ginger variety and maturity at harvest. “Tafin giwa” contains more yellow lipid cells (73 – 200 cells mm^-1) than “Yatsum biri” (57 – 143 cells mm^-1) while the latter possess slightly bigger cells at the various stages of maturity examined. The yellow lipid cell densities varied with ginger variety being maximal at 5 months maturity for “Tafin giwa” and 6 months maturity for “Yatsum biri”

Key words: Ginger Flavour, 6-Gingerol, cell size, Distribution, Variety, Maturity, Light Microscopy

Nigerian Food Journal Vol.22 2004: 23-28