Oleoresin yield and 6-gingerol in two varieties of Nigerian ginger (<i>Zingiberis officinale Roscoe</i>) at various maturity stages

Abstract

Two varieties of ginger at various maturity stages were extracted with acetone to obtain ginger oleoresins which were quantitatively estimated for the 6-gingerol content and pungency. The results showed that the yield of oleoresins ranged within 86-140g.kg^-1 in both ginger varieties with UG14 giving the highest yield and UG26 the lowest. In terms of pungency the range was within 60,000–120,000 scoville heat units in the two varieties with UG18 giving the highest and UG16 the lowest. In terms of the yield of 6- gingerol the range was within 133-216g.kg^-1 of oleoresin. The molar extinction coefficient of the standard gingerol used was 3116 mole^-1 cm^-1 at 282nm. Ginger could be harvested from 4 months maturity after planting for a good yield of oleoresin and 6-gingerol.

Keywords: ginger oleoresin, 6-gingerol, extraction, maturity, drying, harvesting

Nigerian Food Journal Vol. 23 2005: 91-106