ABSTRACT

Pectin was extracted from lime, lemon, orange and grape fruit which are tropical citrus fruits grown in abundance in Nigeria. The extraction method involved the use of acidified alcohol precipitation of pectin from the fruits. The extracted pectins were subjected to some physical and qualitative tests and their uses and behaviours were compared. Some of the physical properties tested includes viscosity, solubility and nature of precipitate. The solubility and viscosity of the extracted pectins was enhanced by heating. A stringy white pecipitate was obtained for all pectins extracted from the four citrus fruits used. Orange peel had the highest yield of 15.42%, lime 11.42%, lemon 9.72% while grapefruit had the least with a yield of 6.64%. in terms of purity (anhydrouronic acid content) lime had the highest level of 67.46%, lemon 52.05%, orange 44.05% and the least pure was recorded for grape fruit 42.57%. Pectins from orange and grape fruit compared favourably with pectins from lime and lemon in terms of yield and firmness of jam and jelly prepared from them. This suggests that these citrus fruits could be cheap sources of raw materials for pectin production. A sensory evaluation conducted showed that there were significant differences in taste, flavour and general acceptability of the samples used at 99% confidence level. Orange and lemon jams were preferred to the jam produced from lime and grape fruit.