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The technological characteristics and the fatty acid composition of Ricinodendron heudelotii (Bail.) seed oil from two different regions of Cameroon were studied. The fatty acid composition was determined by gas chromatography on a capillary column. The oil content varied according to the region (44.9–54.7%). The iodine value (160), saponification value (190) and unsaponifiable matter content (1.6%) were similar for the two types of seeds examined. The oil was composed mainly of linoleic acid (25–30%) and a polyunsaturated fatty acid (PUFA) found to be α‐elaeostearic acid (48–56%). The latter fatty acid is subject to transformation during the esterification processes due to its trienic conjugated bonds. The triacylglycerol profile obtained by reversed phase liquid chromatography showed 20 triacylglycerols with two major ones identified as linoleodi‐α‐elaeostearic (29.7–33.1%) and tri‐α‐elaeostearic (13.1–15.9%).

The effect of particle size and drying temperature on drying rate and oil extracted yields of Buccholzia coriacea (MVAN) and Butyrospermum parkii (ENGL) was investigated. Air drying studies carried out on B. coriacea and B. parkii, tropical food sources subject to high post-harvest losses, have resulted in the establishment of a significant difference between oil yields extracted from samples of various particle size pretreatments (paste, 4 mm, 8 mm and whole kernels) dried at 45 and 60°C with the highest oil yield given by the 4 mm thick slices dried at 45°C. The influence of temperature and particle thickness on the drying rate has been evaluated. The drying constants were found to depend on both temperature and particle thickness. Analysis of the oil extracted from the 4 mm thick slices dried at 45°C showed that apart from the acid value (52.4%), the saponification (181.2 mg g )1 KOH), peroxide (8.6 meq kg )1 ) and the unsaponifiable (7.43%) matter values of the extracted shea butter remain within the limits cited in the literature while a close analysis of the cake suggests that it could be a good mineral source.

The response surface method employing Doehlert's experimental design was used to optimise the cooking of sheanuts to strike a balance between the advantages and disadvantages usually offered by the process. The independent factors investigated were cooking time, cooking temperature and nut size while the responses were moisture content of the kernels, amount of oil extracted, acid and peroxide values of the butter. Second order polynomial models were generated to describe the process for the responses studied. The validity of the models was tested and it was found that they could be used to explain respectively 83%, 99% and 95% of the variation of moisture content, acid value and peroxide value. The cooking process greatly reduced the free fatty acid values of the butter (<6%) but increased its peroxide value (up to 20 meq/kg). The cooking process was significantly influenced by all three independent factors investigated. The optimum conditions defined for the cooking process were: cooking time (95-120 min), cooking temperature (75-90°C) and nut size (40-45 mm). These optimal conditions gave the following responses: moisture content 51.97% w.b., amount of oil extracted 47.47%, acid value (as FFA) 2.76% and peroxide value 3.87 meq/kg. The parameters of the cooking conditions could be set to appropriate values to give butter of either category 1, 2 or 3 in terms of acid and peroxide values.number of experiments r 2 regression coefficient RSEE relative standard error of the estimate Δu increment V titre volume (ml) V 0 volume of blank (ml) x i coded value of variable i x 1 coded value of cooking time (dimensionless) x 2 coded value of cooking temperature (dimensionless) x 3 coded value of nut size (dimensionless) X i real value of variable i X 0 i central value of the real variable i X 1 real value of cooking time (min) X 2 real value of cooking temperature (°C) X 3 real value of nut size (mm) Y 1 moisture content (% w.b.)

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This work analyses the acid, saponification, iodine and peroxide indices, and the fatty acid composition of five Cucurbitaceae (egusi) seed oils from different regions in Cameroon. These seeds are Cucumeropsis mannii (egusi melon), Cucurbita maxima (pumpkin), Cucurbita moschata (musk melon), Lagenaria siceraria (calabash) and Cucumis sativus ("Ibo"egusi). The results show that the saponification, iodine and peroxide indices are influenced by the regions while the acid index and percentage of impurity do not depend on the region of cultivation but on the specie. The values for the indices are as follows: The acid index ranges from 3 -10; iodine, 83 -114; saponification, 204 -231 and peroxide, 3 -8m.equiv.g of O 2 /g of oil. These values are within recommended levels for edible oils. These oils have 4 main fatty acids: Palmitic, stearic, oleic and linoleic acid, the most abundant being linoleic acid (48-69.13%). The fatty acid profile is C18:2 > C18:1 > C18:0 in all the samples, irrespective of the origin. Their chemical properties are similar to those of corn, cottonseed, sesame and sunflower seed oils. These results suggest that they can be good for table, cooking and frying oils and for making mayonnaise. The high linoleic acid level makes them good oils for the fight against cardiovascular illnesses.

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