Clergé Tchiégang

Ricinodendron heutelotii (Bail.) or Tetracarpidium conophorum Müll. oils fed to male rats lower blood lipids.

Ricinodendron heudelotii and Tetracarpidium conophorum (Euphorbiaceae family) are 2 oil-bearing wild plants whose fruits are generally consumed in Cameroon. T conophorum kernels are eaten as nibbles after cooking. Kernels of R heudelotii are used as spice in many dishes in Cameroon. Oil from T conophorum contains a high level of alpha-linolenic acid (72.24%), and oil from R heudelotii kernels is a good source of alpha-eleostearic acid (9c, 11t, 13t; 52.61%), which is a conjugated linolenic acid. Polyunsaturated fatty acids have received considerable interest because their consumption has been associated with beneficial health effects. We hypothesized that the consumption of R heudelotii and T conophorum oils would alter the in vivo lipid profiles and some antioxidants parameters. Therefore, male Sprague-Dawley rats (age, 1 month, n = 18) were fed with a standard, commercial diet (control group), or a diet containing T conophorum oil (TCO group) or R heudelotii oil (RHO group). After 60 days of feeding the respective diets, blood samples were collected and used to determine biochemical parameters. High-protein lipoprotein cholesterol, creatinine, alanine aminotransferase, alkaline phosphatase, total bilirubin, malondialdehyde, and selenium levels were not significantly different (P > .05) between the RHO and TCO groups. The atherogenicity index was higher for the group of rats fed a standard, commercial diet compared with the RHO and TCO groups. The oils examined in this study reduced cholesterol and triglyceride levels in rats compared with the control group fed the standard diet.

Etude des conditions d’extraction de l’huile par pressage des amandes de Ricinodendron heudelotii (Bail.) Pierre ex Pax

Resume Les conditions d’extraction de l’huile par pressage des amandes de Ricinodendron heudelotii (Bail.) apres fragilisation ont ete realisees. La fragilisation des amandes est faite par voie humide et par voie seche a diverses temperatures (50, 70 et 90 °C) et a des temps de sejour variables (5, 10, 15, 20, 30 et 60 min). Les resultats montrent que le pretraitement a 90 °C pendant 60 min donne la plus grande friabilite aussi bien par voie seche que par voie humide soient 60,86% et 58,13% respectivement. Le chauffage et le broyage des amandes ameliorent de maniere significative (p

Variation of the Physical Properties of Sheanut (Vitellaria Paradoxa Gaertn.) Kernels during Convective Drying

The effect of moisture content and drying temperature of Vitellaria paradoxa Gaertn kernels on some of its physical properties was investigated. The kernels which were harvested at a moisture content of about 60% (wet basis) and hence prone to high post harvest losses from two ecological zones of Cameroon (Bangoua in West province and Tchabal in Adamawa province) were dried in a forced convection dryer at 40oC, for 6, 20, 48, 72 and 96 hours to give moisture contents ranging from 10 to 60% wet basis. Ten trees from each of the zones were carefully selected to serve as sources for the ripe kernel bearing shea fruits that were used as samples for this study. For each parameter studied, a sample population of 30 kernels selected at random per tree was used. The results obtained revealed that there was a significant difference in the physical properties of the kernels from different trees irrespective of the locality. The bulk density, true density, sphericity and porosity varied non-linearly with the moisture content. Kernels with larger masses showed a different variation pattern of bulk density and porosity with moisture content compared to the lighter kernels. The variation of the bulk density, sphericity, porosity of sheanut kernels with moisture content and temperature was satisfactorily modelled with empirical equations. The samples underwent considerable shrinkage (up to 35%) during the drying process. Three empirical models were used to describe the shrinkage behaviour of the kernels and it is proposed that these models could be incorporated in drying models.

Etude comparative du ramollissement des fruits de l’aiélé (Canarium schweinfurthii Engl.) par voie humide et par voie sèche

Abstract A comparative study of the softening of aiele ( Canarium schweinfurthii Engl.) fruits collected from five different locations in Cameroon have been carried out. The fruits were processed in water at 45 °C during 10–60 min, or in a dryer directly on grills, or in the dryer in opened or closed glass jars at 45 °C. Physicochemical characteristics were investigated during the softening. The optimum softening times varied between 40 and 60 min with 80–100% of the fruits softened into water or by direct drying. 120 min were necessary to obtain 60–100% of softened fruits in closed or opened jars. The softening rate (% of softened fruits per minute) exhibited a maximum that was observed after 30 and 60 min at 45 °C in water or in the dried methods respectively. Depending from the locations, losses in weight of fruits varied from 0.56% to 1.62% by direct drying, from 1.96% to 4.76% in opened jars, and from 0.04% to 0.58% in closed jars. Contrary, fruits softened in water showed a gain of weight of the fruit pulp varying between 1.30% and 3.21%. There was no significant difference between the total lipids, iodine and acid values of oils obtained by solvent extraction from crude and softened fruits.

Indirect solar drying kinetics of sheanut (Vitellaria Paradoxa Gaertn.) kernels

An indirect solar dryer was tested for drying sheanut kernels. The influence of tray distance from heat source, airspeed and particle size on drying kinetics was investigated. Optimum drying air parameters obtained in the dryer were airspeeds of 1 and 1.4 m/s and a temperature of 40°C–45°C. Sheanut kernel slices dried entirely in the falling rate period. Drying rate decreased with increase in particle size. The effect of particle size on the drying rate suggested that, the drying process was controlled by internal mass transfer mechanisms. Drying kinetics was modelled with characteristic drying curve and diffusive models. Effective moisture diffusivities of sheanut kernel slices calculated without shrinkage were greater than those calculated with the incorporation of shrinkage by a value of about 50%. Acid and peroxide values indicated that butter from the dryer could be classified either as Category 1 or 2 irrespective of the drying conditions to which the kernels were subjected.