No abstract

The global increase in demand for vegetable oils due to their nutritional, pharmaceutical, and industrial importance necessitates investigation on exploitation of new oil bearing crops. This study was undertaken to determine the influence of processing conditions on physical properties of oil expressed mechanically from African oil bean kernels. Central composite rotatable design of response surface methodology (RSM) at 3-factors, 5-levels was adopted; independent variables considered were: moisture content (MC; 8, 10, 12, 14, and 16% dry basis), heating duration (HD; 5, 10, 15, 20, and 25 min), and heating temperature (HT; 50, 70, 90, 110, 130 C) while dependent variables (physical characteristics) include: oil impurities, density, kinematic viscosity, dynamic viscosity, specific gravity, refractive index, and color; all determined using standard methods. Optimum values were obtained using RSM. Optimum oil quality (0.044%m/m impurity, 0.92 kg/m 3 density, 43.86 mm 2 /s kinematic viscosity, 40.8 mPa s dynamic viscosity, 0.9 specific gravity, 1.469 refractive index, and 7.7 color units) was obtained at 8% db, 11.7 min HD, and 59.3 C HT. The quality of the expressed oil falls within permissible limits for edible oils and high nutritional importance. The processing conditions influenced the quality of the mechanically expressed African oil bean oil. Practical applicationsAfrican oil bean is an underutilized plant with potentials for meeting increasing global demand for vegetable oil for nutritional and industrial importance. The application/usage of oil is dependent on its quality attributes which is otherwise dependent on processing parameters like moisture content, heating duration, and heating temperature. These factors need to be controlled during oil expression processes to actually the optimum conditions that will yield good quality oil. The degree of influence of the parameters on oil quality is a useful data to vegetable oil processors, food, and agricultural engineers. The quality parameters of the oil were determined and compared with international standard parameters. Mathematical models were developed to predict the yield and quality attributes of expressed oil from African oil bean kernels at various processing conditions.

No abstract

Purpose: New low-cost oilseeds are needed to meet an ever-increasing demand for oil for food, pharmaceutical, and industrial applications. African oil bean seed is a tropical crop that is underutilized and has high oil yields, but there have been no studies conducted on its mechanical oil expression up to now. The objective of this work was to investigate the effect of moisture content and seed dimensions on mechanical oil expression from the seeds. Methods: Fresh oil bean seeds were procured, de-hulled, and cleaned. Initial seed moisture content, obtained in accordance with the ASAE standard, was 12% dry basis (db). The seeds were further conditioned by dehydration and rehydration prior to oil expression to obtain four other moisture levels of 8, 10, 14, and 16% db. The major diameter of the seeds was measured using digital vernier calipers, and the seeds were classified into size dimensions (< 40, 41-45, 46-50, 51-55, and > 55 mm). The oil yield and expression efficiency were obtained in accordance with standard evaluation methods. Results: The highest oil yield and expression efficiency (47.74% and 78.96%, respectively) were obtained for a moisture content of 8% db and seed dimensions of < 40 mm, while the lowest oil yield and expression efficiency (41.35% and 68.28%, respectively) were obtained for a moisture content of 14% db and seed dimensions between 51-55 mm. A mathematical model was developed to predict oil yield for known moisture content and seed dimensions, with a coefficient of determination R 2 of 95% and the confidence level of the predictive model of 84.17%. The probability of prediction F ratio showed that moisture content influence was more significant than seed dimensions. Conclusions: The higher the moisture content and larger the seed dimensions, the lower the oil yield from African oil bean seeds.

No abstract