Use of Triple Bagging System and Biopesticides for the Optimization of Storage Methods of Corn Grains for an Application in Oil Industry
Abstract— Corn is the second most cultivated cereal in Ivory Coast after rice. The grain germ represents an important source of quality fat, which could fill the deficit in fat both in populations and in industries. Unfortunately, grain production and the quality of fat are affected by storage methods that are often harmful to health. It is in this context that in the present study carried out in Ivory Coast. Surface response methodology (3-factor Central Composite Design) was conducted to monitor the effectiveness of triple bagging system and biopesticide (leaves of Lippia multiflora and Hyptis suaveolens) on the stability of some alteration parameters of the grains intended for use in oil mills. Thus, humidity, peroxide index and acidity were assessed during storage. The independent variables considered were the storage duration (1 to 18 months), the biopesticide / corn ratio (0 to 5%) and the combination of biopesticides (0 to 100% Lippia). Predictive regression equations were constructed for the estimation of each parameter studied (R2 > 0.70). An increase in grain moisture, peroxide index and acidity (P <0.01) was observed with the storage time. However, a threshold concentration of biopesticides has been shown to be effective for the stability of spoilage parameters. The optimization of the results made it possible to determine the ideal conditions for the conservation of the corn kernels. Thus, the addition of 2.5% of biopesticides (20% of Lippia multiflora and 80% Hyptis suaveolens) in a triple bagging system is effective for the stability of the alteration parameters for 18 months. Under these ideal conditions, the experimental values are respectively of the order of 12.30 ± 0.17%; 3.96 ± 0.14 meq O2 / kg and 3.18± 0.08% respectively for humidity, peroxide index and acidity. These values considered to guarantee quality stability are statistically (P> 0.05) equal to those predicted by the mathematical model.
Keywords— Corn storage, triple bagging, biopesticides, lipid quality, surface methodology responses.
Abstract— The article describes the results of experimental research of a new type of heat exchangers in which the heat transfer surface consists of smooth polypropylene fibres with the outer fibre diameter of 0.5 mm and the total heat transfer surface area of 0.14 m2. The research output is the information on the value of the heat transfer coefficient, exchanger heat capacity and pressure loss. This type of heat exchangers is contemplated for applications in areas where high chemical resistance of the equipment is required, as well as a relatively low weight and price and excellent resistance to the formation of wall deposits.
Keywords— heat exchangers, polypropylene fibres, structure.