ESolvent-free, enzyme-catalyzed biodiesel production from mango, neem, and shea oils via response surface methodology

Mango, neem and shea kernels produce non-conventional oils whose potentials are not fully exploited. To give an added value to these oils, they were transesterified into biodiesel in a solvent-free system using immobilized enzyme lipozyme from Mucor miehei. The Doehlert experimental design was used to evaluate the methyl ester (ME) yields as influenced by enzyme concentration-EC, temperature-T, added water content-AWC, and reaction time-RT. Biodiesel yields were quantified by (1)H NMR spectroscopy and subsequently modeled by a second order polynomial equation with interactions. Lipozyme enzymes were more tolerant to high temperatures in neem and shea oils reaction media compared to that of mango oil. The optimum reaction conditions EC, T, AWC, and RT assuring near complete conversion were as follows: mango oil 7.25 %, 36.6 °C, 10.9 %, 36.4 h; neem oil EC = 7.19 %, T = 45.7 °C, AWC = 8.43 %, RT = 25.08 h; and shea oil EC = 4.43 %, T = 45.65 °C, AWC = 6.21 % and RT = 25.08 h. Validation experiments of these optimum conditions gave ME yields of 98.1 ± 1.0, 98.5 ± 1.6 and 99.3 ± 0.4 % for mango, neem and shea oils, respectively, which all met ASTM biodiesel standards

A Review of Cocoa Drying Technologies and the Effect on Bean Quality Parameters

Considering drying as a key farm-based, quality determining unit operation in the cocoa processing chain, this paper reviews recent studies in the drying methods and quality parameters of cocoa beans. Open sun, solar, oven, microwave, and freeze drying methods have been investigated at various levels in the drying of cocoa beans with objectives to improve the drying properties and final quality of cocoa beans. While an open sun dryer employs natural passive mechanisms, the solar drying methods can employ a combination of passive and active mechanisms. The oven, microwave, and freeze drying methods are fully active requiring electrical energy inputs. To improve drying rates in the open sun method, dryer materials and location of drying trays are the parameters optimized since the drying temperature depends on solar intensity. For solar dryers, materials, angles of elevation, heaters, and fans are manipulated to optimize energy absorption and drying parameters. For the oven and microwave methods, drying air properties are directly controlled by electronic systems. Moisture content, mouldiness, bean colour, pH, titratable acidity, fat content, and acetic acid concentration are the most widely evaluated bean quality parameters

Production zones and systems, markets, benefits and constraints of shea (Vitellaria paradoxa Gaertn) butter processing

The shea tree is a multipurpose tree crop indigenous to Sub Saharan African. The tree is highly cherished for the oil that is extracted from its kernels and used nationally and internationally in cosmetics, pharmaceutics and in chocolate formulations. The processing and sales represent significant income earning opportunities for rural women who are the main stakeholders in the production chain. Shea nuts and its products are listed among the top ten Non-Traditional Exports of Ghana. In Burkina Faso it is the fourth most important export crop after gold, cotton and livestock and makes a contribution of about 6 million USD to the national economy. Today the shea tree is the second most important oil crop in Africa after the palm nut tree. About 500 million shea trees grow in Africa which has the potential of producing shea nuts worth about 150 million USD yearly. This represents substantial earnings for the Sub-Saharan African economies when fully exploited. Shea trees grow in 21 Sub-Saharan African countries that can be grouped into 3 zones following their potentials for shea nut production per year: high production zone comprising of Benin, Burkina Faso, Cote D’Ivoire Ghana, Mali, Nigeria, Sudan and Uganda that have potentials of producing 70 000–300 000 tons per year; average production zone comprising of Cameroon, Chad, Central African Republic, Guinea Conakry, Senegal and Togo with potentials of 10 000–70 000 tons per year and low production zones made up of the Democratic Republic of Congo, Ethiopia, Gambia, Guinea Bissau, Niger and Sierra Leone with yearly production potentials less than 10 000 metric tons. Though semi mechanized and some few fully mechanized productions methods are employed in the major shea producing countries of West Africa, most of the rural women still used traditional processing procedures. Major importers of shea are European Union, Japan and the USA. The sector is still constrained by lack of mechanized processing in most localities, dwindling number of shea trees (due to bush burning, exploitation for wood, dependence on natural regeneration which is not very effective), lack of adequate technical and financial support to the sector and limited research on proper propagation methods that may shorten commencement of fruit production period from 10–15 years to about 3–5 years

Activated carbons from open air and microwave-assisted impregnation of cotton and neem husks efficiently decolorize neutral cotton oil

The decolorization of cottonseed oil with activated carbons (ACs) from neem and cotton husks has a dual interest: elimination of undesirable pigments in oil and valorization of the husks; by-products of neem and cottonseed processing, which would otherwise be dumped along riverbanks and farms causing environmental pollution. ACs were produced from neem and cottonseed husks after acid impregnation assisted by microwave heating and in ambient air for the decolorization of neutral cottonseed oil. The experimental data were analyzed by the intraparticle diffusion and the pseudo-second-order kinetic models as well as the Langmuir and Freundlich isotherm models. The method of impregnation and carbonization time had dramatic effects on the specific surface area (800–1500 g/m2), the quantity of burn-off (50–70 %), and methylene blue index (300–5000 mg/g) values which indicated the potential of the prepared activated carbons in the bleaching of vegetable oil and in other applications such as environmental clean-up and in agriculture. Pigment adsorption increased with temperature for all ACs indicating that the decolorization process was endothermic. The quantity of adsorbent equally had a significant effect on the pigment adsorption process for all ACs. All the activated carbons prepared in this work were 30–80 % more efficient in pigment adsorption than bleaching earth that is normally used in decolorizing neutral cotton seed oil in industries. All tested models are adequate to describe pigment adsorption by the ACs. Both methods of preparation of ACs were effective for oil decolorization, but microwave impregnation is more appealing because it requires only 1 h compared to 6 h for ambient air. Optimum decolorization conditions were 90 °C for 40min and adsorbent concentration of 2 %

Production zones and systems, markets, benefits and constraints of shea (

The shea tree is a multipurpose tree crop indigenous to Sub Saharan African. The tree is highly cherished for the oil that is extracted from its kernels and used nationally and internationally in cosmetics, pharmaceutics and in chocolate formulations. The processing and sales represent significant income earning opportunities for rural women who are the main stakeholders in the production chain. Shea nuts and its products are listed among the top ten Non-Traditional Exports of Ghana. In Burkina Faso it is the fourth most important export crop after gold, cotton and livestock and makes a contribution of about 6 million USD to the national economy. Today the shea tree is the second most important oil crop in Africa after the palm nut tree. About 500 million shea trees grow in Africa which has the potential of producing shea nuts worth about 150 million USD yearly. This represents substantial earnings for the Sub-Saharan African economies when fully exploited. Shea trees grow in 21 Sub-Saharan African countries that can be grouped into 3 zones following their potentials for shea nut production per year: high production zone comprising of Benin, Burkina Faso, Cote D’Ivoire Ghana, Mali, Nigeria, Sudan and Uganda that have potentials of producing 70 000–300 000 tons per year; average production zone comprising of Cameroon, Chad, Central African Republic, Guinea Conakry, Senegal and Togo with potentials of 10 000–70 000 tons per year and low production zones made up of the Democratic Republic of Congo, Ethiopia, Gambia, Guinea Bissau, Niger and Sierra Leone with yearly production potentials less than 10 000 metric tons. Though semi mechanized and some few fully mechanized productions methods are employed in the major shea producing countries of West Africa, most of the rural women still used traditional processing procedures. Major importers of shea are European Union, Japan and the USA. The sector is still constrained by lack of mechanized processing in most localities, dwindling number of shea trees (due to bush burning, exploitation for wood, dependence on natural regeneration which is not very effective), lack of adequate technical and financial support to the sector and limited research on proper propagation methods that may shorten commencement of fruit production period from 10–15 years to about 3–5 years

Bleaching of Neutral Cotton Seed Oil Using Organic Activated Carbon in a Batch System: Kinetics and Adsorption Isotherms

In the processing of cotton and neem seeds to obtain oil for diverse uses, enormous quantities of seed husk are generated as waste, which when not properly disposed of, poses environmental problems. One way of reducing this waste is to use it for the production of activated carbon (AC) for its multiple applications. In this work, activated carbon was produced from cotton and neem seed husks by carbonization followed by acid activation. The prepared ACs were characterized for its porosity and surface properties as well as for its ability to bleach neutral cotton seed oil. The prepared ACs are very efficient in the decoloration process, as they removed about 96–98% of the pigments compared to 98.4% removal with commercial bleaching earth. Temperature had a pronounced effect on the bleaching of neutral cotton seed oil. Maximum adsorption was observed at 60 °C for a contact time of 45 min. The adsorption kinetics were modelled by the intra-particle and the pseudo-second order equations while the adsorption isotherms followed the Langmuir and Freundlich equations. It is concluded that the organic ACs are efficient in pigment removal from neutral cotton seed oil and therefore are potential bleaching agents for the vegetable oil industry

Effect of Cooking on Moisture Sorption Isotherms of Sheanut (Vitellaria paradoxa Gaertn.) Kernels: Evidence from Light and Scanning Electron Microscopy

International audienceThe standard static gravimetric method was used to determine moisture sorption isotherms of both raw and cooked sheanut kernels at 40, 50 and 60 A degrees C in the water activity range 0.11-0.96 in order to evaluate the influence of cooking on the moisture sorption capacity of the kernels. Preliminary analysis showed that the kernels lost a significant quantity of its proteins and carbohydrate during the cooking process. Results of analysis of the moisture sorption isotherms revealed that cooked kernels generally had significantly (p < 0.05) lower equilibrium moisture contents (EMC) than the raw ones for both desorption and adsorption processes. The effect of temperature on the sorption processes as portrayed by the desorption isotherms revealed that EMC decreased steadily with increase in temperature within the water activity range 0.10-0.8 a(w) but increased rapidly with increase in temperature above 0.8 a(w) resulting in the overlap of isotherms for all sorption processes. This crossing over of isotherms was attributed to the dissolution of sugars at higher water activities. The protein matrix in the kernel was observed using light microscopy and was found to have been disorientated after cooking. Studies using light and scanning electron microscopy revealed that the reduced ability of cooked kernels to sorb water could be linked to changes in the structure of the kernels brought about by the cooking of the kernels. It is concluded that cooking had a very significant effect on the amount of water sorbed by sheanut kernels