Production, obtention et valorisation des beurres exotiques

Abstract

By definition, “butters” are anhydrous and solid fats at room temperature. A lot of different crude fats and butters are available in Africa and other tropical countries, and their characteristics make often them interesting to valorise. This presentation will focus on a personal experience dealing with production and development of African butters. The production of butters and particularly the shea fat, is done by one of the two basic methods, roughly described as “traditional or modern”. The rural (traditional) vegetable oil extraction processes, which predominate the extraction technologies in many of the shea kernel producing areas, involve water extraction. This method often employs simple small sized and household equipments; it is based on aqueous extraction techniques to produce oil. The work is very hard but provides jobs, money and “consideration” to the women who are traditionally in charge of this work. Such a traditional method yields not more than 35% of the kernel oil contents and the product quality is often poor. It is obvious that a major contributing factor to the low yield is the treatment inability to adequately break the kernel cellular structures, a necessity to obtain an efficient oil/fat extraction. The “modern” methods involve the use of mechanical presses and organic solvents; although the methods are quite high-yielding (with extraction rates around 80%), they are reportedly difficult to perform because of the high latex content in the kernels: in fact the latex agglutinates and clogs the equipment or inhibits an efficient penetration of the extraction solvent. As we all know olein rich vegetable oils are globally abundant but commercial sources of vegetable fats, or “stearin”, are less common. Stearin is used in confectionery for chocolates, cakes, etc. and for margarine industries. The most developed and well-known source of stearin is cocoa butter; the development of this production is historical and is based on the “chocolate business” involving a lot of organisms and industries mainly located in “developed” countries. Beside this, other butters like Shea butter, Illipe, Kokum, Sal and mangoare available sources for substitutes in the production of cocoa butter improvers (CBI), equivalent (CBE) or substitutes (CBS). Other markets for Shea butter exist in the personal care industry; the main reason for this growing interest has been the recognition by the cosmetic industry and consumers of the Sheat butter therapeutic benefits (ultra violet light protection, antiinflammatory, moisturizing, regenerative, anti-eczema and anti-wrinkle properties) due to the presence of a significant fraction of unsaponifiable matters (3-15%) composed of many bioactive chemicals, e.g. triterpene alcohols, phenols, sterols and the poly-isoprenic hydrocarbons like karitenes. In this field of valorisation (cosmetics), the unsaponifiable content is a key factor. In 1992 on the demand of DESLOG company, ITERG worked and patented an interesting method of increasing the unsaponifiable content of Shea butter using cryogenic enrichment by fractionation at about – 30 °C. The final product called CRYOKARITENE (registered trade mark) can be enriched up to more than 50% of unsaponifiable and shows excellent dermo-cosmetic properties.