Abstract
We have investigated techniques for extracting aroma components from fruits for the purpose of utilizing them as flavors. Since many aroma components are unstable to heat, we have researched concentration techniques that do not involve a heat-treatment, such as progressive freeze-concentration and membrane-separation. Aqueous solutions of aroma components were obtained by distillation from various fruits (European pear (La France), peach and apple), and were further concentrated by progressive freeze-concentration or membrane-separation. When the aqueous solutions of aroma components were concentrated about 11 times (volume / volume) by progressive freeze-concentration, the recoveries of many aroma components were about 90%. When the same samples were concentrated 10 times (volume / volume) by reverse membrane osmosis, the solute rejections were about 80-90%. By either method, the aroma components were condensed efficiently. The osmotic pressure of the aqueous solutions, vacuum distillation condensates of fruits juice, were considerably smaller than that of fruit juice. In the case of the La France pear, the osmotic pressure of the aqueous solution was about 1/43 of that of juice, and for peach it was about 1/18. Since the osmotic pressures of the aqueous solutions were low, we considered that the solutions were condensed efficiently. These technologies were applied to produce a new flavor which used La France aroma components. The response of food producers and consumers to the flavor is positive, and some foods and a drink which uses it, have already been commercialized.
