Abstract
From ancient times, konjac has been recognized as a food rich in dietary fiber, and its use is still prevalent in a variety of food preparation applications. Konjac gel is prepared by adding an alkaline gelling agent to konjac flour that has been swelled with water. The effects of this method are rather unfavorable: the konjac becomes alkaline and emits a distinct alkali smell; it has an acrid taste; and it can change the taste and/or texture of other food ingredients. For this reason we searched for methods to prepare neutral konjac using microcapsules with an acid coated with hydrogenated oil. To keep the microcapsules from floating as a result of swelling, we selected konjac flour with a viscosity that would increase rapidly at temperatures 40°C. Our efforts to produce an agreeable flavor led to our selection of calcium hydroxide for the alkali coagulant and fumaric acid for the neutralizing agent. We prepared the content of a microcapsule by mixing fumaric acid with hydrogenated rapeseed oil with a melting point of 67.5°C at a ratio 7: 3. We found that neutral konjac can be prepared when the ratio of a microcapsule to calcium hydroxide is within the range of 0.7 to1.3. Our study of storage methods indicated that the quality can be maintained for a long time when neutral konjac has been subjected to retorting. Thus, a preparation method for industrial neutral konjac has been established.
