Production of High-maltose Syrup and High-protein Flour from Rice by an Enzymatic Method

Abstract

A novel enzymatic process was developed to simultaneously produce high-maltose syrup and high-protein rice flour from milled rice. This process would greatly increase the commercial value of rice. A slurry of rice flour was first liquefied with α-amylase and then centrifuged, the precipitated fraction being recovered as high-protein rice flour. The supernatant fraction was then saccharified with α-amylase and debranching enzymes (isoamylase and/or pullulanase) together to produce high-maltose syrup under various conditions. The yield of high-maltose syrup was affected by the temperature, pH, DE value of the liquefied starch, the enzyme combination and variety of rice. As an example, 0.64 g of high-maltose syrup (83% maltose and 2.6% glucose) and 0.36 g of high-protein rice flour (29% protein, 39% starch and 14% sugar) could be produced from one gram of dry rice (Taichung Native 1).