Study on the preparation and properties of puffing glutinous rice starch

The puffing glutinous rice starch (PGRS) could be obtained by adding glutinous rice starch (GRS) with the moisture content of 21% into the bulking machine and expanding at 225°C and under 0.75 MPa. The gelatinised GRS had increased adhesive strength. Compared with gelatinisation by heating and adding alkali, gelatinisation by puffing was easier to control and had a higher degree of starch gelation. Thermogravimetry (TG) and differential thermogravimetry (DTG) showed that PGRS had improved thermal stability. The starch granule was disintegrated after puffing and therefore more hydrophilic hydroxyls were exposed. The PGRS had increased water-solubility, which was shown in IR spectrometry with a broad and strengthened peak of O-H stretching vibration. Scanning electron micrograph (SEM) found that the PGRS granules were shaped in rough surface, which would have a strong affinity for water. Therefore, it might be widely applied in the adhesive and pharmaceutical industries.