Effects of process variables on the physicochemical properties of brown rice-water chestnut extrudates

• Main Authors: Hsueh, Ya-Ko, 薛雅歌
• Other Authors: Lin, Jen-Shinn
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/97379868466746992362

碩士 === 國立屏東科技大學 === 食品科學系所 === 97 === We anticipate using extrusion technology to develop a functional snack food by adding water chestnut powder in the process of extrusions. The process variables including feed moisture content were set at 15% and 18% and the process including feed composition of brown rice powder and water chestnut powder (100:0, 90:10, 80:20, 70:30, 60:40, 50:50 and 0:100) and different particle sizes (14-30 and 30-50 mesh). The effects of moisture content, moisture retention, water activity, color, water absorption index, water solubility index and resistant starch content of extrudates were investigated in this study. The results indicated when the feed moisture content was at 18% either the particle size of 14-30 or 30-50 mesh gained highest extrudate moisture content, water activity and resistant starch content. When particle size was in the range of 14-30 mesh and feed moisture content was at 15%, produced highest moisture retention and L value except the group with feed composition of 60:40. When particle size was at 30-50 mesh and feed moisture content was at 18%, gained highest moisture retention and L value. The feed moisture content was at 15%, feed composition was at 60:40 and 50:50 and the particle size was at 14-30 mesh produced highest a value, the rest gained greater a value when feed moisture content was set at 18%. The feed moisture content of 15% produced highest a value when the particle size is 30-50 mesh. When the particle size was at 14-30 mesh and the feed moisture content was at 18%, produced greater b value. Changing the particle size to 30-50 mesh, the group with feed moisture content of 15% gained higher b value. The water absorption index showed highest when the particle size was at 14-30 mesh, feed composition was at 80:20 and the feed moisture content was set at 18%. The rests were gained greatest b value at the 15% of feed moisture content. The water absorption index also showed greater when particle size was at 30-50 mesh, feed composition were at 90:10, 70:30, 60:40 and the feed moisture content was at 15%. When particle size was 14-30 mesh, feed moisture content was at 18% produced higher water solubility index. When particle size was at 30-50 mesh, feed composition were 60:40 and 50:50 and the feed moisture content was 15%, produced highest water solubility index.