Sucrose delays the start and the ending of the gelatinization process. These results are in agreement with the results reported by Maaurf, Che Man, Asbi, Junainah, and Kennedy (2001). In their investigation, for example, from 0.0 to 0.2 g sucrose/g starch the delay of onset temperature (To) was about 2.1 °C at water:starch ratio 3:1, which increased from 64.4 to 66.5 °C and the delay of melting temperature (Tm) was about 1.7 °C which climbed from 80.4 to 82.1 °C. The delaying effect was even more pronounced at lower water:starch ratios (1:1). The reason was that the small molecules of sucrose could penetrate into the interior of starch granules during the gelatinization process of corn starch, and the multiple hydroxyl groups contained in the sucrose structure interacted with the starch chains, hindered the water swelling of starch. As a result, gelatinization process was delayed and the gelatinization temperature was increased. Furthermore, the presence of sucrose, reduced the water content and the water activity, thereby affected the interaction between the starch chains and water molecules, and finally influenced the starch gelatinization ( Kohyama & Nishinari, 1991). This was also interpreted by some researchers ( Prokopowich & Biliaderis, 1995) that small carbohydrate molecules which fit well in the hydrogen bonded structure of water had a stabilizing effect on the polymer chains, thus retarded chain reordering. The reverse was true for incompatible solutes that greatly disturbed the water structure.
Sucrose delays the start and the ending of the gelatinization process. These results are in agreement with the results reported by Maaurf, Che Man, Asbi, Junainah, and Kennedy (2001). In their investigation, for example, from 0.0 to 0.2 g sucrose/g starch the delay of onset temperature (To) was about 2.1 °C at water:starch ratio 3:1, which increased from 64.4 to 66.5 °C and the delay of melting temperature (Tm) was about 1.7 °C which climbed from 80.4 to 82.1 °C. The delaying effect was even more pronounced at lower water:starch ratios (1:1). The reason was that the small molecules of sucrose could penetrate into the interior of starch granules during the gelatinization process of corn starch, and the multiple hydroxyl groups contained in the sucrose structure interacted with the starch chains, hindered the water swelling of starch. As a result, gelatinization process was delayed and the gelatinization temperature was increased. Furthermore, the presence of sucrose, reduced the water content and the water activity, thereby affected the interaction between the starch chains and water molecules, and finally influenced the starch gelatinization ( Kohyama & Nishinari, 1991). This was also interpreted by some researchers ( Prokopowich & Biliaderis, 1995) that small carbohydrate molecules which fit well in the hydrogen bonded structure of water had a stabilizing effect on the polymer chains, thus retarded chain reordering. The reverse was true for incompatible solutes that greatly disturbed the water structure.
การแปล กรุณารอสักครู่..
