Comparison of Physicochemical Properties of Starch Phosphates Prepared by Dry Heating and Extrusion Process

건식법과 Extrusion 공정에 의해 제조한 인산전분의 이화학적 성질 비교

Starch phosphates were prepared by dry heating, gelatinizing method and extrusion process using sodium tripolyphosphote (STPP) as a substitution reagent and their physicochemical properities were compared. In the preparation of starch phosphate by dry heating method(DSP), the effect of reaction temperature was the most significant to the DS(Degree of substitution). In the phosphorylation reaction with gelatinized starch(GSP), the substitution ratio was increased with increasing the reaction temperature, but the increase was insignificant above $85^{\circ}C$. By extrusion with the corn starch containing 2.0% STPP at various moisture contents of 20, 25 and 30%, the DS values of extrudate(WESP) were within the range of between 0.0066 and 0.0083. The starch phosphate(DSP) products showed lowering the gelatinization temperature, increasing the clarity of the starch paste. However, WESP showed higher gelatinization temperature than that of raw starch. The starch phosphate prepared by extrusion process showed lower apparent viscosity of paste than that of the DSP at same condition. All of starch phosphates showed reducing the tendency of the paste retrogradation.

옥수수전분에 인산화반응 시약으로 Sodium tripolyphosphate(STPP)를 반응시켜 건식법, 호화법 및 Extrusion 공법에 의하여 인산전분을 제조하고 그 이화학적 성질을 비교하였다. 건식법에 의한 인산전분(DSP) 제조시 반응온도는 인산염 치환도에 가장 큰 영향을 미치는 인자로 작용하였다. 호화법에 의해 인산전분(GSP)을 제조하였을 경우는 건식법보다 치환도가 증가하였으나 반응온도가 $85^{\circ}C$ 이상에서는 큰 변화가 없었다. Extrusion공정에 의한 인산전분(WESP) 제조는 원료수분 20, 25, 30%에서 치환도 $0.0066{\sim}0.0083$의 값을 보였다. DSP 시료의 호화온도는 치환도가 증가할 수록 낮아졌고 투명도가 증가되었으나 WESP 시료는 원료전분보다 높은 호화온도를 보였다. 인산전분 extrudate의 겉보기 점도는 DSP 시료보다 낮은 점도값을 보였다. 모든 인산전분 시료가 원료전분에 비해 높은 노화안정성을 보였다.