Abstract
This study was carried out to evaluate the rheology of flour doughs containing 0.5% of hydroxypropylmethyl-cellulose (HPMC), methylcellulose (MC), and sodium alginate (SA), respectively. Farinograms, alveograms, a rapid visco analyzer (RVA), and rheofermentometer were employed in the analysis. According to the farinogram tests, the hydrocolloid additions caused changes in water absorption, dough development time, stability, and breakdown. The dough containing HPMC had the highest water absorption at $67.4{\pm}0.12%$. The HPMC dough also had the longest development time ($8.2{\pm}1.04$ min), stability ($12.7{\pm}0.42$ min), and breakdown ($7.9{\pm}1.3$ min). From the alveogram tests, P, G, and PIL values increased, whereas the L value decreased. The W values of the HPMC and SA doughs were increased, but that of the MC dough was decreased. According to the RVA results, the HPMC and SA doughs had reduced initial pasting temperatures whereas that of the MC dough was increased, but the difference was not significant. The peak viscosity of the MC dough also increased. Furthermore, all the doughs had increased breakdown times and decreases in final viscosity and setback. In the rheofermentometer tests, the HPMC dough presented the highest $H_m$, and the SA dough had the largest total volume.
HPMC, MC, SA 등의 증점제를 밀가루 중량대비 0.5% 첨가한 밀가루 반죽의 레올로지를 조사하기 위하여 farinogram, alveogram, rapid visco analyzer, rheofermentometer 등을 분석 한 결과는 다음과 같다. Farinogram 시험에서 증점제 첨가로 흡수율, 반죽발전시간, 안정도, 약화도 등이 변화하였다. 흡수율은 HPMC가 $67.4{\pm}0.12%$로 가장 높았고, 반죽발전시간은 HPMC가 $8.2{\pm}1.04$분, 안정도는 HPMC가 $12.7{\pm}0.42$분, 약화도는 HPMC가 $7.9{\pm}1.3$분으로 가장 길었다. Alveogram 시험에서 P, G, P/L 모두 증가되었으나 L은 모두 감소하였다. W는 HPMC와 SA는 증가되었으나 MC는 감소되었다. Rapid visco analyzer 특성에서 초기호화온도는 HPMC와 SA는 낮아졌고, MC는 높아졌으나 그 차이는 크지 않았다 최고점도는 모두 높아졌고, 약화도는 모두 증가되었으며, 최종점도와 set back은 모두 낮아졌다. Rheofermentometer 시험에서 $H_m$은 HPMC가 가장 높았고, 총 부피는 SA가 가장 컸다.
