내열성 α-amylase 처리 압출팽화미분의 이화학적 특성 = Physicochemical properties of rice flour extrudates treated with a thermostable α-amylase

다국어 초록 (Multilingual Abstract)

This study was aimed to prepare rice flour extrudates(RE) desirable for development of on-the-go rice food and investigate their physicochemical properties. In order to cause mechanical and enzymatic hydrolysis of rice starch, rice flour(RF) was extruded with thermostable α-amylase(0, 0.4, 0.8, 3, and 5%) at 80, 85, 95℃ for the I, II, and III sections of barel, respectively, 0.775 kg/min feed rate, 250 rpm screw speed, and 30% moisture content. Expansion ratio(ER) was >1 for RE-0.4 and 0.8% while <1 for RE-3 and 5%, indicating weak puffing by severe hydrolysis and shrinkage during cooling after extrusion. Extrusion with increasing enzyme addition ratio resulted in RE with a lower WAI and higher WSI. WSI of RE-0.4% was 5 times higher than RE-0% while its WAI was a half of RE-0%. Digestibility of RE-5% was lower by 25∼30% than that of RE-0%. Extrusion with α-amylase promoted a reduction in paste viscosity, which was more intense with the amylase addition amount. RE-0.4 and 0.8% showed higher dispersion stability in cold water, especially at >16% concentration, compared to RP and other RE. Results in this study suggested that extrusion with 0.4% amylase would be desirable for development of instant rice food with high digestibility and desirable dispersion properties in cold water.

목차 (Table of Contents)

• ABSTRACT (초록)
• iii
• I. 서 론
• 1
• II. 재료 및 방법
• 4
• 1. 재료
• 4
• 2. 압출팽화
• 5
• 3. 팽화율 측정
• 6
• 4. 미세구조의 측정
• 7
• 5. 전분소화율 측정
• 8
• 6. 수분흡착지수와 수분용해지수의 측정
• 9
• 7. 페이스트의 호화 점도 측정
• 10
• 8. 분산 안정성 측정
• 11
• Ⅲ. 결과 및 고찰
• 12
• 1. 효소처리 압출팽화미분의 팽화율의 변화
• 12
• 2. 효소처리 압출팽화미의 미세구조
• 14
• 3. 효소처리 압출팽화미분의 전분소화율
• 16
• 4. 효소처리 압출팽화미분의 수분흡착지수와 수분용해지수
• 18
• 5. 효소처리 압출팽화미분의 페이스트 호화 점도
• 21
• 6. 효소처리 압출팽화미분의 분산 안정성 측정
• 25
• 7. 결론
• 28
• IV. 요 약
• 30
• V. 참고문헌
• 32