Characteristics and Application of Soybean Hull Fractions Obtained by Microparticulation/Air-Classification

초미세분쇄/공기분급을 이용한 대두피 분획물의 특성과 응용

Soybean hull was microparticulated at cut-off wheel speed of 9,000 rpm and air-classified into fine and coarse fraction at air classifying wheel speeds (ACWS) of 10.000, 15,000 and 20,000 rpm. respectively. Proximate analysis of the coarse and fine fractions of the microparticulated/air-classified soybean hull showed that ash, protein and lipid were enriched in the coarse fractions and carbohydrates in the fine fraction. Dietary fiber were enriched in coarse fractions and dietary fiber and dietary fiber content increased with decreasing ACWS. Mean particle size of fine fractions ranged from $3.1{\mu}m\;to\;5.5{\mu}m$ that of coarse fractions ranged from $9.9{\mu}m\;to\;20.0{\mu}m$ and both increased with decreasing ACWS. The particles were mostly oval-shaped regardless of the fractions. Generally the fraction of low ACWS showed higher viscosity. In water holding capacity, oil absorption and emulsion capacity, there was significant difference between coarse and fine fractions while there was no significant difference as a function of different ACWS. Oil absorption of flying batter was decreased significantly in the fraction of ACWS 15,000. when cakes and cooking were prepared partially substituted with soybean hull fraction, there was no significant changes on their physical and sensory properties up to 10% substitution.

초미세분쇄한 대두피 분말을 공기분급휠속도 (ACWS, air classifying wheel speed) 10,000 rpm, 12,000 rpm 및 20,000 rpm에서 공기분급하였을 경우 회분, 단백질 및 지방은 조분획으로, 탄수화물은 미분획으로 각각 농축되었다. 식이섬유는 조분획으로 농축되었고, ACWS가 감소함에 따라 그 함량이 증가하였다. 분획별 입자크기는 ACWS가 감소함에 따라 증가하였는데 그 범위는 미분획은 $3.1{\mu}m\;to\;5.5{\mu}m$였고, 조분획은 $9.9{\mu}m\;to\;20.0{\mu}m$였으며, 그 형태는 분획에 관계없이 대부분 모서리가 있는 타원형이었다. 전반적으로 낮은 ACWS에서 높은 점도를 보였고, 보수력, 보유력 및 유화력의 경우 조분획과 미분획에 유의적인 차이가 있으나 ACWS에 따라서는 차이가 없었다. 식품응용실험 결과 대두피 분말을 10, 20, 30% 각각 대체시켜 튀김옷으로 활용하였을 때, 기름 흡수량이 대조구에 비하여 감소하였으며, 케익과 쿠키의 제조에 있어서 밀가루를 대두피 분말로 10% 수준까지 성공적으로 대체할 수 있었다.