Abstract
Juices of Golden Queen, Neo-Muscat and Seibell-9110 were prepared with the addition of $SO_2(100ppm)$ in must and juice, of $SO_2(100ppm)$ and pectinase (40mg/l) in must, respectively and then 300mg/1 of Polyclar AT were added on different white wines from grape juices. Phenolics content in grape juices and white wines were determined. and also changes of browning capacity of white wines during the storage periods at $45^{\circ}C$ were investigated by accelerated method. Extraction of total phenol into grape juices was increased significantly in $SO_2-pectinase$ addition lot and content of total phenol of Seibell-9110 juice was two or three times higher than the others. Yield of grape juices was highest in $SO_2-pectinase$ addition lot. Ethanol content of white wines were 11.4-12.0 v/v% , and total acid, fusel oil and methanol content of Neo-Muscat white wine was lower than that of the other white wines. Total phenol content of white wines was 25-50% lower than that of grape juices and 50-80% lower in colour. Browning capacity of white wines was decreased by 25-40% for 18 days at $45^{\circ}C$ with addition of Polyclar AT, but Seibell-9110 white wine prepared from $SO_2-pectinase$ addition lot was not available commercially because of severe browning.
백포도주 양조시 페놀성분의 산화에 의한 갈변을 억제하여 색상과 풍미가 좋은 백포도주를 생산하고자 Golden Queen과 Neo-Muscat 및 Seibell-9110을 착즙전 또는 착즙후 아황산과 pectinase를 처리하여 과즙을 얻고 이를 $18{\sim}20^{\circ}C$에서 7-14일간 발효시켜 백포도주를 양조한 후 각 양조과정중 페놀류의 함량의 변화를 조사하고 양조한 백포도주에 polyclar AT(PVPP)를 처리한 후 열처리기간에 따른 갈변도의 변화를 측정하였다. 과즙중의 충 페놀함량은 파쇄한 과육에 아황산 pet-tinase 병행 처리구의 과즙이 무처리구보다 Golden Queen에서 33%, Neo-Muscat 70%, Seibell-9110에서 40% 더 높았고 청징도와 과즙 수율도 더 높았다. 백포도주의 일반성분은 품종별, 처리구간별 큰 차이가 없었으나 아황산 pectinase 병행 처리구의 메탄을 함량이 타구에 비하여 높았다. 또한 과즙에 비하여 백포도주의 총 페놀함량은 25-50%, 색도는 $50{\sim}80%$ 낮았다. PVPP 처리로 과즙중의 flavonoid phenol 함량은 $10{\sim}24%$, non-flavonoid phenol 함량은 약 3%가 제거되었다. 열처리 $(45^{\circ}C)$ 기간중 백포도주의 갈변은 Neo-Muscat과 Golden Queen의 경우 각 처리구에서 420nm의 흡광도가 0.3 이하로 심하지 않았으나 Seibell-9110의 경우 특히 파쇄한 과육에 아황산과 pectinase를 병행 처리한 구에서 심하게 갈변 하였다.