PT  - JOURNAL ARTICLE
AU  - Masakazu Fukui
AU  - Koki Yokotsuka
TI  - Content and Origin of Protein in White and Red Wines: Changes during Fermentation and Maturation
AID  - 10.5344/ajev.2003.54.3.178
DP  - 2003 Jan 01
TA  - American Journal of Enology and Viticulture
PG  - 178--188
VI  - 54
IP  - 3
4099  - http://www.ajevonline.org/content/54/3/178.short
4100  - http://www.ajevonline.org/content/54/3/178.full
SO  - Am J Enol Vitic.2003 Jan 01; 54
AB  - Soluble protein contents in experimental wines from five grape cultivars grown in Japan from 1990 through 2000 and in commercial Japanese wines from six cultivars grown from 1994 through 2000 ranged from 29.8 to 107.1 mg/L. Very stable soluble proteins in the range of 13.6 to 36.4 mg/L remained in the experimental and commercial wines even after severe heat-chill treatment followed by heavy bentonite fining. Most of the soluble proteins (approximately 90% of the total protein content) in wines were derived from the soluble proteins present in juice. In Chardonnay and Cabernet Sauvignon grapes, yeast proteins and seed and skin proteins were undoubtedly transferred to wines during vinification via skin/seed contact, which contributed to wine protein content. The degree of contribution depended upon the grape variety. During maturation (the early stage of aging) of Chardonnay and Koshu white and Cabernet Sauvignon and Muscat Bailey A red wines, soluble protein content changed only slightly. Polysaccharides or polymeric tannins interacted with the proteins to form complexes or similar entities, thereby stabilizing the soluble proteins in the wines.Acknowledgments: The authors express their gratitude to Tsunemasa Nakao and Yasumichi Okuno, the Institute of Enology and Viticulture, Yamanashi University, for technical assistance.