Manufacture and Characterization of Gua-Nai: A New Dairy Food Produced with an Oriental-Type Culture

Abstract

Gua-nai is a sweet-set gel produced from pasteurized whole or skim milk. The milk-clotting enzymes were elaborated from Chinese wine cake culture raised on steamed glutinous rice (sweet rice). The organisms involved were isolated and identified as Amylomyces rouxii, Rhizopus oryzae, Aspergillus oryzae, and a single yeast, Endomycopsis burtonii. These organisms were employed in the reconstitution of the wine cake culture using sweet rice flour as the medium. During the rice fermentation, a clear, effervescent, pale yellow liquid phase appeared exhibiting both proteolytic and milk-clotting activities and containing ethanol. Taxonomic studies of the mycoflora of the fermenting rice also revealed a gradual disappearance of the filamentous molds, leaving only the yeast in the medium at completion of fermentation. A consumer taste panel did not indicate significant differences between gua-nai made with commercial wine cake culture and that made with the culture reconstituted from isolated microorganisms. © 1987, American Dairy Science Association. All rights reserved.