The Effect of Juice Clarity and Several Conditions Promoting Yeast Growth on Fermentation Rate, the Production of Aroma Components and Wine Quality

Abstract

Special thanks are due to Mr. H. Pool for assistance in the making of the wines and performing gaschromatographic analyses on them.

Optimization of the fermentation conditions of musts from Pedro Ximenez grapes grown in Southern Spain. Production of higher alcohols and esters

“…The sum of the final contents in higher alcohols depends significantly (99%) on the fermentation temperature, which is consistent with the findings of other authors (Houtman and Du Plessis, 1981;Poulard et al, 1983;Ciolfi et al, 1985). On the other hand, no significant differences were found in this work between the degrees of ripeness.…”

“…However, Houtman and Du Plessis (1981) found the production of ethyl esters of fatty acids to be relatively independent of the fermentation conditions, while Soufleros and Bertrand (1980) found low temperatures to favour the synthesis of these compounds by S. cerevisiae. Ough (1982) obtained the highest contents in ethyl hexanoate at 20°C and those of ethyl octanoate and decanoate at 15°C.…”

“…The presence of solid suspended matter -whether naturally occurring substances or inert compounds added -favours the formation of higher alcohols (Crowell and Guymon, 1963;Houtman and Du Plessis, 1981). In this respect, Bertrand et al (1978) found greater production of higher alcohols and ethyl acetate from slurry musts and of higher esters from deslurred musts.…”

Purification of Pectin Lyase fromByssochlamys fulva: Its Application in Wine Fermentation

“…This might be due to the reason that enzymes helped in removing the suspended solids considerably and resulted in low level of turbidity (Houtman et al 1980). Similar findings characterizing the wines made from clarified grape juices have also been reported by other research workers (Williams 1975;Houtman and Duplessis 1981;Liu et al 1987). Wines obtained from enzymatically clarified musts were rated better in terms of color, taste, flavor and appearance compared with nonclarified wines (Joshi and Bhutani 1991).…”

“…Wines obtained from enzymatically clarified musts were rated better in terms of color, taste, flavor and appearance compared with nonclarified wines (Joshi and Bhutani 1991). Similar findings characterizing the wines made from clarified grape juices have also been reported by other research workers (Williams 1975;Houtman and Duplessis 1981;Liu et al 1987).…”