Investigating Yeast Products in Sparkling Wine Production

A team of researchers in Spain has examined the use of commercial yeast products in the production of white and rosé sparkling wines.¹ Using a range of analytical techniques, including gas chromatography–mass spectrometry (GC–MS) and high performance liquid chromatography (HPLC), the team examined four yeast autolysates to find out how they affect the chemical composition, foam, and sensory properties of sparkling wines aged on lees for nine months.   During the production of wine, mannoproteins - highly glycosylated proteoglycans made up of mannose, glucose, and proteins - are released via yeast autolysis. These mannoproteins can have positive effects on the wine, such as an improvement in aroma and a reduction in bitterness. Traditionally the best sparkling wines can take many months to ferment to the perfect quality. The longer the process takes, the higher the associated production costs and the greater the risk of microbiological and organoleptic alterations. To speed up this process commercial yeast products rich in mannoproteins have been developed. The effect of these products on still wines has been extensively studied, and they have been found to improve the quality characteristics of the wine. However, very few studies have examined the effect on sparkling wines.    All of the wine used in the study was produced following the traditional (champenoise) method. The team used GC–MS to determine the monosaccharide composition of the dry yeast products. The percentage of mannose in the four yeast products varied between 53% and 86%; the percentage of glucose was between 14% and 47%. HPLC was used to analyze phenolic compounds and amino acid and biogenic amine content. The foaming properties of the sparkling wine were evaluated according to the Mosalux procedure. By comparing the control and the sparkling wines, the team found that the addition of the yeast products did not affect the foam quality of the wines or the phenolic compound content in any significant way. In fact, the yeast product with the highest mannoprotein content actually enhanced the volatile composition and the subsequent fruity aroma in some of the sparkling wines.   Reference 1. Silvia Pérez-Magariño, Leticia Martínez-Lapuente, Marta Bueno-Herrera, Miriam Ortega-Heras, Zenaida Guadalupe, and Belén Ayestarán, Journal of Agricultural and Food Chemistry63(23), 5670–5681 (2015).