Physiological significance of the cytometric distribution of fluorescent yeasts after viability staining.

This article describes a new method for the early detection of alcoholic fermentation arrest. This methodology is based on the flow cytometric assessment of Saccharomyces cerevisiae yeasts stained with a carboxyfluorescein diacetate fluorescent viability probe. Multicomponent analysis of viable cell distribution constitutes a promising new tool to describe physiological and dynamic changes to heterogeneous viable populations during alcoholic fermentation, through its ability to discriminate between successful processes and those ending prematurely.

Deuterium nuclear magnetic resonance spectroscopy and stable carbon isotope ratio analysis/mass spectrometry of certain monofloral honeys.

Quantitative deuterium nuclear magnetic resonance spectroscopy (NMR) has been used in conjunction with stable carbon isotope ratio analysis/mass spectrometry to refine the detection of sugars that have been added to monofloral honeys. The 13C content of sugars indicates the type of photosynthetic metabolism of the plant that synthesized them; the deuterium content is more characteristic of secondary metabolism and of environmental factors. Consequently, determination of the 13C content of honeys and of proteins extracted from the honeys can be used to detect the addition of C4 plant sugars (cane or corn), but it does not reveal the addition of C3 plant sugars such as beet sugar.