1H qNMR of Alcoholic Cider – Analysis of Small Molecule and Residual Sugar Chemistry

1H quantitative NMR (qNMR) has been utilized to assess the the small molecule and carbohydrate chemistry of a number of home-brewed and commercial alcoholic ciders. A quantitative chemistry distribution of the products of the various fermentations that occur in cider making. Malolactic fermentation as well as fermentation by saccharomyces and wild yeasts occur in the cider making process which traditionally occurred without the intentional addition of yeast by the manufacturer. The distribution of small molecules produced by the yeast and bacterial metabolomes at work in the process can yield information of the sensory perception of ciders produced in different ways. An investigation of the residual sugar chemistry of commercial ciders gives some indication of the process of sweetening commercial cider products with sugar additions after fermentation is complete. These typical commercial ciders are very different in chemistry distribution compared to very dry cider styles such as those found in the Basque region of Spain where fermentation is taken to the extreme resulting in complete conversion of sugars to alcohol but also glycerols to 1,3 propandiol. Finally it was decided to determine how much quantitative chemistry information could be obtained from benchtop NMR systems operating in the 60 MHz range. These benchtop NMR systems have a price and cost-of-ownership that would allow small laboratories of manufacturers to think about their use in QA and QC roles.

1H qNMR analysis of molecular components in hard cider – targeted and non-targeted quantitative chemical analysis