Alcoholic fermentation of bergamot juice does not modify its anticholesterolemic compounds

Bergamot (Citrus bergamia Risso) juice has two anticholesterolemic compounds [brutieridin and melitidin] exhibiting statin-like properties (Di Donna et al., 2009); however, bergamot juice is not directly drunk due to its intense bitter taste. Although it is possible to obtain a flavored wine from bergamot juice, it is not produced for consumption, due to the methanol produced from citrus pectin during winemaking. Acetic acid bacteria can produce flavored and much appreciated methanol-free vinegar from bergamot wine (Caridi and Manganaro, 1996). This research aims to examine the effects of winemaking, if any, on brutieridin and melitidin, to ascertain if flavored methanol-free bergamot wine and bergamot vinegar are valorized by the presence of these compounds. We tested two different combinations: A) mix of bergamot juice and grape must from dried grapes [ratio 1:2] - pH 2.94, °brix 20.80, and B) bergamot juice with the addition of saccharose - pH 2.94, °brix 20.80. The juices were prepared and immediately inoculated in triplicate with 5% precultures of two strains of Hanseniaspora spp. and two strains of Saccharomyces cerevisiae specifically pre-selected. The brutieridin and melitidin content in juices and wines was determined by LC–ESI-MS/UV analysis (Di Donna et al., 2009). The results clearly indicate that winemaking does not modify the two anticholesterolemic compounds: the initial content of 115 ppm of brutieridin in juice A, ranges between 118 and 135 ppm at the end of the alcoholic fermentation. Analogously, its content in juice B varies from 282 to 262÷351 ppm, at the beginning and at the end of winemaking, respectively. A similar behavior was observed for melitidin. The results here presented throw light on the possible use of flavored methanol-free bergamot wine and/or bergamot vinegar as nutraceuticals in the control of blood cholesterol level. Caridi A., Manganaro R. - Production trials of flavored vinegars from bergamot juice. Essenze Derivati Agrumari, 66, 376-388, 1996 (in Italian). Di Donna L. et al. - Statin-like principles of Bergamot fruit: isolation of 3-hydroxymethylglutaryl flavonoid glycosides. Journal of Natural Products, 72, 1352-1354, 2009.