Thirteenth International Conference on Food Studies

Abstract

Grapes are an extraordinary source of native Lactic Acid Bacteria cultures (LABc) with potential oenological capabilities. Bacteria composition in Chile depends on various conditions that define “terroir”, providing a unique microbial footprint. This biodiversity opens an opportunity to find suitable native LABc not yet explored in the wine industry[1]. This work characterizes the biological diversity of Chilean LABc from grapes and to select cultures with malolactic fermentation potential. Biological diversity was evaluated through a spontaneous fermentation of S. Blanc and Chardonnay must. During the fermentation, aliquots were collected to determine kinetic fermentation and LABc presence. LABc were isolated, characterized, and purified by standard microbiological protocol[2]. The fermentative capacity was studied through an exclusionary experiment. First, the morphology stage included: gram stain[3] and catalase test[4]. Then, the carbohydrate fermentation protocol was executed, selecting homofermentative LABc[5]. At the same time, LABc were genetically identified[2]. The homofermentative LABc were grown with 10% ethanol and pH 3.5 to do a survival test[6]. The stressor tolerance test (pH, ethanol, and SO2) using the fittest LABc was done[6]. Finally, a designed culture media was used to determine the citric intake[7] and biogenic amine production[8]. Spontaneous fermentation presents different fermentation kinetics. Although there was a complete and incomplete fermentation for S. blanc and chardonnay, respectively, it was possible to collect a robust group of LABc. At the end of the experiment, 161 native LABc were selected to study fermentative capacity. From 161 LABc, the exclusionary experiment selected one LABc as the fittest bacteria.