Search Results (3)

Background: The cider industry is becoming an increasingly important segment of the apple fruit sector in Argentina. This study evaluated different inoculation strategies using two Patagonian strains to produce ciders with reduced malic acid and enhanced quality from acidic apple musts. Methods: Fermentations were performed using Pichia kudriavzevii NPCC1651 (isolated from cider) and Saccharomyces cerevisiae ÑIF8 (isolated from wine) in pure, simultaneous, and sequential inoculations. Viable cell counts, glucose and fructose consumption kinetics, and malic acid depletion were measured during fermentation, while physicochemical and aromatic profiles of the ciders were also analyzed in the final products. Results: P. kudriavzevii was capable of coexisting with S. cerevisiae until the final stages of fermentation, independently from the inoculation strategy employed. The simultaneous inoculation at a 1:1 ratio and the sequential inoculation initiated with S. cerevisiae showed the best performance. Both strategies produced ciders with high fermentative efficiency and elevated levels of lactic and succinic acids, isoamyl alcohol, 2-phenylethanol, isoamyl acetate, and 2-phenylethyl acetate while reducing acetic acid and ethyl acetate levels. These fermentations also achieved higher malic acid consumption compared to pure cultures. Conclusions: The simultaneous inoculation at a 1:1 ratio is proposed for further pilot-scale testing in natural acidic musts due to its operational practicality and its potential to produce ciders with reduced malic acid and improved sensory quality. Full article

The spontaneous malolactic fermentation (MLF) in a centenary winery from Patagonia, Argentina, is conducted by predominantly mesophilic Oenococcus oeni and Lactiplantibacillus plantarum. In this region, MLF takes place from 14 to 4 °C, leading to heat cellars incurring in higher costs and non-sustainable practices. Previously, psychrotrophic strains of O. oeni had been obtained from a Patagonian wine. The goal of this work was to identify the Lactobacillaceae microbiota related to low-temperature MLF and assess their contribution. Nine sychrotrophicc Lentilactibacillus hilgardii strains were identified by sequencing the 16S rRNA gene, and the strains typified by RAPD-PCR. All strains consumed L-malic acid at 4 and 10 °C in sterile wine. The selected UNQLh1.1 strain revealed implantation capacity and L-malic acid consumption at 4 and 10 °C in the presence of the native microbial consortium. Furthermore, the histidine decarboxylase (hdc) gene was not detected in any of the Len. hilgardii strains. The prevalence of Len. hilgardii under low-temperature conditions represents a novelty compared to previous findings of LAB diversity in the MLF of Patagonian wines. The native Patagonian psychrotrophic Len. hilgardii strains are a new player in fermentations conducted at low temperatures with the potential to be used as a sustainable MLF starter. Full article

The by-products of the food industry are an economic alternative as a source of nutrients to obtain biomass. At the same time, theiruse could solve the environmental problem related to their disposal, which is highly polluting due to their elevated biochemical oxygen demand. In this work, we seek to optimize the production of cellular biomass of two native Patagonian strains of Lactiplantibacillus plantarum (UNQLp 11 and UNQLp155), selected for its oenological and technological properties, using apple pomace (AP), a residue from the juice and cider industry. The supplementation of AP with yeast extract, salts, and Tween 80 (sAP), proved to maintain the growth of the Lpb. plantarum strains, similar to the commercial medium used to grow LAB (De Man, Rogosa, Sharpe, MRS). Cultures grown in sAP medium showed good tolerance to wine conditions (high ethanol content and low pH), demonstrated by its ability to consume L-malic acid. The subsequent inoculation of these cultures in sterile wines (Merlot and Pinot noir) was carried out at laboratory scale, evaluating cell viability and L-malic acid consumption for 21 days at 21 °C. Cultures grown in sAP media showed a similar performance to MRS media. Thus, sAP media proved to be a suitable substrate to grow oenological Lpb. plantarum strains where cultures (with high size inoculums) were able to drive malolactic fermentation, with an L-malic acid consumption higher than 90%. Full article