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Investigating the Influence of Vessel Shape on Spontaneous Fermentation in Winemaking

Publication . Malfeito-Ferreira, Manuel; Granja-Soares, Joana; Chandra, Mahesh; Asryan, Arman Asryan; Oliveira, Joana; Freitas, Victor; Loira, Iris; Morata, Antonio; Cunha, Jorge; Harutyunyan, Mkrtich

The earliest archaeological evidence of wine came from ceramic vessels of the Tran- scaucasian ‘Shulaveri-Shomutepe’ or ‘Aratashen-Shulaveri-Shomutepe culture’ (SSC/AShSh: c. 6000–5200 BC). Western European ‘Bell Beaker culture’ (BB: c. 2500–2000 BC) is characterized by bell- shaped pottery vessels but has so far not been found with residues consistent with wine. Knowing that wild grapes populated both habitats, the absence of wine during the Bell Beaker period remains to be explained. The main goal of this work was to investigate whether the shape of the vessels could influence the performance of spontaneous fermentation, specifically regarding the production of volatile acidity. Crushed grapes or juices from various grape cultivars were fermented in two types of vessels: (i) borosilicate glass beakers (4–5 L) to imitate bell beakers and (ii) Erlenmeyer flasks (5 L) to imitate SSC/AShSh vessels. Fermentations occurred spontaneously, and the wines were analyzed for their conventional physical–chemical parameters (e.g., ethanol content, total acidity, volatile acidity, pH), chromatic characteristics (e.g., wine color intensity, wine hue), and volatile composition by gas-chromatography-flame ionization detection (GC-FID). At the end of fermentation, the yeast species were identified by molecular methods. In addition, wine yields and phenolic composition (e.g., total phenols, anthocyanins, total pigments) were determined for wild grapes in comparison with six red varieties Vitis vinifera L. subsp. sativa (Vinhão, Marufo, Branjo, Melhorio, Castelão and Tempranillo Tinto), chosen as a function of their genetic relatedness with the wild counterpart. Wines produced from V. sylvestris grapes showed higher total acidity and color intensity when compared to the cultivated varieties. Saccharomyces cerevisiae dominated at the end of all spontaneous fermen- tations in all types of vessels and conditions. Wines fermented in Erlenmeyers showed ethanol concentrations as high as 14.30% (v/v), while the highest ethanol level was 12.30% (v/v) in beakers. Volatile acidity increased to a maximum of 4.33 g/L (acetic acid) in Erlenmeyers and 8.89 g/L in beakers. Therefore, the shape of the vessels influenced the performance of fermentation, probably due to the different exposures to air, leading to vinegary ferments more frequently in open mouths than in conical-shaped flasks. These results provide a hypothesis based on fermentation performance for the absence of wine produced in the Iberian Peninsula until the arrival of Phoenician settlers.

2024-08Journal article

Open access

Safebed : improving safety and sustainability of recycled manure solids as bedding material for dairy cows

Publication . Pires, Ana José de Oliveira Nunes; Oliveira, Maria Manuela Castilho Monteiro de; Bexiga, José Ricardo Dias; Fangueiro, David Paulo

ABSTRACT - SAFEBED: IMPROVING SAFETY AND SUSTAINABILITY OF RECYCLED MANURE SOLIDS AS BEDDING MATERIAL FOR DAIRY COWS - Antimicrobial resistance (AMR) and the environmental impact of livestock production pose significant challenges to sustainable dairy farming. The use of recycled manure solids (RMS) as bedding material offers economic and environmental benefits but raises concerns regarding microbial safety, including the persistence of antimicrobial-resistant bacteria and potential pathogens. This study evaluated the effects of biochar supplementation in RMS to mitigate AMR risks, enhance microbial safety, and reduce environmental emissions. Fresh RMS samples were collected from a commercial dairy farm and divided into five treatments: non-supplemented RMS (C-), acidified RMS (C+), and RMS supplemented with 2.5%, 5%, or 10% biochar. Samples were incubated for 30 days at ambient temperature, with assessments on Days 0, 5, 15, and 30. Two assays were conducted: one in a humid period (April–May) and another in a dry period (June–July). Microbial analyses included bacterial quantification, Escherichia coli and Enterococcus spp. isolation, AMR and virulence profiling, and 16S rDNA sequencing for microbial community shifts. In parallel, the environmental study examined RMS characteristics, nutrient retention, and greenhouse gas (GHG) emissions. Results from the bacterial quantification revealed no statistically significant reduction in E. coli and Enterococcus spp. counts with biochar supplementation. However, trends suggested a potential decrease in AMR and virulence factors, with reductions observed in oxytetracycline resistance and biofilm formation. In contrast, the microbiome analysis demonstrated a significant reduction in bacterial loads, with 5% biochar leading to a 59.50% decrease under humid conditions. However, Brucella spp. and Pseudomonas spp. increased in biochar amended RMS. Environmentally, the supplementation with 10% biochar significantly reduced CO₂ (32%) and N₂O (47%) emissions, stabilized nitrogen, and minimized volatilization losses. However, methane emissions were largely unaffected. Addicionally, Biochar supplementation increased micronutrient and heavy metal concentrations (except for molybdenum), as well as potassium and magnesium levels, while decreasing sodium, phosphorus, and total organic carbon content. This study highlights biochar’s potential for improving microbial safety and environmental sustainability in dairy farming. Further research should optimize biochar concentrations, assess long-term effects, and evaluate field-scale applications to fully harness its role in sustainable manure management

2025-06-23Doctoral thesis

Open access