Biogenic amines (BAs) are low molecular weight compounds formed from precursor amino acids, mainly by microbial decarboxylation. The presence of these compounds is important in the food and beverage industry because, in high amounts, they can lead to negative effects on consumers. In this review, we illustrate the critical aspects needed to control the formation of BAs during winemaking and their presence in the final product. Recent biotechnological approaches related to microorganisms and their ability to reduce BAs are illustrated. The current methods used for BA detection and quantification are also presented. These methods are very important to consider, as BAs can serve as markers for the quality assessment of products. The information presented here offers an overview useful for identifying specific parameters and conditions which should be controlled to minimise BA content in wine; knowledge about BAs in foods and beverages has been accumulating in recent years, not only to ensure and improve quality (since BAs have been used as an indicator of spoilage) but especially to guarantee consumer safety due to the potential toxic effects of BAs on humans.

In this study, the evolution of the yeast microflora present on the berry surface, during the ripening of Barbera grapes, was monitored. Sampling was performed in three vineyards located in the “Nizza” Barbera d’Asti DOC zone and different methodologies have been employed. A culture-dependent method based on the identification of strains grown on solid media by ARDRA (Amplified Ribosomal DNA Restriction Analysis) and the D1-D2 domain of ribosomal 26S DNA capillary sequencing was coupled to NGS (Next Generation Sequencing) targeting ITS (Internal Transcribed Sequence) amplicons with the Illumina MiSeq platform. By using culture-dependent techniques, the most frequently detected species was the yeast-like fungus Aureobasidium pullulans, which was dominant in the culturable fraction. Among yeasts, the presence of oligotrophic basidiomycetes such as Cryptococcus spp., Rhodotorula graminis and Sporidiobolus pararoseus was observed at the beginning of ripening. Afterward, upon approaching the harvest, a succession of oxidative or weakly fermentative copiotrophic species occurs, such as Saturnispora diversa, Issatchenkia terricola, Hanseniaspora opuntiae, Starmerella bacillaris and Hanseniaspora uvarum. The massive sequencing revealed a larger number of species, respect to the culture-dependent data. Comparing the two different approaches used in this work, it is possible to highlight some similarities since Aureobasidium, Rhodotorula and Sporobolomyces were detected by both methods. On the contrary, genera Hanseniaspora, Issatchenkia and Saturnispora were revealed by culture-dependent methods, but not by NGS, while Saccharomyces spp. were identified, with low frequency, only by NGS. The integrated application of NGS sequencing and culture-dependent techniques provides a comprehensive view of mycodiversity in the wine-growing environment, especially for yeasts with low abundance.

The role of yeast in wine quality is very important. The use of selected autochthonous yeasts is becoming more and more frequent in enology, not only to obtain a diversification of wines, but also as a link between the wine and its territory of origin. The objectives of this work were to test two indigenous yeasts in a cellar on a pilot scale. The yeasts were a strain of Saccharomyces cerevisiae and a strain of Saccharomyces paradoxus previously isolated in a vineyard in Piedmont (Italy). Studying the oenological characteristics of S. paradoxus is of particular interest, as it is rarely found in the cellar–vineyard environment. Molecular biology methods confirmed the predominance of the strain inoculated in the various fermentation tests. Additionally, products of yeast metabolism, including volatile compounds, were quantified at the end of the alcoholic fermentation and sensory profile of wines was tested by a trained panel of tasters. Our results indicated that both strains have good characteristics to be used as starter in winemaking; S. paradoxus was characterized by a high production of glycerol and the ability to degrade malic acid, together with a lower production of ethanol and a low volatile acidity, while S. cerevisiae conferred to the wine a pleasant smell of rose, as highlighted in the sessions of sensory analysis.

Lignocellulosic biomasses have the potential to generate by‐products with biological activity (i. e., polyphenols) as well as biopolymers (i. e., cellulose, hemicellulose, pectins, lignin). The wine industry is one of the pillars of Italian agri‐food sector. Nevertheless, large quantities of by‐products such as grape stems are produced, which are usually disposed of at a cost, and therefore represent an attractive negative‐cost feedstock for biorefinery. In this work, a sequential protocol for biomass valorization is proposed, characterized by a multidisciplinary strategy using enabling technologies and subcritical water as a green solvent, where physical/chemical treatments synergistically interact with biological treatments. The first phase involved the sequential fractionation of grape stalks, obtaining several product streams rich in polyphenols, hemicellulose, pectin (13.15 % of cumulative yield on biomass), lignin and cellulose. A membrane treatment was employed to recycle materials within the process. Finally, the cellulose‐rich residue was exploited as a fermentation substrate for the last step, producing up to 5.8 g/L of lactic acid by harnessing suitably engineered Clostridium thermocellum strains. The polyphenolic fraction successfully inhibited the growth of Brettanomyces bruxellensis and Acetobacter pasteurianus, microorganisms responsible for major wine off‐flavors. Globally, this study represents a proof‐of‐concept of a second‐generation biorefining process based on locally available waste biomass.