I lieviti del Vino Fiano di Avellino DOCG: la tipicità attraverso le biotecnologie

I microrganismi caratteristici di un prodotto tipico fermentato come il vino, dai quali dipendono molte delle proprietà organolettiche, riflettono, in molti casi, le caratteristiche dell’ambiente e dei sistemi di produzione. Infatti, i prodotti alimentari di nicchia legano la loro storia alla zona di produzione non solo per le tradizioni che si tramandano nel tempo, ma anche e soprattutto per la presenza di specie e ceppi di microrganismi che colonizzano la materia prima, nonché gli ambienti e le attrezzature di lavorazione, contribuendo in maniera decisiva a caratterizzare la tipicità del prodotto finale. Nello spirito delle “Denominazioni d’Origine”, particolare importanza deve essere ancora attribuita a tutti quegli elementi che creano il “legame” tra un determinato prodotto e una particolare zona geografica, la cultura della popolazione e tutti quegli aspetti che possono essere sintetizzati nell’insieme dei fattori storico-sociali nei quali risiedono i motivi dello sviluppo di un prodotto in una data area antropizzata. I microrganismi rientrano sicuramente tra questi fattori e costituiscono, anzi, uno dei “segreti” dei produttori artigianali che, nel tempo, sono stati svelati e convertiti in moderna tecnologia di trasformazione. Anche l’impiego di ceppi “autoctoni”, selezionati durante la trasformazione di prodotti tradizionali e legati allo sviluppo di componenti aromatiche desiderate, al prolungamento della shelf-life, agli aspetti salutistici dei prodotti finiti e cosìvia, può richiedere l’adattamento di protocolli produttivi già esistenti per migliorare le performance del(i) microrganismo(i). Tuttavia, tale innovazione non può essere “selvaggia”, bensì dovrebbe essere rispettosa degli aspetti essenziali e peculiari della tradizione di un prodotto. In questo lavoro svolto nell'areale del Fiano di Avellino DOCG si sono selezionati dall'ambiente vigneto 2 ceppi di Saccharomyces cerevisiae da utilizzare come starter nella produzione di qualità del vino Fian

New trends in technology and identity of traditional dairy and fermented meat production processes

Interest in ecofood tourism is strictly related to the consumption of products associated with the geographical area visited. Local products are often requested by consumers living far from the production zones (e.g. in bistro restaurants that reproduce the atmosphere of typicality). This phenomenon, if on the one hand guaranteeing the continued popularity of certain traditional foods, highlights the inherent dangers that certain types of food pose. They could spread the risks to a much wider area that they might typically inhabit. The higher the demand for certain products, the more variations of the production processes of the traditional products there will be. This is particularly evident for fermented products that do not have trademark protection which allows products made with different technologies and/or raw materials to use the same designation. This paper reports the strengths and the weaknesses of traditional fermented food products, examining the concept of typicality, and evidencing the risks associated with consumption

Identification of predominant lactic acid bacteria and yeasts of Turkish sourdoughs and selection of starter cultures for liquid sourdough production using different flours and dough yields

Eight samples of mature sourdough were collected from fi ve provinces of Turkey. Lactic acid bacteria and yeasts were isolated and identifi ed and used in different combinations to produce liquid sourdoughs. Microbiological and physicochemical characteristics of the experimental sourdoughs made with different fl our types and dough yields were studied. The main lactic acid bacteria species identifi ed were Lactobacillus (L.) sanfranciscensis, Pediococcus pentosaceus, L. plantarum, L. namurencis, L. rossiae, Leuconostoc mesenteroides and L. zymae. L. spicheri, L. paralimentarius, L. mindensis, L. farciminis, L. acetotolerans, L. casei, Enterococcus faecium and Enterococcus durans were also found in sourdoughs at subdominant levels. Among yeasts, mainly Saccharomyces cerevisiae, but also Pichia guiliermondii and Torulaspora delbrueckii were the predominant species of yeasts identifi ed in sourdoughs. Lactic acid bacteria and yeasts of liquid sourdoughs after fermentation were in the range of 9.61–9.89 log cfu/g and 6.55–7.36 log cfu/g, respectively. Various chemical parameters such as pH, total titratable acidity, lactic and acetic acids, ethanol and sugars were determined for liquid sourdoughs. Acidifi cation and metabolite contents of these products were different, depending on the starter culture, fl our type and dough yield. Total titratable acidity was more pronounced in the sourdoughs produced with whole wheat fl our (14.08 mL NaOH) and rye fl our (13.56 mL NaOH), dough yield 250 (13.93 mL NaOH) and control sample (13.12 mL NaOH) which were produced without inoculum

Could halophilic archaea improve the traditional salted anchovies (Engraulis encrasicholus L) safety and quality?

Aims: The positive influence of two selected extremely halophilic archaea strains in the production of salted anchovies (Engraulis encrasicolus, L., 1758) was highlighted. Methods and Results: Anchovies produced with salt artificially contaminated with halophiles exhibited lower loads of staphylococci, Enterobacteriaceae and lactic acid bacteria, and a reduced content of histamine as well as an improved organoleptic acceptance. Conclusions: The findings of this survey are expected to enhance the safety of salted anchovies, with regard to the histamine formation during ripening, and to improve the sensory attributes of this product. Significance and Impact of the Study: This study represents the first report on the positive influence of halophilic archaea in traditional salted anchovies production, thus suggesting new perspectives about a conscious employment of properly selected haloarchaea strains in this traditional manufactur

Investigation of the hygienic safety of aromatic plants cultivated in soil contaminated with Listeria monocytogenes

The present work was undertaken to investigate the survival of Listeria monocytogenes ATCC 19114T in soil during the whole crop cycle of rocket (Eruca sativa Mill.) and basil (Ocimum basilicum L.), to monitor its transfer to the leaves, and to evaluate its viability at harvest. To this purpose, the soil was NePeK fertilized and four trials, obtained with different combinations of soil treatment, listerial inoculums and seed planting, were followed for each aromatic plant. Soil was weekly investigated for total microbial counts and L. monocytogenes evolution. At the starting time, un-inoculated autoclaved soil showed a limited microbial load (103 CFU g dw 1), while un-inoculated non-autoclaved soil contained approximately 108 CFU g dw 1 microorganisms. Listerial persistence in inoculated soil was evaluated by plate counts and confirmed by randomly amplified polymorphic DNA (RAPD) analysis. Trials with nonautoclaved un-inoculated soil, used as control productions, contained about 104 CFU g dw 1 of presumptive Listeria spp., from the beginning till the end of the experimentation, which lasted six weeks. The trials artificially contaminated with approximately 109 CFU g dw 1 of L. monocytogenes showed a decrease of the initial inoculums, which was more rapid, reaching lower levels at harvest, for the trials with non-autoclaved soil (4.95 and 4.81 log CFU g dw 1 for basil and rocket, respectively) than those with autoclaved soil (5.28 and 5.24 log CFU g dw 1 for basil and rocket, respectively). At harvest, plants and soil samples were also analysed by denaturing gradient gel electrophoresis (DGGE). The last analysis showed the presence of L. monocytogenes in soil, but not on the leaves of plants of all inoculated trials

The influence of addition of Borago officinalis with antibacterial activity on the sensory quality of fresh pasta

Borage (Borago officinalis L.) is a herbaceous plant of the Boraginaceae family cultivated throughout the world for several purposes, including food preparations, mainly beverages and salads. Some Italian recipes use borage as a food ingredient, in particular as condiment for pasta. The aqueous extract (AE) from borage leaves can act as biopreservative in foods due to its inhibition towards the main foodborne pathogen bacteria. Fresh pasta, due to the high content of water, is a food product with a limited shelf life. In order to test the suitability of borage to produce fresh pasta with a prolonged shelf life, borage AE was used in dried form as a raw material for the production of tagliatelle pasta. Pasta produced with fresh borage was used as green tagliatelle control, while pasta produced without borage was used as white tagliatelle control. The colour of the three tagliatelle pasta types was different. A sensory panel was used to test the appreciation of these products prepared following three recipes with Sicilian ingredients. Both pastas produced with borage were preferred to control pasta with any preparation based on cheese, meat or fish as principal flavour ingredient. The present study demonstrated the suitability of borage AE as natural preservative for fresh pasta production

Yeast ecology of vineyards within Marsala wine area (western Sicily) in two consecutive vintages and selection of autochthonous Saccharomyces cerevisiae strains

In this work, the yeast ecology associated with the spontaneous fermentation of Grillo cultivar grapes from 10 vineyards was analyzed from grape harvest till complete consumption of must sugars. The microbiological investigation started with the plate count onto two culture media to distinguish total yeasts (TY) and presumptive Saccharomyces (PS). Yeasts were randomly isolated and identified by a combined genotypic approach consisting of restriction fragment length polymorphism (RFLP) of 5.8S rRNA gene and 26S rRNA and sequencing of D1/D2 domain of the 26S rRNA gene, which resulted in the recognition of 14 species belonging to 10 genera. The distribution of the yeasts within the vineyards showed some differences in species composition and concentration levels among 2008 and 2009 vintages. Due to the enological relevance, all Saccharomyces cerevisiae isolates were differentiated applying two genotypic tools (interdelta analysis and microsatellite multiplex PCR of polymorphic microsatellite loci) that recognized 51 strains. Based on the low production of H2S, acetic acid and foam, ethanol resistance, growth in presence of high concentrations of potassium metabisulphite (KMBS) and CuSO4 and at low temperatures, 14 strains were selected and used as starter to ferment grape must at 13 C and 17 C in presence of 100 mg/L of KMBS. Three strains (CS160, CS165 and CS182) showed optimal technological aptitudes

Filamentous Fungi transported by birds during migration across the mediterranean Sea.

The potential for the transport and diffusion of some pathogenic microorganisms by migratory birds is of concern. Migratory birds may be involved in the dispersal of microorganisms and may play a role of mechanical and biological vectors. The efficiency of dispersal of pathogenic microorganisms depends on a wide range of biotic and abiotic factors that influence the survival or disappearance of a given agent in a geographical area. In the present study, 349 migratory birds were captured in four sites (Mazara del Vallo, Lampedusa, Ustica and Linosa), representing the main stop-over points during spring and autumnal migration, and analyzed for the presence of filamentous fungi. A total of 2,337 filamentous fungi were isolated from 216 birds and identified by a combined phenotypic-genotypic approach to species level. Twelve species were identified in the study, with Cladosporium cladosporioides, Alternaria alternata, and Aspergillus niger as the most abundant. The transport of these fungal species isolated in this study is of considerable importance because some of these species can create dangers to human health

Effect of the natural winemaking process applied at industrial level on the microbiological and chemical characteristics of wine.

The composition of yeast and lactic acid bacteria (LAB) communities and the chemical evolution of the large-scale commercial vinification of Catarratto IGT Sicilia, carried out under the biological regime, was followed from grape harvest until bottling. Simultaneously to the maximumgrowth of yeasts, LAB counts reached high level of concentration (6e7 log CFU mLL1) during the first steps of the alcoholic fermentation. Yeast identification was determined applying different molecular methods. The highest species biodiversity was observed on grape and must samples taken soon after pressing. Saccharomyces cerevisiae was detected at dominant concentrations during the entire winemaking process. LAB cultures were grouped and identified by a combined phenotypic and genotypic approach. Leuconostoc mesenteroides, Lactobacillus hilgardii and Lactobacillus plantarum species were identified; the last was the main LAB recognized during vinification. The winemaking process was also chemically monitored. The alcoholic content was approximately 12.67% (v vL1) at bottling; pH, volatile acidity and total acidity showed a moderate increase during vinification. Tartaric, citric and malic acids decreased until bottling, while lactic acid showed a rapid increase at the end of maceration and bottling. Trans-caffeil tartaric acid was the most abundant phenolic compound and volatile organic compounds (VOC) were mainly represented by isoamylic alcohol, isobutanol, ethyl acetate and octanoic acid

Indigenous yeast communities in the environment of ‘Rovello bianco’’ grape variety and their use in commercial white wine fermentation

The indigenous yeast communities associated with several vineyard habitats were analysed. Wild yeasts were isolated, differentiated at strain level and identified. A phylogenetic tree based on partial 26S rRNA genes was constructed. The strains were characterized and the indigenous Saccharomyces cerevisiae GR1 was then used to carry out a vinification process and compared with a commercial yeast. Wines obtained were subjected to chemical and sensory analysis. The comparison between the two products highlighted differences due to the fer- menting strains employed. The vineyard environment was found to strongly influence the composition of yeast communities, thus, confirming the theory of ‘terr- oir’ on the expression of wines. Moreover, vineyard inhabiting birds were in part responsible for the dis- semination of fermentative yeasts during their feedin