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Food fortification is a current practise to increase the bioavailability of certain nutrients. In this study, 5% (w/w) pistachio powder was added to tender wheat flour or durum wheat semolina to evaluate its contribution to augment the amount of lysine in bread. Bread production was carried out by sourdough technology using a selected 3-species lactic acid bacterial (LAB) starter culture (Lactobacillus sanfranciscensis PON100336, Leuconostoc citreum PON10079 and Weissella cibaria PON10030). In order to determine the influence of pistachio powder on the evolution of LAB, sourdough bread productions were compared with control trials obtained from flour or semolina and evaluated for the development of the main microbial groups by plate counts. All sourdoughs were subjected to a long-time fermentation (21 h) and showed levels of LAB around 109 CFU/g, indicating the suitability of pistachio powder for lactic fermentation. Yeasts were also detected, in particular in semolina trials. MySeq Illumina technology was applied to investigate the bacterial composition of sourdoughs evidencing a different distribution of LAB species among the trials with Lactobacillus as being the major bacterial group in almost all sourdoughs, except that produced from flour supplemented with pistachio powder which displayed Weissella as dominant group. Physicochemical parameters were comparable among the trials. After baking, pistachio powder was found not to influence the height of the breads, but pistachio breads were more firm than control breads. Colour of the breads, as well as void fraction and cell density, were influenced by pistachio powder. The amount of lysine increased consistently thanks to pistachio supplementation which also determined a higher presence of o-xylene, p-cymene and limonene and the appearance of alpha-pinene and 1-octen-3-ol in the final breads. Sensory tests showed a higher appreciation of the judges towards the breads produced from flour and semolina supplemented with pistachio powder rather than control breads.

The production of sparkling wines in Sicily is increasing considerably. The most important oenological characteristics of high quality sparkling wines are high content of acidity and low pH. In Sicily, white grape varieties such as those of the cultivar Grillo are characterized by very low concentrations of malic and tartaric acids due to hot climate and reduced rainfall typical of the production area. On the other hand, a very large amount of raceme grapes, characterized by low pH and high content of tartaric and malic acids, is largely produced by Grillo varieties. Hence, the winemaking of racemes might represent a technological solution to increase the quality of the acids in the final wines. At the same time, the selection of yeast strains able to ferment grape must at very low pH is mandatory. With this in mind, the present research was carried out to isolate and selected novel yeast strains from racemes of Grillo cultivar and to set up an innovative ad hoc winemaking protocol to increase the acidity of sparkling base wine. From spontaneous vinifications on Grillo grape racemes, 2873 yeasts were isolated and characterized at the phenotypic and genotypic level. A total of 493 Saccharomyces cerevisiae isolates were subject to intraspecific characterization by interdelta analysis. These strains were also screened on the basis of technological criteria (fermenting power and vigor, SO2 and alcohol tolerance and flocculence) and qualitative features (H2S production). Four strains of S. cerevisiae were selected and inoculated individually into must obtained from Grillo racemes at 12 and 16 % (w/v) of total sugars. All strains displayed a technological potential to drive the fermentation of must into wine at very low pH (2.5-2.8). The inoculation of the strains was performed after a pre-adaptation at pH 2.5. Thus, starters were able to successfully lead fermentation. For the first time an ecological investigation of yeast ecology of raceme grapes has been carried out and an innovative strategy to improve acidity of sparkling base wine in hot climate regions has been designed.

The present work was carried out to select lactic acid bacteria (LAB) resistant to polyphenols in order to develop an ad hoc starter culture for the production of functional fresh ewes’ milk cheeses through the addition of grape pomace powder (GPP). To this purpose, raw ewes’ milk samples were inoculated with individual polyphenols belonging to five classes: flavanols (cathechin, epicatechin and epigallocathechin), flavonols (quercetin), flavones (rutin), hydroxyl-benzoic acid (vanillic acid and syringic acid) and hydroxyl-cinnamic acid (caffeic acid and cumaric acid). These polyphenols are commonly associated with the wine industry by-products and were added in milk to a final concentration of 0.5 mg/mL. All samples were incubated at 30°C and 44°C for 48h in order to select potential mesophilic and thermophilic starter LAB. Plate counts showed the total microbial counts (TMC) till levels of almost 109 CFU/mL and all milk samples were dominated by coccus LAB. All colonies with different morphological appearance were isolated and differentiated on the basis of their phenotypic characteristics and by Randomly Amplified Polymorphic DNA (RAPD)-PCR profiles. A total of 55 strains were collected and subjected to the genotypic analysis by means of 16S rRNA gene sequencing, which identified 5 LAB species belonging to two genera (Enterococcus and Lactococcus). The species most frequently found were Lactococcus lactis. The 55 strains were investigated in vitro for their general dairy aptitudes and four strains of L. lactis (MISE36, MISE94, MISE169 and MISE190) showed technological traits relevant to act as starter strains for cheese production.In order to produce a GPP-fortified fresh cheeses, red grape pomaces of Nero D’Avola cultivar were provided by a winemaking factory (Cantine Europa, Petrosino, Italy). Grape pomaces were dried at 54°C for 48 h and milled through a Retsch apparatus to a particle size of 250 μm. The experimental cheese making trials were carried out in a dairy pilot plant (Biopek, Gibellina, Italy) following the protocol of “pressed” cheeses. For each trial 20 L of pasteurised milk was divided into two plastic vats (10 L each) representing two different trials. Both vats were inoculated with the individual starter LAB cultures (100 mL) to reach a final cell density of 107 CFU/mL. One vat represented the control cheese (CC) production. The second vat represented the experimental cheese (EC) that, after curd extraction, was added with 1% (w/w) GPP. The cheeses were sampled after one month of ripening. All lactococci were able to perform the rapid acidification in CC and EC production, showing that polyphenols of GPP did not slow down starter development. Plate counts and RAPD analysis applied to the colonies isolated from the highest dilutions of samples confirmed the dominance of the added strains. A sensory evaluation of the resulting cheeses, indicated the cheeses processed with the addition of GPP were well appreciated by the judges. Analyses are in progress to evaluate the nutraceutical properties of the experimental cheeses. This research has been supported by the grant MISE-2017-NAZ-0228 - CUP: B78I17000260008

Wine and dairy chains rapresent of the agri-foof leading sectors in Sicily. Composting residues from these two chains would contribute to increase the environmental sustainability of the production with additional advantages represented by the reduction the costs recover soil fertility. This work represents the first attempt to combine the green of the vine cultivation as well as wine and dairy by-products. Raw materials provided potential bioactivators identified as Bacillus subtilis, Bacillus velezensis and Kocuria rhizophila which showed cellulolytic activity. The strain were inocultated in the mass to be composted in order to accelerate the process. Four compost trials were performed: (i) absence of boactivators and mainteinace of umidity with deproteinized whey; (ii) presence of bioactivators and mainteinace of umidity with deproteinized whey; (iii) absence of boactivators and mainteinance of umidity with water; (iv) presence of bioactivators and mainteinace of umidity with water. The experiment lasted 105 days, during which environmental parameters, such as temperature and umidity were monitored. Growth dynamics of the principal functional groups of mesophilic and thermophilic microorganisms were followed. The composting process was monitored during the entire period through the detection of physical-chemical (pH, humidity, TOC, humic acid + fulvic acid, TN, Org-N, C/N, S, Cd, Cr, Hg, Ni, Pb, Cu, Zn) and microbiological parameters (Salmonella spp., Escherichia coli). The characteristics of all composts fulfilled the requirements of the Italian legislation for ther use to amendt soil. Furthemore, germination tests demonstrated the absence of phytotoxicity against Lepidium sativum L..

La fermentazione spontanea è un processo biologico incontrollato durante il quale molti lieviti e/o batteri potrebbero aumentare rapidamente in concentrazioni tali incidere negativamente sulla qualità del prodotto finale. A tal proposito, al fine di ottimizzare la crescita di lieviti con buone attitudini enologiche, si utilizza il metodo “pied de cuve”. Questa tecnica enologica è in grado di realizzare in una determinata massa di mosto dal volume ridotto, una fermentazione alcolica con un ceppo di lievito opportunamente inoculato o con ceppi di lieviti indigeni, naturalmente presenti nel mosto. Al fine di valorizzazione ed aumentare la diffusione di pratiche enologiche basate su un ridotto uso di coadiuvanti tecnologici sono state studiate fermentazioni alcoliche spontanee “gestite” in modo tale eliminare e/o ridurre l’uso delle colture microbiche selezionate commerciali. L’attività di ricerca è stata concepita ed eseguita per valutare la biodiversità microbica delle popolazioni di lieviti e dei principali parametri chimico-fisici, relativi a dei processi innovativi di vinificazione dell’Aglianico di Taurasi. Lo scopo finale è stato quello di validare l’applicabilità tecnologica, sia su base microbiologica che chimico-fisica, di un processo di fermentazione spontanea ma “gestito” mediante l’uso della tecnica del pied de cuve fortificato (PdCF). Tale tecnica ha previsto l’addizione di etanolo, mediante l’uso di vino dell’annata precedente, in un mosto appena ottenuto, ovvero un’alcolizzazione di mosto d’uva. Inoltre, con la presente sperimentazione sono stati valutati anche gli effetti della modifica dei parametri di preparazione del PdCF, ovvero grado di alcolizzazione del mosto [1% (v/v) di etanolo] e rapporto di inoculo PdCF del 5%. Il presente lavoro ha fornito una panoramica sull’ecologia microbica dei vini prodotti utilizzando il PdCF, nonché la fermentazione alcolica spontanea associata al metodo pied de cuve utilizzando uve della cultivar Aglianico di Taurasi vinificate su scala aziendale. L’aggiunta di etanolo nel pied de cuve, prima dell’inizio della fermentazione spontanea, ha favorito lo sviluppo e la dominanza dei lieviti di Saccharomyces cerevisiae autoctoni durante l’intero processo di vinificazione. Allo stesso tempo, tutti i principali parametri chimico-fisici enologici hanno raggiunto valori in linea con gli standard che assicurano la produzione di vini di qualità. Il risultato finale del presente studio, ha confermato che il protocollo di vinificazione PdCF all’1,0% (v/v) di etanolo anche se applicato su scala aziendale consente lo svolgimento di una fermentazione alcolica spontanea riducendo il rischio di alterazioni microbiche e/o chimico-fisiche. Tale metodica se applicata su scala industriale nell’intero comparto vitivinicolo legato alla produzione di Aglianico di Avellino consentirà alle cantine di diversificare l’offerta aziendale attraverso la produzione di vini a fermentazione spontanea con una potenziale “impronta” sensoriale legata a distinte caratteristiche di tipicità. Ciò consentirà di soddisfare la crescente domanda di quei consumatori, sempre più numerosi, attenti agli aspetti qualitativi delle produzioni vinicole.

The present work was carried out to investigate the microbiological characteristics of the ice cubes produced at different levels: 1) home-made (HM) from domestic freezers; 2) produced by ice machines in bars and pubs (BP); 3) produced by ice industries (IN). BP samples were collected from the box stocks. HM and BP samples were transferred into sterile stomacher bags. IN samples were provided in the manufacturers’ plastic bags. Samples were transported into thermal insulated boxes. Five samples per each production level, forming a total of 15 samples (HM1-HM5, BP1-BP5, IN1-IN5), were collected in duplicate in two consecutive months. Each ice sample was thawed in 1 L sterile Dhuram’s bottle at room temperature and subjected to the membrane filtration analyses. Total mesophilic microorganisms (TMM), total psychrotrophic microorganisms (TPM), pseudomonads, members of the Enterobacteriaceae family, coliforms, enterococci, yeasts and moulds were investigated. When the amounts of colonies were uncountable, 1 mL of sample was directly inoculated into agar media. All results were expressed as colony forming units (CFU)/100 mL of thawed ice. TMM were in the range 100-9600, 312-6300 and 130-4000 for HM, BP and IN samples, respectively. Three HM and two IN samples were negative for the presence of TPM. The highest concentration (960) was found for IN2. Pseudomonads were detected in all HM samples but the highest levels were registered for BP1 (390) and IN2 (384). Except IN4, Enterobacteriaceae were found in all samples. All INs and 4 HM samples did not displayed coliforms. By contrast, they were hosted in all BP samples, ranging from 1 to 184. Enterococci were never found in HM samples, but detected in two INs and 3 BPs. Except IN1, moulds were always registered, while yeasts developed from the majority of HM and IN samples and two BP samples. The colonies representative for the different morphologies were randomly picked up from plates, purified to homogeneity and subjected to a phenotypic grouping. Yeasts and bacteria were subjected to the genetic identification by sequencing of D1/D2 domains of 26S rRNA gene and partial sequencing of 16S rRNA gene, respectively, while moulds were identified phenotypically. So far, the species mostly represented among bacteria, as evaluated only by the forward 16S rRNA gene sequence, were Bacillus spp., Pseudomonas spp., Pantoea spp., Pantoea agglomerans, Enterococcus faecium, and Agrobacterium tumefaciens. Candida intermedia and Pichia guillermondii were identified among yeasts and Penicillium spp. among moulds. The work was also aimed to monitor the microbial transfer from ice to humans through drinks. To this purpose, each microorganism was inoculated singly in sterile mineral water to produce contaminated ice cubes using disposable ice cube trays. Inoculums occurred at the highest concentrations found in the ice cubes analysed. The concentrations of the microorganisms were followed in six different types of drinks, including alcoholic (vodka and whiskey), moderate alcoholic (Martini), sparkling (tonic water), sugary (peach tea) and sugary sparkling (coke) drinks. In order to simulate the contamination of drinks by ice during consumption, six ice cubes (corresponding to 60 mL) containing each microorganism were added to 100 mL of each drink (simulating a bar administration) in sterile cups and, after 1 h, the entire volume was analysed by membrane filtration. A physiological solution was used as control. So far, the tests were performed with Penicillium spp. and P. agglomerans. Penicillium was not influenced by the different drinks, since, after 1 h, its level did not change. Regarding P. agglomerans, which is an opportunistic pathogen causing urinary tract infections, its concentration in peach tea was superimposable to that found in physiological solution, while it decreased in all other drinks. In particular, the concentration of this bacterium almost halved in vodka, coke and tonic water, diminished consistently in Martini and completely disappeared in whiskey. Experimentations are in progress to determine the behaviour of the other microorganisms in these systems. These data evidenced that the worst hygienic characteristics were found in BP samples, while the majority of ice cubes produced in specialized industries were characterized by acceptable microbiological parameters. This work indicated that the concentration of P. agglomerans is reduced by alcohol and CO2, but further in vivo assays are necessary to better clarify their role on the other ice microorganisms.

Il consumo di bevande alcoliche ha da sempre accompagnato la storia dell’uomo, riscontrandosi in tutte le civiltà, dalle meno evolute a quelle più progredite. Le scoperte scientifiche del XV secolo hanno messo in luce come tutti i popoli abbiano ampiamente sfruttato il fenomeno della fermentazione di cereali per produrre bevande. Lo stesso vino, inoltre, aveva assunto fin dai tempi più antichi un valore liturgico presso tutte le civiltà che si erano affacciate al Mediterraneo. Anche oggi, e in misura maggiore rispetto al passato, si fa largo uso di bevande alcoliche ottenute sia da fermentazione che da distillazione di liquidi zuccherini. Le bevande alcoliche fermentate sono caratterizzate dalla presenza di concentrazioni variabili di alcol, ottenute da frutta, semi di cereali e tuberi, mediante la fermentazione di soluzioni zuccherine. Nelle bevande alcoliche fermentate, la presenza di alcol etilico è dovuta ad un processo naturale denominato “fermentazione alcolica”, operato da lieviti, mediante il quale le sostanze zuccherine si trasformano in alcol etilico e anidride carbonica. Per la legislazione italiana (D.P.R. n. 162), può essere denominato “vino” esclusivamente il prodotto ottenuto attraverso la fermentazione alcolica spontanea, totale o parziale, dell’uva fresca, dell’uva ammostata o del mosto d’uva con gradazione alcolica non inferiore ai tre quinti della gradazione complessiva. Pertanto, con il termine “vino” si indica il prodotto finale di una lunga catena biotecnologica articolata nelle fasi di preparazione del mosto, di fermentazione, di maturazione e di invecchiamento. Ciascuna delle fasi appena menzionate investe fenomeni chimici, chimico-fisici e biologici che si cerca di regolare con tecniche atte a conservare i caratteri della materia prima e a migliorare la qualità dei vini che ne derivano, anche in considerazione della crescente domanda e del maggiore interesse dei consumatori per un vino di qualità. Sicuramente, la svolta microbiologica ha rappresentato una delle innovazioni tecniche più importanti nella storia dell’enologia, insieme alle osservazioni sugli effetti dell’ossigeno, sui costituenti fenolici e dell’aroma, grazie alla capacità di incidere sul processo di fermentazione. I principali agenti responsabili della fermentazione alcolica sono i lieviti appartenenti al genere Saccharomyces (in particolare Saccharomyces cerevisiae), mentre i batteri lattici sono determinanti per la fermentazione malolattica. Tali microrganismi guidano la vinificazione del succo d’uva e, per questa ragione, osservare e comprendere il loro comportamento in ambiente enologico è di elevata importanza per l’ottenimento di prodotti finiti con caratteristiche organolettiche ottimali. Le interazioni microbiche, infatti, sono di notevole rilevanza in quanto lo sviluppo di microrganismi indesiderati può generare alterazioni e difetti di natura organolettica.

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.

In this paper, we discuss the experimental determination of noise parameters for high-electron-mobility transistor (HEMT) devices and analyze the problems encountered with conventional extraction techniques. HEMT devices are distinguished by a very small minimum noise figure of only a fraction of a dB, and this minimum noise is accomplished with a source reflection coefficient very close to the edge of the Smith chart. These properties impede a direct experimental determination of the optimum noise impedance by means of a tuner, and it has to be extrapolated from measurements of a large number of tuner states. Common linear regression techniques are found to yield erroneous results and even may fail completely to determine the noise parameters. We develop criteria to check the uncertainty of the result from the linear regression and show that, in general, the result needs to be examined for consistency. The occasional failure of extraction is traced back to a consistency violation in the conditions the elements of the correlation matrix need to satisfy. A new iterative technique is suggested for the extraction of noise parameters that warrants consistency. Moreover, a correction of the receiver gain is found to be necessary to obtain a good reproduction of the measured power patterns by the extracted noise parameters. This fact was attributed to thermal drift of the receiver.

We investigated the effect of residual salts from the previous summer’s irrigation on two non-irrigated cover crops—broad bean and common vetch—and on their rhizobial symbiontics. Before sowing, seeds were inoculated with a salt-tolerant strain and a salt-sensitive strain of Rhizobium leguminosarum biovar viciae. An increase in the electrical conductivity of the saturated-soil extract from 2.0 dS m−1 to 6.0 dS m−1 caused a severe reduction of broad bean biomass, while growth of common vetch was almost unaffected by the salinity level. Our results clearly indicate that common vetch as a cover crop may increase the availability of nitrogen in soil more than broad bean also in saline environments. A high ability of both inoculated strains to nodulate Vicia plants was observed under controlled conditions. In contrast, inoculated strains were not able to nodulate plants in salinized soils, showing lower competitiveness compared to natural rhizobial population. Indeed, the new isolates from nodules were salt-sensitive when tested in vitro. The complex interaction among bacteria, plant and soil determined the survival of endogenous salt sensitive rhizobial strains and limited the success of inoculation with exogenous salt resistant rhizobia.

The production of five different green table olive cultivars was studied by a combined strategy consisting of chemical, microbiological and sensory analyses. Cultivable microflora of samples collected during processing was monitored by plate counts on seven synthetic culture media. In all samples Enterobacteriaceae, Pseudomonaceae, staphylococci, lactic acid bacteria and spore-forming bacteria were undetectable. Yeasts and moulds were countable from the day 42 (2 log CFU/ml) till the end of fermentation (6 log CFU/ml). The use of three different approaches for microorganism detection, including a culture-independent methodology, revealed the presence of barely three yeast species during the entire fermentation period: Candida parapsilosis, Pichia guilliermondii and Pichia kluyveri. Biochemical features of technological interest were evaluated for 94 strains in order to investigate their potential role in fermentation of green Sicilian table olives. Olive drupes sampled at picking and periodically during fermentation were also carpologically analyzed, revealing that all the cultivars were suitable for table olive fermentation process. After 120 days of fermentation all products met acceptable commercial standards, although GC–MS analysis evidenced several differences among varieties in terms of aroma components. Results from sensory evaluation led to the conclusion that a revision of technological procedures may improve the final quality of product.

The application of soil solarization (SS), one of the most promising techniques for the control of soilborne pathogens, is seriously limited by the drawback regarding the disposal of the used plastic materials. A possible solution to this problem is the use of biodegradable plastics. The aim of this study was to make comparisons between the impact of SS performed with biodegradable materials and that of SS with plastic films and other pest management techniques (i.e. organic matter amendment, calcium cyanamide and Dazomet fungicide application) on crop productivity, soilborne disease incidence, weed suppression, and soil chemical (total N, NH4-N, nitrate, available phosphorus, organic matter, hydrolysis of fluorescein diacetate) and microbial (cultivable Pseudomonas, DGGE fingerprinting of bacterial 16S- and fungal 28S rRNA gene fragments from total soil community DNA) parameters. We carried out field experiments in two types of soil with different textures (clay and sand) artificially inoculated with Fusarium oxysporum f.sp. lycopersici (vs. tomato) and Sclerotinia minor (vs. lettuce). The temperature of soils covered with solarizing materials was always higher than that of bare soils, but plastic cover was more effective and consistent in rising soil temperature compared to biodegradable materials. Plant growth promotion by SS was limited, especially compared to Dazomet and organic matter applications, and a positive effect was observed only for lettuce in the clay soil. Differently, both plastic and biodegradable solarizing materials were effective in reducing lettuce drop caused by S. minor. Weed development was significantly suppressed by Dazomet application and SS with plastic film, while control with biodegradable materials was limited. SS had a variable and limited effect on chemical and microbial parameters, with a general tendency to reduce richness of bacteria and fungi. Dazomet caused the most pronounced reduction of the microbial community diversity in both soil types and a significant stimulation of the fluorescent Pseudomonas group. Organic amendment significantly enhanced the organic matter content, the hydrolysis of fluorescein diacetate and the Pseudomonas population. Among all measured soil parameters, the size of the fluorescent Pseudomonas population emerged as the most important factor affecting crop productivity. The results of this experimentation show the potential of using biodegradable solarizing materials in place of plastic films, but also indicate the need for improving their properties to obtain performances comparable to those of other pest management techniques.

Atti XXXV Convegno SIA, Napoli, (a cura di Mori M., Fagnano M.).

Two types of white wheat bread (high- and low-type loaves) were investigated for rope spoilage. Thirty of the 56 breads tested developed rope spoilage within 5 days; the high-type loaves were affected by rope spoilage more than the low-type loaves. Sixty-one Bacillus strains were isolated from ropy breads and were characterized on the basis of their phenotypic and genotypic traits. All of the isolates were identified as Bacillus subtilis by biochemical tests, but molecular assays (randomly amplified polymorphic DNA PCR assay, denaturing gradient gel electrophoresis analysis, and sequencing of the V3 region of 16S ribosomal DNA) revealed greater Bacillus species variety in ropy breads. In fact, besides strains of B. subtilis, Bacillus licheniformis, Bacillus cereus, and isolates of Bacillus clausii and Bacillus firmus were also identified. All of the ropy Bacillus isolates exhibited amylase activity, whereas only 32.4% of these isolates were able to produce ropiness in bread slices after treatment at 96°C for 10 min. Strains of lactic acid bacteria previously isolated from sourdough were first selected for antirope activity on bread slices and then used as starters for bread-making experiments. Prevention of growth of approximately 104 rope-producing B. subtilis G1 spores per cm2 on bread slices for more than 15 days was observed when heat-treated cultures of Lactobacillus plantarum E5 and Leuconostoc mesenteroides A27 were added. Growth of B. subtilis G1 occurred after 7 days in breads started with Saccharomyces cerevisiae T22, L. plantarum E5, and L. mesenteroides A27.