[Show abstract][Hide abstract] ABSTRACT: This paper reports on a combined approach (homogenization-HPH, sodium-benzoate and citrus extract) to inactivate spores of Fusarium oxysporum in pineapple juice. In 1st step HPH and antimicrobials were applied as single hurdles. Homogenization alone reduced spores at the undetectable level only through a 3-step treatment at 120/150 MPa; treatments at 1 or 2 steps reduced F. oxysporum spores by 1 and 2 log cfu/mL, respectively. Concerning the effectiveness of the antimicrobials, NIC (not-inhibitory concentration) and MIC values (minimal inhibitory concentration) of Na-benzoate and citrus extract were 181/289 mg/L and 1450/3700 mg/L, respectively.In the last step of the research benzoate (0–100 mg/L) and citrus extract (0–2000 mg/L) were combined through a two variables-five levels CCD (central composite design) and used in combination with a single step HPH treatment at 120 or 150 MPa. The use of Na-benzoate and citrus extract strengthened the effect of homogenization in pineapple juice and reduced spores of F. oxysporum below the detection limit immediately after homogenization.
[Show abstract][Hide abstract] ABSTRACT: The main topic of this paper is the study of the qualitative composition of fungal population in some cellar environments: superficial and inner layer of oak barrels, wall surfaces and aging wine. In addition, the influence of age of barrels and winery climatic conditions on fungal populations was evaluated. Two selected types of cellars were studied (a ground level and climate‐controlled cellar‐industrial winery and an unconditioned underground cellar‐family owned winery); 142 different strains were isolated and then identified through a morphology‐based method. Wood inner layer was characterised by the presence of few oak‐specialised endophytes (Trichoderma viride, Acremonium strictum and Cladosporium cladosporioides), whereas some strains of Aspergillus spp. and Penicillium spp. (principally Aspergillus nidulans, Aspergillus oryzae, Penicillium glabrum and Penicillium aurantiogriseum) connected with humidity and pollution were isolated. Aspergillus spp. and Penicillium spp. were isolated also in wall and barrel surfaces and in aging wine.
No preview · Article · Jun 2012 · International Journal of Food Science & Technology
[Show abstract][Hide abstract] ABSTRACT: Two red wines (Primitivo and Uva di Troia) treated with oak chips inoculated with Penicillium purpurogenum were analysed in order to assess their contents of furfural, cis-β-methyl-γ-octalactone, syringol, eugenol, vanillin and 4-vinylguaiacol. Two different sizes of oak chips (small and big, of length 2 and 8 mm respectively) and two different degrees of toasting (low and high) were used in the study. Aroma compounds were analysed by gas chromatography/mass spectrometry to determine differences among samples after 15 days of chip contact time.
Big oak chips inoculated with P. purpurogenum increased the level of 4-vinylguaiacol, while small oak chips inoculated with P. purpurogenum, in some conditions, increased the level of eugenol. Chip size and degree of toasting also played an important role in the content of eugenol.
The use of oak chips inoculated with mould might be a promising alternative to barrel aging. Moreover, different fungal inocula could contribute to the enrichment of wine with specific compounds (e.g. 4-vinylguaiacol and eugenol).
No preview · Article · Jan 2012 · Journal of the Science of Food and Agriculture
[Show abstract][Hide abstract] ABSTRACT: Oak barrels are commonly used in the aging of wines and spirits because of their positive effects on the product. In recent years the addition of oak chips has been used to introduce desirable wood aromas and flavours into wines. In this study, oak chips in saline solution or laboratory medium were inoculated with Penicillium purpurogenum, Aureobasidium pullulans, Phialemonium obovatum, Phanerochaete chrysosporium and a combination of Ph. chrysosporium and A. pullulans. After 12 weeks of incubation, oak chips (2 g L(-1)) were macerated in a red wine for 17 days. Gas chromatography/mass spectrometry and high-performance liquid chromatography were used to evaluate 14 compounds, namely furfural, furfuryl alcohol, guaiacol, syringol, cis-β-methyl-γ-octalactone, 2-phenylethanol, 4-vinylguaiacol, benzyl alcohol, 2,3-butanediol, γ-butyrolactone, benzaldehyde, 4-ethylguaiacol, gallic acid and ellagic acid.
The microfungal treatments increased the concentration of some components. In particular, P. purpurogenum resulted in a significant improvement in the levels of guaiacol, furfural, syringol, furfuryl alcohol and 2-phenylethanol.
Penicillium purpurogenum and Ph. chrysosporium showed a constant trend (enrichment of furfural and benzaldehyde) independent to some extent of the medium used for chip treatment.
No preview · Article · Dec 2010 · Journal of the Science of Food and Agriculture
[Show abstract][Hide abstract] ABSTRACT: The effect of High Pressure Homogenization (HPH) on Fusarium oxysporum, Emericella nidulans and Penicillium italicum was studied. Moulds were inoculated in Tween 80, tomato juice and diluted tomato juice (ratio juice/water: 1:3) and homogenized with different pressure levels for 1, 2 or 3 times (between 30 and 150 MPa): the number of conidia decreased with the progressive increase of the pressure applied. This effect was more evident when a multi-step process was applied; furthermore the decrease of the fluid viscosity in tomato juice reduced the effectiveness of homogenization. Finally, a discolouration of inoculated P. italicum was observed probably due to the stress caused by high pressure levels.
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to investigate the proteolytic ability of some strains of aspergilli, fusaria, and penicillia and the metabiotic effect of Fusarium oxysporum and Penicillium expansum on Salmonella. The proteolytic activity of the target molds was determined on tomato juice agar and tomato juice, whereas the metabiotic effect of F. oxysporum and P. expansum on Salmonella was assessed in a model system consisting of tryptone soy broth with different amounts of tomato juice added. Fusaria, some aspergilli, and one strain of penicillium showed a proteolytic activity on tomato juice agar. In addition, Salmonella survival was enhanced in tryptone soy broth plus 20 or 50% tomato juice in the model system previously inoculated with F. oxysporum.
No preview · Article · Nov 2008 · Journal of food protection
[Show abstract][Hide abstract] ABSTRACT: The effect of different surface treatments (with olive oil, liquid smoke or pimaricin) on a number of physico-chemical characteristics (namely, moisture, NaCl content, pH, total and soluble nitrogen fractions, lipolytic processes and mould production) of the core and the rind zones of Canestrato Pugliese cheese were studied during the whole ripening period (100 days). Treated cheese data were statistically compared with data obtained for untreated cheese. While for the core zone proteolytic and lipolytic processes, together with all the other physico-chemical properties studied, remained unaffected by the surface treatment, in the layer close to the rind these were influenced significantly by the surface treatment in a manner correlated with the fungal growth.
No preview · Article · Oct 2007 · International Dairy Journal
[Show abstract][Hide abstract] ABSTRACT: The associated mycoflora of the Canestrato Pugliese cheese produced from raw milk, pasteurized milk or by heating the curd in hot whey were compared. In order to evaluate the ability to colonize Canestrato Pugliese cheese, the effects of pH, salt content, temperature and nutritional source on growth of some strains were investigated. The cheese produced according to a traditional protocol harboured a more heterogeneous mycoflora than to modern protocols. However, the species most frequently isolated from our samples (Fusarium moniliforme, Aspergillus niger and Aspergillus flavus) were infrequently associated with cheese and indicated a strong contamination of the ripening rooms used for cheese ripening only for a short while. Moreover, since during mould growth a risk of mycotoxin production in the cheese exists, the isolation of mycotoxigenic moulds could represent a health concern. The results obtained emphasize the need to control relative humidity and hygienic conditions of the ripening houses and provide an improved understanding of fungi of Canestrato Pugliese cheese.
No preview · Article · Apr 2004 · Sciences des Aliments
[Show abstract][Hide abstract] ABSTRACT: Four different yeast species (Metschnikowia pulcherrima, Saccharomycopsis vini, Kluyveromyces marxianus, Cryptococcus albidus), isolated from surface of grapes, were evaluated for biocontrol potential against Penicillium glabrum. In order to investigate the influence of temperature, pH, water activity and yeast cell concentration on Penicillium glabrum inhibition, the individual effects and the interaction of these factors were analyzed by means of a Central Composite Design (CCD). All yeast species tested showed antagonistic effects which were more pronounced at high cell concentrations. The other variables affected the antagonistic effect differentially depending on the yeast species. Results of the experimental design showed that the selective success of a competitive microflora is under environmental control; moreover, when microbial cells are subjected to multiple factors, the effects and the reciprocal interactions of the individual variables cannot be independently evaluated.
No preview · Article · Sep 1998 · Microbiological Research