Search

Over forty-five complex free oligosaccharides (of which several are novel) have been isolated and chemically characterized by gas chromatography and high resolution and high mass accuracy matrix-assisted laser desorption/ionization mass spectrometry (MALDI-FTICR MS) in red and white wines, Grignolino and Chardonnay, respectively. Oligosaccharides with a degree of polymerization between 3 and 14 were separated from simple monosaccharides and disaccharides by solid-phase extraction. The concentrations of free oligosaccharides were over 100 mg/L in both red and white wines. The free oligosaccharidescharacterized for the first time in the present studyinclude hexose-oligosaccharides, xyloglucans, and arabinogalactans and may be the natural byproduct of the degradation of cell wall polysaccharides. The coupled gas chromatography and accurate mass spectrometry approach revealed an effective method to characterize and quantify complex functional oligosaccharides in both red and white wine.

The aim of this work was to evaluate the characteristics of nine kaki vinegars produced using different yeasts and bacteria traditionally involved in wine production, and to evaluate their acidity, density, total phenolic content, and antioxidant activity. Furthermore, the study characterized the volatile fingerprinting by headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) and by two-dimensional gas chromatography coupled to mass spectrometry (GCxGC-TOF-MS). Finally, individual carotenoids were characterized using high performance liquid chromatography (HPLC). More than a thousand distinguishing molecules were found. It was discovered that vinegars fermented with S. cerevisiaeproduced a larger number of volatile chemicals. Among the three vinegars produced with this strain, the one fermented with Acetobacter_vino seemed to have a more elaborate flavour profile than all the other samples. The vinegar produced utilizing the mixture of T. delbruekiiand Acetobacterwas the only kind to have a high concentration of carotenoids.

The bioactivity of probiotic bacteria is well established in the literature at different levels. Some probiotic microorganisms are able to adhere to vaginal epithelial cells (VECs), particularly after topical treatment. A spontaneous study was conducted on women to assess the presence of Lactobacillus plantarumP17630 in vaginal mucosa after food supplement oral administration. Six healthy fertile volunteers were treated for 60 consecutive days with one sachet per day of a commercialised product, containing a total of 50×109CFU of L. plantarumP17630, L. paracaseiI1688 and L. salivariusI1794. After 30 days, 80% of treated subjects showed the presence of L. plantarumP17630 in vaginal mucosa. After 15 days of a wash-out period, the presence of L. plantarumP17630 was attested in the same percentage of subjects, confirming the colonisation. Moreover, during the treatment period, the total lactobacilli amount remained constant and the presence of monitored vaginal pathogen microorganisms decreased in some subjects. Concluding, with this work we showed that continued, regular and persistent oral administration of a probiotic food supplement could guarantee the colonisation and persistence of L. plantarumP17630 in the vaginal ecosystem.

Food allergy is becoming a major public health concern in recent times. Several sesame seed allergenic proteins have been identified. However, sensitization toward these proteins does not follow a common and unique pattern of clinical reactivity, as shown by the differential geographic recognition of single proteins.

The aim of this study was to research decarboxylating bacterial strains and biogenic amine content in a typical Italian goat cheese (Robiola di Roccaverano). The study was performed on fresh and ripened samples of goat cheese manufactured from industrial and artisanal producers. Sixty-seven bacterial strains isolated showed decarboxylating activity, and Enterococcus faecaliswas the most widespread decarboxylating species in all artisanal and industrial products. Pediococcus acidilacticiand Enterococcus malodoratuswere also identified as biogenic amine producers in Robiola di Roccaverano cheese. All the E. faecalisstrains isolated in this study were able to decarboxylate tyrosine. Tyramine was the most abundant biogenic amine in cheese samples, while histamine was the most widespread. High amounts of these two biogenic amines were found in ripened samples (up to 2,067 mg/kg for tyramine and 1,786 mg/kg for histamine), whereas 2-phenylethylamine and tryptamine were present in almost all ripened cheeses at low concentrations. The detection of strains producing biogenic amines and the high concentrations of tyramine and histamine found in ripened Robiola di Roccaverano could represent a potential risk to the consumer.

Fermented cocoa beans (Theobroma cacaoL., Sterculiaceae) from different countries of origin (Ecuador, Ghana, Trinidad) and cocoa beans roasted under defined conditions (industrial roasting; 150–220°C for 20 min, dry roasting in conventional oven) were analyzed for their contents of certain chiral hydroxy acids, catechins, and amino acids. Cocoa beans are fermented, dried, and industrially transformed by roasting for the production of chocolate, cocoa powders, and other cocoa‐related products. Fermentation and roasting conditions influence the contents of chiral compounds such as hydroxy acids, amino acids, and polyphenols, depending on technological procedures as well as some technical parameters. The aim of this work was to check if the content and nature of the named chiral compounds present both in fermented and roasted cocoa beans could be related to the traditional parameters used to classify the variety of seeds and the degree of fermentation. The extent of racemization of amino acids in fermented cocoa beans was low while it slowly increased during roasting, depending on the temperature applied. L‐lactic acid was always higher than the D‐form while citric acid was generally the most abundant hydroxy acid detected in beans. A correlation was found between polyphenol content and degree of fermentation, while epimerization of (−)‐epicatechin to (+)‐catechin was observed during roasting. On the whole, results showed that several chiral compounds could be considered as good quality markers for cocoa seeds and cocoa‐related products of different quality and geographic origin. Chirality, 2007. © 2007 Wiley‐Liss, Inc.

Abstract. Italian traditional pasta is manufactured using Triticum durum semolina. Italian national legislation excludes the use of Triticum aestivum to prepare this traditional food and permits a contamination of durum wheat by T. aestivum in a maximum content of 3%. However, the use of soft wheat is frequent in other European countries. The protection of traditional pasta requires a sensible technique, possibly by passing the use of protein as molecular marker. In fact, proteins are easily denatured by thermal technologies (high-temperature dried pasta). The PCR of some sequences of T. aestivum has been optimized using two sets of primers designed on puroindoline b gene. The specificity of this method has been studied towards T. durum varieties and towards some cereals. Universal ribosomal primers written on internal transcribed spacers region (ITS) have been employed to set up a multiplex PCR protocol. This approach allows obtaining a useful tool to distinguish the presence of soft wheat in pasta. The detection limit of this method is 0.2% T. aestivum in T. durum. The analyses of commercial samples showed that this method works well also on high-temperature dried pasta.

Fatty acid composition of 66 samples of ?Ossolano?, a typical semi-hard cheese produced from raw cow milk in the Ossola valley (North Piedmont, West Italy) was determined. The survey was carried out on 24 summer cheeses produced in mountain farms (1500-2200 m) with milk from pasture-fed cows and 42 winter cheeses produced in valley farms (500-800 m) with milk from hay- and concentrate-fed cows. Seasonal variation in feeding condition was responsible for the observed variations in fatty acid composition of the samples. Long-chain mono- and poly-unsaturated fatty acids were more abundant in the summer cheeses while short- and medium-chain saturated fatty acids were higher in winter products. The ratio of saturated to unsaturated fatty acids was thus lower in summer cheeses compared with winter cheeses. Conjugated linoleic acids, n-3 and n-6 acids were instead higher in summer cheeses according to the results of many authors. The n-6/n-3 ratio is lower in the summer products with an interesting nutritional effect due to the essential role of n-3 polyunsaturated fatty acid in human health. Composition en acides gras du fromage ? Ossolano ? du Pi?mont. La composition en acides gras a ?t? d?termin?e dans 66 ?chantillons d'? Ossolano ?, un fromage ? p?te semi-dure qui est produit ? partir du lait cru dans la vall?e de l'Ossola (Pi?mont du Nord, Italie). Vingt-quatre de ces fromages ont ?t? fabriqu?s en ?t? ? partir de laits produits sur des p?turages de montagne (1500-2200 m) et quarante-deux en hiver ? partir de laits produits dans la vall?e (500-800 m) avec une alimentation ? base de foin et de c?r?ales. Le changement dans l'alimentation a d?termin? le changement de la composition en acides gras des fromages. La proportion en acides gras ? cha?ne longue mono- et poly-insatur?s ?tait significativement plus ?lev?e dans les fromages d'?t?, alors que celle des acides gras satur?s ? cha?ne courte et moyenne ?tait plus ?lev?e dans les fromages d'hiver. Par cons?quent le rapport entre les acides satur?s et acides insatur?s ?tait plus petit dans les fromages d'?t? que dans les fromages d'hiver. Les CLA et les acides n-3 et n-6 sont plus ?lev?s dans les fromages produits en ?t? comme de nombreux auteurs l'ont d?j? soulign?. Le rapport n-6/n-3 est plus petit pour les fromages produits en ?t?, ce qui entra?ne un effet nutritionnel int?ressant gr?ce au r?le essentiel des acides gras poly-insatur?s n-3 dans l'alimentation humaine.

Fatty acid composition of 66 samples of ”Ossolano”, a typical semi-hard cheese produced from raw cow milk in the Ossola valley (North Piedmont, West Italy) was determined. The survey was carried out on 24 summer cheeses produced in mountain farms (1500-2200 m) with milk from pasture-fed cows and 42 winter cheeses produced in valley farms (500-800 m) with milk from hay- and concentrate-fed cows. Seasonal variation in feeding condition was responsible for the observed variations in fatty acid composition of the samples. Long-chain mono- and poly-unsaturated fatty acids were more abundant in the summer cheeses while short- and medium-chain saturated fatty acids were higher in winter products. The ratio of saturated to unsaturated fatty acids was thus lower in summer cheeses compared with winter cheeses. Conjugated linoleic acids, n-3 and n-6 acids were instead higher in summer cheeses according to the results of many authors. The n-6/n-3 ratio is lower in the summer products with an interesting nutritional effect due to the essential role of n-3 polyunsaturated fatty acid in human health.

Abstract:  A non-conventional sensitive and specific method for the detection of Saccharomyces cerevisiae in food is proposed. Polymerase chain reaction (PCR) led to the identification of this yeast in some commercial bakery products. The comparative use of two methods of clean-up of DNA from Triticum spp., S. cerevisiae and some foods shows an improvement in extraction yield for the phenol-free method. Analysis of some sequences of ribosomal genes shows different amplified products for Triticum and S. cerevisiae. Internal transcribed spacer amplification (ITS1/ITS4) produced a single band of about 650 and 800 bp for Triticum and S. cerevisiae, respectively. ITS1/ITS2 universal fungal primers gave a single band of about 300 and 450 bp for Triticum and S. cerevisiae, respectively. Both amplification products are able to distinguish between the yeast and the DNA from T. aestivum and T. durum, showing polymorphism in the ITS1 region. Amplification on two primers designed using the sequence of the ITS1 region of S. cerevisiae rDNA (SC1/SC2) led to a single band of 300 bp, species-specific for the yeast. These primers enabled an unambiguous distinction between fermented foods containing S. cerevisiae and those leavened by baking powders to be made. We suggest that this PCR assay could be used for quality control and for the trace detection of S. cerevisiae as a potential food allergen.