Search results for "RIPENING"
showing 10 items of 135 documents
In-Depth Investigation of the Safety of Wooden Shelves Used for Traditional Cheese Ripening
2021
ABSTRACT The main goal of this research was to characterize the bacterial diversity of the wooden boards used for aging traditional Sicilian cheeses and to evaluate whether pathogenic bacteria are associated with these surfaces. Eighteen cheese dairy factories producing three traditional cheese typologies (PDO Pecorino Siciliano, PDO Piacentinu Ennese, and Caciocavallo Palermitano) were selected within the region of Sicily. The wooden shelf surfaces were sampled by a destructive method to detach wood splinters as well as by a nondestructive brushing to collect microbial cells. Scanning electron microscopy showed the presence of almost continuous bacterial formations on the majority of the s…
Determination of cow’s milk in non-bovine and mixed cheeses by capillary electrophoresis of whey proteins in acidic isoelectric buffers
2000
An improved method for the determination of cow's milk in non-bovine cheese is reported: electrophoresis of whey proteins in acidic, isoelectric buffers. Two background electrolytes (BGEs) have been tested: (i) 50 mM iminodiacetic acid (pH=isoelectric point=2.30 at 25 degrees C), 0.5% hydroxyethylcellulose, 0.1% Tween 20 and 6 M urea (apparent pH 3.1), E=300 V/cm, for the separation of alpha-lactalbumins (alpha-LAs); (ii) a BGE with the same composition, but supplemented with 10% Tween 20, E=450 V/cm, for the fractionation of beta-lactoglobulins (beta-LGs). Surfactants have a discriminating effect on the retention behaviour of the bovine alpha-LA and beta-LG proteins, owing to the different…
Polyphenol Oxidases from Wine Grapes
2017
Wine is produced from grapes which contain enzymes forming unfavorable dark polymers such as melanin, oxidizing proteins, and phenols which may influence their functions. Here we focus on the class of type-3 copper proteins presenting new insights on the structure, the occurrence during the ripening process and during wine making. Then, the reactivity of the enzymes on polyphenols from wine grapes are discussed and the possible consequences on health.
Characterisation of Vernaccia Nera (Vitis vinifera L.) Grapes and Wine
2017
Vernaccia Nera (VN) is a minor Italian red grape cultivar whose oenological properties have not been investigated yet. Traditional winemaking procedures with VN can include grape drying and even triple sequential fermentations, but a rational vinification approach should be based on the grape composition. Since a comprehensive characterisation of the VN grape is still missing, the ripening of VN grapes was monitored by evaluating flavour compounds, proanthocyanidins and anthocyanins. The grapes were used to produce red wine whose chemical composition and sensory properties were assessed. Ripe VN grapes contained high amounts of extractable anthocyanins (0.88 g/kg). The most abundant anthocy…
Effect of leaf removal and ripening stage on the content of quercetin glycosides in Sangiovese grapes
2021
Quercetin haze has been observed over the last few years in some aged Sangiovese wines. This problem could be due to an excess of the quercetin in the wine. Leaf removal increases the exposition of clusters to sunlight, which may enhance flavonol synthesis in the grapes. In this study, we evaluated the dynamics related to extractable flavonols in grapes grown in three usually defoliated Vitis vinifera (L.) cv. Sangiovese vineyards, whose wines showed quercetin precipitates. The particular structure of the vineyards in which the leaf removal experiments were carried out allowed the influence of vineyard, biotype and rootstock on grape flavonol contents at mid-maturation and technological mat…
: J. Sci. Food Agric.
2017
Background: The measurement of carbon isotopic discrimination in grape sugars at harvest (δ13 C) is an integrated assessment of water status during ripening. It is an efficient alternative to assess variability in the field and discriminate between management zones in precision viticulture, but further work is needed to completely understand the signal.; Results: This work, spanning over 3 years, performed in a hillslope toposequence in Burgundy, delineates the relationships between main soil properties (gravel amount, slope, texture) and the grapevine water status assessed by δ13 C. The highest δ13 C, indicating most severe water deficit, was recorded in gravelly soils on steep slopes. The…
Fast detection of bovine milk in Rocquefort cheese with phastsystem by gel isoelectric focusing and immunoblotting
1992
.Summary - A fast procedure for the detection of bovine milk in Roquefort cheese is described. It is based on the separation by rapid isoelectric focusing on Phasteysterne apparatus of 12-caseinsfrom the milk of the 2 species. The presence of bovine milk is also confirmed by the detection in the electrophoretic pattern of a ~-casein derived peptide from bovine milk, during cheese ripening, identified by immunoblotting. By using Ihis procedure, levels of bovine milk as low as 5% were easily delecled in Roquefort cheese ripened for a period varying from 10 days to 5 months.
Review : Compounds involved in the flavor of surface mold-ripened cheeses : Origins and properties
1996
Abstract Cheese flavor is obtained through a series of chemical changes that occur in the curd during the early stages of ripening. Lipid hydrolysis leads to FFA, which serve as substrates for further reactions. Peptides and amino acids, which results from proteolysis, also lead to aroma compounds through enzymic and chemical reactions. This paper is a review of the current knowledge about the compounds that contribute to flavor in mold-ripened cheeses, especially Camembert-type cheese. Discussed are the pathway of formation, the sensory properties (odorous notes and perception thresholds), and the quantities of the main volatile compounds encountered in these types of cheeses.
Inactivation of lactococcal aromatic aminotransferase prevents the formation of flora aroma compounds from aromatic amino acids in semi-hard cheese
1999
The enzymatic conversion of aromatic amino acids to aroma compounds plays a role in the formation of an undesirable floral aroma in Cheddar-like cheeses. In lactococci, the first step of aromatic amino acid degradation is a transamination, catalysed by an aromatic aminotransferase (AraT). We observed previously that in vitro, araT inactivation prevented degradation of aromatic amino acids and decreased degradation of Met and Leu. In this study we evaluated the effect of araT inactivation in Lactococcus lactis on flavour development in St. Paulin-type cheese. The degradation of amino acids was monitored by using radiolabelled amino acids and the volatile compounds formed were analysed by GC-…
Untargeted metabolomics of rind essential oils allowed to differentiate two closely related clementine varieties
2021
[EN] Chemical characterization of clementine varieties (Citrus clementina Hort. ex Tan.) essential oils (EO) can lead to variety identification and valorization of their potential use in food and aroma industries. The goal of this study was the chemometric discrimination between two very closely related and morphologically identical clementine varieties, Clemenules (NL) and Clemenpons (PO), based on their rind EO, to identify the differential volatile organic compounds (VOCs) and to determine their antioxidant capacity. EO rind volatile profile was determined by gas chromatography coupled to mass spectrometry in Citrus fruit at different ripening stages grown two independent years in two di…