Qualche considerazione sul vini dell'Ogliastra

A research on the chemical and chemical-physical characteristics of the «Cannonau» wine has been accomplished. 41 out of the 51 samples exa mined were supplied from private producing and 10 from wine wholesales. 385 The private produced wine has the following composition: alcohol from 10,27 to 17,93%, dry matter from 21 to 41,8‰, ashes from 1,4 to 4,8%, total acidity from 4 to 9,5‰, volatile acidity from O~27 to 3,43‰, fixed acidity from 2,2 to 6,4‰. The wine coming from wine wholesales has the following composition: alcohol from II,91 to 15,98%, dry matter from 19,8 to 29,1‰, ashes from 1,8 to 3,1‰, total acidity from 4,0 to 5,5‰, volatile acidity from 0,39 to 0,81‰, fixed acidity from 3,2 to 4,7‰

Lactic Acid Bacteria and Yeast Inocula Modulate the Volatile Profile of Spanish-Style Green Table Olive Fermentations

In this work, Manzanilla Spanish-style green table olive fermentations were inoculated with Lactobacillus pentosus LPG1, Lactobacillus pentosus Lp13, Lactobacillus plantarum Lpl15, the yeast Wickerhanomyces anomalus Y12 and a mixed culture of all them. After fermentation (65 days), their volatile profiles in brines were determined by gas chromatography-mass spectrometry analysis. A total of 131 volatile compounds were found, but only 71 showed statistical differences between at least, two fermentation processes. The major chemical groups were alcohols (32), ketones (14), aldehydes (nine), and volatile phenols (nine). Results showed that inoculation with Lactobacillus strains, especially L. pentosus Lp13, reduced the formation of volatile compounds. On the contrary, inoculation with W. anomalus Y12 increased their concentrations with respect to the spontaneous process, mainly of 1-butanol, 2-phenylethyl acetate, ethanol, and 2-methyl-1-butanol. Furthermore, biplot and biclustering analyses segregated fermentations inoculated with Lp13 and Y12 from the rest of the processes. The use of sequential lactic acid bacteria and yeasts inocula, or their mixture, in Spanish-style green table olive fermentation could be advisable practice for producing differentiated and high-quality products with improved aromatic profile.Gobierno de España-OliFilm-AGL-2013-48300-

Combined membrane process for dealcoholization of wines: Osmotic distillation and reverse osmosis

The demand of beverages with low or zero alcohol content is fast growing over the last years for health benefits of drinkers and more restrictive policies in alcohol consumption. Membrane processes are nowadays the most commonly used. They have undoubtedly led to improvements in quality, particularly for the low processing temperatures, but determined volatile compounds loss which in many instances resulted in unsatisfactory sensory quality. This study evaluates the combination of two membrane processes for the production of lower alcohol wines: osmotic distillation (OD) and reverse osmosis (RO). It aims for retain the flavour, preserve the good taste of wine with low alcohol content. A red wine (13.2 %v/v) was reduced in alcohol strength of about -5, -6, -8 %v/v through a RO and OD combined process: the initial wine was firstly treated through RO and was subsequently processed through OD to obtain partial dealcoholized wines. Such wines were then compared with those obtained through OD technique. Low alcohol wines were analysed for chemico-physical parameters and volatile composition. The results showed a better retention of the main chemical properties and volatile compounds in wines with low alcohol content obtained through the combined OD and RO process than those through single OD

Chemical evaluation of Carcavelos fortified wine aged in portuguese (Quercus pyrenaica) and french (Quercus robur) oak barrels at medium and high toast

Adega do Casal Manteiga is a winery, publicly owned by the Municipality of Oeiras that produces Carcavelos fortified wine. Carcavelos fortified wine is an appellation of origin and demarcated as D.O.P. (Denominação de Origem Protegida). This study examines the effects of barrels made from botanical species (Quercus pyrenaica, and Quercus robur) and toasting method (medium and high) on a single vintage wine that has been aged for 8 years. Twenty barrels were used, with five replicates for each factor. The barrels were fabricated and toasted using the same cooperage, J.M. Gonçalves in Portugal. Significant differences were seen between the species Q. robur and Q. pyrenaica, with an impact on total phenolic content, including both flavonoids and non-flavonoids. The total phenols of the wine aged in Q. pyrenaica barrels was significantly higher than in the Q. robur barrels, and Q. pyrenaica contained more flavonoids than Q. robur in medium and high toast barrels. Q. pyrenaica showed more non-flavonoid compounds than Q. robur inhigh and medium toasted barrels, but this difference in non-flavonoids was only statistically significant in the high toasted barrels. The degree of toasting had significant effects on the flavonoid content of the wine, as well as the tanning power. Flavonoid content increased for both Q. pyrenaica and Q. robur in the wines that were aged in high tasted barrels compared to those that were medium toasted. The tannin power decreased for both Q. pyrenaica and Q. robur when the toasting increasedinfo:eu-repo/semantics/publishedVersio

Moment-based Estimation of Mixtures of Regression Models

Finite mixtures of regression models provide a flexible modeling framework for many phenomena. Using moment-based estimation of the regression parameters, we develop unbiased estimators with a minimum of assumptions on the mixture components. In particular, only the average regression model for one of the components in the mixture model is needed and no requirements on the distributions. The consistency and asymptotic distribution of the estimators is derived and the proposed method is validated through a series of simulation studies and is shown to be highly accurate. We illustrate the use of the moment-based mixture of regression models with an application to wine quality data.Comment: 17 pages, 3 figure

Co-Existence of Inoculated Yeast and Lactic Acid Bacteria and Their Impact on the Aroma Profile and Sensory Traits of Tempranillo Red Wine

This study investigates the effects of simultaneous inoculation of a selected Saccharomyces cerevisiae yeast strain with two different commercial strains of wine bacteria Oenococcus oeni at the beginning of the alcoholic fermentation on the kinetics of malolactic fermentation (MLF), wine chemical composition, and organoleptic characteristics in comparison with spontaneous MLF in Tempranillo grape must from Castilla-La Mancha (Spain). Evolution of MLF was assessed by the periodic analysis of L-malic acid through the enzymatic method, and most common physiochemical parameters and sensory traits were evaluated using a standardized sensory analysis. The samples were analyzed by GC/MS in SCAN mode using a Trace GC gas chromatograph and a DSQII quadrupole mass analyzer. Co-inoculation reduced the overall fermentation time by up to 2 weeks leading to a lower increase in volatile acidity. The fermentation-derived wine volatiles profile was distinct between the co-inoculated wines and spontaneous MLF and was influenced by the selected wine bacteria used in co-inoculation. Co-inoculation allows MLF to develop under reductive conditions and results in wines with very few lactic and buttery flavors, which is related to the impact of specific compounds like 2,3-butanedione. This compound has been also confirmed as being dependent on the wine bacteria use

Comparative study on freeze-dried lactic cheese starters and ripening cultures for the production of camembert cheese : a thesis submitted in partial fulfillment of the requirements for the degree of Master of Food Technology, Massy [i.e. Massey] University, Albany, New Zealand.

Background and Methodology The key to success in producing cheeses is the performance of the starter cultures (Parente and Cogan, 2004). Storage of freeze-dried cheese cultures at refrigeration and ambient temperature or higher provides convenience to culture handling and transportation, as well as reduce cost. This study investigated the effects of 4 storage temperatures: -18°C, 4°C, 20°C and 37°C on the stability of mesophilic lactic cheese starters and ripening cultures intended for Camembert production. In phase one, a 22 randomized complete block design (RCBD) was used to determine the potential of 14 commercial freeze-dried direct-vat-set (DVS) mixed cultures to produce Camembert after 5 months storage at the 4 temperatures. The cultures used were: O-type: Lactococcus (L.) lactis subsp. lactis, L. lactis subsp. cremoris; LD-type: L. lactis subsp. lactis, L. lactis subsp. cremoris, L. lactis subsp. lactis biovar. diacetylactis and Leuconostoc species (Leuconostoc (Leuc.) lactis and Leuc. mesenteroides subsp. cremoris) and a mould, Penicillum (P.) camemberti. During storage, the cultures were analysed for cell viability, acid production, colour and species composition. The characterised cultures were screened to select the most stable cultures with good potential for Camembert production. In phase two, a 23 RCBD design was used to study the potential of the cultures to produce prototype Camembert cheese using I-Make® Limited domestic cheese kits. The prepared cheeses were characterised for acidity, viable cell counts content, texture, volatile aromatic compounds and proteolysis using standard procedures. Results and Discussion Viable cell counts and acidification potential of cultures decreased (P<0.05) during storage at selected temperatures for 5 months. Cultures stored at 37°C were the most affected. Proportion of citrate-fermenting lactic acid bacteria (LAB) in LD-type starters also decreased in a similar pattern. Cell inactivation at high temperature was probably attributed to high oxidation, browning reactions, lactose crystallization, changes in glass transition temperature (Tg) of culture-lactose matrix and loss of β-galactosidase enzyme activity, which were possibly also affected by water activity (aw) of the culture during storage (Higl et al., 2007; Kurtmann et al., 2009c). Viability and activities of cultures stored at 4 and 20°C after 5 months were comparable to those of -18°C cultures and levels normally used in industry. Thus, the cultures demonstrated good potential for Camembert cheese production. Similar patterns of microbial growth (LAB and P. camemberti) and acidification were observed in both cheeses (O- and LD-types) during cheese fermentation. However, cheeses fermented with O-type starters had better growth and acidification activity (P<0.05), which may be attributed to compositional differences of culture, leading to variable metabolic patterns (Mcsweeney and Fox, 2004). Cheeses produced with cultures stored at 4 and 20°C had lower levels of cell growth and acidity (P<0.05), suggesting that the microorganisms could have been affected by prolonged storage at relatively high temperatures. During cheese ripening, changes in microbial content, acidity, proteolysis, texture and aroma compounds, were similar, and significantly changed (P<0.05) with ripening time. Viable cell counts of LAB reduced, while pH and P. camemberti counts increased. Increase of pH may result from lactate metabolism by P. camemberti creating an alkaline environment due to the deamination activity of the mould (Spinnler and Gripon, 2004). Proteolysis of cheeses was correlated (P<0.05) with LAB and P. camemberti activity as well as the pH of Background and Methodology The key to success in producing cheeses is the performance of the starter cultures (Parente and Cogan, 2004). Storage of freeze-dried cheese cultures at refrigeration and ambient temperature or higher provides convenience to culture handling and transportation, as well as reduce cost. This study investigated the effects of 4 storage temperatures: -18°C, 4°C, 20°C and 37°C on the stability of mesophilic lactic cheese starters and ripening cultures intended for Camembert production. In phase one, a 22 randomized complete block design (RCBD) was used to determine the potential of 14 commercial freeze-dried direct-vat-set (DVS) mixed cultures to produce Camembert after 5 months storage at the 4 temperatures. The cultures used were: O-type: Lactococcus (L.) lactis subsp. lactis, L. lactis subsp. cremoris; LD-type: L. lactis subsp. lactis, L. lactis subsp. cremoris, L. lactis subsp. lactis biovar. diacetylactis and Leuconostoc species (Leuconostoc (Leuc.) lactis and Leuc. mesenteroides subsp. cremoris) and a mould, Penicillum (P.) camemberti. During storage, the cultures were analysed for cell viability, acid production, colour and species composition. The characterised cultures were screened to select the most stable cultures with good potential for Camembert production. In phase two, a 23 RCBD design was used to study the potential of the cultures to produce prototype Camembert cheese using I-Make® Limited domestic cheese kits. The prepared cheeses were characterised for acidity, viable cell counts content, texture, volatile aromatic compounds and proteolysis using standard procedures. Results and Discussion Viable cell counts and acidification potential of cultures decreased (P<0.05) during storage at selected temperatures for 5 months. Cultures stored at 37°C were the most affected. Proportion of citrate-fermenting lactic acid bacteria (LAB) in LD-type starters also decreased in a similar pattern. Cell inactivation at high temperature was probably attributed to high oxidation, browning reactions, lactose crystallization, changes in glass transition temperature (Tg) of culture-lactose matrix and loss of β-galactosidase enzyme activity, which were possibly also affected by water activity (aw) of the culture during storage (Higl et al., 2007; Kurtmann et al., 2009c). Viability and activities of cultures stored at 4 and 20°C after 5 months were comparable to those of -18°C cultures and levels normally used in industry. Thus, the cultures demonstrated good potential for Camembert cheese production. Similar patterns of microbial growth (LAB and P. camemberti) and acidification were observed in both cheeses (O- and LD-types) during cheese fermentation. However, cheeses fermented with O-type starters had better growth and acidification activity (P<0.05), which may be attributed to compositional differences of culture, leading to variable metabolic patterns (Mcsweeney and Fox, 2004). Cheeses produced with cultures stored at 4 and 20°C had lower levels of cell growth and acidity (P<0.05), suggesting that the microorganisms could have been affected by prolonged storage at relatively high temperatures. During cheese ripening, changes in microbial content, acidity, proteolysis, texture and aroma compounds, were similar, and significantly changed (P<0.05) with ripening time. Viable cell counts of LAB reduced, while pH and P. camemberti counts increased. Increase of pH may result from lactate metabolism by P. camemberti creating an alkaline environment due to the deamination activity of the mould (Spinnler and Gripon, 2004). Proteolysis of cheeses was correlated (P<0.05) with LAB and P. camemberti activity as well as the pH ofBackground and Methodology The key to success in producing cheeses is the performance of the starter cultures (Parente and Cogan, 2004). Storage of freeze-dried cheese cultures at refrigeration and ambient temperature or higher provides convenience to culture handling and transportation, as well as reduce cost. This study investigated the effects of 4 storage temperatures: -18°C, 4°C, 20°C and 37°C on the stability of mesophilic lactic cheese starters and ripening cultures intended for Camembert production. In phase one, a 22 randomized complete block design (RCBD) was used to determine the potential of 14 commercial freeze-dried direct-vat-set (DVS) mixed cultures to produce Camembert after 5 months storage at the 4 temperatures. The cultures used were: O-type: Lactococcus (L.) lactis subsp. lactis, L. lactis subsp. cremoris; LD-type: L. lactis subsp. lactis, L. lactis subsp. cremoris, L. lactis subsp. lactis biovar. diacetylactis and Leuconostoc species (Leuconostoc (Leuc.) lactis and Leuc. mesenteroides subsp. cremoris) and a mould, Penicillum (P.) camemberti. During storage, the cultures were analysed for cell viability, acid production, colour and species composition. The characterised cultures were screened to select the most stable cultures with good potential for Camembert production. In phase two, a 23 RCBD design was used to study the potential of the cultures to produce prototype Camembert cheese using I-Make® Limited domestic cheese kits. The prepared cheeses were characterised for acidity, viable cell counts content, texture, volatile aromatic compounds and proteolysis using standard procedures. Results and Discussion Viable cell counts and acidification potential of cultures decreased (P<0.05) during storage at selected temperatures for 5 months. Cultures stored at 37°C were the most affected. Proportion of citrate-fermenting lactic acid bacteria (LAB) in LD-type starters also decreased in a similar pattern. Cell inactivation at high temperature was probably attributed to high oxidation, browning reactions, lactose crystallization, changes in glass transition temperature (Tg) of culture-lactose matrix and loss of β-galactosidase enzyme activity, which were possibly also affected by water activity (aw) of the culture during storage (Higl et al., 2007; Kurtmann et al., 2009c). Viability and activities of cultures stored at 4 and 20°C after 5 months were comparable to those of -18°C cultures and levels normally used in industry. Thus, the cultures demonstrated good potential for Camembert cheese production. Similar patterns of microbial growth (LAB and P. camemberti) and acidification were observed in both cheeses (O- and LD-types) during cheese fermentation. However, cheeses fermented with O-type starters had better growth and acidification activity (P<0.05), which may be attributed to compositional differences of culture, leading to variable metabolic patterns (Mcsweeney and Fox, 2004). Cheeses produced with cultures stored at 4 and 20°C had lower levels of cell growth and acidity (P<0.05), suggesting that the microorganisms could have been affected by prolonged storage at relatively high temperatures. During cheese ripening, changes in microbial content, acidity, proteolysis, texture and aroma compounds, were similar, and significantly changed (P<0.05) with ripening time. Viable cell counts of LAB reduced, while pH and P. camemberti counts increased. Increase of pH may result from lactate metabolism by P. camemberti creating an alkaline environment due to the deamination activity of the mould (Spinnler and Gripon, 2004). Proteolysis of cheeses was correlated (P<0.05) with LAB and P. camemberti activity as well as the pH of samples. Softening of cheese was associated with increased proteolysis and pH due to the growth of P. camemberti (Spinnler and Gripon, 2004). A range of volatile organic compounds, dominated by fatty acids, alcohols and aldehydes were identified in cheese samples as reported in other studies (Sable and Cottenceau, 1999). Changes in 3-methylbutanal and 3-methylbutanol profiles of samples reflected the degradation of leucine,, synthesis of the aldehyde and its degradation to branched alcohols as a consequence of peptidolytic activity of LAB (Yvon and Rijene, 2001) and enzymatic activity of P. camemberti (Molimard and Spinnler, 1996). Increased concentrations of 2-heptanone, 2-nonanone and butyric acid in cheese samples suggested lipolytic activity in all samples (Molimard and Spinnler, 1996). The activity of P. camemberti involved in β-oxidation pathway for producing methyl ketones was also demonstrated confirmed by identified metabolites. Higher proteolysis and softness in LD-cheeses than O-type, suggested a higher degree of cheese ripening (Ardö, 1999), which may be attributed to proteolytic and peptidolytic activity of LD-starters (Tzanetaki et al., 1993). Higher proteolysis may be also associated with higher pH of cheese curd at draining, which facilitated higher syneresis. Increased whey content of curd may retain higher concentration of coagulant enzyme in the curd (Guinee and Wilkinson, 1992) and effectively stimulate the growth of P. camemberti, thus probably allowing proteolysis to occur more readily (Grappin et al., 1985). A relatively higher concentration of 3-methylbutanal was found in O-type cheeses than in LD-type. This suggests that LAB in O-type starters may exhibit higher activity in degrading leucine to 3-methylbutanal than LD-type starters (Yvon and Rijene, 2001). 2,3-butandione was suspected in LD-type cheeses but not in O-type samples, demonstrating the active role of citrate-fermenting bacteria of LD-starters (Mcsweeney and Fox, 2004). Results indicate that storage temperature of cultures had a significant (P<0.05) impact on viable cell counts and acidity of samples. In spite of reduced cell counts, proteolysis, texture and aroma of the prototype cheese samples were not affected (P<0.05). Although there were no differences between the Camembert cheeses, 4 and 20°C cultures used in cheese-making may enhance the ripening process (Ardö, 1999) than -18°C cultures, as indicated by relatively higher proteolysis and degree of softening. Lower levels of 3-methylbutanal in samples containing 4 and 20°C cultures was probably due to the reduced aminotransferases activity of LAB (Yvon and Rijene, 2001) after prolonged storage at the two temperatures. The slightly higher levels of 2-heptanone, 2-nonanone and butyric acids in samples with 4 and 20°C cultures were probably due to increased lipolytic activity of enhanced growth of P. camemberti (Molimard and Spinnler, 1996) during cheese ripening. Conclusion LAB starter cultures and P. camemberti can be stored for 5 months at 4 and 20°C without affecting their activities and the quality of prototype Camembert produced. Camembert cheese samples produced in this study had typical characteristics of this type of cheese. Cheese fermented with LD-type starters showed extra flavour enhancement potential and the products had higher degree of softening due pronounced proteolysis. Cultures stored at 37°C for 5 months were characterised by poor viable cells and capability to the produce acid, therefore, they were not suitable for Camembert cheese production

Analytical methods in wineries: is it time to change?

A review of the methods for the most common parameters determined in wine—namely, ethanol, sulfur dioxide, reducing sugars, polyphenols, organic acids, total and volatile acidity, iron, soluble solids, pH, and color—reported in the last 10 years is presented here. The definition of the given parameter, official and usual methods in wineries appear at the beginning of each section, followed by the methods reported in the last decade divided into discontinuous and continuous methods, the latter also are grouped in nonchromatographic and chromatographic methods because of the typical characteristics of each subgroup. A critical comparison between continuous and discontinuous methods for the given parameter ends each section. Tables summarizing the features of the methods and a conclusions section may help users to select the most appropriate method and also to know the state-of-the-art of analytical methods in this area

A note on the effect of calcium alginate coating on quality of refrigerated strawberries.

peer-reviewedAn alginate-based edible coating was investigated for the preservation of the quality of strawberries during cold storage (5 °C). Strawberries were immersed, successively, in sodium alginate and calcium chloride solutions to generate a surface coating of calcium alginate. The quality of coated and non-coated strawberries was evaluated by weight loss, visible decay, titratable acidity, total soluble solids and reducing sugar concentration over a 14-day storage period. Results showed that coating with calcium alginate had no significant effects on weight loss or physicochemical parameters when compared to control fruit, but it did result in the postponement of visible decay during refrigerated storage