Antimicrobial properties and volatile profile of bread and biscuits melanoidins.

This work gives novel information about the antimicrobial effect and volatiles of melanoidins isolated from Maria biscuit, common and soft bread. Melanoidins were isolated from scraped and sieved crusts (1 mm), after gluten digestion, 10 kDa ultrafiltration, and diafiltration. Finally, they were freeze-dried. Headspace solid-phase dynamic extraction coupled with a gas chromatograph with a mass spectrometer was used to determine the volatile profiles. The antimicrobial effect was evaluated against isolated strains of the most relevant food spoilage and pathogen microorganisms, together with some molds and yeasts. Melanoidins from common bread exhibited the most extensive antimicrobial activities and showed the most composite volatile profile. No undesirable compounds, such as furfural and 5-hydroxy-methyl-furfural, were found in any of the melanoidins studied. The obtained data pointed out that bakery melanoidins can exert effective food technological properties as natural antimicrobials that can improve shelf-life and security of foodstuffs, together with a possible contribution to food aroma.

Effects of an Extract from Olive Fruits on the Physicochemical Properties, Lipid Oxidation and Volatile Compounds of Beef Patties.

The aim of this work was to evaluate the effect of an olive extract (OE) on the physicochemical and microbiological characteristics, lipid oxidation and volatile compounds of beef patties stored both aerobically and under modified atmosphere packaging for 15 days at 4 °C. The antioxidant and antimicrobial effects of the OE were compared to those of sulfite. Four formulations were elaborated according to the antioxidant and dose used: without antioxidant, C; 300 mg potassium metabisulfite/kg product, S; 150 mg OE/kg product, OE1; and 250 mg of OE/kg product, OE2. The parameters analyzed were pH, water activity, color, lipid oxidation (TBARS and volatile organic compounds: hexanal, 2-pentyl-furan, 1-pentanol, 2,3-octanedione and nonanal, 1-octen-2-ol) and total viable counts. The OE delayed the loss of the bright red color of the patties and reduced the lipid oxidation in both types of packaging compared to the control patty. Sulfite was the most effective antioxidant for inhibition of the total viable counts. An OE could be used as a natural antioxidant to delay the lipid oxidation of meat without negatively affecting its physicochemical properties.

Application of the Just-About-Right Scales in the Development of New Healthy Whole-Wheat Muffins by the Addition of a Product Obtained from White and Red Grape Pomace.

The aim of this study was to evaluate the adequacy of sensory attributes, by the use of just-about-right (JAR) scales and penalty analysis, of new healthy whole-wheat muffins with high fibre content due to the addition of two products obtained from white and red grape pomace. Furthermore, the nutritional, colour and texture properties of the muffins were evaluated. For that, five formulations of whole-wheat muffins were studied: a control muffin made with 100% whole-wheat flour and muffins made with 10 and 20% of white and red grape pomace product, respectively. The incorporation of grape pomace products in the recipe led to muffins with "high-fibre content", which would imply healthy properties in these muffins. The hardness and chewiness increased whereas the springiness, cohesiveness, resilience and colour parameters decreased when the grape pomace products were incorporated. The sensory analysis indicated high levels of acceptability of the muffins that incorporated white and red grape pomace products at concentrations of 10%. The penalty analysis showed that none of the attributes evaluated affected the acceptability of the new muffins significantly; only the darker colour of the muffins caused by the red grape pomace product could affect the acceptability, although this fact was not clearly demonstrated.

Chemopreventive Potential of Powdered Red Wine Pomace Seasonings against Colorectal Cancer in HT-29 Cells.

This study evaluates the antiproliferative and antigenotoxic actions of powdered red wine pomace seasonings (Sk-S, seedless; W-S, whole; Sd-S, seeds). In vitro gastrointestinal digested and colonic fermented fractions of the seasonings were used as cell treatments. Phenolic acids from Sk-S showed the highest bioaccessibility in the small intestine, whereas polyphenols contained in Sd-S might be the most fermentable in the colon. Dietary fiber from Sk-S was the best substrate for short chain fatty acids production by gut microbiota. Colon cancerous (HT-29) cell viability was inhibited by 50% (IC50 values) at treatment concentrations ranging from 845 (Sk-S) to 1085 (Sd-S) µg/mL prior digestion, but all digested fractions exhibited similar antiproliferative activities (mean IC50 = 814 µg/mL). Oxidative DNA damage in cells was also attenuated by the treatments (200 µg/mL, 24 h preincubation), with all colonic fermented fractions displaying similar genoprotective action. These results suggest the potential of red wine pomace seasonings as chemopreventive agents in colorectal cancer.

Use of Commercial Dry Yeast Products Rich in Mannoproteins for White and Rosé Sparkling Wine Elaboration.

In sparkling wines, mannoproteins released during yeast autolysis largely affect their final quality. This process is very slow and may take several months. The aim of this work was to study the effect of several commercial dry yeast autolysates on the chemical composition, foam, and sensory properties of white and rosé sparkling wines aged on lees for 9 months during two consecutive vintages. The addition of these products in the tirage phase did not affect either the content of phenolic compounds, amino acids, and biogenic amines or the foam properties. The commercial product with the highest mannoprotein content and the highest purity caused significant changes in the volatile composition of the wines and enhanced the fruity aromas in both Verdejo and Godello sparkling wines.

Study of the effect of vintage, maturity degree, and irrigation on the amino acid and biogenic amine content of a white wine from the Verdejo variety.

BACKGROUND: The aim of this study was to determine the effect of three factors directly related to the amino acid content of grapes and their interaction. These three factors were vintage, maturity degree and irrigation. The evolution of amino acid was also assessed during the winemaking along with the effect of maturity and irrigation on the biogenic amine formation. The grapes used for this study were of the Verdejo variety. RESULTS: The results indicated that there was a strong vintage effect on amino acid content in grapes, which seemed to be clearly related to climatic conditions. The effect of maturity on amino acid content depended on vintage, irrigation and the amino acid itself although it was observed that irrigation caused the increase of most amino acids present in the berry. Irrigation did not affect the evolution of nitrogen compounds during the alcoholic fermentation process but the maturity degree in some of the amino acids tested did so. No direct relationship could be established between irrigation or maturity degree and biogenic amines. However, it should be noted that the biogenic amine content was very low. CONCLUSIONS: Vintage has a strong effect on the amino acid content in grapes which appears to be related to weather conditions. No direct relationship has been found between irrigation or maturity degree and biogenic amines content. Furthermore, it is noted that biogenic amine content found in final wines was very low.

Changes in polysaccharide composition during sparkling wine making and aging.

The evolution in polysaccharide composition and molecular weights during sparkling wine making and aging was studied for the first time in this work. Different autochthonous grape varieties from Spain (Verdejo, Viura, Malvasía, Albarín, Godello, Garnacha and Prieto Picudo) were used to elaborate sparkling wines following the champenoise method. Principal component analysis showed differentiation of wines according to polysaccharide families. This differentiation was due to the process of aging on yeast lees, but not to the variety employed. The content of mannoproteins during aging was positively correlated (r = 0.792) with total polysaccharides from grapes. After six months of aging the highest content of mannoproteins and polysaccharides rich in arabinose and galactose was obtained. Also a shift to lower molecular weights was observed. The combination of these two characteristics could imply a better foam stability and thus sensory quality of sparkling wines.

Characterization of volatile compounds and olfactory profile of red minority varietal wines from La Rioja.

BACKGROUND: The aim of this work was to study for the first time the volatile compounds and olfactory profile of La Rioja red wines made with the local varieties Vitis vinifera cv. Monastel and Maturana Tinta de Navarrete, using Tempranillo as a reference variety. The impact of vintage on these compounds was also evaluated, and chemometric techniques were applied to achieve a possible differentiation of the wines. RESULTS: A clear classification of wines according to grape variety and vintage was obtained. Volatile compounds that differentiated wines by grape variety were varietal aromas whereas vintage was mainly differentiated by compounds formed during the alcoholic fermentation and extracted from wood during the elaboration process in wooden barrels. Sensory analysis also allowed differentiation of wines by grape variety. Tempranillo wines were characterized by liquorice notes, whereas Maturana Tinta de Navarrete wines were the least fruity and showed herbaceous and pepper notes. The sensory profile of Monastel varied between vintages. CONCLUSION: These minor grape varieties could provide a good alternative to the most widespread variety in La Rioja: Tempranillo. The use of these varieties produced wines with their own personality and different aromatic profile from other wines on the market.

Effect of the aging on lees and other alternative techniques on the low molecular weight phenols of Tempranillo red wine aged in oak barrels.

The effect of different alternative techniques to the traditional aging on lees on the low molecular weight phenolic compounds of red wines was study as well as their evolution during the aging in oak wood barrels for six months. The study was carried out with Tempranillo red grapes from two consecutive vintages. The techniques assayed were the traditional aging on lees with or without the addition of exogenous ß-glucanase enzymes, the use of yeast derivative preparations also with or without the addition of exogenous ß-glucanase enzymes, the micro-oxygenation applied together with the aging on lees, and the use of non-toasted oak wood chips. Hydroxycinnamic acids were the compounds most affected by these treatments, mainly in the wines treated with chips and commercial yeast derivative products, which showed higher concentrations of the free acids, compounds that play an important role in wine stabilization color since they can act as anthocyanin copigments. The differences found between the assayed treatments were more important in the 2007 vintage than in the 2008. However, a more significant effect of micro-oxygenation in the 2008 vintage was observed, which could be related to the fact that in this vintage the treatment was longer. In the 2008 vintage, the differences between treatments decreased along the aging in barrel. This vintage effect could be associated to the differences in the phenolic concentration of the initial wines. In this sense more research should be done to corroborate this fact.

Effect of aging on lees and of three different dry yeast derivative products on Verdejo white wine composition and sensorial characteristics.

A study was made of the effect of aging on lees and of three different commercial yeast derivative products of different composition and degree of purification on the phenolic compounds, color, proteins, polysaccharides, and sensorial characteristics of white wines. The results obtained showed that the lees and yeast derivative products can interact or adsorb some of the phenolic compounds present in wines, reducing their concentration. This reduction depends on the treatment applied, the phenolic compound analyzed, and the stage of vinification or aging process. The use of lees and yeast derivative products can reduce the color intensity and the browning of the wines immediately following treatment. The monosaccharide and polysaccharide content of yeast derivative products depends on the manufacturing process and degree of purification of the product, both of which have an influence on wine treatments. After 6 months in the bottle, both the aging on lees and the treatment with commercial yeast derivative products gave rise to wines with better sensorial characteristics than in the case of the control wines.

Wine consumption habits and consumer preferences between wines aged in barrels or with chips.

BACKGROUND: The use of oak wood pieces in winemaking is increasing, but the acceptance of this technique by consumers is unknown. For that reason, the main aim of this study was to measure consumers' opinion of red wines made with this new technique, their acceptance of them and their intention to purchase these wines. A preference ranking test was also carried out. RESULTS: A specific questionnaire was drawn up for this study and 65 frequent red wine consumers tasted four wines, two aged traditionally in barrels and two macerated with chips, and a forced choice preference test was carried out. Fifty-five per cent of respondents said that they would not buy wines made using oak chips, although most respondents would buy these wines if, after tasting them, they were as pleasant and had the same quality as the wines aged traditionally in barrels. CONCLUSION: Wines obtained with oak wood fragments were not significantly rejected either by consumers who answered the questionnaire or by consumer tasters, which could be due to the large disparity of preferences found among tasters. The results clearly indicate that producers should develop each wine taking into account the specific preferences of each consumer group.

Techniques for improving or replacing ageing on lees of oak aged red wines: The effects on polysaccharides and the phenolic composition.

Alternative techniques to the ageing on lees are being looked for in order to guarantee the improvements provided by this technique but eliminating its disadvantages. The aim of this work was to study the effect of ageing on lees and other alternative techniques (addition of ß-glucanase enzymes to the lees; use of different yeast commercial preparations with or without ß-glucanase enzymes; use of non-toasted oak chips; and ageing on lees together with micro-oxygenation) on the phenolic compounds, colour, proteins, polysaccharides and sensorial characteristics of red wines during vinification and ageing in oak barrels for 6months on two consecutive vintages. Only the use of lees together with micro-oxygenation seemed to have a positive effect on the colour stability, due to the formation of new pigments that allows the intensity and blue notes of wines to be maintained during the barrel ageing process. All the techniques studied released total and neutral polysaccharides, although the type and content of these compounds depended on the technique used, and the yeast derivative added. No clear effect was observed with the use of ß-glucanase enzymes. The sensory analysis showed that some of the wines treated were better valued than the control wines. The results obtained indicated that is difficult to select the technique that allows us to obtain the best quality wine.

Effect of micro-oxygenation and wood type on the phenolic composition and color of an aged red wine.

Many studies have recently been published focused on the effects of micro-oxygenation on the quality of wines, its application modes, and doses, etc. However, there are still few scientific papers on how previously micro-oxygenated wines perform during storage or barrel aging. This study focused on the evolution of the phenolic composition, especially of anthocyanins, and color, together with astringency and tannins, during micro-oxygenation before barrel aging. In addition, to evaluate whether wine evolution during aging depends on barrel type, wines were aged in four different oak barrel types. Tempranillo wines, some micro-oxygenated before malolactic fermentation and others not, were aged for 12 months in American, French, Central European, and Spanish oak, following wine evolution during that period. The study was carried out for two consecutive vintages. Results showed that all wines evolved similarly; therefore, the micro-oxygenation treatment neither accelerated nor delayed the typical changes of aging. Slightly different evolutions were detected according to the barrel wood type, whether or not the wine was micro-oxygenated. The varied evolutions must therefore be associated with the differences from each oak type (structure, grain and density, composition, etc.).

Volatile compounds of red wines macerated with Spanish, American, and French oak chips.

The volatile composition of a red wine aged for 2 months with three different Spanish oak chips (Quercus pyrenaica and Quercus petraea) from different regions of Castilla y León was compared with that of wines aged with American and French chips. In general, the extraction kinetics showed that the maximum concentration of the volatile compounds extracted from wood can be reached in only 1 month. In the final wines, the levels of furanic aldehydes and eugenol were higher in the wines macerated with Spanish chips, whereas cis-whiskey-lactone, vanillin, and methyl vanillate showed higher levels in wines treated with American chips. Among the wines treated with the different Spanish chips, the differences observed in the volatile composition were more related to the geographical origin of the forest than to the botanical species. In general, the wines macerated with Spanish chips showed levels of oak-related volatile compounds that were more similar to those macerated with French chips than to those macerated with American chips.

Optimization of a solid-phase extraction method using copolymer sorbents for isolation of phenolic compounds in red wines and quantification by HPLC.

Different solid-phase extraction (SPE) cartridges for the isolation of most of the phenolic compounds present in wines in low concentration were assayed and compared with the C18 SPE sorbent, which is the most common sorbent used for the isolation of these compounds. The use of C18 cartridges has several disadvantages; therefore, a SPE method using copolymer cartridges was developed, optimized, and validated. The method proposed seems to be a good alternative to replace C18 cartridges for the isolation of wine phenolic compounds. The advantages of the proposed SPE method with the HLB cartridge are that interferences can be eliminated with water without losing the compounds of great interest; the method has very good repeatability, reproducibility, and high percentages of recovery; it has a higher sensitivity and loading capacity than silica-based C18 cartridges due to the larger surface area of this type of sorbent, and the method is not adversely affected by drying, being more reproducible than C18 cartridge.

Volatile compounds and sensorial characterization of wines from four Spanish denominations of origin, aged in Spanish Rebollo (Quercus pyrenaica Willd.) oak wood barrels.

The evolution of almost 40 oak-related volatile compounds and the sensorial characteristics of red wines from four Spanish denominations of origin (DOs) (Bierzo, Toro, Ribera de Duero, and Rioja) during aging in barrels made of Rebollo oak wood, Quercus pyrenaica, were studied and compared to the same wines aged in American and French oak barrels. Each oak wood added unique and special characteristics to the wine, and in addition, each wine showed a different ability to extract the compounds, which result in these characteristics from the oak wood. In general, wines aged in Q. pyrenaica wood were characterized by high levels of eugenol, guaiacol, and other volatile phenols. In regards to compounds like cis-whiskylactone or maltol, the behavior of this wood is very similar to that of American oaks. When considering phenolic aldehydes and ketones, the levels of these compounds are intermediate between those of French and American woods and depend greatly on the type of wine. The type of oak, on the other hand, does not affect the chromatic characteristics of the wines. In sensory analysis, the biggest differences are found in the olfactory phase. Among the four DOs studied, wine aged in Q. pyrenaica presented the highest notes of wood, with more aromas of roasting, toasting, milky coffee, spices, or wine-wood interactions. The wines aged in barrels made of Q. pyrenaica wood were highly regarded, and preference was shown for them over those same wines when they had been aged in barrels of American or French oak.

Importance of chip selection and elaboration process on the aromatic composition of finished wines.

The evolution of volatile compounds extracted from wood while being macerated for 1 month with four different commercial chips (different geographical origins and toasting degrees) was studied. Furthermore, the effect of the microoxygenation process between alcoholic and malolactic fermentation also was studied. The wood volatile compounds in wines macerated with the four types of chips evolved in the same way. However, the amounts of compounds extracted depended on the type of chip used. There were differences in the levels of vanillin, cis-whiskey lactone, furfural, trans-isoeugenol, and cis-isoeugenol in wines in accordance with the type of wood chips (French or American), and the last two compounds along with 5-methyl furfural presented differences that were directly related to the toast level. However, no effects of microoxygenation treatment on the extraction of volatile compounds extracted from chips were observed. Therefore, the results obtained in this study highlight the importance of chip selection on the aromatic characteristics of finished wines.