Antioxidant activity in decaffeinated beverages: instant coffee and black tea

Aunque la popularidad de las bebidas descafeinadas ha incrementado entre los consumidores de café y té, apenas se ha prestado atención al posible descenso en la actividad antioxidante producido por el proceso de descafeinización. Con el objetivo de estudiar ese posible descenso, se realizaron medidas del color, del contenido en polifenoles y de catequinas y la actividad antioxidante medida por tres métodos (ABTS, DPPH y FRAP) en cinco tés y seis cafés comerciales así como en sus respectivos descafeinados de la misma marca. Ninguna de las once bebidas presentó diferencias significativas en todos los análisis y no se observó una diferencia clara entre los productos que habían sido descafeinados y los que no. El análisis de las correlaciones mostró que mientras en el té, los polifenoles son el principal antioxidantes, en el café las melanoidinas presentan también una importancia significativa. Con el análisis factorial se observó que tanto las muestras de café como las de té, se asociaban en función de la marca y no en función de su contenido en cafeína. ____________________________________ Although decaffeinated beverages are rising in popularity among coffee and tea drinkers, little is known about the effect of the decaffeination process on the antioxidant activity (AA) of those beverages. Measures of colour, polyphenols and catechins contents and three antioxidant tests (ABTS, DPPH and FRAP tests) were carried out in five commercial black teas and six soluble coffees as well as their respective decaffeinated products from the same brand. None of the beverages showed significant differences in all the analysis and no clear differences between regular and decaffeinated beverages were reported. Correlations between methods showed that, whereas polyphenols are the most important factor for the tea AA, there are other compounds in coffee such as melanoidns which have a greater contribution. When the factorial analysis was carried out, it was observed that samples are associated according to their brands rather than according to their caffeine content. Therefore, factors associated with the brand, are in fact, what determines the AA of the beverage

Development of innovative seasonings from wine pomace and their applications in meat products

La tesis se centra en el desarrollo de sazonadores procedentes del orujo de uva, un subproducto de la elaboración del vino, y en el estudio de sus aplicaciones en alimentos con bajos contenidos de sal. Los sazonadores desarrollados han mostrado su capacidad para mejorar la conservación de los alimentos retrasando el crecimiento de microorganismos, la oxidación de las grasas (enranciamiento) y de las proteínas de productos cárnicos. El uso de estos sazonadores puede permitir mejorar la calidad de los alimentos incidiendo en aspectos tecnológicos (conservación) pero también en aspectos nutricionales ya que además de permitir reducir el contenido en sal contribuye a enriquecerlos con fibra, potasio y antioxidantes. Por último, el uso de este tipo de sazonadores mitigó la formación de algunos de los compuestos indicados como poco saludables que se forman durante el cocinado de los productos cárnicos, a la vez que se incentivó la formación de compuestos aromáticos positivos.The present thesis proposes the utilization of different seasonings derived from wine pomace to improve both the quality and the safety of meat products. This new alternative allows the integral utilization of winery byproducts. The seasoning derived from seedless wine pomace showed the highest antimicrobial and antioxidant effects, with the ability to inhibit the growth of spoilers and pathogens and to delay lipid and protein oxidation at 2% (w/w). Its activity against meat spoilage flora enabled salt reduction in beef patties without compromising their microbial stability. Together with the reduction in sodium, the use of this seasoning produced an increase in levels of potassium, fiber and polyphenols. Furthermore, the quality of cooked meat was improved, following mitigation of the formation of meat cooking carcinogens and the enhancement of pyrazine formation with a positive impact on cooked meat odor

Effect of a New Natural Seasoning on the Formation of Pyrazines in Barbecued Beef Patties

The formation of pyrazines in food cooking is required to obtain satisfactory “roasted” flavor.The aim of this work was to evaluate the effect of a new red wine pomace seasoning (RWPS) on the formation of pyrazines in barbecued beef patties. Five pyrazines were successfully identified, 2,5-dimethylpyrazine being the most abundant. Although 2-ethyl-5-methylpyrazine was in lower levels, it presented the highest odor units, due to its low threshold. RWPS enhanced the formation of the five identified pyrazines (2.1 times), without relevant changes in the proportion between them.The highest increase was observed for 2-ethyl-6-methylpyrazine (3 times higher than in control). These results were corroborated by electronic nose analysis, presenting RWPS beef patties higher odor intensities. Mechanisms to explain these effects are also proposed in the present work, and the high content of polyphenols seems to be the major cause of the observed results.The use of RWPS could improve the flavor characteristics of meat products or enable using less intense cooking conditions with no changes in the flavor.Autonomous Government of Castilla y Le´on through the research Projects BU282U1

Aplicación de un sazonador obtenido del hollejo de uva tinta como sustituto de la sal para la elaboración de pechugas de pollo marinadas: estudio de sus propiedades físicas, químicas y sensoriales y su estabilidad microbiológica

The aim of this work was to elaborate low-salt marinated chicken breasts by the addition of a seasoning obtained from red grape skins. The marinated chicken breasts were prepared by immersion in five different brines: only water (control), 0.5% and 2% of salt, 0.5% of salt and 2% of seasoning and 2% of salt and 2% of seasoning. The marinated breasts were stored under refrigeration and their shelf-life and physical-chemical composition were evaluated. The consumers’ acceptance of the product was also evaluated. The breast marinated with a brine of 0.5% of salt and 2% of seasoning had the same shelf-life than those marinated with 2% of salt. From a sensory point of view, the color of the chicken breasts marinated with the seasoning was the less accepted attribute. However, two groups of consumers were found, one more willing to try and accept new products and other more reluctant to try innovative foods.El presente trabajo tuvo como objetivo elaborar pechugas de pollo marinadas con bajo contenido de sal adicionando un sazonado obtenido de la Hollejo de uva tinta. Las pechugas de pollo marinadas se prepararon por inmersión en cinco salmueras diferentes: solo agua (control), 0,5% y 2% de sal, 0,5% de sal y 2% de sazonador y 2% de sal y 2% de sazonador. Una vez marinadas, las pechugas se almacenaron en refrigeración, y se evaluaron su vida útil y su composición fisicoquímica. Asimismo, se valoró la aceptación del producto por parte de los consumidores. La pechuga marinada con salmuera de 0,5% de sal y 2% de sazonador tuvo la misma vida útil que las marinadas con 2% de sal. Desde el punto de vista sensorial, el atributo que registró menor aceptación fue el color de las pechugas de pollo marinadas con el sazonador. Sin embargo, fue posible identificar dos grupos de consumidores, uno con mayor disposición a probar y aceptar nuevos productos y otro más reticente a probar alimentos innovadores.Autonomous Government of Castilla y León [BU282U13

Influence of red wine pomace seasoning and high-oxygen atmosphere storage on carcinogens formation in barbecued beef patties

Polycyclic aromatic hydrocarbons (PAHs) and heterocyclic aromatic amines (HAs) are carcinogenic compounds formed in barbecued meat. Conditions that reduce their formation are of major interest. This study aims to evaluate the influence of red wine pomace seasoning (RWPS) and high-oxygen atmosphere storage on the formation of PAHs and HAs in barbecued beef patties. In general, the levels of PAHs and HAs quantified were low. The storage (9 days) promoted higher formation of PAHs in control patties without increase of HAs. RWPS patties cooked at preparation day presented higher levels of PAHs and HAs than control. Nevertheless, RWPS patties cooked after storage presented lower levels of PAHs and HAs than control. ABTS assay pointed out that higher radical scavenging activity may be related to with lower PAHs or HAs formation. In conclusion, RWPS can be an interesting ingredient to inhibit the formation of cooking carcinogens in barbecued patties stored at high-oxygen atmosphere.Autonomous Government of Castilla y León through the research project BU282U13 and from project NORTE-01-0145-FEDER-000011 – Qualidade e Segurança Alimentar — uma abordagem (nano) tecnológica

Adaptation and Validation of QUick, Easy, New, CHEap, and Reproducible (QUENCHER) Antioxidant Capacity Assays in Model Products Obtained from Residual Wine Pomace

Evaluation of the total antioxidant capacity of solid matrices without extraction steps is a very interesting alternative for food researchers and also for food industries. These methodologies have been denominated QUENCHER from QUick, Easy, New, CHEap, and Reproducible assays. To demonstrate and highlight the validity of QUENCHER (Q) methods, values of Q-method validation were showed for the first time, and they were tested with products of well-known different chemical properties. Furthermore, new QUENCHER assays to measure scavenging capacity against superoxide, hydroxyl, and lipid peroxyl radicals were developed. Calibration models showed good linearity (R2 > 0.995), proportionality and precision (CV < 6.5%), and acceptable detection limits (<20.4 nmol Trolox equiv). The presence of ethanol in the reaction medium gave antioxidant capacity values significantly different from those obtained with water. The dilution of samples with powdered cellulose was discouraged because possible interferences with some of the matrices analyzed may take place.The autonomous government of Castilla y León (Project BU268A11-2

Effect of Skin Wine Pomace and Sulfite on Protein Oxidation in Beef Patties During High Oxygen Atmosphere Storage

Meat storage in high oxygen atmosphere has been reported to induce protein oxidation reactions decreasing meat quality. The incorporation of antioxidants has been proposed to reduce the extent of these reactions. In this study, the ability of red and white skin wine pomaces as well as sulfites to inhibit protein oxidation were tested in beef patties stored for up to 15 days at 4 °C in a high oxygen atmosphere (70 % O2 and 30 % CO2). SO2 (300 ppm) effectively protected against protein oxidation measured as radical formation by electron spin resonance (ESR) spectroscopy, as thiol loss by the DTNB assay and as myosin heavy chain (MHC) disulfide crosslinking by SDS-PAGE. Pomace from red wine production with a total phenol of 9.9 mg gallic acid equivalent/g protected against protein radical formation and against MHC crosslinking, but not against thiol loss by addition of 2.0 % (w/w) to the beef patties. Pomace from white wine production with a total phenol of 4.0 mg gallic acid equivalent/g only protected against MHC cross-linking. For both types of wine pomace, protein modifications not seen for sulfite addition were observed and were proposed to involve covalent phenol addition to proteins. Red wine pomace may be an alternative to sulfite as a meat additive for protection of beef patties against protein oxidation.Autonomous Government of Castilla y León through the research projects (BU268A11-2 and BU282U13) and the Danish Council for Independent Research |Technology and Production within the Danish Agency for Science Technology and Innovation for granting the project entitled: BAntioxidant mechanisms of natural phenolic compounds against protein cross-link formation in meat and meat systems^ (11-117033)

Antioxidant effect of seasonings derived from wine pomace on lipid oxidation in refrigerated and frozen beef patties

This work evaluates the ability of three different seasonings (obtained from wine pomace) to inhibit lipid oxidation in raw and cooked beef patties. Seasonings were incorporated to beef patties recipe as other solid ingredient at the level of 2 g/100 g. The storage conditions assayed were: refrigeration (4 C, 15 days) with high-oxygen atmosphere (70% O2, 30% CO2) and freezing ( 18 C, 6 months). Two independent experiments with 3 replicates were carried out. Furthermore, the inhibitory effect on lipid oxidation was compared with the effectiveness of sulfites, an antioxidant widely used in the meat industry. Both types of storage significantly induced increases of thiobarbituric acid reactive substances (TBARS) and volatile organic compounds (VOCs) (hexanal, 1-pentanol, 1-hexanol, 1-octen-3-ol, 2,3- octanedione, and 2-pentylfuran) measured with gas chromatographyemass spectrometry (pvalue < 0.05). The three seasonings showed different effectiveness to inhibit lipid oxidation under the three conditions studied, being the seasoning made from seedless wine pomace the most effective. This seasoning significantly inhibited the formation of VOCs, revealing their potential capacity to delay the formation of rancid odors during storage of meat products. Samples with sulfites presented contrary results respect to TBARS levels, which were reduced in refrigerated samples but promoted in the frozen patties.Autonomous Government of Castilla y Le on, Spain through the research projects BU268A11-2 and BU282U1

Total antioxidant capacity of new natural powdered seasonings after gastrointestinal and colonic digestion

New powdered seasonings, rich in natural antioxidant compounds, have successfully been applied recently in different food matrices. Once ingested, the antioxidants contained in these seasonings may exert protective effects against oxidative stress along the gastrointestinal tract. This fact was evaluated by submitting the different seasonings under study to simulated digestion followed by assessing the reducing and antiradical capacities of the digested fractions. Enzymatic gastrointestinal digestion enhanced 2–3 times both antioxidant activities and colonic fermentation increased more than 10-fold the radical scavenging ability of digested fractions compared with undigested seasonings. Digested fractions derived from the seedless wine pomace seasoning presented generally the highest antioxidant properties. The results were evaluated considering bioaccessibility factors to have a more realistic overview of the potential antioxidant capacities of the seasonings and of the probable beneficial effects of their consumption on the prevention of oxidative damage along the gutAutonomous Government of Castilla y León through the research project BU282U1