Dataset on absorption spectra and bulb concentration of phenolic compounds that may interfere with onion pyruvate determinations

We present data on absorption spectra (400–540 nm) and concentration of phenolic compounds quercetin, myricetin, kaempferol, rutin, catechin, epicatechin gallate(ECG) and epigallocatechin gallate (EGCG), inyellow, redand whit eonions.These data are related to the article entitled “Variability inspectrophotometric pyruvate analyses for predicting onion pungency and nutraceutical value” (Berettaetal.,2017) [1]. Given the relevance of pyruvate determinations for estimating onion pungency and functional value, it is important to identify compounds that can interfere with pyruvate determinations when using two previously published analytical procedures, namely Schwimmer and Weston(1961) (SW) [2] and Anthon and Barret(2002)(AB)[3], which are based on spectrophotometry and light-absorbanceat 420 nm and 515 nm, respectively. The data presented in this article are absorption spectra for 7 onion phenolic compounds in the range 400–540 nm, which include wavelengths used by the two pyruvate analytical methods (Schwimmer and Weston,1961; Anthon and Barret, 2002)[2,3] that were compared in our reference article (Beretta et al.,2017) [1]. Additionally, bulb content data for these 7 phenolic compounds in onion cultivars and F2 progenies with different bulb color were included to allow further analyses.Inst. de BiotecnologíaFil: Beretta, Hebe Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bannoud, Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Insani, Ester Marina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; ArgentinaFil: Galmarini, Claudio Romulo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Consulta; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Horticultura; Argentina.Fil: Cavagnaro, Pablo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Consulta; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Horticultura; Argentina

Caracterización química y cuantificación del rendimiento de extracción de pigmento en siete accesiones mexicanas de Bixa orellana

Achiote (Bixa orellana) is a plant used for obtaining a natural dye rich on carotenoids (mainly bixin and norbixin); it is also the plant species with the highest content of tocotrienols in nature. In the present work, the pigment extraction yield of seven Mexican accessions of Bixa orellana was quantified. Also color parameters and content of tocotrienols, tocopherols, norbixin, bixin, total phenolic compounds and antioxidant capacity were evaluated in the corresponding annatto extracts. The highest percentage of pigment extraction yield was obtained with KOH (4.84%). Accessions 43 (L*= 4.01 ± 0.79, C*= 7.33 ± 1.07, h= 25.76 ± 6.35) and 50 (L*= 3.17 ± 0.64, C*= 6.81 ± 0.53, h= 26.41 ± 4.41) had the lowest color values, meaning these accessions had a darker and redder color. Four accessions showed the highest content of bixin: accession 48 (3.1%), 45 (2.6%) 43 (2.4%) and 47 (2.2%). Accession 50 had showed the highest content of total phenolic compounds and of tocotrienols (T3), mainly the isoform δ-T3 (5.03 ± 0.64 mg g−1 Seed Dry Weight), as well as the highest antioxidant capacity.El achiote (Bixa orellana) es una planta utilizada para obtener un colorante natural rico en carotenoides (principalmente bixina y norbixina); además, es la especie vegetal con el mayor contenido de tocotrienoles. En este trabajo, se determinó el rendimiento de extracción de pigmento de siete accesiones mexicanas de Bixa orellana. También se evaluaron los parámetros de color y el contenido de tocotrienoles, tocoferoles, norbixina, bixina, compuestos fenólicos totales y la capacidad antioxidante en extractos de annato. El mayor porcentaje de rendimiento de extracción de pigmento fue obtenido con KOH (4.847905%). Las accesiones 43 (L*= 4.01 ± 0.79, C*= 7.33 ± 1.07, h= 25.76 ± 6.35) y 50 (L*= 3.17 ± 0.64, C*= 6.81 ± 0.53, h= 26.41 ± 4.41) presentaron los valores más bajos de los párametros de color, lo que significa que estas accesiones tuvieron un color más oscuro y más rojo. Cuatro accesiones mostraron el mayor contenido de bixina: accesión 48 (3.1%), 45 (2.6%) 43 (2.4%) and 47 (2.2%). La accession 50 mostró el mayor contenido de compuestos fenólicos totales y de tocotrienoles (T3), principalmente la isoforma δ-T3 (5.03 ± 0.64 mg g-1 Peso Seco), así como también la mayor capacidad antioxidante.Fil: Raddatz Mota, D.. Universidad Autónoma Metropolitana; MéxicoFil: Pérez Flores, L. J.. Universidad Autónoma Metropolitana; MéxicoFil: Carrari, Fernando Oscar. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; ArgentinaFil: Insani, Ester Marina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; ArgentinaFil: Asis, Ramón. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Mendoza Espinoza, J. A.. Universidad Nacional Autónoma de México; MéxicoFil: Díaz de León Sánchez, F.. Universidad Autónoma Metropolitana; MéxicoFil: Rivera Cabrera, F.. Universidad Autónoma Metropolitana; Méxic

Relationships between bioactive compound content and the antiplatelet and antioxidant activities of six allium vegetable species

Allium sp. vegetables are widely consumed for their characteristic flavour. Additionally, their consumption may provide protection against cardiovascular disease due to their antiplatelet and antioxidant activities. Although antiplatelet and antioxidant activities in Allium sp. are generally recognised, comparative studies of antiplatelet and antioxidant potency among the main Allium vegetable species are lacking. Also, the relationship between organosulfur and phenolic compounds and these biological activities has not been well established. In this study, the in vitro antiplatelet and antioxidant activities of the most widely consumed Allium species are characterised and compared. The species total organosulfur and phenolic content, and the HPLC profiles of 11 phenolic compounds were characterised and used to investigate the relationship between these compounds and antiplatelet and antioxidant activities. Furthermore, antiplatelet activities in chives and shallot have been characterised for the first time. Our results revealed that the strongest antiplatelet agents were garlic and shallot, whereas chives had the highest antioxidant activity. Leek and bunching onion had the weakest both biological activities. Significantly positive correlations were found between the in vitro antiplatelet activity and total organosulfur (R=0.74) and phenolic (TP) content (R=0.73), as well as between the antioxidant activity and TP (R=0.91) and total organosulfur content (R=0.67). Six individual phenolic compounds were associated with the antioxidant activity, with catechin, epigallocatechin and epicatechin gallate having the strongest correlation values (R>0.80). Overall, our results suggest that both organosulfur and phenolic compounds contribute similarly to Allium antiplatelet activity, whereas phenolics, as a whole, are largely responsible for antioxidant activity, with broad variation observed among the contributions of individual phenolic compounds.Inst. de BiotecnologíaFil: Beretta, Hebe Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bannoud, Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Insani, Ester MarinaI. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; ArgentinaFil: Berli, Federico Javier. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias; ArgentinaFil: Hirschegger, Pablo. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias; ArgentinaFil: Galmarini, Claudio Romulo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Consulta; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias; ArgentinaFil: Cavagnaro, Pablo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Consulta; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias; Argentin

Multiomics analyses reveal the roles of the ASR1 transcription factor in tomato fruits

The transcription factor ASR1 (ABA, STRESS, RIPENING 1) plays multiple roles in plant responses to abiotic stresses as well as being involved in the regulation of central metabolism in several plant species. However, despite the high expression of ASR1 in tomato fruits, large scale analyses to uncover its function in fruits are still lacking. In order to study its function in the context of fruit ripening, we performed a multiomics analysis of ASR1-antisense transgenic tomato fruits at the transcriptome and metabolome levels. Our results indicate that ASR1 is involved in several pathways implicated in the fruit ripening process, including cell wall, amino acid, and carotenoid metabolism, as well as abiotic stress pathways. Moreover, we found that ASR1-antisense fruits are more susceptible to the infection by the necrotrophic fungus Botrytis cinerea. Given that ASR1 could be regulated by fruit ripening regulators such as FRUITFULL1/FRUITFULL2 (FUL1/FUL2), NON-RIPENING (NOR), and COLORLESS NON-RIPENING (CNR), we positioned it in the regulatory cascade of red ripe tomato fruits. These data extend the known range of functions of ASR1 as an important auxiliary regulator of tomato fruit ripening.Fil: Dominguez, Pia Guadalupe. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Conti, Gabriela. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Agrobiotecnología y Biología Molecular; Argentina. Universidad de Buenos Aires. Facultad de Agronomía; ArgentinaFil: Duffy, Tomás. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Insani, Ester Marina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Alseekh, Saleh. Max Planck Institute of Molecular Plant Physiology; Alemania. Center Of Plant Systems Biology And Biotechnology; BulgariaFil: Asurmendi, Sebastian. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Fernie, Alisdair R. Max Planck Institute of Molecular Plant Physiology; Alemania. Center Of Plant Systems Biology And Biotechnology; BulgariaFil: Carrari, Fernando Oscar. Universidad de Buenos Aires. Facultad de Agronomía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentin

Variation for health-enhancing compounds and traits in onion (Allium cepa L.) germplasm

Consumption of onion has been associated with reduced incidence of chronic diseases. Phenolic, organosulfur and carbohydrate compounds present are largely responsible for these effects. This study examined compositional variation for health-enhancing compounds in a genetically diverse collection of onion cultivars. Total antioxidant activity and aroma profiles were characterized. Significant variation in bulb concentration for total and individual phenolic compounds, thiosulfinates, carbohydrates, and total and soluble solids was found. The range of variation was particularly large (>50-fold difference between the cultivars with the highest and lowest content) for fructo-oligosaccharides (FOS) and the polyphenols quercetin, epigallocatechin gallate and epicatechin gallate. Amino acid profiles varied significantly as well with substantial variation (~10 fold) observed in both total and essential amino acids. Total antioxidant activity was positively correlated with polyphenols content, and quercetin in particular (r = 0.83), suggesting a major contribution from phenolic compounds to onion antioxidant properties. Significant positive correlation was also found between solids and thiosulfinates content (r = 0.74) and between solids and FOS (r = 0.81), suggesting a dilution/concentration effect for organosulfur compounds and FOS in onion bulbs. The present study revealed broad variation for health-enhancing compounds content in onion germplasm, which can be exploited in breeding programs aiming at increasing onion nutraceutical value.Fil: Insani, Ester Marina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Agroindustria. Instituto de Tecnología de los Alimentos; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Nacional de Investigaciones Agropecuarias Castelar. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; ArgentinaFil: Cavagnaro, Pablo Federico. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Departamento de Producción Agropecuaria. Cátedra de Horticultura y Floricultura; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Salomón, Virginia María. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Agroindustria. Instituto de Tecnología de los Alimentos; ArgentinaFil: Langman, Leandro Ezequiel. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Agroindustria. Instituto de Tecnología de los Alimentos; ArgentinaFil: Sance, Maria Mirta. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; ArgentinaFil: Pazos, Adriana Alejandra. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Agroindustria. Instituto de Tecnología de los Alimentos; ArgentinaFil: Carrari, Fernando Oscar. Instituto Nacional de Tecnología Agropecuaria. Centro Nacional de Investigaciones Agropecuarias Castelar. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Filippini de Delfino, Olga Susana. Universidad Nacional de Luján; ArgentinaFil: Vignera, Laura. Universidad Nacional de Luján; ArgentinaFil: Galmarini, Claudio Romulo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Mendoza-San Juan. Estación Experimental Agropecuaria La Consulta; Argentina. Universidad Nacional de Cuyo; Argentin

Galacturonosyltransferase 4 silencing alters pectin composition and carbon partitioning in tomato

Pectin is a main component of the plant cell wall and is the most complex family of polysaccharides in nature. Its composition is essential for the normal growth and morphology pattern, as demonstrated by pectin-defective mutant phenotypes. Besides this basic role in plant physiology, in tomato, pectin structure contributes to very important quality traits such as fruit firmness. Sixty-seven different enzymatic activities have been suggested to be required for pectin biosynthesis, but only a few genes have been identified and studied so far. This study characterized the tomato galacturonosyltransferase (GAUT) family and performed a detailed functional study of the GAUT4 gene. The tomato genome harbours all genes orthologous to those described previously in Arabidopsis thaliana, and a transcriptional profile revealed that the GAUT4 gene was expressed at higher levels in developing organs. GAUT4-silenced tomato plants exhibited an increment in vegetative biomass associated with palisade parenchyma enlargement. Silenced fruits showed an altered pectin composition and accumulated less starch along with a reduced amount of pectin, which coincided with an increase in firmness. Moreover, the harvest index was dramatically reduced as a consequence of the reduction in the fruit weight and number. Altogether, these results suggest that, beyond its role in pectin biosynthesis, GAUT4 interferes with carbon metabolism, partitioning, and allocation. Hence, this cell-wall-related gene seems to be key in determining plant growth and fruit production in tomatoFil: Godoy, Fabiana de. Universidade de São Pablo. Departamento de Botânica; BrasilFil: Bermúdez, Luisa. Universidade de São Pablo. Departamento de Botânica; BrasilFil: Lira, Bruno Silvestre. Universidade de São Pablo. Departamento de Botânica; BrasilFil: Souza, Amanda Pereira de. Universidade de São Pablo. Departamento de Botânica; BrasilFil: Elbl, Paula. Universidade de São Pablo. Departamento de Botânica; BrasilFil: Demarco, Diego. Universidade de São Pablo. Departamento de Botânica; BrasilFil: Alseekh, Saleh. Max Planck Institute for Molecular Plant Physiology; AlemaniaFil: Insani, Ester Marina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; ArgentinaFil: Buckeridge, Marcos. Universidade de São Pablo. Departamento de Botânica; BrasilFil: Almeida, Juliana. Universidade de São Pablo. Departamento de Botânica; BrasilFil: Grigioni, Gabriela Maria. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Tecnología de Alimentos; ArgentinaFil: Fernie, Alisdair Robert. Max Planck Institute for Molecular Plant Physiology; AlemaniaFil: Carrari, Fernando. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; ArgentinaFil: Rossi, Magdalena. Universidade de São Pablo. Departamento de Botânica; Brasi

Variability in spectrophotometric pyruvate analyses for predicting onion pungency and nutraceutical value

Onion pyruvate concentration is used as a predictor of flavor intensity and nutraceutical value. The protocol of Schwimmer and Weston (SW) (1961) is the most widespread methodology for estimating onion pyruvate. Anthon and Barret (AB) (2003) proposed modifications to this procedure. Here, we compared these spectrophotometry-based procedures for pyruvate analysis using a diverse collection of onion cultivars. The SW method always led to over-estimation of pyruvate levels in colored, but not in white onions, by up to 65%. Identification of light-absorbance interfering compounds was performed by spectrophotometry and HPLC analysis. Interference by quercetin and anthocyanins, jointly, accounted for more than 90% of the over-estimation of pyruvate. Pyruvate determinations according to AB significantly reduced absorbance interference from compounds other than pyruvate. This study provides evidence about the mechanistic basis underlying differences between the SW and AB methods for indirect assessment of onion flavor and nutraceutical value.Inst. de BiotecnologíaFil: Beretta, Hebe Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bannoud, Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Insani, Ester Marina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; ArgentinaFil: Galmarini, Claudio Romulo. Universidad Nacional de Cuyo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Consulta; ArgentinaFil: Cavagnaro, Pablo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Consulta; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias; Argentin

Heterologous production and characterization of a thermostable GH10 family endo-xylanase from Pycnoporus sanguineus BAFC 2126

Xylanases are key enzymes for agricultural biomass saccharification for the production of cellulosic ethanol. Success in enzymatic lignocellulose bioconversion is restricted by enzyme production costs, activity and stability under harsh reaction conditions, and their performance when interacting into cellulolytic cocktails. In this work, we present the heterologous expression and enzymatic characterization of a novel endo-β-1,4 xylanase of glycoside hydrolase family 10 (GH10ps) from the white-rot basidiomycete Pycnoporus sanguineus BAFC 2126. Recombinant expression of GH10ps in Pichia pastoris showed that it is a robust enzyme active at a wide range of pHs and temperatures, and with a half-life of 3 h at 70 °C and a stability higher than 48 h at 60 °C. Recombinant GH10ps was also capable of releasing xylooligosaccharides and xylose from pretreated agricultural waste biomass and also complemented commercial cellulases in lignocellulose bioconversion to fermentable sugars.Instituto de BiotecnologíaFil: Niderhaus, Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Garrido, Mercedes Maria. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Insani, Ester Marina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; ArgentinaFil: Campos, Eleonora. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; ArgentinaFil: Wirth, Sonia Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; Argentin

GH10 XynA is the main xylanase identified in the crude enzymaticextract of Paenibacillus sp. A59 when grown on xylan orlignocellulosic biomass

A novel bacterial isolate with polysaccharides degrading activity was identified as Paenibacillus sp., andnamed Paenibacillus sp. A59. Even though it is a strict mesophile, optimal xylanase activity of the crudeenzymatic extract was achieved between 50◦C and 70◦C and more than 60% of the activity was retainedafter incubation for 48 h at 50◦C, indicating thermotolerance of the enzymes involved. The extract wasalso active on pre-treated sugarcane residue (SCR) and wheat straw, releasing xylobiose and xylose asthe main products, therefore confirming its predominantly xylanolytic activity. By zymograms and massspectrometry of crude enzymatic extracts of xylan or SCR cultures, a 32 kDa GH10 beta- 1,4- endoxylanasewith xylanase and no CMCase activity was identified. We named this enzyme XynA and it was the onlyxylanase identified under both conditions assayed, suggesting that it is a good candidate for recombinantexpression and evaluation in hemicelluloses deconstruction applications. Also, a protein with two S-layerhomology domains (SLH) and a large uncharacterized C-terminal domain as well as an ABC substratebinding protein were identified in crude extracts of SCR cultures. We propose that Paenibacillus sp. A59uses a system similar to anaerobic and other Gram positive bacteria, with SLH-domain proteins anchoringpolysaccharide-degrading enzymes close to the membrane and the substrate binding protein assistingtranslocation of simple sugars to the cell interior.Fil: Ghio, Silvina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Recursos Naturales. Instituto de Suelos; ArgentinaFil: Insani, Ester Marina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; ArgentinaFil: Piccinni, Florencia Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; ArgentinaFil: Talia, Paola Monica. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; ArgentinaFil: Grasso, Daniel Horacio. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Recursos Naturales. Instituto de Suelos; ArgentinaFil: Campos, Eleonora. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Oxidative stability and its relationship with natural antioxidants during refrigerated retail display of beef produced in Argentina

The objective of this study was to determine if pasture or grain diets affect oxidative/antioxidative status and the color stability of beef during retail display. Ten crossbreed steers were fed on pasture. Five of them were randomly assigned to remain on this diet, and the other five were finished on feedlot system (grain diet) during 110 days until slaughter. Slices of Psoas major steaks were randomly distributed among retail display times (1, 3, 5, 7 and 9 days). Lipid and protein oxidation were higher in Psoas major steaks from grain diet than in pasture diet (P < 0.05). After 3 days of display, lipid oxidation increased in meat from grain diet, whereas in meat from pasture diet the first evidence was after 7 days (P < 0.05). Protein oxidation was higher in meat from grain diet than in meat from pasture diet at day 9 of display (1.15 ± 0.92 vs. 1.91 ± 0.70 μg/g, respectively; P < 0.05). Antioxidant vitamins, α-tocopherol and β-carotene were higher at time = 0 in pasture Psoas major steaks (P < 0.05) and were differentially reduced throughout storage. While α-tocopherol decreased 41% and 57% for pasture and grain beef respectively (P < 0.05), β-carotene levels remained practically unaffected in grain beef. After 7 days of display “a” value was higher for Psoas major steaks from pasture diet (P < 0.05). Besides, “L” parameter showed higher values for samples from grain diets but it was no affected by display time. No differences were observed between both treatments for “b” value, but a significant decrease (P < 0.05) was observed along storage. Superoxide dismutase and catalase activity was stable throughout storage, while glutathione peroxidase activity decreased significantly (P < 0.05). The results in this study demonstrated that the higher initial level and synergistic action (under light and air) of α-tocopherol and β-carotene found in pasture-finished animals improved the oxidative and color stability of beef, as showed by a better retention of redness at the end of retail display.Fil: Insani, Ester Marina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Tecnología de Alimentos; ArgentinaFil: Eyherabide, A. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Tecnología de Alimentos; ArgentinaFil: Grigioni, Gabriela Maria. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Tecnología de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Sancho, Ana Maria. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Tecnología de Alimentos; ArgentinaFil: Pensel, Norma Ana. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Tecnología de Alimentos; ArgentinaFil: Descalzo, Adriana Maria. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Tecnología de Alimentos; Argentin