Isolation of bovine β-lactoglobulin from complexes with chitosan

A simple, economical and non-toxic method is described for the solubilization of undenatured β-lactoglobulin (β-lg) from complexes with chitosan. The effect of pH (8-10), ionic strength (0.08-0.3 m) and volume ratio between sodium acetate solutions and whey on the dissociation of β-lg-chitosan complexes was evaluated. Following a single extraction step with the addition of 10 mL of 0.1 m sodium acetate solution at pH 9 to the β-lg-chitosan complexes obtained from 1 mL of cheese-whey, a recovery of 90% of β-lg with a protein purity of 95% was achieved, suggesting that electrostatic interactions play a key role in the complexation of β-lg with chitosan. The presence of free chitosan in solution was ruled out according to gas chromatography with flame-ionization detector analysis after acid hydrolysis. NMR spectroscopy showed that the recovered β-lg after further dialysis had structural features very similar to the native protein.This work was supported by the Comisión Interministerial de Ciencia y Tecnología (CICYT), Project Nos. AGL2004-07227-C02-02 and AGL2004-03322.Peer Reviewe

Detection and quantitation of additions of soybean proteins in cured-meat products by perfusion reversed-phase high-performance liquid chromatography

Perfusion liquid chromatography has been applied in this work to the determination of soybean proteins in commercially available cured meat products, enabling the detection of additions of soybean proteins in cured meat products to which the addition of these vegetable proteins is forbidden and the quantitation of soybean proteins in cured meat products to which the addition of these proteins is allowed up to a certain limit. The analytical methodology is based on a sample treatment (fat extraction and soybean protein solubilization) prior to chromatographic analysis. Fat extraction with acetone and soybean protein solubilization with a buffer solution at basic pH (pH 10 or 9) were necessary to obtain selective and sensitive conditions. Use of water-acetonitrile-trifluoroacetic acid or water-tetrahydrofuran-trifluoroacetic acid linear binary gradients at a flow rate of 3 mL/min, a temperature of 50 degrees C, and UV detection at 280 nm enabled chromatographic analysis of soybean proteins in cured meat products in less than 3 min.The authors thank the Comunidad Autónoma de Madrid\ud (Spain) for project 07G/0025/2003. Dr. C. García-Ruiz\ud also thanks the Ministerio de Ciencia y Tecnolog a for her\ud contract from the Ramón y Cajal program (RYC-2003-001). F. Castro-Rubio thanks the Ministerio de Educación\ud y Ciencia (Spain) for her predoctoral grant

Enhancing Brand Awareness for Sustainable Choices

The objective of this research is to propose a brand management model guiding consumer choice toward sustainable options. The model assumes varying consumer awareness levels regarding product and service sustainability. Likewise, products and services are perceived to possess differing degrees of sustainability. Therefore, brands should focus on communicating their sustainability aspects to target consumers at the same awareness level. The model aims to create momentum by progressively conveying more information about product and service sustainability, leading to increased consumer awareness or at least improved consumer knowledge. Independent variables included brand image and price, while the dependent variable was participants’ purchase intentions. To test the model, field research consisting of a quasi-experiment involving 402 consumers has been conducted. Brand-level analysis of the results demonstrated that more sustainable brands gained preference among the participants after receiving information about the sustainability aspects. However, this gained preference was partially diminished when participants became aware of the product’s prices

Assessment of milk fat content in fat blends by 13 C NMR spectroscopy analysis of butyrate

Butyric acid (butyrate) is a candidate marker of milk fat in complex fat blends, since it is exclusive of milk triacylglycerols (TAGs) from different ruminant species. In this work, we determined the amount of milk fat used for the preparation of fat blends by 13C Nuclear Magnetic Resonance (13C NMR) spectroscopy-based quantification of butyrate. When tested on fat samples spiked with known amounts of reference bovine milk fat (BCR-519 certified material), the relative composition of the mixtures was reliably assessed through the integration of the diagnostic 13C NMR carbonyl (C1) or α-carbonyl methylene (C2) resonances of butyrate. NMR data exhibited strict correlation with high resolution-gas chromatography (GC) of fatty acid methyl esters (R2 = 0.99), which was used as an independent and well-established method for the determination of butyrate. Thus, 13C NMR can be used for the direct assessment of milk fat content in fat mixtures, at a limit of detection lower than 5%, with clear advantages over the traditional GC methods in terms of speed, robustness and minimal sample handling. The natural variability of butyrate in milk has been taken into account to estimate the uncertainty associated with the milk fat content in unknown fat blends

Horizonte Europa. Avance del próximo Programa Marco de la UE

Resumen del trabajo presentado al Seminario CIAL, celebrado el 11 de octubre de 2018 en el salon de Actos del Instituto de Investigación en Ciencias de la Alimentación (CIAL).En Enero de 2021 se iniciará Horizonte Europa, un nuevo Programa Marco de la UE, que será la continuación de Horizonte 2020. Horizonte Europa es un programa que incorpora novedades con respecto al anterior y, aunque aún no está totalmente definido, su estructura básica, la financiación y los nuevos instrumentos propuestos ya se conocen. En este seminario se hará un pequeño recorrido por este nuevo Programa Marco, para que los investigadores se vayan familiarizando con las novedades del mismo.Peer reviewe

Alergia a proteínas lácteas

La alergia alimentaria es una reacción inmunológica mediada por IgE, que se origina en ciertos individuos como respuesta a la ingesta de un determinado alimento que, en el resto de la población, es perfectamente saludable. Constituye un serio problema de salud pública, de gran importancia por el aumento de la prevalencia en los últimos años, con síntomas que afectan seriamente a la calidad de vida de los individuos alérgicos, y que pueden ser leves o graves (incluso mortales). Aproximadamente, la mitad de los casos de alergias alimentarias durante la infancia se asocian a alérgenos de origen animal, siendo la leche de vaca el segundo alérgeno más frecuente, probablemente porque es el primer antígeno alimentario con el que el ser humano entra en contacto en cantidades importantes. La alergia a leche de vaca tiene gran repercusión por la importancia de este alimento en los primeros años de vida de los niños. Los principales alérgenos de la leche son las proteínas séricas (particularmente, β-lactoglobulina, α-lactoalbúmina y, en menor grado, seroalbúmina bovina) y las caseínas. Mediante provocación con proteínas purificadas de leche de vaca, se ha observado que la β-lactoglobulina es la proteína que induce con mayor frecuencia respuestas clínicas. Hasta el momento la evitación del alimento es el tratamiento preventivo más recomendado, aunque presenta dificultades, limitaciones y riesgos. Sin embargo, se está avanzando en otros campos como en la producción de alimentos hipoalergénicos o en el desarrollo de nuevas formas de inmunoterapia. Estas terapias son particularmente exitosas si comienza desde una edad temprana o poco después de que la alergia se desarrolle por primera vez.Los autores agradecen la financiación de los proyectos CYTED A.1.2, CM S-0505/AGR/0153, CONSOLIDER-INGENIO CDS-2007-00063 y AGL-2008-01740.Peer Reviewe

Mineral contents and distribution between the soluble and the micellar phases in Ca enriched UHT milks

Peer Reviewe