Genetically modified maize: exploring consumer acceptance

Recent EU regulations have imposed mandatory labelling of all food products that consist of or contain genetically modified organisms (GMOs). Labelling should state that "this product contains genetically modified organisms". This study examines how different label messages may affect the attitude of consumers in tasting a specific food product (corn chip) derived from maize presented with five different labels ("organic corn", "conventional corn", "product that contains genetically modified corn", "product that contains genetically modified corn approved by EU", "non- classified corn"). Results of 100 Greek young students show that the label claiming that the product contains genetically modified corn, evokes a deeply rooted negative attitude as more than half of participants (59%) refused to taste even a single piece of the product. The label claiming that the product is genetically modified but approved by EU is viewed as more credible but still 29% refuse to sample. The conclusion is that although the feeling of trust increases considerably when the label message is supported by a certifying agency, still a large proportion (almost one third) of participants of technological level education refuse to taste a product that has been approved by the EU for almost a decade. This result demonstrates with an emphatic way the phobia surrounding genetically modified food. On the contrary, products labelled as "organic" were tasted by the majority of participants, even without any kind of certification. Key words : Genetically modified maize, labelling, acceptanceConsumer/Household Economics, Research and Development/Tech Change/Emerging Technologies,

Autenticación de aceite de oliva mediante análisis de ADN

Olive oil, which has been produced mainly in the Mediterranean area since the ancient times, has a high nutritional value linked to many health benefits. Extra virgin, which is the purest form of olive oil, has excellent quality and premium prices. Many cases of adulteration and fraud necessitate the development of reliable and accurate methods for olive oil authentication. DNA-based methods analyze the residual DNA extracted from olive oil and use molecular markers for genetic identification of different species, subspecies or cultivars because these markers act as signs which reflect distinct genetic profiles. This study reviews the process by which DNA from olive oil is extracted and analyzed by the most recently used markers in the authentication of olive oil, such as Simple Sequence Repeats (SSR) or microsatellites and the single nucleotide polymorphisms (SNPs). Methods of analysis such as qPCR and digital PCR are also discussed with a special emphasis placed on the method of High-Resolution Melting (HRM), a post-polymerase chain reaction method, which enables rapid, high performing identification of genetic variants in the DNA regions of interest without sequencing, and may differentiate very similar cultivars which differ in only one nucleotide in a specific locus.El aceite de oliva, producido principal­mente en el área mediterránea desde la antigüedad, tiene un alto valor nutricional vinculado a muchos benefi­cios para la salud. El aceite de oliva virgen extra, que es la forma más pura de aceite de oliva, tiene una excelente calidad y precios premium. Muchos casos de adulteraciones y fraudes requieren el desarrollo de métodos fiables y precisos para la autenticación del aceite de oliva. Los métodos basados en el ADN analizan el ADN residual extraído del aceite de oliva y usan marcadores moleculares para la identificación genética de diferentes espe­cies, subespecies o cultivares, porque estos marcadores actúan como signos que producen perfiles genéticos distintos. Este estudio revisa el proceso mediante el cual el ADN del aceite de oliva es extraído y analizado por los marcadores utilizados más recientemente en la autenticación del aceite de oliva, como las repeticiones de secuencia simple (SSR) o los micro satélites y los polimorfismos de un solo nucleótido (SNP). Los métodos de análisis como qPCR y PCR digital también se analizan haciendo especial énfasis en el método de fusión de alta resolución (HRM), un método de reacción en cadena posterior a la polimerasa, que permite la identificación rápida y con alto rendimiento de variantes genéticas en regiones del ADN de interés sin secuenciación, y pueden diferenciar cultivares muy similares, que difieren en un solo nucleótido, en un lugar específico

Parámetros de calidad de aceites de oliva de las variedades de aceitunas griegas Koroneiki y Megaritiki con hueso y deshuesadas con diferente grado de maduración

Virgin olive oil is a natural functional food and its beneficial role in health as an integral ingredient of the Mediterranean diet is universally recognized. The effects of olive pitting, degree of ripeness and variety (Greek varieties Koroneiki and Megaritiki) were investigated on the physicochemical characteristics, antioxidant constituent contents and capacity and on the fatty acid profile of olive oil. Ripeness resulted in a decrease (P < 0.05) in phenolic and tocopherol contents and the unsaturated/saturated and C18:1ω-9/C18:2ω-6 fatty acid ratios. The pitting technique resulted in a significant increase in phenolic and tocopherol contents, in most cases, without significantly affecting the fatty acid profile and sums. Olive oils from the Koroneiki variety showed significantly higher (P < 0.05) monounsaturated/polyunsaturated fatty acid ratios, which are particularly important for the stability of the oil against oxidation. It was concluded that olive oil from pitted olives maintains a high content in bioactive compounds and a high level of antioxidant activity.El aceite de oliva virgen es un alimento funcional natural cuyo papel como ingrediente esencial de la dieta mediterránea, con propiedades beneficiosas para la salud, ha sido reconocido universalmente. Se ha estudiado el efecto del deshuesado de las aceitunas, grado de maduración y variedad (variedades griegas Koroneiki y Megaritiki) sobre las características físico-químicas, perfil de ácidos grasos y capacidad de los componentes antioxidantes de los aceites de oliva. La maduración ocasionó una disminución (P < 0,05) del contenido de fenoles y tocoferoles y de la relación de ácidos insaturados/ saturados así como de la relación de los ácidos C18:1ω-9/C18:2ω6. El deshuesado incrementa significativamente el contenido fenólico y de tocoferoles, sin afectar significativamente, en la mayoría de los casos, al perfil y cantidad de ácidos grasos. Los aceites de oliva de la variedad Koroneiki mostraron relaciones de ácidos grasos monoinsaturados/poliinsaturados significativamente mayores (p < 0,05) que son particularmente importantes para la estabilidad del aceite frente a la oxidación. En conclusión, el aceite de oliva deshuesado mantiene un alto contenido de compuestos bioactivos y un alto nivel de actividad antioxidante

Оценка надежности высоконадежных систем с учетом ЗИП

Предложены приближенные верхние и нижние оценки коэффициента готовности высоконадежной восстанавливаемой системы со структурной избыточностью. Полученные расчетные соотношения могут использоваться для оценки надежности высоконадежных систем с учетом различных стратегий пополнения ЗИП

Non-destructive assessment of the oxidative stability of intact macadamia nuts during the drying process by near-infrared spectroscopy

We have developed a rapid non-destructive method to assess the oxidative stability of intact macadamia nuts using near-infrared spectroscopy (NIRS). Intact macadamia nuts of the cultivars HAES 344 ‘Kau’, HAES 660 ‘Keaau’, IAC 4–12 B, and IAC Campinas B were harvested and immediately oven-dried for 4 days at 30 °C, 2 days at 40 °C, and 1 day at 60 °C to achieve 1.5% kernel moisture content. At each drying step nuts were withdrawn and their moisture content, peroxide value (PV), and acidity index (AI) determined. The best partial least square model for PV prediction was obtained using the Savitzky-Golay (SG) second derivative resulting in a standard error of prediction (SEP) of 0.55 meq·kg−1 and a coefficient of determination (R2C) of 0.57. The best AI prediction-model result was obtained using the SG second derivative (SEP = 0.14%, R2C = 0.29). Based on the maximum quality limits of 3 meq·kg−1 for PV and 0.5% for AI, the SEP values represented 18% and 28%, respectively. Therefore, the prediction method can be considered useful since the errors are lower than the quality limits. Thus, NIRS can be used to assess the oxidative stability of intact macadamia kernels

On the Characterization and Correlation of Compositional, Antioxidant and Colour Profile of Common and Balsamic Vinegars

Commercially available common and balsamic vinegars were examined, using a combination of spectrophotometric, chromatographic, colorimetric and spectroscopic methods. Total phenolic content, antioxidant activity, radical scavenging capacity, phenolic profile, colour parameters, Fourier Transform Infrared (FT-IR) absorbance spectra and Nuclear Magnetic Resonance (1H NMR) spectra were comparatively studied. The main scope was the assessment of vinegar antioxidant and metabolic profiles and the identification of the most appropriate features influencing their type and subtypes. Red grape balsamic vinegars exhibited the strongest antioxidant profile. High total phenolic content and radical scavenging-antioxidant activity of vinegars was strongly correlated with high hue-angle and colour density values and low lightness and a* values. FT-IR spectra analysis confirmed the presence of organic acids and carbohydrates and, in combination with Gas Chromatography-Mass Spectrometry (GC-MS), the occurrence of phenolic compounds. NMR spectroscopy enabled the identification of 27 characteristic metabolites in each type of vinegar. The combination of all applied techniques provides critical information on compositional differences among the vinegars and could serve as an application tool for similar fermentation products