Modulating the bitterness of Empeltre olive oil by partitioning polyphenols between oil and water phases: Effect on quality and shelf life

Bitterness is a positive sensorial attribute of olive oil that mainly depends on phenol concentration. However, excessive bitterness may be unpleasant for consumers. The aim of this investigation was to evaluate if partitioning polyphenols between oil and water phases could modulate the bitterness of an Empeltre olive oil containing a phenolic concentration higher than the typical content for this olive oil variety. The linear relationship observed between the percentage of oil in the extraction system and the percentage of phenols removed from the oil permitted estimating the olive oil-to-water ratio required to reduce the concentration of phenols for a given value in order to modulate Empeltre olive oil bitterness. Olive oils after liquid–liquid extraction did not develop any negative sensory attributes, and their physicochemical parameters were not substantially affected. Liquid–liquid extraction using water as a solvent is a procedure capable of effectively reducing the total phenol compounds of Empeltre extra virgin olive oil and, as a consequence, of reducing its bitterness intensity without affecting the highest commercial category determined by the parameters legally established by European Community regulations just after extraction and during nine months of storage

Effects of pulsed electric fields on yield extraction and quality of olive oil

The effect of the application of pulsed electric field (PEF) treatments of different intensities (0–2 kV/cm) on Arbequina olive paste in reference to olive oil extraction at different malaxation times (0, 15, and 30 min) and temperatures (15 and 26 °C) was investigated. The extraction yield improved by 54 % when the olive paste was treated with PEF (2 kV/cm) without malaxation. When the olive paste was malaxated at 26 °C, the application of a PEF treatment did not increase the extraction yield as compared with the control. However, at 15 °C, a PEF treatment of 2 kV/cm improved the extraction yield by 14.1 %, which corresponded with an enhancement of 1.7 kg of oil per 100 kg of olive fruits. The application of a PEF treatment could permit reduction of the malaxation temperature from 26 to 15 °C without impairing the extraction yield. Param-eters legally established (acidity, peroxide value, K232, and K270) to measure the level of quality of the virgin olive oil were not affected by the PEF tres. A sensory analysis revealed that the application of a PEF treatment did not generate any bad flavor or taste in the oil

The evolution of Arbequina olive oil quality during ripening in a commercial super-high density orchard in north-east Spain

The objective of this work was to follow the maturity of the olives in a commercial Arbequina super-high density orchard and to study the evolution of the olive oil quality. For this objective, the physicochemical, nutritional and sensory parameters were studied. The free acidity was found to be similar during ripening whereas the peroxide index and K232, K270 decreased. The total phenol content and oxidative stability showed a similar trend. First, it increased and then decreased. alpha-tocopherol, saturated fatty acid and pungency decreased. The polyunsaturated content increased while the MUFAS/PUFAS ratio decreased. In 2010, the crop maturity was quicker, and the maturity indexes were higher than in the 2009 crop for the same picking date. Even in the same orchard, the maturity is changing in each crop season. For this reason, it is necessary to choose the optimal harvesting date

Changes in the Physicochemical and Nutritional Parameters of Picual and Arbequina Olive Oils during Frying

Deep fat frying is an important cooking process in Mediterranean countries. Olive oil is a very convenient fat to use for this culinary purpose. The chemical composition of olive oils differs from edible oils in terms of fatty acid and antioxidant compounds that gives olive oil its greater stability. The aim of this work was to describe the stability of Picual and Arbequina olive oil during deep frying of frozen potatoes in comparison with high oleic sunflower oil. Changes in different physicochemical and nutritional parameters were studied during frying. Picual olive oil had a higher stability in comparison with high oleic sunflower oil and Arbequina olive oil. Picual olive oil is very suitable for frying because it is able to undergo the greatest number of frying cycles without exceeding the limits allowed by regulations. This behavior is due to its phenolic content, the lower loss in tocopherol and better stability. Practical Applications: The information gained from this research could be very appropriate for consumers and for the industry to know which variety of olive oil is more suitable for frying longer frying cycles without exceeding the limits allowed by regulation and remain in good quality

Pilot Study of an Integrative New Tool for Studying Clinical Outcome Discrimination in Acute Leukemia

Acute leukemia is a heterogeneous set of diseases affecting children and adults. Current prognostic factors are not accurate predictors of the clinical outcome of adult patients and the stratification of risk groups remains insufficient. For that reason, this study proposes a multifactorial analysis which integrates clinical parameters, ex vivo tumor characterization and behavioral in vivo analysis in zebrafish. This model represents a new approach to understand leukemic primary cells behavior and features associated with aggressiveness and metastatic potential. Xenotransplantation of primary samples from patients newly diagnosed with acute leukemia in zebrafish embryos at 48 hpf was used to asses survival rate, dissemination pattern, and metastatic potential. Seven samples from young adults classified in adverse, favorable or intermediate risk group were characterized. Tumor heterogeneity defined by Leukemic stem cell (LSC) proportion, was performed by metabolic and cell membrane biomarkers characterization. Thus, our work combines all these parameters with a robust quantification strategy that provides important information about leukemia biology, their relationship with specific niches and the existent inter and intra-tumor heterogeneity in acute leukemia. In regard to prognostic factors, leukemic stem cell proportion and Patient-derived xenografts (PDX) migration into zebrafish were the variables with highest weights for the prediction analysis. Higher ALDH activity, less differentiated cells and a broader and random migration pattern are related with worse clinical outcome after induction chemotherapy. This model also recapitulates multiple aspects of human acute leukemia and therefore is a promising tool to be employed not only for preclinical studies but also supposes a new tool with a higher resolution compared to traditional methods for an accurate stratification of patients into worse or favorable clinical outcome

Cristallisation à basse température du polybutène-1 : étude par effet Raman

The polarization and the relative heights of the Raman bands for a melt quenched polybutene-1 glass were measured as a function of the temperature from 93 to 233 K. This study shows that there is a crystallization in the sample with a transition to the II crystalline modification at 193 K and the transformation form II → form I at 233 K.L'étude de la variation avec la température de la polarisation et des hauteurs relatives des raies du spectre Raman d'un verre de polybutène-1 obtenu par trempe dans l'azote liquide du polymère fondu, nous permet de mettre en évidence, au-dessous de la température de transition vitreuse TG, la cristallisation du matériau sous la forme cristalline instable II à 193 K et la transformation de cette forme vers la forme stable I à 233 K

Etude des modes Raman de déformation angulaire des CH2 dans le polyéthylène

Raman studies were carried out in the 1 400-1 500 cm-1 région on polyethylene samples of various crystallinities and différent stretching ratios. These studies lead to a new assignment of the 1 440 and 1 460 Raman bands to bending modes of amorphous phase CH2 groups which allows us to explain the différence between the Raman spectrum of the polyethylene melt and that of the amorphous phase of semicrystalline samples. Polarization effects in stretched polyethylene Raman spectra show that the amorphous chains are oriented perpendicular to the stretching direction, this is explained by the présence in this material of sharp folds and Pechhold defects (kinks) which involve no disorientation of the crystalline chains.L'étude des spectres Raman d'échantillons de polyéthylène semi-cristallins ayant des cristallinités et des taux d'orientation différents conduit à une nouvelle attribution des raies de fréquence 1 440 et 1 460 cm-1. Cette attribution fait intervenir les vibrations de déformation angulaire des groupements CH2 de la phase amorphe et permet d'expliquer les différences existant entre le spectre Raman du polyéthylène fondu et celui de la phase amorphe du matériau semi-cristallin. On montre également que dans le polyéthylène ultra-étiré, la phase amorphe s'oriente perpendiculairement à la direction d'étirement, ce qui est compatible avec la présence de repliements et de défauts de Pechhold (kinks) qui ne donnent pas lieu à une désorientation des chaînes cristallines