CSIC - Instituto de la Grasa
CSIC - Instituto de la Grasa
Ruiz-Mendez M.V.,CSIC - Instituto de la Grasa
Chemico-Biological Interactions | Year: 2011
In this article, denaturing with aniline and refining process of the oil responsible for toxic oil syndrome is briefly reviewed. The aspects considered include description of conditions of the main refining steps in relation to aniline derivatives formation, with special focus on the deodorization stage. In this last step of the refining process, an increase in the temperature, applied to such an unusual oil, could have given rise to the formation of anilides and 3-N-phenylamino-1,2-propanediol esters. © 2011 Elsevier Ireland Ltd. All Rights Reserved.
Cayuela J.A.,CSIC - Instituto de la Grasa |
Weiland C.,University of Huelva
Postharvest Biology and Technology | Year: 2010
Two commercial portable spectrometers were compared for orange quality non-destructive predictions by developing partial least squares calibration models, reflectance mode spectra acquisition being used in both. One of them was a Vis/NIR spectrometer in which the radiation reflected by the fruit is collected and conducted by optic fiber to the three detectors (350-2500nm) of the instrument. The other is an AOTF-NIR with a reflectance post-dispersive optical configuration and InGaAs (1100-2300. nm) detector. Four orange varieties were included in calibrations. The parameters studied were soluble solids content, acidity, titratable acidity, maturity index, flesh firmness, juice volume, fruit weight, rind weight, juice volume to fruit weight ratio, fruit colour index and juice colour index. The results indicate good performance of the predictive models, particularly for the direct NIR prediction of soluble solids content, and maturity index, the prediction of this last parameter being notable for its relevance and novelty. The RPD ratios for these parameters were in the range from 1.67 to 2.21 with the Labspec spectrometer, which showed better predictive performance, and from 1.03 to 2.33 with the Luminar instrument. © 2010 Elsevier B.V.
Garcia-Gonzalez D.L.,CSIC - Instituto de la Grasa |
Aparicio R.,CSIC - Instituto de la Grasa
Journal of Agricultural and Food Chemistry | Year: 2010
Olive oil, a traditional food product with thousands of years of history, is continually evolving toward a more competitive global market. Being one of the most studied foods across different disciplines, olive oil still needs intensive research activity to face some vulnerabilities and challenges. This perspective describes some of them and shows a vision of research on olive oil for the near future, bringing together those aspects that are more relevant for better understanding and protection of this edible oil. To accomplish the most urgent challenges, some possible strategies are outlined, taking advantage of the latest analytical advances, considering six areas: (i) olive growing; (ii) processing, byproduct, and environmental issues; (iii) virgin olive oil sensory quality; (iv) purity, authentication, and traceability; (v) health and nutrition; (vi) consumers. The coming research, besides achieving those challenges, would increase the understanding of some aspects that are still the subject of debate and controversy among scientists focused on olive oil. © 2010 American Chemical Society.
Mellado-Ortega E.,CSIC - Instituto de la Grasa |
Hornero-Mendez D.,CSIC - Instituto de la Grasa
Food Chemistry | Year: 2012
Liquid chromatography in conjunction with UV-visible spectroscopy and atmospheric pressure chemical ionisation (APCI) mass spectrometry has been used for the structural assignment of the lutein esters, including the regioisomeric forms, naturally occurring in the endosperm of tritordeum (×Tritordeum Ascherson et Graebner), a novel cereal. The distinctive mass spectrometry fragmentation pattern of lutein, characterized by a favored loss of the moieties at the position 3′ of the -end ring, allowed an unambiguous structural identification of four monoesters (lutein 3′-O-linoleate, lutein 3-O-linoleate, lutein 3′-O-palmitate, lutein 3-O-palmitate) and four diesters (lutein dilinoleate, lutein 3′-O-linoleate-3-O-palmitate, lutein 3′-O-palmitate-3-O-linoleate, lutein dipalmitate). This is the first time that the regioisomers of carotenoid esters have been identified in a cereal. Evidences for a preferential xanthophyll acyltransferase activity regarding the position (3 or 3′) and the acyl moiety are discussed. Further studies should be carried out in order to identify the acyltransferase enzymes and the acyl donor molecules involved in the xanthophyll esterification process. © 2012 Elsevier Ltd. All rights reserved.
Romero C.,CSIC - Instituto de la Grasa |
Brenes M.,CSIC - Instituto de la Grasa
Journal of Agricultural and Food Chemistry | Year: 2012
The most abundant phenolic compounds in olive oils are the phenethyl alcohols hydroxytyrosol and tyrosol. An optimized method to quantify the total concentration of these substances in olive oils has been described. It consists of the acid hydrolysis of the aglycons and the extraction of phenethyl alcohols with a 2 M HCl solution. Recovery of the phenethyl alcohols from oils was very high (<1% remained in the extracted oils), and the limits of quantification (LOQ) were 0.8 and 1.4 mg/kg for hydroxytyrosol and tyrosol, respectively. Precision values, both intraday and interday, remained below 3% for both compounds. The final optimized method allowed for the analysis of several types of commercial olive oils to evaluate their hydroxytyrosol and tyrosol contents. The results show that this method is simple, robust, and reliable for a routine analysis of the total concentration of these substances in olive oils. © 2012 American Chemical Society.
Hidalgo F.J.,CSIC - Instituto de la Grasa |
Zamora R.,CSIC - Instituto de la Grasa
Food Chemistry | Year: 2014
The reaction between m-diphenols (resorcinol, 2-methylresorcinol, 2,5-dimethylresorcinol, 3-methylphenol, orcinol, and phloroglucinol) and 2-alkenals (2-pentenal and 2-octenal) was studied in an attempt to understand the chemical pathways involved in the scavenging ability of m-diphenols for the 2-alkenals produced as a consequence of lipid oxidation. Phenols reacted chemically with 2-alkenals producing a number of 2H-chromenols, chromandiols, chromanols, and dihydropyrano[3,2-g]chromenes, which were isolated and identified by 1D and 2D nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS). The identification of all these compounds resulted in the construction of a general pathway for these reactions. These results confirm that the 2-alkenal-scavenging ability of m-diphenols is a consequence of their structure. This is a complex reaction in which many different products are formed. The most stable products were the chromandiols. However, the main reaction products were the 2H-chromenols. These products were unstable and disappeared as a consequence of polymerisation and browning reactions. © 2014 Elsevier Ltd. All rights reserved.
Castellano J.M.,CSIC - Instituto de la Grasa |
Guinda A.,CSIC - Instituto de la Grasa |
Delgado T.,CSIC - Instituto de la Grasa |
Rada M.,CSIC - Instituto de la Grasa |
Cayuela J.A.,CSIC - Instituto de la Grasa
Diabetes | Year: 2013
Oleanolic acid (OA), a natural component of many plant food and medicinal herbs, is endowed with a wide range of pharmacological properties whose therapeutic potential has only partly been exploited until now. Throughout complex and multifactorial mechanisms, OA exerts beneficial effects against diabetes and metabolic syndrome. It improves insulin response, preserves functionality and survival of β-cells, and protects against diabetes complications. OA may directly modulate enzymes connected to insulin biosynthesis, secretion, and signaling. However, its major contributions appear to be derived from the interaction with important transduction pathways, and many of its effects are consistently related to activation of the transcription factor Nrf2. Doing that, OA induces the expression of antioxidant enzymes and phase II response genes, blocks NF-κB, and represses the polyol pathway, AGEs production, and hyperlipidemia. The management of type 2 diabetes requires an integrated approach, which includes the early intervention to prevent or delay the disease progression, and the use of therapies to control glycemia and lipidemia in its late stages. In this sense, the use of functional foods or drugs containing OA is, undoubtedly, an interesting path. © 2013 by the American Diabetes Association.
Ruiz-Barba J.L.,CSIC - Instituto de la Grasa |
Jimenez-Diaz R.,CSIC - Instituto de la Grasa
Food Microbiology | Year: 2012
A new starter culture consisting of two Lactobacillus pentosus strains was developed and successfully used for Spanish-style green olive fermentations in an industrial study. The inoculum, consisting of L.pentosus LP RJL2 and LP RJL3 strains, was inoculated in 10,000kg glass fiber containers at 10 6CFU/ml and 10 5CFU/ml, final concentration respectively, in five different olive processing plants in the south of Spain. As a control, uninoculated fermentors were also used. In all inoculated fermentors, the paired starter rapidly colonized the brines to dominate the natural microbiota and persisted throughout fermentation. A decline in pH to reach about 5.0 was achieved in the first 15-20 days, reaching about 4.0 at the end of the process. The lactic acid concentration in brines increased rapidly in the first 20 days of fermentation (0.3-0.4g/100ml) to give values higher than 0.8g/100ml at the end of the process. In contrast, increasing lactic acid concentration was slower in uninoculated than in the inoculated brines, and the final concentrations were lower. Although reaching similar values at the end of the process, the decline in pH in uninoculated fermentors was slower than in the inoculated ones. These results show the efficacy of the new starter culture to control the lactic acid fermentation of Spanish-style green olives. © 2011 Elsevier Ltd.
Raposo F.,CSIC - Instituto de la Grasa |
De La Rubia M.A.,CSIC - Instituto de la Grasa |
Fernandez-Cegri V.,CSIC - Instituto de la Grasa |
Borja R.,CSIC - Instituto de la Grasa
Renewable and Sustainable Energy Reviews | Year: 2012
Anaerobic digestion is considered a competitive source for the production of renewable energy as far as efficiency and cost are concerned. To evaluate the anaerobic biodegradability of an organic substrate such as feedstocks, a test known as biochemical methane potential (BMP) has been commonly used. Current worldwide interest in using different organic substrates for anaerobic bioconversion is growing but there is a lack of clear references and comparability as a result of multiple factors that affect BMP determination. Several batch methods have been used to determine the methane potential. However, these technical approaches vary significantly from one reported method to the next another. In this review, the research works on the influence of different parameters of BMP determination have been discussed for critical and comparative evaluation. In addition, the extensive literature previously published dealing with BMP assays has been compiled and summarized focusing on two main subjects: firstly, methane yields of substrates, and secondly, the description of the various experimental procedures used to achieve the reported data. © 2011 Elsevier Ltd. All rights reserved.
Garcia-Gonzalez D.L.,CSIC - Instituto de la Grasa |
Aparicio R.,CSIC - Instituto de la Grasa
Food Chemistry | Year: 2010
This paper describes a novel approach to determine the individual contribution of volatile compounds to the overall sensor responses of metal oxide semiconductor (MOS) sensors when they are applied to a complex mixture of compounds such as food aroma. A methodology entailing the use of a sensor array or electronic nose (EN) as non-destructive detector in-parallel with the flame ionization detector of a gas chromatograph (GC) is described and illustrated in the context of virgin olive oil aroma analysis. Aspects related to the experimental set up and data processing are examined. The capability of gas chromatography for obtaining qualitative and quantitative information of the volatile compounds present in virgin olive oil was used to find relationships between these compounds and the sensor responses by means of a coupled system GC-EN. The sensor responses that resulted from this coupling (sensorgrams) served to prove the sensor sensitivity to alcohols, aldehydes, and those compounds that are responsible to sensory defects in virgin olive oil (e.g. aldehydes and acids). © 2009 Elsevier Ltd. All rights reserved.