Time filter

Source Type

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. Source

Venegas-Caleron M.,Rothamsted Research | Venegas-Caleron M.,CSIC - Instituto de la Grasa | Sayanova O.,Rothamsted Research | Napier J.A.,Rothamsted Research
Progress in Lipid Research | Year: 2010

It is now accepted that omega-3 polyunsaturated fatty acids, especially eicosapentaenoic acid (EPA; 20:5Δ5,8,11,14,17) and docosahexaenoic acid (DHA, 22:6Δ4,7,10,13,16,19) play important roles in a number of aspects of human health, with marine fish rich in these beneficial fatty acids our primary dietary source. However, over-fishing and concerns about pollution of the marine environment indicate a need to develop alternative, sustainable sources of very long chain polyunsaturated fatty acids (VLC-PUFAs) such as EPA and DHA. A number of different strategies have been considered, with one of the most promising being transgenic plants "reverse-engineered" to produce these so-called fish oils. Considerable progress has been made towards this goal and in this review we will outline the recent achievements in demonstrating the production of omega-3 VLC-PUFAs in transgenic plants. We will also consider how these enriched oils will allow the development of nutritionally-enhanced food products, suitable either for direct human ingestion or for use as an animal feedstuff. In particular, the requirements of aquaculture for omega-3 VLC-PUFAs will act as a strong driver for the development of such products. In addition, biotechnological research on the synthesis of VLC-PUFAs has provided new insights into the complexities of acyl-channelling and triacylglycerol biosynthesis in higher plants. © 2009 Elsevier Ltd. All rights reserved. Source

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. Source

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. Source

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. Source

Discover hidden collaborations