Pyropheophytin a – Determination of thermal degradation products of chlorophyll a in virgin olive oil

Gertz, Christian; Fiebig, Hans‐Jochen

doi:10.1002/ejlt.200600164

Cited by 25 publications

(24 citation statements)

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“…The standard of chlorophyll a, from spinach, was bought from Sigma-Aldrich (C5753) according to the suggestion of Gertz and Fiebig (2006). Pheophytin was obtained by acidification with hydrochloric acid from the chlorophylls (Sievers and Hynninem, 1977).…”

Section: Chromatographymentioning

confidence: 99%

“…The method for controlling % PPP is not, however, easily implemented in all laboratories despite the effort made by researchers (Gertz and Fiebig, 2006) to simplify the initial procedure (Mínguez-Mosquera et al, 1992). The request for rapid methods to detect virgin olive oil freshness is widely claimed by producers, sellers and consumers (Aparicio et al, 2013), and it obviously includes the determination of all the parameters that evolve over time, such as pigments.…”

Section: Mathematical Modelling Of the Concentration Of Pigments Overmentioning

confidence: 99%

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Predicting extra virgin olive oil freshness during storage by fluorescence spectroscopy

et al. 2018

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SUMMARY:Virgin olive oil quality relates to flavor and unique health benefits. Some of these properties are at the most desirable level when the oil is just extracted, since it is not a product that improves with age. On the contrary, the concentrations of many compounds change during its shelf-life. These changes reveal the aging of the oil but do not necessarily mean decay in sensory properties, so in some cases an aged oil from healthy olives may be better qualified than a fresh one from olives affected by fermentation. The aim of this work is to analyze different methodologies proposed for assessing the quality of virgin olive oil with implications in freshness and aging of the oil, and to highlight the possibilities of rapid spectrofluorimetric techniques for assessing oil freshness by checking the evolution of pigments during storage. The observed change in the selected spectral features and mathematical modelling over time was compared with the accepted model for predicting the amount of pyropheophytin a, which is based on isokinetic studies. The best regression was obtained for 655 nm (adjusted-R 2 = 0.91) wavelength, which matches the distinctive band of pigments. The two mathematical models described in this study highlight the usefulness of pigments in the prediction of the shelf-life of extra virgin olive oil. KEYWORDS:Freshness; Pigments; Pyropheophytin; Spectrofluorimetry; Virgin olive oil RESUMEN: Predicción de la frescura del aceite de oliva virgen extra durante el almacenamiento mediante espec troscopía de fluorescencia. La calidad del aceite de oliva virgen está relacionada con su flavor y sus beneficios únicos para la salud. Algunas de estas propiedades se encuentran en el nivel más deseable cuando el aceite está recién extraído, ya que no es un producto que mejore con el tiempo. Por el contrario, las concentraciones de muchos compuestos cambian a lo largo de la vida útil. Estos cambios revelan el envejecimiento del aceite, pero no implican necesariamente la alteración de las propiedades sensoriales, por lo que en algunos casos un aceite envejecido procedente de aceitunas sanas puede presentar mejor calidad que uno fresco procedente de aceitunas afectadas por procesos de fermentación. El objetivo de este trabajo es estudiar diferentes metodologías propuestas para evaluar la calidad del aceite de oliva virgen con implicaciones en la frescura y el envejecimiento del aceite, destacando las posibilidades de las rápidas técnicas espectrofluorométricas para evaluar la frescura del aceite verificando la evolución de los pigmentos durante el almacenamiento. El cambio observado en las características espectrales seleccionadas y su modelado matemático a lo largo del tiempo se comparó con el modelo aceptado para predecir la cantidad de pirofeofitina a, que se basa en estudios isocinéticos. Los dos modelos matemáticos descritos en este estudio pusieron de manifiesto la utilidad de los pigmentos en la predicción de la vida útil del aceite de oliva virgen extra. La mejor regresión se obtuvo para 655 nm (R 2...

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Section: Chromatographymentioning

confidence: 99%

Section: Mathematical Modelling Of the Concentration Of Pigments Overmentioning

confidence: 99%

Predicting extra virgin olive oil freshness during storage by fluorescence spectroscopy

et al. 2018

View full text Add to dashboard Cite

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“…The determination of chlorophyll pigments was carried out by implementing the method proposed by Gertz and Fiebig (2006) to quantify the pirofeofitina a. A sample of 300 mL was diluted in 1 mL of hexane.…”

Section: Determination Of Chlorophyll Pigmentsmentioning

confidence: 99%

Chemical changes of thermoxidized virgin olive oil determined by excitation–emission fluorescence spectroscopy (EEFS)

Tena

Aparicio

García‐González

2012

Food Research International

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“…A number of approaches were investigated to determine deWciencies of extra virgin olive oils resulting from inappropriate technological treatments, such as spectrophotometry for the determination of conjugated fatty acids, stigmastadiene for the detection of decoloration or high temperature deodoration [2] and the formation of pyropheophytine from chlorophyll [3][4][5][6] or the isomerization of 1,2-diglycerides to 1,3-diglycerides [7,8] for the recognition of weak thermal treatments. These methods primarily aimed at detecting adulteration of extra virgin oils by treated oils of minor quality, which does not necessarily aVect the sensorial quality.…”

Section: Introductionmentioning

confidence: 99%

Fatty acid methyl and ethyl esters as well as wax esters for evaluating the quality of olive oils

Biedermann¹,

Bongartz

Mariani³

et al. 2008

Eur Food Res Technol

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A promising correlation between chemical analysis and sensorial evaluation was conWrmed: extra virgin olive oils with low contents of methyl and ethyl esters of fatty acids as well as straight chain wax esters were sensorially evaluated as being of high quality, whereas some with high contents were even devaluated as not being of extra virgin quality. Methanol and ethanol formed during fermentation in degrading olives are esteriWed, largely by transesteriWcation with fatty acids from the triglycerides, and in this way transferred into the pressed oil. The presence of high contents of methyl and ethyl esters in degrading olives was conWrmed. Wax esters from the skin of the olives are extracted at low yields, whereby the yield increases when the olives are soft and possibly degrading. High wax ester contents may, therefore, stand for mild oils, but also for deWcient oils.

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Pyropheophytin a – Determination of thermal degradation products of chlorophyll a in virgin olive oil

Cited by 25 publications

References 0 publications

Predicting extra virgin olive oil freshness during storage by fluorescence spectroscopy

Predicting extra virgin olive oil freshness during storage by fluorescence spectroscopy

Chemical changes of thermoxidized virgin olive oil determined by excitation–emission fluorescence spectroscopy (EEFS)

Fatty acid methyl and ethyl esters as well as wax esters for evaluating the quality of olive oils

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