References of "Douny, Caroline"
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See detailDevelopment of an HPTLC method for determination of hypoglycin A in aqueous extracts of seedlings and samaras of Acer species.
Habyarimana, Jean Belt Adélite ULiege; Baise, Etienne; Douny, Caroline ULiege et al

E-print/Working paper (2017)

Hypoglycin A (HGA) is a toxin contained in seeds of the sycamore maple tree (Acer pseudoplatanus). Ingestion of this amino acid causes equine atypical myopathy (AM) in Europe. Another variety, A. negundo ... [more ▼]

Hypoglycin A (HGA) is a toxin contained in seeds of the sycamore maple tree (Acer pseudoplatanus). Ingestion of this amino acid causes equine atypical myopathy (AM) in Europe. Another variety, A. negundo, is claimed to be present where AM cases were reported in the US. For unknown reasons, occurrence of this disease has increased. It is important to define environmental key factors that may influence toxicity of samaras from Acer species. In addition, the content of HGA in seedlings needs to be determined since AM outbreaks, during autumn period when the seeds fall but also during spring when seeds are germinating. The present study aims to validate a reliable method using high performance thin layer chromatography for determination and comparison of HGA in samaras and seedlings. The working range of the method was between 20 μg HGA to 408 μg HGA per ml water, corresponding to 12 - 244 mg/kg fresh weight or 40 - 816 mg/kg dry weight, taking into account of an arbitrary average dry matter content of 30%. Instrumental limit of detection and limit of quantification were of 10 µg HGA/ml and 20 µg HGA/ml water, respectively. Instrumental precision was 4% (RSD on 20 repeated measurements) while instrumental accuracy ranged between 86% and 121% of expected value. The HGA recovery of the analytical method estimated from spiked samaras and seedlings samples ranged between 63 and 103%. The method was applied to 9 samples of samaras from Acer pseudoplatanus, A. platanoides and A. campestre and 5 seedlings samples from A. pseudoplatanus. The results confirm detection of HGA in samaras from A. pseudoplatanus and the absence of detection in samaras of other tested species. They also suggest that detected levels of HGA are highly variable. This confirmed the suitability of the method for HGA detection in samaras or seedling. [less ▲]

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See detailDEVELOPMENT OF ANALYTICAL TOOLS FOR THE DETERMINATION OF MARKERS OF LIPID ALTERATION IN FOOD
Douny, Caroline ULiege

Doctoral thesis (2017)

It is now well-known that n-3 polyunsaturated fatty acids (omega-3 PUFA) have beneficial effects on health but are also rapidly oxidized in potentially toxic compounds, which means that healthy food ... [more ▼]

It is now well-known that n-3 polyunsaturated fatty acids (omega-3 PUFA) have beneficial effects on health but are also rapidly oxidized in potentially toxic compounds, which means that healthy food products, rich in n-3 PUFA, can become toxic for the consumer if not stored or processed appropriately. The main objective of this work was to develop new analytical tools to study markers of lipids alteration in food, in order to allow an adequate monitoring of possible toxic compounds in n-3 PUFA rich food products. The first chapter of this PhD thesis is a literature review about fatty acids, their oxidation and the different oxidation products generated. The different analytical techniques used to study the oxidative stability of polyunsaturated fatty acids and their degradation products in food are also described. Chapter 2 describes the development of a gas chromatography coupled to mass spectrometry (GC-MS) method to analyze the fatty acids in food. The method was applied to eggs and pork (both standard and n-3 enriched) submitted to various cooking processes and storage conditions. This study confirmed that the fat of standard eggs or pork from the Belgian market cannot be considered as a source ofn-3 PUFA.. Indeed, in this work, we measured no n-3 PUFA in meat or only around 2 % for eggs, while the fat of both enriched eggs and pork contained about 10 % of n-3 fatty acids. After storage or cooking without culinary fat no change of the fatty acid profile was observed, in standard eggs or pork. We made the same observation for n-3 enriched products, except for some cooking processes (pan-frying and oven cooking), which induced a slight but significant loss of n-3 fatty acids in n-3 enriched eggs or pork. The fairly stable behavior of the fatty acids after various cooking and storage experiments indicates that the fatty acid profile is not a good marker of lipid alteration. As a consequence, this work was oriented to the development of analytical tools to evaluate the presence of toxic aldehydes in food and feed as secondary oxidation products coming from polyunsaturated fatty acids. Chapter 3 is dedicated to the study of the oxidative stability of linseed oil, an oil rich in n-3 fatty acids. Section 3.1 describes the development of a liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) method to evaluate the aldehyde content in linseed oil. After optimisation of the extraction, derivation, detection and quantification steps, the method was validated according to guidelines from the European legislation as well as the recommendations of the AFNOR protocol NF V 03-110 (AFNOR, 2010). The evaluated parameters included specificity/selectivity, recovery, precision, accuracy, uncertainty, limits of detection and quantification, determined using the concept of accuracy profiles. When the method was applied to first pressure linseed oil stored for several days at 60 °C according to the Schaal oven test, it was shown that 4-hydroxy-2E-hexenal (4-HHE) was the most produced aldehyde. In Section 3.2, the different patterns of oxidation of linseed oil in real-time and accelerated aging assays were investigated, in order to verify the hypothesis commonly accepted for vegetal oil that one day aging at 60 °C is equivalent to one month real time aging at room temperature. Oxidation was evaluated with the peroxide value and para-anisidine value, as well as the content in conjugated dienes and aldehydes. All four indicators of oxidation showed very different kinetic behaviours at 20 and 60 °C, showing that the hypothesis (1 day at 60 °C = 1 month at 20 °C) is not valid for linseed oil. Chapter 4 describes the adaptation and the validation of a LC-MS/MS method to determine aldehydes in animal feed samples. Indeed, as animal feed is often enriched with linseed to increase the human intake of n-3 fatty acids through the consumption of food from animal origin, the study of the oxidative stability of n-3 enriched animal feed is also of interest. To achieve that goal, the LC-MS/MS method previously developed for linseed oil was adapted to include more aldehydes and was validated using the same guidelines as in section 3.1. Finally, chapter 5 presents the discussion and conclusions about the developed methods and the results obtained as well as their comparison with literature. Future prospects to improve the evaluation of and the exposure to the markers of lipid alteration in food are proposed. [less ▲]

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See detailDevelopment of an analytical method for the simultaneous measurement of 10 biogenic amines in food
Douny, Caroline ULiege; Benmedjadi, Soumaya; Blaszczyk, Marie et al

Poster (2016, October 21)

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See detailDevelopment of an LC-MS/MS analytical method for the simultaneous measurement of aldehydes from polyunsaturated fatty acids degradation in animal feed
Douny, Caroline ULiege; Bayram, Pinar; Brose, François ULiege et al

in Drug Testing and Analysis (2016), 8(5-6), 458-464

Knowing that polyunsaturated fatty acids can lead to the formation of potentially toxic aldehydes as secondary oxidation products, an analytical method using liquid chromatography coupled to tandem mass ... [more ▼]

Knowing that polyunsaturated fatty acids can lead to the formation of potentially toxic aldehydes as secondary oxidation products, an analytical method using liquid chromatography coupled to tandem mass spectrometry detection (LC-MS/MS) has been developed to evaluate the concentration of eight aldehydes in animal feed: malondialdehyde (MDA), 4-hydroxy-2-nonenal (4-HNE), 4-hydroxy-2-hexenal (4-HHE), crotonaldehyde (CRT), benzaldehyde (BNZ), hexanal (HXL), 2,4-nonadienal and 2,4-decadienal. The developed method has been validated according to the criteria and procedure described in international standards. The evaluated parameters were: specificity/selectivity, recovery, precision, accuracy, uncertainty, limits of detection and quantification, using the concept of accuracy profiles. These parameters have been determined during experiments realized on 3 different days with grounded Kellogg’s® Corn Flakes® cereals as model matrix for animal feed and spiked at different levels of concentration. Malondialdehyde, 4-HHE, 4-HNE, crotonaldehyde, benzaldehyde and hexanal can be analysed in the same run in animal feed with a very good accuracy, with recovery rates ranging from 86 to 109% for a working range going from 0.16 to 12.50 mg/kg. Concerning 2,4-nonadienal and 2,4-decadienal, their analysis can be realized as well but in a limited range of concentration and with a limited accuracy. Indeed, recovery rates ranged between 54 and 114% and coefficient of variation for the intermediate precision between 11 and 25% for these two compounds. [less ▲]

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See detailLinseed oil presents different patterns of oxidation in real-time and accelerated aging assays
Douny, Caroline ULiege; Razanakolona, Rina; Ribonnet, Laurence et al

in Food Chemistry (2016), 208

This study aimed at verifying if the hypothesis that one day at 60 °C is equivalent to one month at 20 °C could be confirmed during linseed oil aging for 6 months at 20 °C and 6 days at 60 °C using the ... [more ▼]

This study aimed at verifying if the hypothesis that one day at 60 °C is equivalent to one month at 20 °C could be confirmed during linseed oil aging for 6 months at 20 °C and 6 days at 60 °C using the “Schaal oven stability test”. Tests were conducted with linseed oil supplemented or not with myricetin or butyl-hydroxytoluene as antioxidants. Oxidation was evaluated with the peroxide and p-anisidine values, as well as the content in conjugated dienes and aldehydes. All four indicators of oxidation showed very different kinetic behaviors at 20 and 60 °C. The hypothesis is thus not verified for linseed oil, supplemented or not with antioxidant. In the control oil, the conjugated dienes and the peroxide value observed were respectively of 41.8 ± 0.8 Absorbance Unit (AU)/g oil and 254.3 ± 5.8 meq. O2/kg oil after 6 months at 20 °C. These values were of 18.2 ± 1.3 AU/g oil and 65.2 ± 20.3 meq. O2/kg after 6 days at 60 °C. [less ▲]

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See detailEffect of storage and cooking on the fatty acid profile of omega-3 enriched eggs and pork meat marketed in Belgium
Douny, Caroline ULiege; El Khoury, Rawad; Delmelle, Julien et al

in Food Science & Nutrition (2015), 3(2), 140-152

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See detailMonitoring Antibiotic Use and Residue in Freshwater Aquaculture for Domestic Use in Vietnam
Pham Kim, Dang; Chu, Jacqueline; Nga Thuy, Do et al

in EcoHealth (2015), 12

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See detailLes nouveaux outils de diagnostic et de pronostic de la myopathie atypique
Habyarimana, Jean Belt Adélite ULiege; BOEMER, François ULiege; Amory, Hélène ULiege et al

in Proceeding de la 41ème Journée de la Recherche équine (2015)

In equines, ingestion of hypoglycin A, a toxin produced in the seeds (samaras) of sycamore maple (Acer pseudoplatanus) tree alters the energetic metabolism of muscle cells and results in atypical myopathy ... [more ▼]

In equines, ingestion of hypoglycin A, a toxin produced in the seeds (samaras) of sycamore maple (Acer pseudoplatanus) tree alters the energetic metabolism of muscle cells and results in atypical myopathy (AM). This alterations leads to a characteristic biochemical profile of acylcarnitines (AC) that enables to confirm the diagnosis of AM. This study aims at validating a methodology for the dosage of hypoglycin A in vegetal extracts but also in blood. In addition, the biochemical profile in AC has been determined in AM cases (5 survivors and 13 deceased) and in 5 horses suffering from exercise-induced myopathy. The AC profiles of these horses have been compared to the one of healthy horses (n = 35). This study showed that hypoglycin A was present in seeds and spring seedlings of sycamore and also in blood of AM cases horses. In addition, the establishment of AC profile contributes to the diagnostic and helps to assess the prognosis of AM cases. [less ▲]

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See detailImpact of aging technique, muscle and previous vacuum storage time on oxidative stability of beef packaged under high-oxygen atmosphere
Didimo Imazaki, Pedro Henrique ULiege; Douny, Caroline ULiege; Scippo, Marie-Louise ULiege et al

Conference (2014, December 11)

The aim of this study was to compare the effect of aging technique (wet-aging vs. carcass-aging), muscle (longissimus dorsi vs. rectus femoris) and previous vacuum storage time on color and lipid ... [more ▼]

The aim of this study was to compare the effect of aging technique (wet-aging vs. carcass-aging), muscle (longissimus dorsi vs. rectus femoris) and previous vacuum storage time on color and lipid stability of beef packaged in high-oxygen atmosphere. After a seven-day wet- or carcass-aging step, longissimus dorsi and rectus femoris muscle cuts from 4 Belgian Blue cows were vacuum packaged and stored at −1 °C for up to 28 days. At different times, part of these samples was repackaged under modified atmosphere – 70 % O2:30 % CO2 –, and stored during 7 days at +4 °C. The following parameters were evaluated at different intervals: color (CIE L*a*b*), metmyoglobin %, lipid oxidation (TBARS), antioxidant enzyme activities (catalase, glutathione peroxidase and superoxide dismutase), alpha-tocopherol and fat content. The sensitivity of modified atmosphere repacked meat cuts to oxidation was influenced by the conditions of the previous aging period (wet > carcass conditions), muscle (rectus femoris > longissimus dorsi) and length of the vacuum storage. Oxidation stability could be associated with catalase activity, and no association could be established with the alpha-tocopherol content. [less ▲]

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See detailStabilité oxydative des viandes blanc bleu belge conditionnées sous atmosphère riche en oxygène après maturation sous vide ou en carcasse
Didimo Imazaki, Pedro Henrique ULiege; Douny, Caroline ULiege; Scippo, Marie-Louise ULiege et al

in Viandes et Produits Carnés (2014, November)

The aim of this study was to evaluate the physico-chemical stability of Belgian Blue beef packaged under high-oxygen atmosphere as a function of a previous aging technique (wet-aging in vacuum conditions ... [more ▼]

The aim of this study was to evaluate the physico-chemical stability of Belgian Blue beef packaged under high-oxygen atmosphere as a function of a previous aging technique (wet-aging in vacuum conditions vs. carcass-aging). Two muscles (longissimus dorsi vs. rectus femoris) were studied. After a seven-day wet- or carcass-aging step, muscle cuts from 4 Belgian Blue cows were vacuum packaged and stored at −1 °C for up to 28 days. Each 14 days, part of these samples was repackaged under modified atmosphere (70 % O2:30 % CO2), and stored during 7 days at +4 °C. The following parameters were evaluated: color, metmyoglobin %, metmyoglobin reducing activity, fat content, fatty acid profile, lipid oxidation, antioxidant enzyme activities and alpha-tocopherol content. The sensitivity of modified atmosphere repacked meat cuts to oxidation was influenced by the conditions of the previous aging period (wet > carcass conditions), muscle (rectus femoris > longissimus dorsi) and length of the vacuum storage. [less ▲]

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See detailEffect of fuel and kiln type on the polycyclic aromatic hydrocarbon (PAH) levels in smoked shrimp, a Beninese food condiment
Kpoclou, Euloge; Anihouvi, Victor; Azokpota, Paulin et al

in Food Additives & Contaminants. Part A. Chemistry, Analysis, Control, Exposure & Risk Assessment (2014), 31(7), 1212-1218

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See detailMicrobial, biochemical and sensorial quality assessment of Algerian farmed tilapia (Oreochromis niloticus) stored at 4 and 30°C
Dergal, Nadir; Abi-Ayad, S.M.E.-A.; Degand, Guy ULiege et al

in African Journal of Food Science (2013), 7(12), 498-507

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See detailValidation of a LC-MS analytical method for the measurement of aldehydes in meat and oil
Tihon, Angélique; Douny, Caroline ULiege; Bayonnet, Pierre ULiege et al

Poster (2013, April 18)

Detailed reference viewed: 31 (8 ULiège)