Publications of Marianne Sindic
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See detailDetermination of the growth potential of Listeria monocytogenes in various types of Belgian artisanal cheeses by challenge tests
Gerard, Amaury ULiege; El-Hajjaji, Soundous ULiege; Van Coillie, Els et al

in Food Microbiology (2020), 92

Cheese potentially allowing the growth of Listeria monocytogenes must be free of the pathogen in 25 g before being put on the market, while 100 cfu/g is tolerated when the pathogen is unable to grow ... [more ▼]

Cheese potentially allowing the growth of Listeria monocytogenes must be free of the pathogen in 25 g before being put on the market, while 100 cfu/g is tolerated when the pathogen is unable to grow. Challenge tests were performed in order to assess the growth potential of L. monocytogenes in at least one batch of 32 Belgian cheese varieties from 32 factories. All varieties were grouped in four categories: unripened acid-curd cheeses, mold-ripened soft cheeses, smear-ripened soft cheeses and ripened semi-hard cheeses. Associated microflora and cheese physicochemical characteristics were also studied. A cocktail of three strains was used to inoculate cheese on the first day of shelf-life, and samples were stored until the end of shelf-life at 7-9 °C. Growth potential was considered as the difference (a) between median contamination at the end and at the beginning of the test or (b) between the highest value at the end of the test and the lowest value at its beginning. L. monocytogenes always decreased in unripened acid-curd cheeses but showed extended growth in 21 out of 25 batches of ripened soft cheese. Contrasting results were obtained for semi-hard cheeses, as important intra- and inter-batch variability was observed. For the latter, the recommended method based on medians to calculate the growth potential led to erroneous food safety considerations, and it should always be advised to focus on absolute levels. [less ▲]

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See detailWhat is the fate of Listeria monocytogenes in various types of Belgian artisanal cheeses?
Gerard, Amaury ULiege; Van Coillie, Els; Bentaib, Azeddine ULiege et al

Conference (2020, June 24)

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See detailHypoglycaemic activity of preheated (roasting) Aframomum citratum (C. Pereira) K. Schum and Tetrapleura tetraptera (Schumach & Thonn.) fruits beverage on Streptozotocin-induced rats
Eyenga, Manga ULiege; Takuissu, N.G.R; Ziyyat, A. et al

in Journal of Pharmacognosy and Phytotherapy (2020), 12(2), 44-61

Tetrapleura tetraptera and Aframomum citratum fruits are used as spices and in the traditional pharmacopeia in Cameroon. They are mostly combined and preheated for many purposes while cooking. The effects ... [more ▼]

Tetrapleura tetraptera and Aframomum citratum fruits are used as spices and in the traditional pharmacopeia in Cameroon. They are mostly combined and preheated for many purposes while cooking. The effects of roasting on the phenolic content of spices, phenolic profile of a beverage made with the mix of roasted spices and its hypoglycaemic activity on diabetes complications were investigated. Aqueous extract (infusion: 100°C; 1/5 g/ml) was prepared, and the total polyphenols and flavonoids contents before and after heat treatment were quantified. Four formulations of T. tetraptera/A. citratum (95/5; 90/10; 85/15; 80/20) were assessed and the in vitro glucose adsorption capacity of the extracts was studied to retain the most effective formulation (AEF). Phenolic and derivatives compounds of AEF were analysed using HPLC-DAD methodology. The AEF hypoglycaemic activity (250 mg/kg bw) and the various complications of hyperglycaemia after Streptozotocin induction (55 mg/kg) were examined on rats. Significant (p<0.05) improvements in phytochemical content were noticed for T. tetraptera and AEF extracts after heat treatment. Among the phenolic compounds identified, flavone, protocatechic, chlorogenic, p-Coumaric acids, and naringin showed the highest concentrations. Significantly, the effect of AEF is the same as the administration of AEF-Glibenclamide (Glibenclamide) and Acarbose after 4h when assessing the anti-hyperglycaemic test. The influence of Glibenclamide (the reference drug) is significantly improved by AEF, and this synergy has the best anti-hyperglycaemic, hypoglycaemic, hypotriglyceridaemic potential and boosts catalase, superoxide dismutase activities while reducing Malondialdehyde (liver, pancreas, haemolysates) and hydroperoxide (liver, plasma, and kidney) contents compared with the use of single AEF. [less ▲]

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See detailSurvey on the prevalence of Listeria monocytogenes in Belgian artisanal cheeses
Gerard, Amaury ULiege; El-Hajjaji, Soundous ULiege; Van Coillie, Els et al

in Biotechnologie, Agronomie, Société et Environnement (2020), 24(3), 155-161

Description of the subject. Cheese is a vector of Listeria monocytogenes. By default, European Commission imposes its absence in cheese before sales, but fixes pH and water activity thresholds below which ... [more ▼]

Description of the subject. Cheese is a vector of Listeria monocytogenes. By default, European Commission imposes its absence in cheese before sales, but fixes pH and water activity thresholds below which it cannot grow. Objectives. To study pH and water activity of Belgian cheeses and the prevalence of L. monocytogenes in these products. Method. Salt content, pH and water activity of 134 cheeses were determined. Absence of L. monocytogenes in 25 g of cheese was also checked. Results. Three samples had pH or water activity under threshold values from regulation. Nevertheless, all unripened cheeses were acid in comparison with data from foreign countries. Listeria monocytogenes was isolated from 1.49% of the samples. Conclusions. Belgian artisanal cheeses could allow the growth of L. monocytogenes, and the bacterium was isolated from two samples. Further experiments should be performed to understand the fate of the pathogen in these products. [less ▲]

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See detailOptimisation of phenolic compounds and antioxidant activity extraction conditions of a roasted mix of Tetrapleura tetraptera (Schumach & Thonn.) and Aframomum citratum (C. Pereira) fruits using response surface methodology (RSM)
Eyenga, Manga ULiege; Brostaux, Yves ULiege; Ngondi J. L., et al

in Saudi Journal of Biological Sciences (2020)

The therapeutic abilities of Tetrapleura tetraptera and Aframomum citratum fruits used as spices are attributed to their bioactive molecules, including polyphenols. Sometimes used together and heated ... [more ▼]

The therapeutic abilities of Tetrapleura tetraptera and Aframomum citratum fruits used as spices are attributed to their bioactive molecules, including polyphenols. Sometimes used together and heated, they can undergo denaturation. The aim of the current study is to optimize the extraction of phenolic compounds and antioxidant potential of a roasted mix of Tetrapleura tetraptera and Aframomum citratum (95/5: w/w) fruits using RSM in a home food consumption context. The mix of spices was chosen according to the highest content of TPP and preliminary studies were performed to select the influencing variables. Roasting temperatures (130-170°C), roasting times (10-15 min) and brewing times (8-15 min) were investigated with a rotatable central composite design. Experimental results were fitted to the second-order polynomial model where multiple regressions and ANOVA were used to determine the coefficients of the model and the optimal conditions for the considered responses. The two spices are good sources of phenolic compounds, and they also show significant (p<0.05) dose-dependent radical scavenging activities (DPPH assay and inhibition of βcarotene discoloration) and reductive activities (FRAP assay and Phosphomolybdenum method). They significantly inhibit bovine serum albumin and 5-LOX denaturation. Brewing time and roasting time significantly (p<0.05) influence the responses and there is a strong (R2=0.93) correlation between the TPP and TAC of the beverage. The quadratic model fit well and the different factors used to test its accuracy and fitness were in satisfactory ranges. For TPP extraction (38.90 mgGAE/g dw) and TAC (50.75 mg TE/g dw) expression, the optimal conditions were reached at a roasting temperature of 150°C, roasting time of 12.62 min, brewing time of 11.91 min and a desirability of 0.95. The novel information on the optimisation of the process can be further used by scientists, consumers and herbalists for effective handling of fruits during the extraction process. [less ▲]

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See detailLa réalisation de tests de provocation et d'études de vieillissement pour évaluer la croissance de Listeria monocytogenes au sein des denrées alimentaires: le cas de produits laitiers fermiers
Gerard, Amaury ULiege; El-Hajjaji, Soundous ULiege; Daube, Georges ULiege et al

in Food Science and Law (2020), 2020/2

Listeria monocytogenes est la bactérie pathogène responsable de la listériose, une toxi-infection d’origine alimentaire dont le nombre de manifestations n’a cessé d’augmenter depuis une dizaine d’années ... [more ▼]

Listeria monocytogenes est la bactérie pathogène responsable de la listériose, une toxi-infection d’origine alimentaire dont le nombre de manifestations n’a cessé d’augmenter depuis une dizaine d’années au sein de l’Union européenne. En 2018, cette toxi-infection s’est traduite par la mort de plus de 15 % des personnes infectées. De nombreux aliments sont susceptibles de permettre la croissance de ce pathogène, ou au minimum sa survie. Parmi les techniques disponibles pour évaluer la croissance de L. monocytogenes au sein d’une denrée alimentaire figurent les tests de provocation et les études de vieillissement. La première méthode consiste en une inoculation de la bactérie au sein ou en surface du produit à étudier, ce dernier étant ensuite conservé jusqu’à sa date limite de consommation. Les niveaux de contaminations initiale et finale permettent alors de calculer un potentiel de croissance et de se prononcer quant aux risques pour la sécurité sanitaire liés à la présence de L. monocytogenes au sein de l’aliment concerné. Les études de vieillissement se basent quant à elles sur une contamination naturelle de la denrée alimentaire par L. monocytogenes. Dans ce cas, le lot contaminé complet doit être conservé jusqu’à la date limite de consommation. La proportion des unités dépassant la limite de 100 ufc/g est alors calculée. Le Laboratoire Qualité et Sécurité des Produits Agroalimentaires de Gembloux Agro-Bio Tech – Université de Liège a fait de l’étude de la croissance de L. monocytogenes au sein des produits laitiers fermiers l’une de ses principales thématiques de recherche. [less ▲]

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See detailGestion d’une contamination en Listeria monocytogenes dans une production artisanale de produits laitiers : retour d’expériences
Laine, Aurélie ULiege; De Laubier, Juliette ULiege; Patz, Viviane ULiege et al

in Food Science and Law (2020), 2020/2

When a contamination with Listeria monocytogenes is detected in a craft dairy product, most often product directly at the farm, crisis management and the urgency to return to a normal situation can lead ... [more ▼]

When a contamination with Listeria monocytogenes is detected in a craft dairy product, most often product directly at the farm, crisis management and the urgency to return to a normal situation can lead to difficult moment for the producer. DiversiFerm advisors accompany producers facing this situation to help them control this microbiological contamination. For this, in addition to informing and supporting producer in mandatory procedures to be taken, an in-depth investigation of production and processing practices will be carried out, a plan of microbiological and recommendations for corrective action will be proposed to the producer until the contamination in new productions disappears. Based on the results of the investigation and analyses, a set of advice and recommendations for the control of the hazard L. monocytogenes, in the short and medium term, are provided to producers to help them cope with this situation. The article presents an overview of the intervention approach followed on the basis of feedback from DiversFerm advisers. [less ▲]

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See detailSmart ulvan films responsive to stimuli of plasticizer and extraction condition in physico-chemical, optical, barrier and mechanical properties
. Guidarra, M.; Yaicha, H.; Benelhadja, S. et al

in International Journal of Biological Macromolecules (2020), 150

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See detailCharacterization of the microbial diversity of Belgian artisanal cheese using metagenetics
Gerard, Amaury ULiege; Ô, Quihn My; Taminiau, Bernard ULiege et al

Poster (2020, January 31)

More than 450 artisanal cheeses have been identified in Belgium during a survey, including some typical products, like Maquée, Herve or Abbaye. Microbial communities vary between types of cheeses. Cheese ... [more ▼]

More than 450 artisanal cheeses have been identified in Belgium during a survey, including some typical products, like Maquée, Herve or Abbaye. Microbial communities vary between types of cheeses. Cheese microflora can originate from raw milk, production and ripening environments, or intentionally added starters1. Moreover, cheese cores and crusts generally represent two distinct ecosystems. Internally, anaerobic lactic acid bacteria are generally found, while an increased microbial diversity is observed on cheese surface, where oxygenation allows the growth of bacteria, yeasts and molds1. Microbial communities of cheeses are thus extremely complex. The main goal of this study was to characterize the bacterial diversity of Belgian artisanal cheeses. Twenty-six artisanal cheeses, including unripened, soft and semi-soft cheeses, were studied in triplicate. Samples were collected in 26 farms directly after production or after ripening, for unripened and ripened cheeses, respectively. After DNA extraction and amplification of regions V1-V3 of the gene coding for bacterial 16S rRNA, DNA was sequenced using Illumina MiSeq technology. Obtained sequences were grouped into operational taxonomic units (OTUs) by phylotype at the species level, using Mothur2. Conserving 10,000 sequences for each sample, 3,201 OTUs have been identified. These OTUs belong to five major phyla. At a deeper taxonomic level, only 16 genera represent more than 0.1 % of the sequences in at least one type of cheese. α- and β-diversity were also studied and compared between types of cheese. [less ▲]

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See detailAssessment of growth and survival of Listeria monocytogenes in raw milk butter by durability tests
El-Hajjaji, Soundous ULiege; Gerard, Amaury ULiege; De Laubier, Juliette ULiege et al

in International Journal of Food Microbiology (2020)

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See detailIs Butter a Product at Risk Regarding Listeria monocytogenes? - A Review
El-Hajjaji, Soundous ULiege; Gerard, Amaury ULiege; Sindic, Marianne ULiege

in Food Reviews International (2020)

This review gathers information on the occurrence and survival of Listeria monocytogenes in butter. Whether it is the cattle, the equipment or the barn environment, dairy farms represent a big reservoir ... [more ▼]

This review gathers information on the occurrence and survival of Listeria monocytogenes in butter. Whether it is the cattle, the equipment or the barn environment, dairy farms represent a big reservoir of L. monocytogenes. Processing environments can also be a source of contamination. Yet, the level of contamination of butter by the pathogen is low. The growth potential of L. monocytogenes in butter is also reduced due to various factors. Among other parameters, the influence of pH and water droplets size and distribution on the behavior of the pathogen is discussed. [less ▲]

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See detailPreheated (roasting) Aframomum citratum (C. Pereira) K. Schum and Tetrapleura tetraptera (Schumach & Thonn.) fruits beverage in vivo hypoglycaemic activity on streptozotocin-induced rats
Eyenga, Manga ULiege; Takuissu, NGR; Ziyyat, A et al

in Journal of Pharmacognosy and Phytotherapy (2020)

Tetrapleura tetraptera and Aframomum citratum fruits are used as spices and in the traditional pharmacopeia in Cameroon. They are mostly combined and preheated for many purposes while cooking. The effects ... [more ▼]

Tetrapleura tetraptera and Aframomum citratum fruits are used as spices and in the traditional pharmacopeia in Cameroon. They are mostly combined and preheated for many purposes while cooking. The effects of roasting on the phenolic content of spices, phenolic profile of a beverage made with the mix of roasted spices and its hypoglycaemic activity on diabetes complications were investigated. Aqueous extract (infusion: 100°C; 1/5 g/ml) was prepared, and the total polyphenols and flavonoids contents before and after heat treatment were quantified. Four formulations of T. tetraptera/A. citratum (95/5; 90/10; 85/15; 80/20) were assessed and the in vitro glucose adsorption capacity of the extracts was studied to retain the most effective formulation (AEF). Phenolic and derivatives compounds of AEF were analysed using HPLC-DAD methodology. The AEF hypoglycaemic activity (250 mg/kg bw) and the various complications of hyperglycaemia after Streptozotocin induction (55 mg/kg) were examined on rats. Significant (p<0.05) improvements in phytochemical content were noticed for T. tetraptera and AEF extracts after heat treatment. Among the phenolic compounds identified, flavone, protocatechic, chlorogenic, p-Coumaric acids, and naringin showed the highest concentrations. Significantly, the effect of AEF is the same as the administration of AEF-Daonil (Glibenclamide) and Acarbose after 4h when assessing the anti-hyperglycaemic test. The influence of Daonil (the reference drug) is significantly improved by AEF, and this synergy has the best anti-hyperglycaemic, hypoglycaemic, hypotriglyceridaemic potential and boosts catalase, superoxide dismutase activities while reducing Malondialdehyde (liver, pancreas, haemolysates) and hydroperoxide (liver, plasma, and kidney) contents compared with the use of single AEF. [less ▲]

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See detailVariabilities of Tetrapleura tetraptera (Schumach & Thonn.) taub. and Aframomum citratum (C. Pereira) K.Schum from three Agro-ecologic zones in Cameroon and effect of extraction methods on the phenolic compounds recovery
Eyenga, Manga ULiege; Fauconnier, Marie-Laure ULiege; Ngondi, Judith Laure et al

Scientific conference (2020)

The fruits of Tetrapleura tetraptera and Aframomum citratum were identified among the most commonly used and available spices in Cameroonian cities. They are mainly collected in the bimodal forest (Zone V ... [more ▼]

The fruits of Tetrapleura tetraptera and Aframomum citratum were identified among the most commonly used and available spices in Cameroonian cities. They are mainly collected in the bimodal forest (Zone V), unimodal forest (Zone IV) and the highlands (Zone III)2 zones. They are part of the traditional pharmacopeia in Central and West African countries. The aim of this study was to characterize fruit samples harvested on the three agroecological zones (AEZ) and to examine few traditional extraction methods for the phenolic compounds recovery in a domestic food consumption situation. Tetrapleura tetraptera fruits were harvested in twelve villages spread over three AEZ (Zones V, IV, III) and Aframomum citratum fruits were selected in nine villages spread over two AEZ (Zones V, IV). Various analysis (dry matter, ash,total fat, crude proteins, total sugars, crude fibre contents; energy, water activity and pH; Fe, Ca, Mg and K contents; total polyphenols and flavonoids contents) using standard analytical, colorimetric, spectroscopy and spectrophotometric procedures were used. For both extraction methods investigated (Maceration, infusion, decoction), an extraction ratio of 1/5 was used. Statistical analysis and Principal Component Analysis (PCA) were performed. The results showed that concerning Tetrapleura tetraptera samples, crude fibre content is significantly (p<0.05) high on samples from Zones IV and III while samples from Zone V possess more sugars, calories, minerals and phenolic compounds. About Aframomum citratum, samples from Zone IV are the most sweet and the ones from Zone V contain more protein, fibre, phenolic and minerals (especially samples from the East region) contents. For both species, decoction was the most efficiency extraction method. The result gives a graphic representation of the studied characteristics which can serve as a decision-making tool (for sampling) to guide the various stakeholders involved in the valuation and exploitation of these fruits. [less ▲]

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See detailTemperature dependent studies on nutritional, total polyphenols, flavonoids content and antioxidant activities of Aframomum citratum (C. Pereira) K.Schum and Tetrapleura tetraptera (Schumach & Thonn.) fruits
Eyenga, Manga ULiege; Fotso Youovop, Janvier; Ngondi, Judith laure et al

in Biotechnologie, Agronomie, Société et Environnement (2020)

Description: Hard shelled fruits, Tetrapleura tetraptera and Aframomum citratum non-timber forest products are used as spices and for many medicinal recipes. Mostly used together, they undergo heat ... [more ▼]

Description: Hard shelled fruits, Tetrapleura tetraptera and Aframomum citratum non-timber forest products are used as spices and for many medicinal recipes. Mostly used together, they undergo heat treatment before being milled when cooking "Mbongo Tchobi", a black spicy stew from central and coastal regions in Cameroon. Objectives: Evaluate the impact of roasting these spices on the physicochemical properties (dry matter, ash, raw protein, total sugar, raw fibre, pH, aw, total energy, total fat), phytochemical content (total polyphenol, total flavonoids) and the antioxidant activities (total antioxidant activity, FRAP, DPPH and lipid peroxidation inhibition assays) of their aqueous extracts in a home food consumption context. Methodology: Tetrapleura tetraptera and Aframomum citratum fruits from Ngola locality in YoKadouma (East region in Cameroon) locality were collected, sorted, cleaned and dried (72h, 45°C) in an oven. Cut into small pieces, a part was heated using roasting parameters deduced from preliminary tests (140°C/10min; 180°C/20min and 150°C/12min respectively for T. tetraptera, A. citratum and a formulation 95/5 of the two spices). The heated and unheated spices were ground and an infusion was prepared from boiling water in the proportion of 1/5 (g/ml) for both types of spices. Physicochemical and phytochemical characteristics (dry matter, total ash, fat, sugar, crude fibre and energy contents, pH, aw, total flavonoids and polyphenols) as well as the antioxidant activities of the aqueous extracts of the two spices and a mix of the two spices were evaluated before and after the heat treatment. Results: Heat treatment significantly (p˂0.05) reduces fat and total sugars contents but improves raw fibre contents for all spices. Phenolic content is more important for heated spices and percentage differences before and after heat treatment are between 8 and 23.20% for both spices. Extracts obtained with heated spices possess the best antioxidant potential. Strong significant positive correlations have been established between the phenolic compounds and the reductive antioxidant activities and negative correlations with the antiradical antioxidant activities as they are expressed as IC50 (mg/ml). Conclusion: In most of the features studied, the heated formulation (95/5) possesses the highest characteristics studied and the choice of heating these spices under the roasting parameters identified should be guided by the desire of improving the antioxidant potential because of the nutritional losses observed after heat treatment. [less ▲]

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See detailIn vitro Biological activities of aqueous extracts of Tetrapleura tetraptera (Schumach & Thonn.) taub. and Aframomum citratum (C. Pereira) K.Schum from three Agroecologic zones in Cameroon
Eyenga, Manga ULiege; Fauconnier, Marie-Laure ULiege; Ngondi, Judith Laure et al

in Asian Pacific Journal of Tropical Medicine (2020), 13(2), 71-80

Study some phytochemical constituents and biological activities of twelve samples of Tetrapleura tetraptera (Schumach & Thonn.) taub. and nine of Aframomum citratum (C. Pereira) K.Schum fruits collected ... [more ▼]

Study some phytochemical constituents and biological activities of twelve samples of Tetrapleura tetraptera (Schumach & Thonn.) taub. and nine of Aframomum citratum (C. Pereira) K.Schum fruits collected in three Agroecologic zones in Cameroon: Bimodal forest zone (ZONE V), Unimodal forest zone (ZONE IV) and highlands zone (ZONE III). Methods: Fresh fruits extracts were obtained by aqueous infusion (100°C/15min) and evaluated by spectrophotometric methods for total polyphenol (TPP), total flavonoids (TFLV) contents and antioxidant (DPPH, Total Antioxidant Capacity by the Phosphomolybdenum method or TAC, Iron reducing power or FRAP and inhibition of linoleic acid peroxidation or B.CAROT assays) and anti-inflammatory (Inhibitions of Protein denaturation and 5-LOX activity respectively INH.PROT and INH.5-LOX) properties. Principal Component Analysis providing a transparent view of information was performed. Results: T. tetraptera has the highest levels of TPP, TFLV and biological activities. For both species, fruits from ZONE V have the most important TPP, TFLV levels and biological activities. TPP and TFLV content of A. citratum and T. tetraptera fruits are positively and significantly (p<0.05) correlated. All extracts biological activities (0.25, 2.5, 25, 250 mg/mL) are dose-dependent and they have shown strong antioxidant and anti-inflammatory activities, but less than references (Ascorbic Acid, Diclofenac, Quercetin, and Butylated Hydroxytoluene). There is a positive correlation between TPP, TFLV and TAC, FRAP, B.CAROT assays and inverse correlations are observed with the IC50 (g/mL) of DPPH, INH.5-LOX and INH.PROT assays for both species. Conclusion: The fruits reveal their variabilities and those from ZONE V for both species are economically and healthcare challenging for herbalists, pharmaceutical firms, scientists and consumers. Indeed, most important extraction yield of bioactive compounds correlated with significant biological activities and the use of less material compare to an implementation in others AEZ with the same results are noted. [less ▲]

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See detailAdvanced monitoring of milk quality to address the demand of added-value dairy products
Bastin, Catherine; Dehareng, Frédéric; Gengler, Nicolas ULiege et al

in Book of Abstracts of the 71st Annual Meeting of the European Federation of Animal Science (2020)

Consumers are seeking for local, healthy and direct-from-producers dairy products. Hence, assessing the suitability of milk to be processed in dairy products either directly in the farms or through local ... [more ▼]

Consumers are seeking for local, healthy and direct-from-producers dairy products. Hence, assessing the suitability of milk to be processed in dairy products either directly in the farms or through local dairy plants is of great interest. Moreover, several studies demonstrated the usefulness of mid-infrared (MIR) spectrometry for the prediction of various traits related to the nutritional and technological properties of milk. This study presents 5 groups of MIR predicted traits related to various aspects of dairy products: (1) milk coagulation traits, (2) cheese and butter yields, (3) nutritional quality, (4) texture and, (5) sensory quality. The MIR prediction equations of these 5 groups of traits were applied on standardized spectra from individual milk samples collected in the frame of the Walloon milk recording scheme. After edits, more than 780,000 records collected between 2017 and 2019 were used. The MIR predictions for coagulation time and curd firmness were combined to define a new trait with 5 levels assessing the overall milk coagulation property, from poorly coagulating milk to optimal milk for coagulation. Casein and calcium contents and titrable acidity were also studied in relation to milk coagulation properties. The nutritional quality of milk was assessed through the content in fat of PUFA and the health promoting index (i.e., UFA / (C12 + C14 x 4 + C16). The spreadability of butter was defined as the ratio of C18:1 cis-9 to C16:0. The sensory quality of milk was assessed through SCC and the content of free fatty acids. Results showed that about 10% of the records were classified as poorly coagulating milk; these records had lower calcium and casein contents with lower MIR predicted cheese yield. Also, 60% of the cows were never classified in the poorly coagulating milk class while 5% of the cow produced poorly coagulating milk at least half of the time. Moreover, cheese yield was highly correlated with the protein and fat contents. The results also showed the influence of days in milk, parity, herd and breed on all traits. Local breeds (i.e., Dual Purpose Belgian Blue and Eastern Red) showed favourable milk fat profile for nutritional quality of milk and texture of dairy products even if these breeds tend to have higher proportion of suboptimal milk for coagulation. These results indicates that dairy farmers have the opportunities to monitor and improve milk quality for the production of added-value dairy products. [less ▲]

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See detailIn vitro Biological activities of aqueous extracts of Tetrapleura tetraptera (Schumach&Thonn.) taub.andAframomumcitratum(C. Pereira) K.Schum from three Agroecologic zones in Cameroon: The polyphenol variabilities
Eyenga, Manga ULiege; Fauconnier, Marie-Laure ULiege; Ngondi, J. L. et al

Conference (2019, December)

The aim of this study is to study few phytochemical, nutritional and physicochemical constituents of twelve samples of Tetrapleura tetraptera (Schumach&Thonn.) taub.and nine of Aframomumcitratum(C ... [more ▼]

The aim of this study is to study few phytochemical, nutritional and physicochemical constituents of twelve samples of Tetrapleura tetraptera (Schumach&Thonn.) taub.and nine of Aframomumcitratum(C. Pereira) K.Schum fruits collected in three Agro-ecologic zones in Cameroon: Bimodal forest zone (ZONE V), Unimodal forest zone (ZONE IV) and highlands zone (ZONE III). T. tetraptera fruits were spread over three Ago-ecological Zones (Zones V, IV, III) and A. citratum fruits were spread over two AEZ (Zones V, IV). Various analysis (dry matter, ash, total fat, crude proteins, total sugars, crude fibre contents; energy, water activity and pH; Fe, Ca, Mg and K contents; total polyphenols and flavonoids contents) using standard analytical, colorimetric, spectroscopy and spectrophotometric procedures were used. Phenolic compounds characterization was done on both spices aqueous extracts using HPLC. The results showed that concerning T. tetraptera samples, crude fibre content is significantly (p<0.05) high on samples from Zones IV and III while samples from Zone V possess more sugars, calories, minerals and phenolic compounds. About A. citratum, samples from Zone IV are the most sweet and the ones from Zone V contain more protein, fiber, phenolic and minerals (especially samples from the East region) contents.On T. tetraptera aqueous extracts, Gallic, chlorogenic, benzoic, 2-OH cinnamic, salycilic acids and flavone, gallocatechin, epigallocatechin gallate, naringin, phlorizin were among the predominant compounds identified. Localities from the littoral region (Nyanon, barebakem, NkwangsiII, MantemII) corresponding to Zone IV and III possess the smallest total polyphenols contents. However, the spices from Zone III have the lowest. About A. citratum, samples from Zone IV are the most sweet and the ones from Zone V contain more protein, fiber, phenolic and minerals (especially samples from the East region) contents. On aqueous extracts, a total of six dominant (in terms of quantity and frequency) phenolic compounds (Gallic, Chlorogenic, Protocatechuic, 2-OH Cinnamic, Caffeic, p-Coumaric acids) and five flavonoids (epigallocatechin gallate, resveratrol, phlorizin, rutin, epicatechin, luteolin) were observed on the extracts. Theobromine is present only in spices from the East region, while Kojic acid is present on spices from centre and Littoral regions. Samples from Zone IV (Lolodorf, Nyanon and Bonepoupa II) possess the smallest amounts of Total polyphenols. For both species, total phenolic acids content and total flavonoids content of aqueous extracts significantly (p<0,05) varied from one locality to another. [less ▲]

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See detailChallenge-testing Belgian artisanal cheeses for Listeria monocytogenes
Gerard, Amaury ULiege; Van Coillie, Els; Bentaib, Azeddine ULiege et al

Poster (2019, October 03)

Introduction Listeria monocytogenes is the bacterium responsible for listeriosis, a foodborne disease for which the number of cases increased during the recent years in the European Union (1). Various ... [more ▼]

Introduction Listeria monocytogenes is the bacterium responsible for listeriosis, a foodborne disease for which the number of cases increased during the recent years in the European Union (1). Various types of cheese have already been identified as eventual vectors of L. monocytogenes (2). Cheese is considered as suitable for the growth of the pathogen, following Regulation (CE) N°2073/2005, if it presents a pH > 4.4, a water activity > 0.92 or a combination of a pH > 5.0 with a water activity > 0.94 (3). To assess the real growth potential of L. monocytogenes in a panel of 32 artisanal cheeses, challenge-tests were performed. Materials and Methods Between July 2018 and January 2019, 32 challenge-tests were performed on Belgian artisanal cheeses, sampled to cover the variability of process met in Belgium (4). Three batches were sampled directly after production for each of the 32 types of cheeses, excepting if theoretical growth potential calculated using the online tool Sym’Previus was ≤ 0. In this case, only one batch was studied. A cocktail of three strains of L. monocytogenes was used to inoculate the cheeses. Samples were stored at 7°C during the two first thirds of shelf life, and were then transferred to 9°C for the remaining third. The growth potential of the bacterium in each product was calculated on the basis of enumerations at beginning and end of shelf life. Discussion The results were contrasted between types of cheese. A growth of L. monocytogenes was never observed in fresh cheeses. It seems thus that these products should not represent a danger for food safety. In mold-ripened and smear-ripened soft cheese, the pathogen was able to grow, sometimes for more than 5 log cfu/g. Only one exception was observed, for a Herve cheese, with a decrease of at least 0.5 log cfu/g for each of the three batches. Regarding semi-hard/hard cheeses, the growth of L. monocytogenes was generally not allowed. However, in 3 batches out of 32, a limited growth was observed, always around 1 log cfu/g. Statistical analyses were not able to explain the divergence in the results for this cheese family. [less ▲]

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See detailVariability of physicochemical properties of ‘Deglet Nour’ date fruits collected from different oases in Djerid Region, Tunisia
Rihab, Taha; Ben Maachia, Silhem; Sindic, Marianne ULiege et al

in Journal of Horticulture and Postharvest Research (2019), 3(1), 85-100

Purpose : Quality and physical characteristics of date palm changes during growth and maturation stages of fruits in main production areas in the south of Tunisia. Research Method: The effect of season ... [more ▼]

Purpose : Quality and physical characteristics of date palm changes during growth and maturation stages of fruits in main production areas in the south of Tunisia. Research Method: The effect of season, ripening date and climatic conditions (temperature and relative humidity) on physicochemical characteristics of fresh dates “Deglet Nour” grown at four different oases were evaluated using multivariate analysis. Main findings: Dates from Traditional Mountain Oases (TMO) had the highest values of length, width, weight, moisture content for the two seasons. Those from Modern Palm Plantation (MPP) had the highest values of fiber content, water activity, glucose and fructose in 2014. In 2014 and 2015, date palm fruits of Modern Continental Oases (MCO) had the highest values of sucrose. The lower values of the different parameters were registered for dates from Traditional Continental Oases (TCO). Meteorological data from the experimental station recorded higher temperature and relative humidity during fruit maturation (July, August and September) in 2014 compared to 2015. Results showed that the good quality of dates was obtained in oases TMO that had higher relative humidity and lower temperature compared to other oases (MPP, MCO, and TCO). Such changes may have resulted from earlier pollination and higher temperatures during the maturation period. Considering the two seasons 2014 and 2015, the highest thermal coefficients were observed in MCO (3726 and 3704, respectively) and the lower ones in TCO (3083 and 3025, respectively). Research limitation: No limitations were founded. Originality/Value: Seasons and oases climate significantly affected the physical and biochemical quality characteristics of date palm fruits. This engendered in the longest maturity period recorded in TCO. MPP where we recorded the highest spring temperatures, showed the shorted development cycle. [less ▲]

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