Catherine Brabet

Influência da temperatura do ar de secagem e da concentração de agente carreador sobre as propriedades físico-químicas do suco de açaí em pó

The objective of this work was to study the influence of inlet air temperature and maltodextrin concentration on the physicochemical properties of acai juice powder produced by spray drying. The process was carried out in a mini spray dryer and the maltodextrin 10DE was used as carrier agent. Inlet air temperature varied from 138 to 202 °C and maltodextrin concentration varied from 10 to 30%. The characteristics analyzed were: moisture content, hygroscopicity, anthocyanin retention, color, particle size distribution, and morphology. The increase in the temperature resulted in particles with larger size, less moisture content, more hygroscopy and with lower anthocyanin retention, besides promoting a reduction in the color parameter L* and in the hue angle H*. The increase of maltodextrin concentration resulted in less hygroscopy, particles with larger size, , with higher luminosity (L*), lower C* values and higher H* values. With respect to morphology, the increase in the temperature led to the formation of a great number of particles with smooth surface, which is due to the higher heat transfer and, consequently, to the faster formation of a membrane around the atomized drop.

Aspergillus korhogoensis, a Novel Aflatoxin Producing Species from the Côte d’Ivoire

Several strains of a new aflatoxigenic species of Aspergillus, A. korhogoensis, were isolated in the course of a screening study involving species from section Flavi found contaminating peanuts (Arachis hypogaea) and peanut paste in the Côte d’Ivoire. Based on examination of four isolates, this new species is described using a polyphasic approach. A concatenated alignment comprised of nine genes (ITS, benA, cmdA, mcm7, amdS, rpb1, preB, ppgA, and preA) was subjected to phylogenetic analysis, and resulted in all four strains being inferred as a distinct clade. Characterization of mating type for each strain revealed A. korhogoensis as a heterothallic species, since three isolates exhibited a singular MAT1-1 locus and one isolate exhibited a singular MAT1-2 locus. Morphological and physiological characterizations were also performed based on their growth on various types of media. Their respective extrolite profiles were characterized using LC/HRMS, and showed that this new species is capable of producing B- and G-aflatoxins, aspergillic acid, cyclopiazonic acid, aflavarins, and asparasones, as well as other metabolites. Altogether, our results confirm the monophyly of A. korhogoensis, and strengthen its position in the A. flavus clade, as the sister taxon of A. parvisclerotigenus.

Development and in-house validation of a rapid and simple to use ELISA for the detection and measurement of the mycotoxin sterigmatocystin

AbstractSterigmatocystin (STG) is a highly toxic secondary fungal metabolite structurally closely related to the well-known carcinogenic aflatoxins. Its presence has been reported in grains and grain-based products as well as in other foodstuffs like nuts, green coffee beans, spices, beer and cheese. Due to the lack of suitable data on the occurrence of STG, in 2013, the European Food Safety Authority (EFSA) could not characterise its risk for human health and recommended that more data on STG in food and feed needed to be collected. In order to provide a new tool for the specific detection of STG, a competitive enzyme-linked immunosorbent assay (ELISA) was developed, optimised and validated in this study based on a sensitive monoclonal antibody specific to STG with no cross-reactivity with aflatoxins. The sample preparation method for rice, wheat and maize was based on a modified QuEChERS (quick, easy, cheap, effective, rugged and safe) approach. The assay was validated for the detection of STG in rice, wheat and maize in accordance with the guidelines for validation of semi-quantitative screening methods included in Commission Regulation (EU) 519/2014. The screening target concentration (STC) was set at 1.5xa0μg/kg. The cutoffs for rice, wheat and maize were 1.2, 1.2 and 1.3xa0μg/kg and the false suspected rates were 0.34, 1.15 and 0.78%, respectively. Good correlation was found between the results obtained by the STG ELISA and LC-MS/MS method for naturally contaminated rice samples. This validated method can be applied as a sensitive and high-throughput screening for the presence of STG in a range of agricultural commodities.n Graphical abstractA new enzyme-linked immunosorbent assay based on an antibody specific to sterigmatocystin for the detection of this mycotoxin in corn, wheat and rice.

Évaluation des pratiques post récolte favorables à la contamination de l’arachide par les mycotoxines dans trois régions de Côte d’Ivoire

Objectif: Les techniques post recoltes jouent un role determinant dans la contamination de l’arachide par les aflatoxines. Cette etude a pour objectif de contribuer a reduire la contamination de l’arachide par les aflatoxines en Cote d’Ivoire par l’identification des pratiques post recoltes a risque. Methodologie et resultats: Un questionnaire a permis de recueillir les renseignements sur lesdites pratiques dans trois regions : nord, centre et ouest. Le sechage de l’arachide se fait au soleil quel que soit la localite et dure en moyenne 4 a 14 jours. Les arachides sont sechees et conservees en coques dans le nord. Dans les zones de centre et ouest, les gousses sont soit sechees puis decortiquees, soit decortiques avant sechage. Le stockage des graines ou des gousses se fait dans des sacs en polyethylene dans les maisons (86%) ou en vrac dans des greniers (14%). La recolte peut etre conservee jusqu’a 9 mois avant consommation ou vente. 58,1% des productrices ont des pertes dues a l’effet des moisissures. La contamination fongique de l’arachide s’opere dans 55,8 % des cas, durant le sechage et le stockage, et dans 34,9 % des cas au cours de l’apparition des fleurs au champ. Conclusion et application des resultats: Les etapes de sechage et de stockage representent un risque de contamination par les aflatoxines. Une maitrise des techniques post recolte permettrait de reduire la contamination par les aflatoxines. Il ressort de cette etude quune formation des productrices aux bonnes pratiques de production reduirait la contamination parcours aflatoxines. Mots cles: post-recolte, sechage, conservation, arachide, aflatoxines English Title: Evaluation of post-harvest practices favorable to the contamination of peanut by mycotoxins in three regions of Cote dIvoire English Abstract Objective: Post harvest techniques take a decisive role in peanuts by aflatoxins contamination. The aim of this study is to help to reduce aflatoxin contamination of groundnuts in Cote dIvoire by identifying post-harvest practices at risk. Methodology and results: A survey permit to collect information on post-harvest practices in three regions: north, center and west. Peanuts are dried at sun whatever the locality and lasts on average 4 to 14 days. Peanuts are dried and kept in pods in the north. In the central and western areas, pods are either dried and then shelled, or shelled before drying. The storage of seeds or pods is done in polythene bags in homes (86%) or bulk in granaries (14%). Peanuts can be kept until 9 months before consumption or sale. 58.1% of producers have losses due to effect of molds. Fungal contamination of peanuts occurs in 55.8% of cases, during drying and storage, and in 34.9% of cases during flowering in the field. Conclusion and application of results: Drying and storage stages represent a risk of contamination by aflatoxins. Mastering post-harvest techniques would reduce aflatoxin contamination. This study shows that training producers in good production practices would reduce aflatoxin contamination. Keywords: post-harvest, drying, storage, peanut, aflatoxins