The antifungal and antiaflatoxinogenic activities of the essential oils (EOs) from the leaves of Cymbopogon schoenanthus, Cymbopogon citratus, Cymbopogon nardus, and their pair combinations were investigated. Antifungal susceptibility and the efficacy of paired combinations of EOs were assessed using agar microdilution and checkerboard methods, respectively. Identification and quantification of chemical components of the EOs were carried out by gas chromatography-mass spectrometry and gas chromatography-flame ionization detector (GC-MS and GC-FID), respectively. Aflatoxins were separated and identified by High-Performance Liquid Chromatography (HPLC) and then quantified by spectrofluorescence. The EO of C. nardus exhibited the highest inhibitory activity against Aspergillus flavus and Aspergillus parasiticus. The combination of C. citratus and C. nardus and that of C. nardus and C. schoenanthus exhibited a synergistic effect against Aspergillus flavus and Aspergillus, respectively. Both C. citratus and C. schoenanthus EOs totally inhibited the synthesis of aflatoxin B1 at 1 µL/mL. C. citratus blocked the production of aflatoxins B2 and G2 at 0.5 µL/mL. Both C. citratus and C. schoenanthus totally hampered the production of the aflatoxin G1 at 0.75 µL/mL. The combination of C. citratus and C. schoenanthus completely inhibited the production of the four aflatoxins. The study shows that the combinations can be used to improve their antifungal and antiaflatoxinogenic activities.

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.

Ground cherry (Physalis pubescens L.) is one of the most promising exotic fruits and some interesting functional products could be developed from these berries. The fresh juice was yellowish or orangey and had a light, sweet taste with acidic nature (pH 3.5). The titratable acidity was 1.43, polyphenols 76.6 mg/100 mL and vitamin C 38.8 mg/100 mL. Physalis juice was rich in carotenoids (70 mg/mL). The juice had a high level in minerals such as phosphorus (578 mg/100 mL), potassium (1,196 mg/100 mL), zinc (2.4 mg/ 100 mL) and boron (1 mg/100 mL). The essential amino acids in the juice such as isoleucine, valine and tryptophan (42.97, 39.92 and 39.83 mg/100 mL) were higher than those recommended by Food and Agriculture Organization/ World Health Organization/United Nations Union (FAO/WHO/UNU). (Résumé d'auteur

Fruits is a scientific journal for original articles and reviews on fruit crops in temperate, Mediterranean, subtropical and tropical regions

Acetic acid bacteria are involved in many food and beverage fermentation processes. They play an important role in cocoa bean fermentation through their acetic acid production. They initiate the development of some of the flavor precursors that are necessary for the organoleptic quality of cocoa, and for the beans’ color. The development of starter cultures with local strains would enable the preservation of the microbial biodiversity of each country in cocoa-producing areas, and would also control the fermentation. This approach could avoid the standardization of cocoa bean fermentation in the producing countries. One hundred and thirty acetic acid bacteria were isolated from three different cocoa-producing countries, and were identified based on their 16S rRNA gene sequence. The predominate strains were grown in a cocoa pulp simulation medium (CPSM-AAB) in order to compare their physiological traits regarding their specific growth rate, ethanol and lactic acid consumption, acetic acid production, and relative preferences of carbon sources. Finally, the intraspecific diversity of the strains was then assessed through the analysis of their genomic polymorphism by (GTG)₅-PCR fingerprinting. Our results showed that Acetobacter pasteurianus was the most recovered species in all of the origins, with 86 isolates out of 130 cultures. A great similarity was observed between the strains according to their physiological characterization and genomic polymorphisms. However, the multi-parametric clustering results in the different groups highlighted some differences in their basic metabolism, such as their efficiency in converting carbon substrates to acetate, and their relative affinity to lactic acid and ethanol. The A. pasteurianus strains showed different behaviors regarding their ability to oxidize ethanol and lactic acid into acetic acid, and in their relative preference for each substrate. The impact of these behaviors on the cocoa quality should be investigated, and should be considered as a criterion for the selection of acetic acid bacteria starters.