title: Natural occurrence of mycotoxins and toxigenic capacity of Alternaria strains from mouldy peppers.
abstract: Sweet pepper (Capsicum annuum) is an important crop cultivated worldwide, with Argentina being one of the major producers in South America. The fruit is susceptible to several fungal diseases, leading to severe economic losses for producers. In this study, Alternaria was found as the prevalent genus in mouldy peppers (50% fruits infected). Morphological identification revealed that all 64 Alternaria isolates belonged to small-spored species, most of them corresponding to A. tenuissima, A. arborescens and A. alternata species-groups. Their secondary metabolite profile was evaluated in vitro; alternariols were synthesized by most of the isolates (91% for alternariol and 92% for alternariol monomethyl ether). A high number of Alternaria spp. also produced tenuazonic acid (64%), altenuene (84%) and tentoxin (72%). In addition, damaged pepper fruits were analysed for the presence of tenuazonic acid and alternariols. A total 32 out of 48 spoiled pepper fruits were contaminated with at least one of these metabolites. Half of the samples were positive for tenuazonic acid (range 8-11,422μg/kg), while alternariol and its monomethyl ether were less frequently detected (21 and 29%, respectively) and at lower concentrations. This is the first report on the natural occurrence of Alternaria mycotoxins in Argentinean sweet pepper, and highlights a consumer risk when mouldy fruits are used in industrialized products because these compounds are not destroyed by conventional heat treatments.
authors: Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Orgánica, Laboratorio de Microbiología de Alimentos, Buenos Aires, Argentina. Electronic address: ldacruzcabral@qo.fcen.uba.ar.
authors: Lucía
authors: L
authors: da Cruz Cabral
authors: Ministerio de Agroindustria de la Provincia de Buenos Aires, Buenos Aires, Argentina; Universidad Nacional de La Plata, Facultad de Ciencias Agrarias y Forestales, Buenos Aires, Argentina.
authors: Laura
authors: L
authors: Terminiello
authors: Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Orgánica, Laboratorio de Microbiología de Alimentos, Buenos Aires, Argentina.
authors: Virginia
authors: V
authors: Fernández Pinto
authors: Technical University of Denmark, Department of Systems Biology, Kgs. Lyngby, Denmark.
authors: Kristian
authors: K
authors: Fog Nielsen
authors: Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Orgánica, Laboratorio de Microbiología de Alimentos, Buenos Aires, Argentina.
authors: Andrea
authors: A
authors: Patriarca
mesh_terms: D000528:Alternaria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D001118:Argentina; D005506:Food Contamination / Q000032:analysis; D005638:Fruit / Q000382:microbiology; D007783:Lactones / Q000378:metabolism; D009183:Mycotoxins / Q000032:analysis* / Q000378:metabolism; D029222:Piper nigrum / Q000382:microbiology*; D013020:South America; D013720:Tenuazonic Acid / Q000378:metabolism; D014675:Vegetables / Q000737:chemistry / Q000382:microbiology*
chemical_list: D007783:Lactones; D009183:Mycotoxins; D013720:Tenuazonic Acid
keywords: Alternaria; Alternariols; Mycota; Pepper fruits; Secondary metabolites; Tenuazonic acid