Isolamento e seleção de fungos filamentosos termorresistentes em etapas do processo produtivo de néctar de maçã

Abstract

). Os ascósporos destes fungos podem permanecer em estado de dormência em restos de frutas apodrecidas e no solo ( RAJASHEKHARA; SURESH; ETHIRAJ, 2000;TOURNAS;TRAXLER, 1994), necessitando ativação térmica para germinarem, o que normalmente corresponde aos processamentos térmicos comerciais aplicados a produtos de frutas (ENIGL; KING Jr.; TOROK, 1993).Estes microrganismos ainda são conhecidos por produzirem várias micotoxinas, como a patulina, durante seu desenvolvimento nos produtos de frutas, o que representa um grave AbstractHeat resistant molds are able to survive the pasteurization process applied to apple products. This study aimed at detecting and identifying heat resistant molds during the processing of apple nectar (pH 3.4; 11.6 °Brix) in order to select the most heat resistant mold. The isolation was carried out after heat shock at 70 °C, during 2 hours, and incubation at 30 °C, in PDA (3% agar), where rose bengal was added. The identification of macro and microscopic structures was carried out after incubation in three different media (G25N, CYA, MEA) and temperatures. Different heat shocks, from 80 °C/20 minutes to 97 °C/15 minutes, were applied to select the most heat resistant mold. Eleven strains were selected, of which five were heat-resistant: three strains were isolated from apple and concentrated apple juice and were identified as Neosartorya fischeri; one strain, isolated from apple, was identified as Byssochlamys fulva and one strain, isolated from the product after the first pasteurization, was identified as Eupenicillium sp. The most heat-resistant strains belong to N. fischeri and B. fulva, which were able to survive at 95 °C/20 minutes. Among the six remaining, one was identified as Aspergillus sp., however, none of them was heat resistant. Keywords: heat resistant molds; N. fischeri; B. fulva; apple nectar. ResumoOs fungos filamentosos termorresistentes são capazes de sobreviver aos processos de pasteurização aplicados aos produtos de frutas. Este estudo visou isolar e identificar fungos termorresistentes durante o processamento de néctar de maçã (pH 3,4 e 11,6 °Brix), de forma a selecionar o bolor mais termorresistente. O isolamento foi obtido após choque térmico de 70 °C/2 horas e incubação a 30 °C em PDA (3% de ágar) acrescido de rosa de bengala. A identificação foi baseada na morfologia e nas estruturas micro e macroscópicas observadas após incubação das cepas em três diferentes meios (G25N, CYA e MEA) e temperaturas. O fungo mais termorresistente foi selecionado pela aplicação de choques térmicos (de 80 °C/20 minutos até 97 °C/15 minutos). Foram detectadas 11 linhagens de bolores, sendo 5 termorresistentes. Dentre estas, três cepas, isoladas da matéria-prima e do concentrado de maçã, foram identificadas como Neosartorya fischeri; uma cepa isolada da matéria-prima foi identificada como Byssochlamys fulva, e uma cepa isolada do produto após a primeira pasteurização foi identificada como Eupenicillium sp. As cepas mais resistentes foram as de N. fischeri e B. fulva, que sobreviveram ao...

Survey of molds, yeast and Alicyclobacillus spp. from a concentrated apple juice productive process

“…Another study also found this HRM from a concentrated apple juice process in a step after pasteurization (Salomão et al , 2008b). …”

Modeling the growth of Byssochlamys fulva and Neosartorya fischeri on solidified apple juice by measuring colony diameter and ergosterol content

“…Microorganisms and preparation of spore suspension B. fulva IOC 4518 strain was isolated from apple juice concentrate by Salomão et al (2008) and N. fischeri was isolated and identified in samples taken from an apple nectar processing line by Salomão (2002). The preparation of B. fulva and N. fischeri spores started by the pre-sporulation in Petri dishes containing Potato Dextrose Agar (PDA) media (pH 3.5) for 7 days at 30°C.…”

Human Pathogenic Paecilomyces from Food

“…In Brazil, heat resistant fungi have been isolated from different commercial juices such as, pineapple [33], apple [34,35], caja, umbu (typical Brazilian fruits) [36], passion fruit [37], and Byssochamys species are the most frequent. In the USA, the most common cause of beverage spoilage is B. spectabilis [38].…”