RESUMO
The phytochemical components and antioxidant capacity of Açaí (Euterpe oleracea) give it nutritional and bioactive characteristics with anti-cancer and anti-inflammatory properties; it is exported mainly from Brazil to various places worldwide. In Ecuador, the cultivated Euterpe oleracea variety has an abundant production that has not been used or studied in depth; because of this, it is relevant to expand the study of this fruit's phytochemical and antioxidant properties. This paper presents the results of evaluating the concentration of antioxidants and antioxidant activity in different stages of maturation and geographical locations of the Açaí, for which samples obtained in the Ecuadorian provinces of Sucumbíos and Orellana have been evaluated. Antioxidant concentrations were determined with a UV/VIS spectrophotometer at 450-760 nm wavelengths. Antioxidant capacity was determined using the ABTS and FRAP methods. It was evidenced that the values of total polyphenols and total flavonoids decrease with increasing ripening; the opposite effect occurs with total anthocyanins that have a higher concentration in ripe fruits and evidencing an antioxidant capacity that decreases with ripening determined by both methods (FRAP and ABTS).
RESUMO
Changes in temperature, relative humidity, and moisture content of green coffee beans were monitored during transportation of coffee from Brazil to Italy. Six containers (three conventional and three prototype) were stowed in three different places (hold, first floor, and deck) on the ship. Each prototype was located next to a conventional container. The moisture content of the coffee in the container located on the first floor was less affected by environmental variations (0.7%) than that in the hold and on the deck. Coffee located in the hold showed the highest variation in moisture content (3%); in addition, the container showed visible condensation. Coffee transported on the deck showed an intermediary variation in moisture (2%), and there was no visible condensation. The variation in coffee moisture content of the prototype containers was similar to that of the conventional ones, especially in the top layers of coffee bags (2 to 3%), while the increase in water activity was 0.70. This suggests that diffusion of moisture occurs very slowly inside the cargo and that there are thus sufficient time and conditions for fungal growth. The regions of the container near the wall and ceiling are susceptible to condensation since they are close to the headspace with its high relative humidity. Ochratoxin A production occurred in coffee located at the top of the container on the deck and in the wet bags from the hold (those found to be wet on opening the containers at the final destination).
Assuntos
Coffea/química , Manipulação de Alimentos/métodos , Embalagem de Alimentos/métodos , Ocratoxinas/biossíntese , Sementes/química , Coffea/microbiologia , Contaminação de Alimentos/análise , Microbiologia de Alimentos , Umidade , Temperatura , Meios de TransporteRESUMO
Esporos de A. ochraceus, A. carbonarius e A. niger foram inoculados em três meios de cultura: Agar extrato de levedura Czapeck (CYA), Agar Glicerol 18per center com dicloran (DG18), Agar Extrato de levedura e malte com 40 per center de glicose (MY40G). As placas foram incubadas em 5 temperaturas diferentes: 8, 25, 30, 35 e 41ºC. O crescimento dos fungos foi avaliado medindo o diâmetro da colônia a cada 24h. O objetivo deste trabalho foi determinar a influência de três meios de cultura com atividade de água diferente tempo de incubação e temperaturas, sobre o crescimento de A. ochraceus, A. carbonarius and A. niger. Nenhuma das espécies cresceu à 8ºC em nenhum dos meios de cultura. Para A. carbonarius, 30ºC foi a melhor temperatura para o seu crescimento enquanto para A. niger temperaturas acima de 30ºC foram melhores em todos os meios de cultura. A. ochraceus apresentou bom crescimento a 25 e 30ºC em todos os meios de cultura, enquanto seu crescimento à 35ºC foi mais lento, especialmente no meio CYA. A 41ºC, A. ochraceus não cresceu em nenhum dos meios de cultura estudados e A. carbonarius foi significantemente inibido. A. niger cresceu à temperatura de 41ºC e apresentou-se como o fungo mais xerofílico, comparado com A. carbonarius e A. ochraceus.
Assuntos
Aspergillus , Aspergillus niger , Aspergillus ochraceus , Técnicas In Vitro , Meios de Cultura , Crescimento , Pesos e MedidasRESUMO
The objective of this paper was to determine the influence of three culture media with different water activities, times of incubation and temperatures on the growth of A. ochraceus, A. carbonarius and A. niger. Spores of A. ochraceus, A. carbonarius and A. niger were inoculated onto three culture media: Czapeck Yeast extract Agar (CYA), Dichloran 18% Glycerol Agar (DG18) and Malt Yeast extract 40% Glucose Agar (MY40G). The plates were incubated at five different temperatures (8, 25, 30, 35 and 41ºC). The growth of fungi was evaluated every 24h, measuring the colony diameter (mm). None of the species grew at 8ºC in any culture media. For A. carbonarius, 30ºC was the best temperature for growth while for A. niger temperatures above 30ºC were better in all culture media. A. ochraceus presented good growth at 25 and 30ºC in all culture media, while at 35ºC, growth was slower, especially on CYA. At 41ºC, A. ochraceus did not grow in any culture media and A. carbonarius was significantly inhibited. A. niger grew at 41ºC and was shown to be the most xerophilic fungi when compared to A. carbonarius and A. ochraceus.
Esporos de A. ochraceus, A. carbonarius e A. niger foram inoculados em três meios de cultura: Agar extrato de levedura Czapeck (CYA), Agar Glicerol 18% com dicloran (DG18), Agar Extrato de levedura e malte com 40% de glicose (MY40G). As placas foram incubadas em 5 temperaturas diferentes: 8, 25, 30, 35 e 41ºC. O crescimento dos fungos foi avaliado medindo o diâmetro da colônia a cada 24h. O objetivo deste trabalho foi determinar a influência de três meios de cultura com atividade de água diferente tempo de incubação e temperaturas, sobre o crescimento de A. ochraceus, A. carbonarius and A. niger. Nenhuma das espécies cresceu à 8ºC em nenhum dos meios de cultura. Para A. carbonarius, 30ºC foi a melhor temperatura para o seu crescimento enquanto para A. niger temperaturas acima de 30ºC foram melhores em todos os meios de cultura. A. ochraceus apresentou bom crescimento a 25 e 30ºC em todos os meios de cultura, enquanto seu crescimento à 35ºC foi mais lento, especialmente no meio CYA. A 41ºC, A. ochraceus não cresceu em nenhum dos meios de cultura estudados e A. carbonarius foi significantemente inibido. A. niger cresceu à temperatura de 41ºC e apresentou-se como o fungo mais xerofílico, comparado com A. carbonarius e A. ochraceus.