ABSTRACT
Abstract This study was aimed at optimizing the ultrasound-assisted extraction (UAE) of phenolic compounds from jussara and blueberry fruits using the response surface methodology (RSM). UAE was found to be more efficient to extract phenolic compounds from both fruits than the conventional extraction. The optimum extraction conditions for the jussara fruits were: extraction time between 30 and 62 min for total anthocyanins and total phenolics, fruit:solvent ratio of 10% and 6% (w/v) for total anthocyanins and total phenolics, respectively. The ethanol concentration was non-significant (p> 0.05). Acidified water was found to be an extracting solvent as efficient as ethanol in the extraction of phenolic compounds from jussara fruits. The optimum extraction conditions for blueberry anthocyanins were: ethanol concentration between 20-70% vol, and fruit: solvent ratio greater than 20% (w/v) within the range studied. The extraction time was not significant (p> 0.05). For total phenolic content: the concentration of ethanol was between 40-80%, and fruit: solvent ratio greater than 20% (w/v) and extraction time over 50 minutes. It was possible to adjust the mathematical model for the coordinates a* (verde vs vermelho) and C* (color saturation) of the jussara extracts.
ABSTRACT
A Ilha de Marajó possui o maior rebanho bubalino do Brasil, sendo a Microrregião de Arari a principal produtora de leite e queijo de búfala. O objetivo do presente estudo foi caracterizar, por meio de análises físico-químicas e microbiológicas, o Queijo do Marajó tipo manteiga e verificar se há diferenças de suas características entre as estações do ano, chuvosa e seca. A acidez, pH e a porcentagem de gordura no extrato seco foram atributos de composição centesimal que apresentaram diferença significativa (P<0,05) pelo teste Tukey, entre as duas estações do ano. Os demais componentes (umidade, gordura, proteína total, cinza, EST e sal) desse queijo não variaram em função da época do ano. Quanto às características microbiológicas, as contagens foram maiores na estação chuvosa, exceto para as de Escherichia coli, que mantiveram-se constantes e adequadas à legislação. As contagens de Staphylococcus aureus foram altas e fora dos padrões da norma vigente. A contagem de aeróbios mesófilos foi maior na época das chuvas. Não foi detectada a presença dos patógenos Listeria monocytogenes e Salmonella sp. Apesar dos queijos analisados se enquadrarem nas legislações estadual e nacional, no tocante à composição química, os resultados indicam contagem S. aureus muito elevadas, o que enfatiza a necessidade da implementação imediata de Boas Práticas de Fabricação para a inocuidade dos produtos, a fim de atingir consonância com as contagens microbiológicas da legislação vigente.
Marajó Island has the biggest water buffalo herd in Brazil, and the Microregion of Arari is the main water buffalo's milk and cheese producer. This study aimed to characterize physicochemical and microbiological composition of Marajó's butter-type cheese and to verify differences in its characteristics between rainy and dry seasons of the year. Acidity, pH and percentage of fat in dry matter (% FDM) were attributes that showed significant difference (P<0.05) by Tukey test between the two seasons. The remaining Marajó's butter-type cheese components (moisture, fat, total protein, ash, salt and total dry matter) did not vary along the year. Regarding to microbiological characteristics, in general, the count was higher in the rainy season, except for Escherichia Coli, wich remained constant. Values found for total coliforms were medium to low. For E. coli values meet legal requirements (less than 101CFU g-1) and, therefore, were satisfactory. Counts of Staphylococcus aureus were high, with 0% of samples within the standards of the norm in the rainy season and 9.1% in the dry season. The aerobic mesophilic count was different between the periods of the year and was higher in the rainy season. Presence of the pathogens Listeria monocytogenes and Salmonella sp. was not detected. Despite the cheeses analyzed are in accordance with national legislation regarding chemical composition, the results indicate counts of S. aureus very high, emphasizing the need for immediate implementation of Good Manufacturing Practices so the safety of products will be in agreement with actual legislation.