RESUMO
Sodium metabisulfite is the main additive used in the prevention of melanosis in shrimp; however, it has currently been employed with great variation in concentration by producers. Thus, the aim of the present study was to determine the correlation between the concentration of the sodium metabisulfite solution and immersion time of the whole shrimp to obtain the concentration of sulfur dioxide (SO2) in the edible muscle of farmed shrimp (Litopenaeus vannamei) in accordance with the limit established by law. For this, solutions of sodium metabisulfite at different concentrations (1%, 2 %, 3 %, 4% and 5%) were prepared and samples of L. vannamei shrimp (100g) were immersed during 10, 20 or 30 minutes at temperature of 7;C. For all treatment assayed the concentration of SO2 was determined in the edible muscle of farmed shrimp (L. vannamei). The results show that for the conditions used in this study, the correlations were linear, with significant increase (P 0.05) in the SO2 concentration in the edible muscle of shrimps both increasing sodium metabisulfite concentration as increasing immersion times, suggesting the immersion of shrimps in a 3% solution for a time of 13 minutes in order to obtain SO2 concentration of 100ppm in its edible muscle in accordance with Brazilian legislation
O metabissulfito de s;dio ; o principal aditivo usado na preven;;o da melanose em camar;o, por;m, atualmente, ; empregado com grande varia;;o de suas concentra;;es pelos produtores. Assim, o objetivo deste estudo foi determinar a correla;;o entre a concentra;;o da solu;;o de metabissulfito de s;dio e do tempo de imers;o do camar;o inteiro para obter a concentra;;o final de di;xido de enxofre (SO2) no m;sculo comest;vel de camar;o cultivado (Litopenaeus vannamei), de acordo com os limites estabelecidos pela legisla;;o. Para isso, foram preparadas solu;;es de metabissulfito de s;dio em diferentes concentra;;es (1%, 2%, 3%, 4% e 5%); e amostras de camar;o L. vannamei (100g) foram imersas durante 10, 20 e 30 minutos ; temperatura de 7;C. Para todos os tratamentos, foram realizadas an;lises da concentra;;o de SO2 no m;sculo comest;vel do camar;o cultivado (L. vannamei). Os resultados demonstraram que, para as condi;;es empregadas nesta pesquisa, as correla;;es encontradas foram lineares, ocorrendo um aumento significativo (P 0,05) nos teores de SO2 no m;sculo comest;vel do camar;o, tanto com o aumento da concentra;;o das solu;;es de metabissulfito de s;dio, quanto com o aumento no tempo de imers;o, sendo poss;vel sugerir a imers;o dos camar;es em solu;;o a 3% por um tempo de 13 minutos, de forma a se obter, em seu m;sculo comest;vel, a concentra;;o de 100ppm de SO2, de acordo com
RESUMO
The dehydrated ostrich egg yolks were analyzed in order to assess their constituents after being dried by means of two dehydration methodologies, that is the spray-drying technology and the freeze-drying technique. The egg yolk samples were dehydrated by spray dryer with compressed air flow at 30 L/min, feeding bomb flow at 0.5 L / h, and drying air temperature at 125ºC. In using the freeze-drying technology, the samples were processed at temperature of - 49 C for seven hours under the pressure of 0.02955 mmHg. After being dehydration, the centesimal composition of dried samples was determined. Cholesterol contents were determined by HPLC, in movable phase, acetonitrile/izopropanol (80:20) at flow of 1mL/min, on Nova Pack column C18 (15.0cm x 4.6cm x 5.0m), and wavelength at 210nm. The powder particles diameter sizes were achieved by optical microscopy. Statistically significant differences (p 0.05) were found in comparing the averages of centesimal compositions of ostrich egg yolks dehydrated by spray-dryer and those dried by freeze drying technology. The freeze-dried egg yolk showed higher lipid contents, but lower cholesterol contents. The freeze-dried particles were irregular, larger and more stable than those atomized powders. By means of freeze-drying technique, the retention of ostrich egg yolk lipid and protein contents was observed, although lower cholesterol q
As gemas de ovo de avestruz foram analisadas quanto às características de seus constituintes após serem desidratadas por meio de técnica de spray-dryer e pela metodologia de liofilização. As amostras foram desidratadas pela técnica de spray-dryer com vazão de ar comprimido de 30 L/ min, vazão da bomba de alimentação de 0,5 L/ h e sob a temperatura do ar de secagem de 125ºC. Pela metodologia de liofilização, as amostras foram tratadas a temperatura de - 49 C durante sete horas e sob pressão de 0,02955 mmHg. Após a desidratação, foi determinada a composição centesimal das amostras. O colesterol foi determinado por HPLC, em fase móvel, acetonitrila/isopropanol (80:20) à vazão de 1mL/min e em coluna Nova Pack C18(15cm x 4,6cm x 5m), em comprimento de onda de 210nm. O diâmetro das partículas do pó obtido foi avaliado em microscópio óptico. As médias de composição centesimal das gemas de ovo de avestruz desidratadas pelo método spray-dryer e por liofilização diferiram estatisticamente (p 0,05). A gema liofilizada apresentou maior conteúdo lipídico, porém menor taxa de colesterol. As partículas liofilizadas mostraram-se irregulares, maiores e mais estáveis do que as atomizadas. O método de secagem por liofilização conservou o teor lipídico e protéico da gema de ovo de avestruz, bem como menor concentração de colesterol na amostra quando comparado à secagem por meio de spray-dryer