Eliane Teixeira Mársico

Validade comercial de filés de Tilápia do Nilo (Oreochromis niloticus) resfriados embalados em atmosfera modificada e irradiados

This paper investigated the effects of modified atmosphere packing (60% N2 and 40% CO2) and irradiation (with a 1.5kGy dose) either used alone or combined on the shelf life of fillets of refrigerated Nile Tilapia. A total of 120 fillets were used in the experiments in order to test four different treatments and included samples: packed in air (control), packed in modified atmosphere, packed in air and irradiated, and finally, packed in modified atmosphere and irradiated. Regular monitoring of physicochemical parameters (TVB, pH, ammonia and TBARS), bacteriological conditions (heterotrophic aerobic mesophilic and psychrotrophic bacteria) and sensory acceptance were performed. The results consistently indicated an increasing deterioration of the fillets with time, however those treated with irradiation, modified atmosphere or both combined had longer shelf lives (around two weeks) in comparison with the control (4 days only).

Trace elements in fish and oysters from Sepetiba Bay (Rio de Janeiro – Brazil) determined by total reflection X-ray fluorescence using synchrotron radiation

Trace elements were determined in fish and oysters from Sepetiba Bay, Brazil, by total reflection Xray fluorescence using synchrotron radiation (SRTXRF). Cr, Mn, Fe, Ni, Cu, Zn and Se were determined in fish muscles and organs and in oyster soft tissue. SRTXRF was shown to be a good tool for the analysis of trace elements from biological tissue samples. Overall, the levels of the analysed metals were higher in oysters than in the fish samples. Metals were not uniformly distributed throughout the body of the analysed fish. The detected concentrations of Cr, Zn and Se were very high in some samples, surpassing the maximum limits established by Brazilian legislation.

Concentration of Biogenic Amines in Rainbow Trout (Oncorhynchus mykiss) Preserved in Ice and its Relationship with Physicochemical Parameters of Quality

Biogenic amines are formed as a result of amino acid decarboxylation and are linked to food deterioration. Analysis of these metabolites may be of great importance to determine food quality. The aim of this study was to quantify the biogenic amines (putrescine and cadaverine), and evaluate the physicochemical parameters (pH, ammonia and total volatile bases) of rainbow trout meat (Oncorhynchus mykiss). Fifteen samples were packed in ice and transported in a Styrofoam container to the laboratory. Analyses were performed daily until the 15th day of storage. Biogenic amines concentrations and pH increased significantly throughout the storage period. No significant differences were observed in total volatile bases values over the time. Ammonia was detected after the 11th day of storage. Based on these results, cadaverine and putrescine may be used as a quality index of rainbow trout; however, total volatile bases may not be adequate parameter for this matrix.

Total mercury in sharks along the southern Brazilian Coast

Pesquisou-se a concentracao de mercurio total na porcao muscular de 39 exemplares de tubaroes de tres diferentes especies Prionace glauca, Isurus oxyrhynchus, Sphyrna zygaena, capturados na costa sul do Brasil, Santa Catarina. O teor de mercurio foi determinado por espectrofotometria de absorcao atomica por vapor frio. Observou-se ampla variacao na concentracao de mercurio total com valor individual maximo excedendo o limite estabelecido pela legislacao brasileira, de 1.0µg.g-1 em um exemplar femea de P. glauca. Nessa especie, a concentracao de Hg-total aumentou proporcionalmente ao comprimento total (r=0,62; P<0,0001). Nao foi evidenciada diferenca estatisticamente significativa entre exemplares femeas e machos.

Influence of good manufacturing practices on the shelf life of refrigerated fillets of tilapia (Oreochromis niloticus) packed in modified atmosphere and gamma-irradiated

This study evaluated the influence of good manufacturing practices (GMP) on the shelf life of refrigerated fillets of Nile tilapia (Oreochromis niloticus) packed in modified atmosphere packaging (MAP) and irradiated. In a first series of experiments, 120 tilapia fillets kept under controlled sanitary conditions were purchased from a fish market managed by a cooperative. A second lot totaling 200 tilapia fillets was obtained under controlled storage conditions from a pilot plant. The combined effects of MAP (40% CO2 and 60% N2) and irradiation (1.5 kGy) were investigated by monitoring physical and chemical (total volatile bases and pH), bacteriological (aerobic heterotrophic mesophilic and psychrophilic bacteria) and sensory (acceptance test) changes in the samples. The quality of samples decreased with storage time regardless of the treatment, remaining higher in fillets produced in the pilot plant in comparison with the commercially produced fillets. The observed shelf life of nonirradiated commercially produced fillets was only 3 days, compared to 8 days for those produced in the pilot plant, probably due to GMP in the latter. It was concluded that, even with a combination of proven conservation methods for meats, the adoption of good manufacturing practices still remains essential before, during, and after the filleting process in order to ensure the effectiveness of the entire treatment.

Development and validation of a method for the determination of low-ppb levels of macrocyclic lactones in butter, using HPLC-fluorescence.

An analytical method was developed and validated for the simultaneous determination of four macrocyclic lactones (ML) (abamectin, doramectin, ivermectin and moxidectin) in butter, using liquid chromatography with fluorescence detection. The method employed heated liquid-liquid extraction and a mixture of acetonitrile, ethyl acetate and water, with preconcentration and derivatization, to produce stable fluorescent derivatives. The chromatographic run time was <12.5 min, with excellent separation. The method validation followed international guidelines and employed fortified butter samples. The figures of merit obtained, e.g. recovery (72.4-106.5%), repeatability (8.8%), within-laboratory reproducibility (15.7%) and limits of quantification (0.09-0.16 μg kg(-1)) were satisfactory for the desired application. The application of the method to real samples showed that ML residues were present in six of the ten samples evaluated. The method proved to be simple, easy and appropriate for simultaneous determination of ML residues in butter. To our knowledge, this is the first method described for the evaluation of ML in butter.

Determination of Trace Elements in Honey from Different Regions in Rio de Janeiro State (Brazil) by Total Reflection X-Ray Fluorescence

Trace and minor elements in Brazilian honey were analyzed by total reflection X-ray fluorescence spectroscopy. Up to 12 elements (K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Se, Br, and Sr) were detected in 160 samples of honey from 4 regions of Rio de Janeiro State (Barra Mansa, Teresópolis, northern and southern Nova Friburgo). The results showed the samples from Teresópolis had higher rates of essential and nonessential elements than samples from the other regions, except for Ni. K and Ca were the most abundant elements in all samples, in the range of 116.5 to 987.0 μg g(-1) . Ni, Cu, Zn, Se, and Sr were identified in small concentrations (0.01 to 12.08 μg g(-1) ) in all samples, indicating a low level of contamination in all the regions.

Quality Index Method (QIM) to assess the freshness and shelf life of fish

ABSTRACT The aim of this work was to develop a sensory method as the objective measure of quality of the fishes at all the key stages of fishery chain, from catch to consumer. The Quality Index Method (QIM) is based on a structured scaling for quality measurements and provides accurate and precise information concerning the freshness and a prediction of the remaining shelf-life for specie-specific fishes. The method is discussed and some future outlooks and need are pointed in order to stimulate the implementation of QIM in the relevant parts of the fishery chain giving unique information of the quality. Key words: sensory analysis; fish quality; QIM, shelf life * Author for correspondence: daniellabernardi@hotmail.com INTRODUCTION Consumers demand for high-quality, safe, and healthy foods is increasing on a global basis (Sen 2005). Consumer studies appear to indicate that quality is still the key buying cue for fish purchases (Alasalvar et al. 2011). Besides, in order to secure the food safety, it is important to keep the quality of fishes at a high level in each link of the whole complex chain from catch to consumer (Hyldig and Nielsen 2004). Fresh fish is a highly perishable product. The supplies of fishes are unstable and fresh fish can be stored only for a short time. For commercialization, it is essential to estimate accurately its freshness, one of the most important aspects of fish and fish products (Olafsdottir 1997; Huidobro et al. 2001). Thus, the need for rapid analytical techniques to measure the food quality and freshness is greater than ever. Many methods have been tested, but sensory evaluation is still considered as the most effective technique to assess fish freshness and quality deterioration (Martinsdottir 2002; Alasalvar et al. 2011). Often fish is sold and priced on freshness criteria. The fishes are brought on shore at designated landing sites where it is graded by fish inspector into different price groups based on the freshness using sensory analysis (Chebet 2010). Therefore, researchers have been working to improve the sensory methods (Huidobro et al. 2001). The European fisheries research institutes, in close cooperation between the seafood industry, developed a new tool, by which sensory assessment is performed in a systematic and safe way with an objective quality assessment method, called the Quality Index Method (QIM) (Martinsdottir et al. 2001). Based on a structured scaling method, the QIM is suggested as a practical and objective tool for evaluating the fresh fish in production management in official seafood inspection as well as other parts of the chain (Hyldig and Green-Petersen 2004). Besides the

Validade comercial de sardinhas inteiras e refrigeradas avaliada por análises físico-químicas, bacteriológicas e sensorial

Theshelf life of sardines of Sardinella brasiliensis and Cetengraulis edentulus species kept on ice at +2°Cwas determined by physical-chemical, bacteriological and sensory parameters. In both samples, the levels of Total Volatile Bases (TVB) and Trimethylamine (TMA) reached the limits recommended by law (30mg N 100g-1 for TVB and 4mgN100g-1 for TMA) after 14 and 8 days of storage, respectively. The contents of histamine, putrescine and cadaverine remained at levels below 2.0µg g-1 in both samples during the storage period. The hypoxanthine production ranged from 0.65 to 2.62µmol g-1 in samples of S. brasiliensis and 1.40 to 2.09µmol g-1 in samples of C. edentulus. The initial count of Enterobacteriaceae was 3.81logCFU g-1 and 3.82logCFU g-1 reaching, after 18days of storage, 6.57logCFU g-1 and 6.87logCFU g-1, in samples of S. brasiliensis and C. edentulus, respectively. For heterotrophic bacteria aerobic mesophilic and psychrotrophic count the limit of 7logCFU g-1 recommended by international legislation was reached after12 and 8days of storage in samples of S. brasiliensis and after 12 and 6days of storage in samples of C. edentulus, respectively. The quality index method suggested for samples of S. brasiliensis, a limit of acceptable consumption less than 11 and for samples of C. edentulus a limit of acceptability below 14. As a result of this study, we recommend a shelf life of ten days for the S. brasiliensis and nine days for the C. edentulus.

Development and nutritional and sensory evaluation of cachapinta (Pseudoplatystoma sp) pâté

This study developed a technique for the preparation of pâté from cachapinta (Pseudoplatystoma sp) waste. For this, frozen minced cachapinta fish was crushed in a mini cutter and homogenized with all other ingredients. The prepared pâté was stored in seamed and thermally treated cans (volume 170 g). Weight proportions of mean moisture, ash, protein, and lipid contents of the minced fish were 75.49, 1.00, 15.00, and 7.92 (g/100 g), respectively. The formulation of the developed pâté is in accordance with legislation for fish products. Cachapinta pâté is a product with high content of polyunsaturated fatty acids, low level of trans fat, and good indices of nutritional quality. Tests of sensory acceptance, purchase intent, and sensory attributes (except spreadability) averaged a score above 6.0, indicating acceptability of the product. Our study suggests that the potential of minced cachapinta for pâté production is high, and that it can contribute a value-added product to seafood consumption.