Crab Meat Research Articles

Increasing the Yield of Irish Brown Crab (Cancer pagurus) during Processing without Adversely Affecting Shelf-Life.

During the processing of Irish Brown Crab (Cancer pagurus), protein and moisture are released and losses up to 10% (by weight) are common. The objective of this study was to investigate the use of clean label ingredients to reduce this loss, without adversely affecting shelf-life or promoting the growth of spoilage bacteria. Following preliminary studies, 5% (w/v) sodium caseinate (SC) and (5%, w/v) potato starch (PS), with and without (0.5%, w/v) ascorbic acid (AA) were selected. Ninety crabs (30 per treatment) were soaked and boiled in water (control 1), AA (control 2), SC, PS, SC plus AA, or PS plus AA and analyzed for cook loss as well as pH, aw, water holding capacity (WHC), and microbial shelf-life (total viable count (TVC), total Enterobacteriaceae count (TEC), and spoilage bacteria) during 28 days storage at 4 °C. On average, 11.1% of the control 1 weight was lost during processing. This was reduced to 8.0% when treated with AA (control 2) and to 3.5%, 4.7%, 5.8%, and 2.3% with SC, PS, SC plus AA, and PS plus AA, respectively. None of these treatments negatively impacted on shelf-life and similar growth curves were observed for TVC, TEC, Pseudomonas spp., Clostridium spp., lactic acid bacteria (LAB), and hydrogen disulphide producing bacteria, regardless of treatment. It was therefore concluded that, subject to sensory evaluation and validation under commercial conditions, these natural ingredients could be used to substantially increase the yield and hence commercial value of crab meat, without adversely affecting shelf-life.

Crab-meat-isolated psychrophilic spore forming bacteria inactivation by electron beam ionizing radiation

The present work was performed to evaluate the potential of electron beam ionizing radiation for the inactivation of three psychrophilic spore forming bacteria (Bacillus mycoides, Bacillus weihenstephanensis and Psychrobacillus psychrodurans) isolated from ready-to-eat brown crab (Cancer pagurus). Inactivation curves for the three spores were performed in both types of crab meat, brown and white. Also the effect of pH and water activity (aw) on the lethal efficacy of ionizing radiation, for the three different psychrophilic spore forming bacteria, was evaluated. The effects of pH, aw and their possible interactions were assessed in citrate-phosphate buffers of different pH, ranging between 7 and 4, and aw, ranging from <0.99 to 0.80. A reduction of aw increased the spores resistance between >0.99 and 0.90, while an aw reduction from 0.90 to 0.80 had a minor impact on their resistance. In contrast to aw, the effect of pH showed a greater variability depending on the spore species. While pH did not affect the resistance of B. weihenstephanensis at any aw, B. mycoides showed slightly higher resistance at pH 5.5 at aw of 0.90 and 0.80. pH showed a significant effect on the resistance of P. psychrodurans. For the two types of crab meat, slightly differences were observed in 6D values. B. weihenstephanensis was the most resistant, requiring 7.3–7.6 kGy to inactivate 6 Log10-cycles of this spore forming bacterium, while for B. mycoides and P. psychrodurans 6.1–6.3 and 5.4–5.3 kGy respectively were necessary to reach the same inactivation level in crab meat. An agreement between spore resistance in crab meats and lab media, with similar characteristics in pH and aw, was also observed. The results obtained in this research demonstrated the potential for ionizing radiation to achieve an appropriate inactivation level of spores naturally present in brown crab with the application of doses lower than 10 kGy.

Convolutional neural network guided blue crab knuckle detection for autonomous crab meat picking machine

The Atlantic blue crab is among the highest-valued seafood found in the American Eastern Seaboard. Currently, the crab processing industry is highly dependent on manual labor. However, there is great potential for vision-guided intelligent machines to automate the meat picking process. Studies show that the back-fin knuckles are robust features containing information about a crab’s size, orientation, and the position of the crab’s meat compartments. Our studies also make it clear that detecting the knuckles reliably in images is challenging due to the knuckle’s small size, anomalous shape, and similarity to joints in the legs and claws. An accurate and reliable computer vision algorithm was proposed to detect the crab’s back-fin knuckles in digital images. Convolutional neural networks (CNNs) can localize rough knuckle positions with 97.67% accuracy, transforming a global detection problem into a local detection problem. Compared to the rough localization based on human experience or other machine learning classification methods, the CNN shows the best localization results. In the rough knuckle position, a k-means clustering method is able to further extract the exact knuckle positions based on the back-fin knuckle color features. The exact knuckle position can help us to generate a crab cutline in XY plane using a template matching method. This is a pioneering research project in crab image analysis and offers advanced machine intelligence for automated crab processing.

Effect of the Cooking Process on the Gelling Properties of Whole and Minced Jumbo Lump of Blue Crab (Callinectes sapidus)

ABSTRACTCommercially, crab meat is obtained by hand-picking after a cooking process, followed by pasteurizing or canning. Jumbo lump is one of the pieces of meat obtained from the blue crab. The aim of this study was to evaluate the effect of the commercial cooking process (boiling and steaming) on the mechanical and functional properties of whole jumbo lump and the gels obtained from cooked and minced jumbo lump from blue crab (Callinectes sapidus). The gels were prepared combining the washing process and microbial transglutaminase. The boiling and steaming processes showed a different effect on the textural and color properties. Whole jumbo lump pieces cooked by immersion in boiling water showed a higher hardness value as compared to steamed jumbo lump pieces, suggesting a different internal structural. The cooking processes used in this study did not modify the water holding capacity, gelling capability, or color of the minced jumbo lump. The addition of microbial transglutaminase to washed minced jumbo lump improved the hardness, cohesiveness, and chewiness of gels elaborated with boiled or steamed jumbo lump, which allowed the textural properties similar to those of the whole jumbo lump.

Biomaterial compounds and bioactivity of horseshoe crab Carsinoscorpius rotundicauda biomass harvested from the Madura Strait

Carsinoscorpius rotundicauda or horseshoe crab biomass has great potential in pharmaceutical aspects, one of them as an antibacterial substance. Information related to the benefits of Carsinoscorpius rotundicauda biomass such as meat and blood is essential because in fact, this species is considered a pest by fishermen, a low market value and has no legal protection in Indonesia. The purpose of this study was to determine the content of biomaterial compounds of meat and bioactivity of Carsinoscorpius rotundicauda plasma on bacterial inhibition from three different stations harvested from the waters in Madura Strait. The observation of the utilization of the potential from horseshoe crab biomass ie meat and plasma was performed by measuring the content of biomaterial compound in horseshoe crab meat by HPLC method and zone of inhibition test for gram-positive and gram-negative bacteria in horseshoe crab plasma. Analysis of the relationship between the two parameters used the Principal Component Analysis. The highest content of biomaterial compounds of monoterpenoid and zoosterol is found in horseshoe crab from Bangkalan waters, namely monoterpenoid (18.33 ppm) and zoosterol (22.67 ppm), while the smallest compound content obtained in horseshoe crab from Probolinggo waters, namely monoterpenoid (13.67) ppm and zoosterol (17.33 ppm). The bioactivity of Dark Blue Plasma (BDP) and Light Blue Plasma (LBP) samples of horseshoe crab obtained around the Madura Strait has the ability to inhibit gram-positive bacteria higher than gram-negative bacteria. The total average of DBP plasma inhibitory power on Staphylococcus aureus was 10.00 mm and 10.07 mm on Bacillus, while that in LBP sample, Staphylococcus aureus was 9.11 mm and Bacillus was 9.67 mm. The high biomaterial compound content of horseshoe crab is in line with the ability of horseshoe crab plasma to inhibit Bacillus and Staphylococcus aureus.

Development and nutritional analysis of crab crackers

This study was carried out to develop crab crackers with brackish water blue crab (Callinectes amnicola) and marine water crab (Portunus validus), to determine the nutritional composition, the sensory and physical attributes of the developed crackers. The nutritional composition of fresh C. amnicola and fresh P. validu swere determined.Three different ratios of handpicked crab meat to cassava starch (flour) were used in the formulation of crab crackers. Protein content was higher in P.validus (16.25%) compared to C.amnicola (15.70%), the lipid content was less than 1.00% in both crabs and moisture content was higher in C. amnicola.The protein content of the developed crab crackers increased with increase in the ratio of the crab meat, while reverse is the case in linear expansivity. It was observed that the developed crab crackers with crab meat to cassava starch ratio of 1:3 were generally accepted and significantly (P<0.05) different from all other formulations. There was no significant difference in the taste and crispiness of the crackers developed with both crab species. The development of sensory acceptable crab crackers of high nutritional value can be a strategy to increase crab consumption and improve the quality of the diet of children and adults.Keywords: Crabs, crab crackers, nutritional composition, physical properties, sensory evaluation

Microbiological quality of surimi-based imitation crab

A survey was conducted to evaluate the microbiological quality of sliced, vacuumpacked, surimi-based imitation crab at the retail level, during a 3-month storage period. The roll shaped product imported from France, was sliced and packed in a fishery processing plant in the region of Thessaloniki. Twenty five samples were examined each month, and a total of 75 samples were examined during the three month storage period of the product. Psychrotropic, lactic acid and coliform bacteria, Escherichia coli I, yeasts, Staphylococcus aureus, Salmonella spp., Listeria spp. and Escherichia coli Θ157:Η7, were used as microbial indices, to evaluate the microbiological quality of the product. The following conclusions were derived from the evaluation of the results of the microbiological examinations. 1) The microbiological condition of the crab meat analogs examined on the 15th day of storage, was found satisfactory, since microbial populations were very low, while pathogenic bacteria were not detected in any of the examined samples. 2) The overall microbiological quality of the samples examined at the end of the second month of storage, was also good, since psychrotrophic and lactic acid bacteria exceeded 1Θ7 log cfu/g only in one sample), while coliform bacteria were not detected in 60% of the samples and Escherichia coli I was detected only in one sample. The mean value of the yeasts was 2.84 log cfu/g, while molds were not detected in any of samples examined. 3) The microbiological quality of the samples examined at the end of the three months storage period was not satisfactory, since the microbial indices in the majority of the samples (80%), were rather high. S. aureus, Salmonella spp, Listeria s pp. and E. coli 0157:H7 were not detected in any sample, during the three month storage period.

Sources of polychlorinated dibenzo-p-dioxins and dibenzofurans, and biphenyls in Chinese mitten crabs

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) in Chinese mitten crabs from several areas were determined. The toxic equivalents (TEQs) for the mean PCDD/F and total PCDD/F and dioxin-like PCBs were 2.9 ± 2.7 and 5.7 ± 4.0 pg TEQ g−1, respectively. The mean concentrations of PCBs and dl-PCBs were 282 and 59 times the concentrations of PCDD/Fs, respectively. PCDD/F and PCB sources in the crab food web were assessed. The total TEQ of PCDD/F and PCB supplied by crab compound feed was 2.1 times the TEQ in crab meat. Broken corn, aquatic biota, and water contributed around 12% of the total TEQ inputs for crab meat. The contribution from sediment was around 164 times that from crab meat, and sediment may be the most important source of PCDD/Fs and PCBs in cultured crabs. Principal component analysis (PCA) and stable isotope ratios for nitrogen (δ15N) and carbon (δ13C) supported the TEQ results. The mean total PCDD/F and dl-PCB TEQ exposure for humans consuming crabs was 3.4 pg TEQ per kilogram of body weight per day. The PCDD/Fs and PCBs in >80% of the crab samples would not cause the tolerable daily intake to be exceeded.

Influence of the Type of Processing of Crab Meat in the Physical-Chemical and Microbiological Parameters

Influence of the Type of Processing of Crab Meat in the Physical-Chemical and Microbiological Parameters

Toxic and essential elements in seafood from Mausund, Norway.

In annual surveys conducted during the period 2012-2015, concentrations of the toxic or essential elements B, Se, Cd, Sn, Cs, Hg, Pb, Al, Cr, Mn, Fe, Ni, Cu, Zn, and As were analyzed in brown meat of edible crab (Cancer pagurus), and filets of cod (Gadus morhua) and halibut (Hippoglossus hippoglossus) in one of the most important commercial crab fishing areas in Norway, at Mausund in Frøya municipality in Sør-Trøndelag, Norway. Concentrations of the elements were analyzed in sediments in 2015. Several salmon farms are located in this area. Samples were extracted by HNO3 and analyzed using inductively coupled plasma mass spectroscopy (ICP-MS). Crab, cod, and halibut were caught in a total of five locations. One of these locations was in the proximity of a salmon farm. In edible crabs, the mean ranks were significantly different between two locations only for Sn (p = 0.034). When all data were pooled, the mean ranks statistics showed significant difference between all years for the elements Se (p = < 0.001), Cs (p = 0.005), Mn (p = 0.002), Zn (p = 0.006), and As (p = 0.001) in edible crab. The study showed elevated levels of Cd in edible crabs in 2012, 2013, 2014, and 2015, with the highest levels in 2015. In cod, there were significant differences between locations for the elements B (p = 0.003), and Pb (p = 0.04), as well as between the years for the elements B, Sn, Cs, Hg, Cr, and As (p = < 0.01). The study showed elevated level of Pb in cod in 2013. Halibut showed no significant differences between years or locations for any elements. The Cd, Hg, and Pb values of the sediments in this study indicate that local geogenic sources cannot be considered a major cause of high values in local biota.

Physicochemical Characteristics of Glucosamine from Blue Swimming Crab (Portunus pelagicus) Shell Prepared by Acid Hydrolysis

The aim of this research was to characterize glucosamine hydrochloride (GluHCl) from the shell of blue swimming crab (Portunus pelagicus). The crab shell was finely milled and processed to chitin prior to HCl hydrolysis using 30 % HCl for 30 min at 100 ºC for glucosamine production. The resultant glucosamine was recovered by crystallization using 95 % ethanol and was dried in a hot air oven. The color of the glucosamine crystals, expressed as L*, a*, and b*, was 83.01, 5.03, and -3.38, respectively. Crab shell glucosamine had high purity, which could be strongly stained by ninhydrin and presented at the same Rf of standard D-glucosamine using thin layer chromatography. Furthermore, prepared glucosamine exhibited similar Fourier transform infrared (FTIR) spectrum as standard D-glucosamine. Glucosamine from blue swimming crab shell had high purity as determined by HPLC and contained 808.15 mg D-glucosamine/g sample. The maximal transition temperature (Tmax) and the total enthalpy (ΔH) of prepared glucosamine were 194 ºC and 754.42 J/g, respectively. As a consequence, with the presented method, the resultant glucosamine was characterized to be D-glucosamine. Therefore, blue swimming crab shell, a byproduct from crab meat processing, has high potential as a raw material to produce glucosamine for food and nutraceutical applications.

A Predictive Model for the Growth of Listeria monocytogenes in Commercial Blue Crab (Callinectes sapidus)

During the processing and handling of commercial blue crab (Callinectes sapidus), Listeria monocytogenes can potentially contaminate cooked meat and grow to hazardous levels. To manage this risk, predictive models are useful tools for designing and implementing preventive controls; however, no model specific for blue crab meat has been published or evaluated. In this study, a cocktail of L. monocytogenes strains was added to pasteurized blue crab meat, which was incubated at storage temperatures from 0 to 35°C. At selected time intervals, L. monocytogenes was enumerated by direct plating onto modified Oxford agar. A primary model was fitted to kinetic data to estimate the lag-phase duration (LPD) and growth rate (GR). Listeria monocytogenes replicated from 0 to 35°C, with GR ranging from 0.004 to 0.518 log CFU/h. Overall, the LPD decreased with increasing temperature, displaying a maximum value of 187 h at 0°C; however, this trend was not consistent. The LPD was not detected at 10°C, and it occurred inconsistently from trial to trial. A secondary GR model (R2 = 0.9892) for pasteurized crab meat was compared with the L. monocytogenes GR in fresh crab meat, demonstrating bias and accuracy factors of 0.98 and 1.36, respectively. The model estimates varied from other published data and models, especially at temperatures ≥5°C, supporting the need for a specific predictive tool for temperature deviations.

An assessment of the application of ultrasound in the processing of ready-to-eat whole brown crab (Cancer pagurus)

This study assesses the potential of incorporating ultrasound as a processing aid in the production of whole cooked brown crab (Cancer pagurus). The FDA recommended heat treatment to reduce Listeria monocytogenes by 6 log10 cycles in this product is a F707.5 of 2min. An equivalent F value was applied at 75°C in presence and absence of ultrasound in water alone or in water with 5% w/v NaCl added. Heat penetration, turbidity and conductivity of the cook water and also salt and moisture content of the crab meat (white and brown) were determined. Ultrasound assisted cooking allowed a reduction of the cooking time by up to 15% while still maintaining an F707.5 of 2min. Ultrasound also enhanced the rate and total amount of compounds released from the crab, which suggests that crabs cooked in the presence of ultrasound would be expected to be cleaner. Ultrasound also proved to be effective in reducing the salt content but hardly affected the final moisture content of the crab meat.

Postmortem changes in physiochemical and sensory properties of red snow crab (Chionoecetes japonicus) leg muscle during freeze storage

In order to evaluate the maximal storable period of the raw crab for a non-thermal muscle separation, the quality changes of the leg meat of red snow crab (Chionoecetes japonicus) during freeze storage were investigated. Fresh red snow crabs were stored at −20 °C for 7 weeks, and the leg muscle was separated by a no heating separation (NHS) method every week. During the storage, considerable loss of the leg muscle did not occur and microbiological risk was very low. In contrast, discoloration appeared at 2-week storage on around carapace and the leg muscle turned yellow at storage 3-week. In physiochemical parameters, protein and free amino acids gradually decreased with storage time, expected that proteolytic enzymes still activated at −20 °C. At 4-week storage, the sensory acceptance dropped down below point 4 as low as inedible and notable inflection points in pH and acidity were observed. The volatile base nitrogen was low, though a little increase was recorded. These results suggested that the maximal storable period at −20 °C of the raw material was within 2 weeks and it was depended on external factor such as the discoloration. The present study might be referred as basic data for approaches to solve quality loss occurred in non-thermal muscle separation.

Survey for Listeria monocytogenes in and on Ready-to-Eat Foods from Retail Establishments in the United States (2010 through 2013): Assessing Potential Changes of Pathogen Prevalence and Levels in a Decade

A multiyear interagency Listeria monocytogenes Market Basket Survey was undertaken for selected refrigerated ready-to-eat foods purchased at retail in four FoodNet sites in the United States. Food samples from 16 food categories in six broad groups (seafood, produce, dairy, meat, eggs, and combination foods) were collected weekly at large national chain supermarkets and independent grocery stores in California, Maryland, Connecticut, and Georgia for 100 weeks between December 2010 and March 2013. Of the 27,389 total samples, 116 samples tested positive by the BAX PCR system for L. monocytogenes , and the pathogen was isolated and confirmed for 102 samples. Among the 16 food categories, the proportion of positive samples (i.e., without considering clustering effects) based on recovery of a viable isolate of L. monocytogenes ranged from 0.00% (95% confidence interval: 0.00, 0.18) for the category of soft-ripened and semisoft cheese to 1.07% (0.63, 1.68) for raw cut vegetables. Among the 571 samples that tested positive for Listeria-like organisms, the proportion of positive samples ranged from 0.79% (0.45, 1.28) for soft-ripened and semisoft cheese to 4.76% (2.80, 7.51) for fresh crab meat or sushi. Across all 16 categories, L. monocytogenes contamination was significantly associated with the four states (P < 0.05) but not with the packaging location (prepackaged by the manufacturer versus made and/or packaged in the store), the type of store (national chain versus independent), or the season. Among the 102 samples positive for L. monocytogenes , levels ranged from <0.036 most probable number per g to 6.1 log CFU/g. For delicatessen (deli) meats, smoked seafood, seafood salads, soft-ripened and semisoft cheeses, and deli-type salads without meat, the percentage of positive samples was significantly lower (P < 0.001) in this survey than that reported a decade ago based on comparable surveys in the United States. Use of mixed logistic regression models to address clustering effects with regard to the stores revealed that L. monocytogenes prevalence ranged from 0.11% (0.03, 0.34) for sprouts (prepackaged) to 1.01% (0.58, 1.74) for raw cut vegetables (prepackaged).

Macronutrient Analysis Of Crab Meat Analogue Made From Non-Consumable Fish With Alginate Addition

The crab meat analogue products using alginates and proteins such as soybean. A mixture of sh added alginate croslinking with calcium chloride making gel and water retention. The purpose of this study to analysis macronutrient from the effects of alginate addition to the characteristics of the crab meat analogue. The formulation was made from the combination of alginate from Sargassum sp. The formulation was applied to the surimi from silver giddy (Gerres Kapas Blkr) to make crab meat analogue with different concentrations (0.25%, 0.5%, 0.75%, 1%). Parameters used to study the effects were moisture content, total ash, protein content, fat content, thiobarbituric acid value and sensory evaluation. The chemical analysis, moisture content, and ash content analysis showed a signi cant difference among the treatments, while the thiobarbituric acid value showed no difference among the samples. Based on sensory evaluation, the most preferred product was formula A (0.25% alginate) in terms of texture, taste, juiciness and overall acceptance with the characteristics of 2.47% ash content, 75.98% moisture content, 0.47% fat content, 12. 07% protein content, thiobarbituric acid value of 0.69 μmol/g. Keyword : crab meat analog, alginate, macronutrient, non consumable, Sargassum sp.

Effects of high pressure processing on protein fractions of blue crab (Callinectes sapidus) meat

The studies about the effect of high pressure processing (HPP) on the myofibrillar proteins of crab meat are scarce in the literature. The aim of this study is to evaluate the effect of high pressure processing (HPP) at 100, 300 and 600MPa (10°C/5min) on the muscular protein fractions of blue crab meat (Callinectes sapidus) and compares the effect of high pressure treatments and the thermal cooking process on the yielding of crab meat. Differential scanning calorimetry analysis of raw crab meat showed two peaks at 48.18 and 76.76°C corresponding to myosin and actin denaturation. The increasing in the pressure level resulted in a decrease in denaturation enthalpy of both proteins. Data from Fourier transform infrared spectroscopy indicated changes in the secondary protein structures in which a reduction in α-helix and an increase in β-turn were observed as a result of denaturation induced by HPP. Electrophoresis analysis (SDS-PAGE) showed myofibrillar protein denaturation as the pressure level increased. The HPP at 100 and 300MPa resulted in a significant increase in the yielding of meat extracted when compared to the thermal treatment (90°C/20min). Higher sensory scores were obtained in 300 and 600MPa suggesting higher acceptance. Results suggest the feasibility of applying HPP as an alternative to the thermal treatment to process crab meat.High pressure processing (HPP) technology has been successfully applied to several seafood products. However, it is important to study the effect of HPP on the food components, mainly proteins in the crab meat to optimize the processing parameters to get high-quality products. In the present study, the benefit of using HPP as an alternative to the commercial thermal processing for extraction of crab meat has been confirmed. Applying 600MPa (10°C/5min) to the whole blue crab resulted in a higher yield of extracted crab meat compared with the other treatments. However, using a range of 100–300MPa (10°C/5min) also increases the yielding of extracted crab meat when compared to the thermal process, and moreover, the extraction procedure is faster. The quality and the functional properties of the crab meat with fresh appearance is preserved after the treatment at 100MPa. These results could promote subsequent applications of pressurized crab meat in the crab industry, especially with the HPP treatments in a range between 100 and 300MPa.

Caracterí­­sticas microbiológicas da carne de caranguejo-uçá (Ucides cordatus) comercializada na cidade de São Luí­­s - MA

Com o objetivo de caracterizar microbiologicamente a carne de caranguejo-uçá (Ucides Cordatus) comercializada na cidade de São Luí­­s í MA, foram analisadas 110 amostras da carne, 30 em 3 mercados (10/mercado) e 80 em 8 feiras livres (10/feira), na cidade de São Luí­­s í MA, utilizando a metodologia segundo a Instrução Normativa No 62, de 26 de agosto de 2003, do MAPA para Coliformes a 45°C, Bactérias mesófilas, Staphylococcus spp e Salmonella spp. Para isolamento do gênero Aeromonas spp foi utilizado o método convencional; as espécies foram identificadas pela chave Aerokey II. Foram aplicados 10 questionários socioeconômicos com manipuladores, foram coletados swabs das mãos de 20 manipuladores para pesquisa de Staphylococcus coagulase positivo. Resultados evidenciaram 57 amostras contaminadas por coliformes a 45°C; presença de bactérias aeróbias mesófilas e Staphylococcus sp nas 110 amostras de carne analisadas; Staphylococcus aureus em 45 amostras; Aeromonas cavie em 82 amostras; Aeromonas hydrophilla em 32 amostras e Aeromonas veronii biovar veronii em uma amostra. Foi verificada ausência de Salmonella spp nas 110 amostras e identificado Staphylococcus aureus nas mãos dos 20 manipuladores. Diante dos resultados, conclui-se que a carne de caranguejo dos mercados e feiras de São Luí­­sí MA encontraí se imprópria para o consumo.

The distribution of elements in the body of invasive Chinese mitten crabs (Eriocheir sinensis H. Milne-Edwards, 1853) from Lake Dąbie, Poland

The Chinese mitten crab (Eriocheir sinensis) is an invasive species in the Baltic Sea catchment area. Its numbers in fishery are steadily growing and can potentially become a considerable export product. However, the meat of these crustaceans is known to accumulate contaminants, such as trace elements. Therefore, in this study we examined the content of Al, As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, U, Zn in the claws, legs, and carapace of Chinese mitten crabs from Lake Dąbie (south-western catchment area of the Baltic Sea). Concentrations of Mo and U were within the sensitivity limit of the analytical method, and the average concentrations (inmgkg−1dw) of the remaining elements ranged from 0.016 (Cd, claw meat) to 191 (Fe, carapace). The meat had very high concentrations of essential metals (Fe>20, Cu>17, Zn>16, Mn>2, in mgkg−1 dw). The concentrations of Pb and Cd were 5 and 100 times lower than the threshold for foods established by the Commission Regulation (EC) No 1881/2006. The meat of crabs from Lake Dąbie should be safe for consumers and may be a source of elements playing important functions in metabolic processes.

Effects of Conservation Method and Time on Fatty Acid Composition, Taste, and Microstructure of Southern King Crab (Lithodes santolla Molina, 1782) Meat

ABSTRACTThis study reports the changes in fatty acids, taste, and microstructure of cooked southern king crab meat (Lithodes santolla) during storage at 0°C for 10 days and at −20°C for 90 days. At the end of both storage times, the iodine value decreased by 16.5%, while 83.5% of the initial fatty acid quality remained unchanged. The polyene ratio decreased by 32% at 0°C and 35.9% at −20°C, whereas the atherogenic and thrombotic indices remained at values that do not represent any risk to human health. Free amino acids that contribute to taste (taste activity value, TAV > 1) were: glycine and alanine (sweetness), arginine (bittersweetness), and histidine (bitterness). The bittersweet taste imparted by arginine (initial TAV = 16.4) was prevalent even at the end of frozen storage (TAV = 7.9). The umami taste was elicited by disodium 5′-adenosine monophosphate (AMP) nucleotide. The equivalent umami concentration in g MSG/100 g meat changed from 0.031 to 0.045 in refrigerated samples and to 1.6 in frozen samples. A loss of the original fibrous structure of the meat was evidenced during both treatments. Refrigerated samples presented a disintegrated and homogeneous texture at 10 days, while freezing formed a spongy tissue at 90 days.