Aquatic Meat Research Articles

Accumulation of heavy metals in meat and their relationship with water and food intake of aquatic animals in Kermanshah, western Iran

ABSTRACT Accumulation of heavy metals in aquatic meat can have a destructive role in food safety and is also closely related to the water and feed consumed by animals. Thus, the aim of this study is to evaluate the heavy metals in three aquatic species and their relationship with water and food. Fresh samples included 65 trout, 40 carp, and 45 shrimp, and their water and food were collected from Kermanshah aquaculture. After the preparation phase, the concentration of heavy metals was determined by using inductively-coupled plasma-mass-spectrometry. Lead in carp, arsenic in shrimp, cadmium, and mercury in trout had the highest concentrations of toxic metals. The lead, arsenic, and mercury concentrations in all three farmed aquatic species were higher than the maximum permissible limits. A significant correlation coefficient was observed between the concentration of these metals in the meat and their consumed water and food (p≤0.001). Of the essential metals, except for selenium in trout, and zinc in all three aquatic species, the concentration of other metals was higher than that of the permissible consumption limit. There was also a significant correlation between the concentration of essential metals and their consumed feed (p<0.001). The target hazard quotient of toxic metals was less than 1, but the target cancer risk for arsenic and mercury was in the range of carcinogenicity. Thereby, it is vital to monitor the quality of aquatic meat and pay special attention to their water and feed sources in this region of Iran, which will consequently guarantee human health.

The preservable effects of ultrasound-assisted alginate oligosaccharide soaking on cooked crayfish subjected to Freeze-Thaw cycles.

To improve the quality of cooked and frozen crayfish after repeated freeze-thaw cycles, the effects of alginate oligosaccharide (1%, w/v) with ultrasound-assisted (40W, 3min) soaking (AUS) on the physicochemical properties were investigated. The AUS samples improved water-holding capacity with 19.47% higher than the untreated samples. Low-field nuclear magnetic resonance confirmed that mobile water (T22) in the samples after 5 times of freeze-thaw cycles was reduced by 13.02% and 29.34% with AUS and without treatment, correspondingly; and with AUS and without treatment, average size of the ice crystals was around 90.26μm2 and 113.73μm2, and average diameter of the ice crystals was 5.83μm and 8.14μm, respectively; furthermore, it enhanced the solubility and zeta potential, lowered the surface hydrophobicity, reduced the particle size, and maintained the secondary and tertiary structures of myofibrillar protein (MP) after repeated freeze-thawing. Gel electrophoresis revealed that the AUS treatment mitigated the denaturation of MPs. Scanning electron microscopy revealed that the AUS treatment preserved the structure of the tissue. These findings demonstrated that the AUS treatment could enhance the water retention and physicochemical properties of protein within aquatic meat products during temperature fluctuations..

A near‐infrared spectroscopy method for the detection of texture profile analysis of Litopeneo vannamei based on partial least squares regression

AbstractAmong aquatic products freshness testing methods, spectral detection method is the most commonly used rapid nondestructive testing method, and the quality structure index can be used as the judgment index of aquatic products freshness, so studying the near‐infrared (NIR) spectroscopy detection method of aquatic products based on texture index is helpful to improve the detection accuracy of freshness of products. In order to find a method for NIR spectroscopy based on texture indicators, we took shrimp as the research target, collected total 216 NIR spectral data of 680–2600 nm and texture index of sample for 8 consecutive days, and established a quantitative prediction model. In this study, we compared the effects of six spectral pretreatments on partial least squares regression (PLSR) models, including multiple scattering correction, standard normal variate transformation, mean centering, Savitzky–Golay (S‐G) smoothing, moving average method, and normalization. The results show that the PLSR model based on S‐G smoothing has the best model accuracy in prediction after the S‐G smoothing algorithm has preprocessed the spectral data. In addition, principal component analysis and the Mahalanobis distance algorithm were used in the study to remove abnormal samples to improve the accuracy of the model. Finally, the quantitative prediction model for qualitative construct indicators constructed based on the S‐G smoothing algorithm and the PLSR algorithm had better prediction results than the other models algorithm we considered, with a correlation coefficient (R) of 0.868 for the cohesive validation set and 0.781 for the elastic validation set of qualitative construct indicators. Finally, based on the above study, this study developed a prediction graphical user interface system for qualitative metrics of texture.Practical ApplicationsMost of the existing aquatic meat freshness detection methods are offline detection based on physical and chemical tests, and some use spectral technology to detect the chemical parameters of aquatic meat freshness. This project innovatively applies NIR spectroscopy technology to aquatic products. The physical parameters of meat freshness can be quickly detected online. By preprocessing the data samples and selecting the response characteristic wavelengths, a NIR spectroscopy prediction model of texture indicators with self‐learning ability and high precision is constructed, and the texture is established based on this. Indicator NIR spectroscopy prediction system. This whole process provides new research methods and analytical tools for rapid nondestructive testing of aquatic product freshness.

Comparison of the Nutritional Composition of Bullfrog Meat from Different Parts of the Animal.

The objective of this study was to evaluate the nutritional content of bullfrog meat from different parts of the animal, including fore-chest, thigh and calf. Bullfrog meat was found to be a rich source of proteins, essential amino acids and minerals, but with a low fat content, compared with other aquatic meat products. There was no significant difference (p>0.05) between thigh and calf in mineral content (K, P, Na, Mg, Ca, Zn, Fe, Cu, and Mn), but the contents of K, P, and Mg were higher in thigh and calf than in the fore-chest (p<0.05). The salt-soluble, water-soluble and insoluble protein bands in sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) electrophoresis, from fore-chest, thigh and calf were similar, with the most abundant bands being 35 kDa (salt-soluble protein), 35–48 kDa (water-soluble protein) and 48 kDa (insoluble protein). The results showed that the insoluble protein content in the fore-chest meat was higher than that in the thigh meat and calf meat, but the salt-soluble protein fraction was the most abundant in thigh meat. These results showed that the nutrients in different parts of bullfrog meat were different.

Changes in the Microbial Communities of Tiger Frog (Rana tigrina) Meat during Refrigerated Storage

Microbial activity is the major cause of the spoilage of aquatic meat products during storage. This study investigated the changes of the microbial compositions of the tiger frog (Rana tigrina) meat stored aerobically at 4°C for 12 days using 16S rRNA amplicon high-throughput sequencing analysis. The microbial diversity and species richness of the frog meat were abundant at the initial phase of storage but decreased substantially with prolongation of the storage time. Proteobacteria was the prevalent phylum identified from the frog meat, with a relative abundance of 40.29% at day 0 increasing to 96.77% at day 6 and 95.41% at day 12. At the genus level, Shewanella, Pseudomonas, and Acinetobacter were the three dominant genera in the spoiled samples and contributed to frog meat spoilage. Their proportions were 41.67, 28.48, and 5.94% at day 6 and 29.94, 23.48, and 18.44% at day 12, respectively. The present study is conducive to understanding the pattern and process of frog meat spoilage during refrigeration and could be used to develop efficient control measures to mitigate the predominant psychrotrophic spoilers in aerobically stored frog meat.

Adulteration of aquafeed with melamine and melamine‐formaldehyde chemicals; Ex situ study of impact on haematology and antioxidant systems in Clarias gariepinus

Adulteration of aquafeed has raised critical concern regarding quality and safety of aquatic meats. This study assessed the impact of melamine (MEL) and melamine-formaldehyde (MEF) chemicals (adulterants) on haematology, gill and liver antioxidant enzymes activities of Clarias gariepinus. Fish were fed diets contaminated with MEL and MEF at 3.0 g Kg−1 (0.3%) dietary inclusion for 45 days, followed by a depuration trial that lasted for 30 days. Body biomass of MEL- and MEF-treated groups decreased markedly, relative to the control. Haematological parameters such as red blood cell, white blood cell, haemoglobin and packed cell volume contents of the treated groups reduced prominently, while antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase) activities were suppressed, particularly in the liver of the treated groups. Additionally, toxicity of MEL and MEF caused significant increase in malondialdehyde (MDA) content in the gill and liver tissues of the exposed groups. However, antioxidant enzymes activities and haematology were restored to the normal physiological condition, during the recovery (depuration) phase. MEL- and MEF-induced toxic effects on the exposed fish and the findings of the current study provides baseline information and insight on the adverse impact of these chemicals in aquatic models.

Country-specific dietary shifts to mitigate climate and water crises

Undernutrition, obesity, climate change, and freshwater depletion share food and agricultural systems as an underlying driver. Efforts to more closely align dietary patterns with sustainability and health goals could be better informed with data covering the spectrum of countries characterized by over- and undernutrition. Here, we model the greenhouse gas (GHG) and water footprints of nine increasingly plant-forward diets, aligned with criteria for a healthy diet, specific to 140 countries. Results varied widely by country due to differences in: nutritional adjustments, baseline consumption patterns from which modeled diets were derived, import patterns, and the GHG- and water-intensities of foods by country of origin. Relative to exclusively plant-based (vegan) diets, diets comprised of plant foods with modest amounts of low-food chain animals (i.e., forage fish, bivalve mollusks, insects) had comparably small GHG and water footprints. In 95 percent of countries, diets that only included animal products for one meal per day were less GHG-intensive than lacto-ovo vegetarian diets (in which terrestrial and aquatic meats were eliminated entirely) in part due to the GHG-intensity of dairy foods. The relatively optimal choices among modeled diets otherwise varied across countries, in part due to contributions from deforestation (e.g., for feed production and grazing lands) and highly freshwater-intensive forms of aquaculture. Globally, modest plant-forward shifts (e.g., to low red meat diets) were offset by modeled increases in protein and caloric intake among undernourished populations, resulting in net increases in GHG and water footprints. These and other findings highlight the importance of trade, culture, and nutrition in diet footprint analyses. The country-specific results presented here could provide nutritionally-viable pathways for high-meat consuming countries as well as transitioning countries that might otherwise adopt the Western dietary pattern.

Misunderstandings, myths and mantras in aquaculture: Its contribution to world food supplies has been systematically over reported

This paper re-evaluates the contributions to global food supplies of ‘aquatic animal-source food’ from aquaculture and capture fisheries, and ‘terrestrial animal-source food’ from livestock farming. Four common misunderstandings in the scientific and policy literature are addressed: (1) aquaculture was the fastest growing food production sector over the past three decades, (2) the growth of global aquaculture production is slowing down, (3) aquaculture has surpassed capture fisheries as the main source of fish for human consumption, and (4) production of aquatic animal-source foods has outstripped that of terrestrial animal-source food. These misunderstandings result partly from misuse of statistics: although possessing a relatively high annual growth rate in percentage terms, production of aquatic animal-source food increased from a much lower basal production level than the production of terrestrial animal-source food. Misunderstanding also arose partly from differences in the ways that aquatic and terrestrial animal-source food production are reported in global statistics. These differences systematically biased the reported gross weight of aquatic animal-source food produced globally upwards relative to that of terrestrial animal-source food. Comparing edible portions of aquatic and terrestrial animal-sources foods revealed the following four main points: first, although having a high annual growth rate in percentage terms, growth in the production of edible aquatic food has lagged far behind that of terrestrial meat by volume; second, aquaculture production has continued to increase despite a declining growth rate and is likely to do so in the future to meet the needs of an increasingly populous and affluent world; third, capture fisheries still produce more edible aquatic food than aquaculture, and fourth, global production of beef exceeds that of farmed aquatic meat. Poultry is the largest animal-source food producing sector and is growing faster than aquaculture by volume.

Effects of macro-nutrient, micro-nutrient composition and cooking conditions on in vitro digestibility of meat and aquatic dietary proteins

Animal and aquatic meats represent important sources of dietary protein and micro-nutrients. Although red and processed meats carry some risks for human health, sensory and nutritional advantages drive meat consumption. Therefore, it is important to understand how meat processing and cooking influence healthiness. The research aim was to investigate relationships of meat composition (proximates, amino acids and minerals) and cooking conditions (raw, 90 s microwave, 200 °C oven for 10 or 30 min) on protein digestibility, for a selection of four animal (beef, chicken, pork, kangaroo) and four aquatic meats (salmon, trout, prawn, oyster). Lean meats were minced before cooking followed by in vitro gastro-intestinal digestion and analysed for progress of hydrolysis, and size ranges of peptides using MALDI-TOF-MS. Correlation matrix analysis between compositional and functional parameters indicated that digestibility was significantly linked with protein and metal concentrations, likely reflecting moisture-dependent solubility and inter-mixing of sarcoplasmic metallo-proteins and insoluble myofibrillar proteins.

Muscle and carapace tissue–diet isotope discrimination factors for the freshwater crayfish Cherax destructor

This study examined a range of diets and two tissue types (muscle and carapace, representing protein and chitin biochemistry respectively) of Cherax destructor (Clark, 1936) to allow more accurate use of isotope data in trophic source estimates. The resulting Δ13Ctissue–diet and Δ15Ntissue–diet discrimination factors of muscle and carapace tissues showed significant differences among diets. For muscle, Δ13Ctissue–diet was higher (2.11–2.33‰) when C. destructor was fed with lamb, turkey and mixed animal and plant-based diets, 1.27–1.96‰ when C. destructor was fed with beef and kangaroo diets and negative (–1.36‰) when C. destructor was fed with an aquatic meat (tuna) diet. The Δ15Ntissue–diet discrimination factors were lower for muscle when C. destructor was fed aquatic meat (0.12‰) and mixed plant–animal diets (1.67‰), but higher for terrestrial meat diets (2.79–3.74‰). The Δ13Ctissue–diet for carapace followed similar patterns to that of muscle, but Δ15Ntissue–diet values were lower for carapace than muscle. Strong correlations were observed between muscle and carapace for δ13C (r=0.96, P&lt;0.0001) and δ15N (r=0.82, P&lt;0.0012) across the six diets evaluated, indicating that carapace can be used as a non-lethal alternative to muscle during field sampling.

Development and validation of short-amplicon length PCR assay for macaques meat detection under complex matrices

ABSTRACTThe macaque (Macaca fascicularis) monkeys are the third largest primate population in tropical forests. Being the potential carrier of Simian Immunodeficiency and Ebola and Corona viruses, as well as being a religiously-protected and wildlife-protected species could not save the macaques from being over-hunted and consumed. Despite having needs, methods to detect monkey species in foods are rarely documented. To fill this gap, this article describes a monkey-specific polymerase chain reaction assay targeting a short-site (120 bp) of mitochondrial d-loop gene because the short-length targets are thermodynamically more stable than the longer ones under degrading states. Specificity was tested against 17 terrestrial and aquatic meat and fish species and no cross-species amplification was detected under raw, processed, and admixed states. The sensitivity of the assay was 0.0001 ng DNA under pure states and 0.1% monkey meats in binary meat mixtures. Finally, the assay was validated by digesting the polymerase chain reaction products with AluI and CViKI-1 and distinctive restriction fingerprints for macaque species were demonstrated.