Bio-chemical composition, functional, and rheological properties of fresh meat from fish, squid, and shrimp: A comparative study

Shrimp Lipid Bioactives with Anti-Inflammatory, Antithrombotic, and Antioxidant Health-Promoting Properties for Cardio-Protection

Marine animals, especially shrimp species, have gained interest in research, due to the fact that they contain a plethora of biomolecules, specifically lipids, which have been proven to possess many health benefits in various diseases linked to chronic inflammation or other exogenous factors. This review refers to the lipid composition of a large number of shrimp species, as well as the effects that can alternate the lipid content of these crustaceans. Emphasis is given to the potent anti-inflammatory, antioxidant, and antithrombotic properties of shrimp bioactives, as well as the effects that these bioactives hold in other diseases, such as cancer, diabetes, neurodegenerative disorders, and more. The various health-promoting effects deriving from the consumption of shrimp lipid bioactives and the usage of products containing shrimp lipid extracts are also addressed in this study, through the exploration of several mechanisms of action and the interference of shrimp lipids in these biochemical pathways. Nevertheless, further research on this cultivatable edible species is needed, due to their existing limitations and future prospects which are discussed in this paper.

Optimized spray-dried conditions' impact on fatty acid profiles and estimation of in vitro digestion of spray-dried chia/fish oil microcapsules

Long-chain polyunsaturated fatty acids (LCPUFA) are of interest due to their potential health properties and have a significant role in reducing the risk of various chronic diseases in humans. It is commonly used as a supplement. However, lipid oxidation is an important negative factor caused by environmental, processing, and limited water solubility of LCPUFA, making them difficult to incorporate into food products. The objective of this research work was to prevent oxidation, extend shelf life, enhance the stability of fatty acids, and to achieve controlled release by preparing spray-dried powder (SDM). For spray-drying, aqueous emulsion blends were formulated using a 1:1 ratio of chia seed oil (CSO) and fish oil (FO) and using a laboratory-scale spray-dryer with varying conditions: inlet air temperature (IAT, 125-185 °C), wall material (WM, 5-25%), pump speed (PS, 3-7 mL/min), and needle speed (NS, 3-11 s). The maximum alpha-linolenic acid (ALA) content was 33 ± 1%. The highest values of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the microcapsules were 8.4 ± 0.4 and 13 ± 1%, respectively. Fourier transform infrared and X-Ray diffraction analysis results indicated that SDM was successfully formulated with Gum Arabic and maltodextrin (MD). The blending without encapsulation of CSO and FO was digested more efficiently and resulted in more oil being released with simulated gastric fluid (SGF), simulated intestinal fluid (SIF), and SGF + SIF conditions without heating. No significant changes were observed for saturated, monounsaturated, and LCPUFA, whether exposed or not to gastrointestinal conditions. However, compared to the release of SDM, it can be useful for designing delivery systems for the controlled release of essential fatty acids.

Paramyosin from field snail (Bellamya quadrata): Structural characteristics and its contribution to enhanced the gel properties of myofibrillar protein

To assess the blending effect of field snails with grass carp muscle, the effects of paramyosin (PM) and actomyosin (AM) with different mixture ratios on the gel properties of the binary blend system were investigated in our work. The purified PM from field snail muscle was about 95 kDa on SDS-PAGE. Its main secondary structure was α-helix, which reached to 97.97 %. When the amount of PM increased in the binary blend system, their rheological indices and gel strength were improved. The water holding capacity (WHC) increased to 86.30 % at a mixture ratio of 2:8. However, the WHC and the area of immobile water (P22) dramatically decreased, and the area of free water (P23) increased when the mixture ratio exceeded 4:6. The low level of PM in binary blend system promoted the formation of a homogenous and dense gel network through non-covalent interactions as observed results of SEM and FTIR. When there were redundant PM molecules, the development of heterostructure via hydrophobic interaction of tail-tail contributed to the reduced gel properties of the binary blend system. These findings provided new insight into the binary blend system of PM and AM with different ratios to change the gel properties of myofibrillar protein.

First successful head-start program of leatherback sea turtles (Dermochelys coriacea) in Thailand and proposed dietary strategy

Leatherback sea turtle (Dermochelys coriacea) hatchlings have previously been kept alive for over a year in captive conditions but these were the few survivors of initially larger groups. In this report, newly hatched leatherback sea turtles were randomly harvested from two nests in Thailand and successfully reared before release back to the wild. In captivity, the survival of the turtles decreased sharply during the first 4 or 5 months, and then steadied until the end of the 12-month trial. The survival of yearlings from one nest was 13.3% and from the other nest 46.7%. Their growth was exponential, reaching 1.36-3.35 kg (n = 9) at the end of program. The causes of death of the reared turtles were accidents (25.0-38.5%) and infections from water and live food (61.5-75.0%). The dietary requirements of the turtles were investigated by determining the digestibility of protein and carbohydrate in vitro, using enzymes from the digestive tracts of hatchlings that had died in an accident (70.1-92.9 g body weight). The results indicated that the most suitable source of protein was wheat gluten, followed by soybean meal, nonruminant meat and bone meal, fish meal, nonruminant meat meal, pork meal, and skimmed milk, while suitable carbohydrate sources were mashed cassava, corn, wheat flour, and alpha starch, followed by cereal meal and rice flour. Findings from the current report provide a practical protocol for head-starting leatherback sea turtles, and indicate the possible basis of an effective artificial diet for this species.

Comparative investigation of various modification methods on Trachypenaeus Curvirostris surimi gel: Gelling properties, rheological behaviors and structure characteristics

The aim of this study was to compare the investigations of various contents of egg white protein (2.0%-8.0%, EWP), microbial transglutaminase (0.1%-0.4%, MTGase), and konjac glucomannan (0.5%-2.0%, KGM) on the gelling properties and rheological behavior of Trachypenaeus Curvirostris shrimp surimi gel (SSG), and assessed the modification mechanisms through the analysis of structure characteristics. The findings suggested that all modified SSG samples (expect SSG-KGM2.0% ) had the higher gelling properties and the denser network structure than those of unmodified SSG. Meanwhile, EWP could give SSG a better appearance than MTGase and KGM. Rheological results showed that SSG-EWP6% and SSG-KGM1.0% had the highest G' and G″, demonstrating that the formation of higher levels of elasticity and hardness. All modifications could increase gelation rates of SSG along with the reduction of G″ during the degeneration of protein. According to the FTIR results, three modification methods changed SSG protein conformation with the increasing α-helix and β-sheet contents and the decreasing of random coil content. LF-NMR results indicated that more free water could be transformed into immobilized water in the modified SSG gels, which contributed to improve the gelling properties. Furthermore, molecular forces showed that EWP and KGM could further increase the hydrogen bonds and hydrophobic interaction in SSG gels, while MTGase could induce the formation of more disulfide bonds. Thus, compared with another two modifications, EWP modified SSG gels showed the highest gelling properties.

Total mercury and fatty acids content in selected fish marketed in Quito - Ecuador. A benefit-risk assessment

Total mercury and fatty acids contents were determined in muscles of croaker, snapper, dolphinfish, blue marlin, and shark, from different markets in the Metropolitan District of Quito, Ecuador. Fifty-five samples were collected and analyzed for total mercury using cold vapor atomic fluorescence spectrometry, and the fatty acids were analyzed using gas chromatography equipped with a flame ionization detector. The lowest total mercury levels were found in snapper [0.041 µg·g^-1 wet weight (ww)] while blue marlin showed the highest (5.883 µg·g^-1 ww). EPA + DHA ranged from 1.0 mg·g^-1 in snapper to 2.4 mg·g^-1 in shark. A high omega-3/omega-6 ratio was found for all fish types; however, the HQ_EFA for the benefit-risk ratio was above 1, suggesting an evident risk to human health. Based on our results, consumption of croaker and dolphinfish is recommended up to one serving per week, considering the importance of EFAs intake and avoiding fish with elevated MeHg content. Therefore, Ecuadorian authorities could enhance public standards for seafood safety and develop consumer advice for pregnant women and young children to determine good fish choices or those to avoid.

Increasing the Efficiency of Food Material Cutting during Inclined and Shear Movements of Knife

Mathematical models for predicting the resistance forces that are developed during the inclined and sliding cutting of food materials have been developed. The dependence of the actual cutting angle on the angle of inclination and sliding speed of the cutting edge at various sharpening angles have been investigated. For the inclined cutting mode, the dependence of the useful resistance force on the cutting speed has been determined at various angles of inclination of the cutting edge and designed sharpening angles. For the sliding cutting mode, the dependence of the useful resistance force on the feeding speed has been demonstrated at various sliding speed values and designed knife sharpening angles. The dependence of the transformed dimensionless sharpness of the knife on the angle of inclination of the cutting edge and the sliding speed has been established for different constructional sharpness values of the knife. The results of the study indicate that the useful resistance force is significantly reduced during the inclined and sliding cutting processes when compared with the normal cutting process, and a change in the pattern of fiber destruction, which significantly increases the cutting efficiency of cutting tools, is obtained.

Nutritional Composition of Salmonidae and Acipenseridae Fish Eggs

Analysis of the physicochemical properties of fresh eggs (raw material for caviar production) of the Salmonidae [sea trout (Salmo trutta L. 1758) and rainbow trout (Oncorhynchus mykiss, Walbaum 1792)] and the acipenseridae [siberian sturgeon (Acipenser baeri Brandt, 1869)], as well as sturgeon hybrids (Acipenser baeri Brandt, 1869 × Acipenser gueldenstaedti Brandt & Ratzeburg, 1833), included determination of basic physicochemical parameters (pH, dry weight, content of protein, fat, fiber and ash), amino acid composition and fatty acid profile. Compared to the Acipenseridae, Salmonidae eggs yielded a 22.5% higher total protein content, a 40.0% higher level of essential amino acids (EAA) and a 57.5% lower crude fat content. The sea trout eggs showed also a completely different fatty acids profile and hence values of lipid indices (lowest PUFA value – 11.72%, highest SFA value – 39.86%). The rainbow trout and sturgeon eggs had a similar fatty acid profile, and were characterized by a high nutritional and dietary value.