Incorporation of Prosopis cineraria Extract Improved the Mechanical, Barrier and Antioxidant Properties but Not the Antibacterial Activity of Tigertooth croaker Fish Scale Gelatin Film.

Scale gelatin films derived from croaker fish and infused with Prosopis (Prosopis cineraria) extract (PE) at concentrations of 0.3% and 0.7% were produced. A control film, void of extract, was employed for comparative purposes. The thickness of each film was found to be statistically insignificant (p > 0.05). The results show that the highest solubility (78.57 ± 3.57%) was found for the glycerol film, and the least permeability was found for the water vapor (0.74 ± 0.09 ×10-10g s-1m-1Pa-1); however, the water vapor permeability (WVP) and water solubility (WS) of the films that contained PE were considerably lower than those of the control film (p < 0.05). In contrast to the control film, those infused with 0.7% PE exhibited exceptional UV-barrier properties (>99%) and favorable thermal characteristics. The highest and lowest antioxidant activities were found for the 7% Prosopis cineraria extract (56.96 ± 2.6%) and the glycerol film (40.66 ± 2.46%), respectively. No antibacterial activity was observed in these films. Microscopic pictures showed that all three films had a uniform and plain surface. Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) analysis revealed distinct amide bands and protein-polyphenol interactions within the films that contained the extract.

Risk assessment of trace element accumulation in two species of edible commercial fish Scomberoides commersonnianus and Cynoglossus arel from the northern waters of the Oman Sea.

Concentrations of heavy metals, namely, cadmium, copper, zinc, lead, and chromium were measured in the muscle tissue of Scomberoides commersonnianus and Cynoglossus arel from the northern waters of the Oman Sea. Human health risk assessment for Iranian child and adult consumers were also evaluated. The mean concentration of zinc and copper were lower than international standards of maximum permissible limits (MPL). The estimated daily and weekly intakes (EDI and EWI) of all metals were lower than permissible tolerable daily intake (PTDI). The permissible frequency of fish consumption (CRmm) of S. commersonnianus and C. arel showed that they are safe for both children and adults even at a high meal frequency (>16 meals/month). Target hazard quotient (THQ) and risk index (HI) values were higher than 1 for Cu in adults, Cu and Zn in children with consumption rate of 7 times per week. Therefore, consumption of these spices of Oman Sea more than 7 times per week can threaten the health of consumers.

Effect of phlorotannins on melanosis and quality changes of Pacific white shrimp (Litopenaeus vannamei) during iced storage.

Effect of phlorotannins (PT) treatments on the ployhenoloxidase (PPO) activity and quality changes of Pacific white shrimp during a 16-day period of storage in ice were studied. Among seaweeds, Sargassum tenerimum had the highest amount of PT (10.00 mg phloroglucinol/g), PPO inhibitory activity (71.94%) and therefore selected for PT extraction. The shrimp treated with 5% PT (w/v) showed the least melanosis score, pH, TVB-N values and lipid oxidation among all treatments throughout the iced storage. Lower counts of mesophilic and psychrotrophic bacteria (1-2 log CFU/g) were obtained with 5% PT treatment compared to the control at the last day of storage (P < 0.05). Sensory evaluation proved that 5% PT treatment could cause a 4-days increase in the shelf-life of shrimp compared to the control, PT1% and PT2% treatments. Therefore, 5% phlorotannins from S. tenerimum could be used as a safe melanosis inhibitor for the treatment of shrimp.

Assessment of metal accumulation in two fish species (Tenualosa ilisha and Otolithes ruber), captured from the north of Persian Gulf.

The relationship between size (length and weight) and metal concentrations in different tissues of two commercially valuable fish species (Hilsa shad, Tenualosa ilisha and tiger tooth croaker, Otolithes ruber) from the north of Persian Gulf were evaluated. Concentrations of the metals in fish species ranged as follows: Cd 0.08-1.34; Pb 0.67-4.43; Cu 3.07-23.38; Co 0.64-5.03; Ni 2.15-7.69 µg/g dry weight, respectively. Metal content in both fish varied with type of metals and tissues. Results showed significant positive relationships between metals and fish size in T. ilisha, while those in O. ruber were not significant in most cases.

A new species of freshwater crab of the genus Sodhiana Yeo & Ng, 2012 (Decapoda: Brachyura: Gecarcinucidae) from southern Iran.

A new species of freshwater crab, Sodhiana iranica n. sp. (Decapoda: Brachyura: Gecarcinucidae), is described from Bastak, Iran. This is fourth species of Sodhiana Yeo & Ng, 2012, described, and is the second one known from Iran. It can be distinguished from congeners by the form of its carapace and the structure of the male first gonopod.

Effects of refrigerated storage on the microstructure and quality of Grouper (Epinephelus coioides) fillets.

Refrigerated storage is the simplest method of preserving for short time handling and storage of fish. The objective of this study was to investigate the effects of refrigerated storage on the microstructure, physicochemical (proximate composition, pH, TVB-N, LHC), microbial (total mesophilic count, TMC and total psychrotrophic count, TPC) and sensory changes of grouper (Epinephelus coioides) fillets during a 14-day period at +4 °C. The estimated TVB-N value was significantly different in all days of storage. TPC value reached to a limiting level for human consumption (10(7) micro-organism/g) after the 10th day of storage while TMC remained under the limited acceptability until 14 days. Cellular tissue damage was observed after 7 days of storage. The shelf life of grouper was approximately ~8-9 days according to the results of sensory, chemical and microbial analysis.

Metal concentrations in two commercial fish from Persian Gulf, in relation to body length and sex.

The relationship between sex, size (length and weight) and metal concentrations in the tissues of two commercially valuable fish species (silver pomfret, Pampus argenteus and tiger tooth croaker, Otolithes ruber) from Persian Gulf were evaluated. Concentrations of the metals in fish species ranged as follows: Mn 0.743-11.279; Cd 0.175-2.375; Pb 2.406-11.297; Zn 10.837-80.389; Fe 2.263-86.110; Cu 1.503-6.333 µg/g dry weight, respectively. Metal content in both fish varied with type of metals, organ, and sex. Results showed that, except in a few cases, significant relationships between metal concentrations and fish size were negative.