Alam Akm Nowsad

Thermal gelation characteristics of breast and thigh muscles of spent hen and broiler and their surimi

Spent hen (98 weeks) and broiler (12 weeks) breast and thigh muscles were minced (1 mm orifice diameter) and washed with 0.1% NaCl. A portion of both unwashed and washed mince was mixed with cryoprotectants (CP) at the rate of 4% sucrose, 4% sorbitol, and 0.2% Na-tripolyphosphate to produce surimi and kept frozen at -20°C. The mince and surimi were ground with 3% NaCl and a small amount of water to adjust the final moisture content of 80%. The pastes were stuffed into the sausage casing and heated at 90°C for 15 min to produce gel. The effects of washing, heating and CP on colour composition and thermal gelation properties of hen and broiler minces and surimi were compared. Broiler mince was lighter and less red in colour, higher in protein and lower in moisture, lipid and collagen. Gel strength and breaking strength were higher in spent hen surimi compared to broiler surimi under similar gelation conditions. Gel elasticity, springiness and water retention properties were almost identical in two surimi. Gel quality was markedly deteriorated in spent hen surimi but not so in broiler surimi after 8 weeks frozen-storage. Although CP increased the gel strength of fresh surimi (non-frozen, 0 week storage) from both hen and broiler, they were more effective in broiler surimi than hen surimi in protecting the functional quality of gel.

Evaluation of artificially contaminated fish with formaldehyde under laboratory conditions and exposure assessment in freshwater fish in Southern Bangladesh

Formalin can be added as preservative to fresh foods to prevent spoilage and extend shelf life. Formalin contains 37-40% formaldehyde, which is classified as carcinogenic to humans. To assess the public health risk associated with formaldehyde exposure in freshwater fish in Southern Bangladesh, formaldehyde concentrations (mg/kg) were determined in tilapia, Indian major carp rui, Chinese carp and a minor carp from local market and in laboratory simulations (0.5, 1.0, 2.0 and 4.0% formaldehyde solution for 5, 15, 30 and 60 min) with spectrophotometric and high performance liquid chromatography (HPLC) methods. A food frequency questionnaire was used to collect fish consumption (kg/kg BW. d) data from 400 respondents. A probabilistic exposure assessment was conducted using @Risk®7.0 software. Fish treated with formalin at increasing concentrations and exposure time showed increased trends of formaldehyde acquisition irrespective of fish species and analytical methods used (p < .05). Compared to spectrophotometry, the HPLC method was shown to be more sensitive and is therefore the preferred method for formalin quantification. Maximum exposure to formaldehyde (0.28 mg/kg BW. d) was calculated for tilapia using HPLC analysis. Margin of exposure (MoE) provides high priority (<10,000) for tilapia and Indian major carp rui at P99 under spectrophotometric analysis whereas as determined using HPLC, tilapia had MoE values much lower than 10,000 at P99, P95 and P90 (both total population and consumers). Exposure to formaldehyde associated with freshwater fish consumption is a public health concern in Southern Bangladesh and needs further assessment and risk management strategies.