ABSTRACT
Identification of meat species origin using reliable techniques is a critical requirement for ensuring label compliance, protection of consumer preference and prevention of fraudulence in the meat trade. Although a plethora of protein and DNA based meat species identification techniques are in vogue, need for rapid test suitable for under-resourced laboratories catering point-of-care (PoC) services was construed. Present study deals with development of rapid sheep (Ovis aries) meat identification technique using DNA extraction by alkaline lysis (AL) and loop-mediated isothermal amplification (LAMP) technique. The AL-LAMP specifically amplifies sheep-specific signal of mitochondrial D loop region under an isothermal temperature of 60 °C with an analytical sensitivity of 0.5 ng sheep DNA. The test was highly specific to sheep and performed well even in the presence of DNA of closely related meat animal species such as goat, cattle, buffalo and chicken. The novel primers designed for the AL-LAMP successfully detected sheep meat in raw and cooked meat samples heated up to 121 °C for 30 min. Sheep-specific AL-LAMP assay could detect 0.1% mutton-in-beef adulteration. Novel AL-LAMP assay being simple, rapid and reliable for sheep meat authentication in just 120 min; hence, it could be conveniently used by terminal laboratories engaged in rendering on-site or PoC services.
ABSTRACT
The processing of sous vide chicken sausages was optimized under vacuum packaging condition and cooking at 100 â for 30 min (SV30), 60 min (SV60) and 120 min (SV120) and compared with aerobically cooked control at 100 â for 30 min. Sous vide processing of chicken sausages (SV30) produced higher (p < 0.05) cooking yield, Hunterlab a* values and sensory attributes without affecting proximate composition and shear force values relative to control. The sodium dodecyl sulphate-polyacrylamide gel electrophoresis and scanning electron microscopy results revealed no significant changes in protein quality and emulsion ultra-structure due to SV30 processing relative to control sausages. Sous vide processing of chicken sausages enriched with rosemary diterpene phenols retained the freshness and quality up to 120 days during storage at 4 ± 1 â relative to control sausages that were spoiled on 20th day. Lipid oxidation and microbial growth remained below the spoilage levels for all the SV-processed sausages throughout the storage and addition of rosemary diterpene mixture at 0.02% v/w reduced the microbial growth and improved (p < 0.05) the sensory attributes. Our results demonstrate that sous vide processing minimizes lipid oxidation and microbial growth of chicken sausages with improved product quality and shelf-life at 4 ± 1 â.
