Meat and Meat Product Testing

Mandli, Jihane, et al. Food chemistry 255 (2018): 380-389.

Due to its lower cost compared to other meats, pork is often added to food products and is considered a potential adulterant in raw meat. To detect the presence of different animal species in food, food control laboratories must be able to differentiate between the animal species used in the raw materials.

An ELISA/immunosensor was developed for the sensitive detection of pork adulteration in meat. Two forms of ELISA were conducted. First, the extracted IgG was directly immobilized on a microplate. This assay was able to identify pork adulteration levels as low as 0.01% within 14 hours and 15 minutes. To shorten the assay time, a competitive ELISA was developed, where a standard IgG was immobilized to compete with the extracted IgG. This assay detected pork adulteration levels as low as 0.1% in 45 minutes.

Wang, Kangkang, et al. Journal of Food Composition and Analysis 107 (2022): 104375.

Nitrofurans (NFs) are synthetic antimicrobial drugs widely used as feed additives in food animals or veterinary medicine. However, the most common NFs have been banned worldwide for use in animal husbandry due to their carcinogenic and teratogenic risks. Research has shown that NFs rapidly metabolize in vivo into protein-bound metabolites, resulting in a very short half-life, making them undetectable within hours after administration. The metabolites produced are toxic and remain highly stable over a long period (weeks or even months). Furthermore, these metabolites can be passed along the food chain, posing serious safety risks to human health. Currently, effective regulation of NF residues in meat products focuses primarily on detecting these highly stable metabolites.

A rapid and sensitive analytical method was developed to simultaneously monitor four nitrofuran metabolites (NFMs) in meat products using ultra-high-performance liquid chromatography with fluorescence detection (UHPLC-FLD). The NFMs were derivatized with 4-(N,N-diphenylamino)benzaldehyde (DABA) through isothermal ultrasonic treatment within 20 minutes. Results confirmed that the four NFM derivatives exhibited strong fluorescence responses at specific excitation (λ_ex = 260 nm) and emission (λ_em = 500 nm) wavelengths, and all NFM derivatives were fully separated on a reversed-phase Syncronis C18 column within 10 minutes. The limits of detection (LOD) and quantification (LOQ) of this novel method ranged from 0.21 to 0.28 μg/kg and 0.69 to 0.92 μg/kg, respectively. The four NFMs demonstrated good linearity (R > 0.998), and the recoveries were high, ranging from 91.6% to 104.0%. This method was successfully applied to the determination of NFM content in fish, shrimp, and chicken.

Wang, Menglin, et al. Journal of Food Composition and Analysis 127 (2024): 105969.

The fluorescence intensity of lomefloxacin and chlortetracycline hydrochloride is significantly enhanced after complexing with Al³⁺, and the synchronous fluorescence spectra of the two complexes can be well separated at Δλ = 70 nm. Based on this, a new method was developed in this study for the determination of lomefloxacin and chlortetracycline hydrochloride residues in meat products using Al³⁺-sensitized synchronous fluorescence spectroscopy.

The results showed that the concentrations of the two antibiotics had a good linear relationship with synchronous fluorescence intensity in the ranges of 1–550 ng/mL and 5–1800 ng/mL, respectively. The detection limits for lomefloxacin and chlortetracycline hydrochloride were 0.0378 μg/kg and 0.3530 μg/kg, respectively. The recovery rates of lomefloxacin and chlortetracycline hydrochloride in meat samples were 86.1–90.2% and 85.3–96.5%, respectively. The newly established synchronous fluorescence spectroscopy method is characterized by high sensitivity, good selectivity, low detection limits, fast detection speed, and high accuracy. It has been successfully applied to the detection of lomefloxacin and chlortetracycline hydrochloride residues in meat samples with satisfactory results.