Steroid hormones, small lipophilic substances, are often illegally used as growth-promoting agents in the animal husbandry and breeding industry. Residual hormones in dairy products can enter the human body through the food chain causing a series of health hazards. Residues of steroid hormones in dairy products have become the focus of worldwide concern about veterinary drug residues. Regulations have been issued to limit the content of steroid hormones in dairy products in China. This paper discusses the structure, classification and functions of steroid hormones, and summarizes the maximum residue limits, detection methods, contents and health risks of steroid hormones in dairy products, aiming to provide a reference for further research of steroid hormones in dairy products.

In this paper, the extraction of furfural compounds (hydroxymethyl furfural, furfural, furyl methyl ketone and methyl furfural) from cheese and condensed milk for analysis by high performance liquid chromatography (HPLC) was optimized. The optimal parameters were determined as follows: 30 min ultrasonic extraction using ultrapure water as the extraction solvent at a solid-to-solvent ratio of 0.05:12 (g/mL). After release of bound furfural compounds and deprotenization, the HPLC analysis was performed. Under the optimized conditions, recoveries for spiked samples were more than 95%. The content of furfural compounds in processed cheese was significantly higher than that in cheese, and the content of furfurals in sweetened condensed milk was significantly higher than that in evaporated milk. Moreover, the amount of furfural compounds relative to per gram of protein in cheese, condensed milk and liquid dairy products followed the decreasing order of sweetened condensed milk > processed cheese > browning yogurt > room temperature yogurt > condensed milk > low temperature yogurt > ultra-high temperature sterilized milk > cheese > pasteurized milk.