Dairy products are favored by more and more consumers because of their rich nutrients and good taste, and have become an important part of consumers’ dietary structure. At the same time, the food safety of dairy products has become the focus of consumers’ attention. Therefore, controlling dairy food safety is a top priority for every dairy company. This article expounds on the food safety control measures for ensuring quality and safety in each link of the dairy product production process. To ensure the safety of milk sources, pasture construction and management and risk control during breeding activities need to be considered. The control of raw and auxiliary materials needs to be carried out by considering the acceptance system, storage of raw and auxiliary materials, and upstream supplier management and control. The control of the production process needs to be carried out from the aspects of personnel, equipment, ingredient and environmental management. In addition, this review highlights the importance of big data technology in dairy food safety risk analysis. We expect that this review will be helpful to relevant enterprises in improving their work on food safety management.

A spectrophotometric method for the determination of tea polyphenols in milk tea powder was developed by using Folin-phenol reagent. Crucial operating parameters such as extraction reagent, number of extraction cycles, temperature and derivatization reagent were investigated. Extraction using 70% methanol solution as the extraction reagent in a hot water bath at 70 ℃ performed twice and oxidization of the resulting extract with Folin-phenol reagent proved optimal. The detection wavelength was selected as 765 nm, and gallic acid was used as the calibration standard for the quantitation of tea polyphenols. The recoveries for whole milk powder spiked at concentration levels of 850–4 500 mg/kg were in the range of 98.9%–104.9%. Good stability and accuracy were achieved. When milk tea powder samples with different contents of tea polyphenols were detected in six replicates, relative standard deviations (RSDs) of 0.29%–0.84% were obtained, indicating good precision. This method proved to be accurate, easy to operate and repeatable with simple and easily available instruments, and thus suitable for the analysis of tea polyphenols in milk tea powder.

In this paper, an ion chromatography method for the determination of galactooligosaccharides (GOS) in milk powder was established. The protein in the sample was precipitated by acetonitrile, and GOS was extracted with acetonitrilewater and purified using a C18 column (or RP column) to remove impurities. The analyte was separated using an ion chromatograph equipped with quaternary gradient pumps and detected with a pulse amperometric detector. The calibration curve of this method had good linearity in the range of 10–300 μg/mL, and the results from repeated sample measurements were stable. The recovery rates from blank samples spiked at levels of 500–2 000 mg/100 g were 82.1%–98.0%. To sum up, this method required simple sample pretreatment and gave accurate results, and it could be suitable for the determination of the GOS content in milk powder samples.

A method for determination of hippuric acid and benzoic acid in dairy products by high performance liquid chromatography (HPLC) is described.The protein samples was precipitated by adding lead acetate and centrifuged,and then the analytes were separated on a C18 column with a mobile phase consisting of ammonium acetate and methanol solution and detected with a UV detector at 230 nm.The results showed that hippuric acid and benzoic acid displayed a good linearity relationship in the concentration range of 1-100 mg/kg.The recovery rate was 95.3％-103.6％.The method proved to be simple,accurate and repeatable.

A method for the determination of fructose,glucose,sucrose,maltose and lactose in fermented milk drink by high performance liquid chromatography (HPLC) with refractive index detector was developed.The samples were extracted with water.The method was performed on a carbonhydrate column using acetonitdle-water as mobile phase.The average spiked recoveries of fructose,glucose,sucrose,maltose and lactose spiked in the concentration range of 0.2％-10.0％ were between 92.6％ and 102.0％ with relative standard deviation (RSD,n =6) less than 3.00％.The limit of quantitation was 0.2％.The results indicated that this method is accurate,simple,reproducible and suitable for the analysis of fructose,glucose,sucrose,maltose and lactose in fermented milk drink.

An analytical method to determine lactulose in ultra high temperature (UHT) sterilized milk by liquid chromatographic separation,evaporative light-scattering detection and external standard quantitation is described in this paper.After the protein was precipitated by adding hydrochloric acid,the separation was performed with satisfactory results on a NH2 column using 75％ acetonitrile in water as the mobile phase.The precision expressed as relative standard deviation (n =6) was 0.77％,and the average recovery was in the range of 98.7％-102.6％.This method was simpler and less time consuming with good repeatability than traditional enzymatic hydrolysis method.It can provide an alternative way of determining lactulose in UHT sterilized milk.

A method for the determination of sucralose in dairy products by high performance liquid chromatography (HPLC) was developed.Samples were deproteinized by adding lead acetate followed by cleanup on an Oasis HLB solid-phase extraction cartridge.The separation was performed on a C18 column with 15％ acetonitrile in water as the mobile phase,and the analyte was detected with an evaporative light-scattering detector (ELSD) detector.The recovery of sucralose at spiked concentration levels of 7.5-70 mg/kg was 94.6％-101.3％.The limit of quantitation at a signal-to-noise ratio of 10 was 7.5 mg/kg.This method proved to be accurate,simple and suitable for the analysis of sucralose in dairy products.

A method for the determination of abamectin residues in dairy products and feed by using high performance liquid chromatography (HPLC) with fluorescence detection after precolumn derivation with trifluoroacetic anhydride and N-methyl imidazole was developed.Abamectin residues were extracted with acetonitrile,cleaned up on a tC18 solid phase extraction cartridge.After precolumn derivatization,the separation was performed on C18 column by gradient elution with methano-acetonitrile-water as mobile phase.The analyte were detected with a fluorescence detector and quantified by an external standard method.The recovery of abamectins spiked into milk powder at 1.5 μg/1 000 g (or 1 000 mL for milk) was higher than 90％.The limit of quantitation was 2 μg/kg for dairy products and 10.0 μg/kg for feed.This method proved to be accurate,simple reproducible,and suitable for the analysis of abamectin residues in dairy products and feed.

A method for detecting acesulfame-K, saccharin sodium, benzoic acid, sorbic acid, dehydroacetic acid, methyl vanillin and ethyl vanillin in dairy products by using high performance liquid chromatography (HPLC) is described. The sample was deproteinated and filtered, then separated on a C18 column with a mobile phase made up of methanol and ammonium acetate solution, and detected for absorbance at 230 nm. The seven substances were completely separated within 35 min. Their calibration curves were linear in the range of 1–100 mg/kg with correlation coefficients (R2) all above 0.999 0 under the selected conditions, and the recovery of the proposed method was 80.0% –105.7%. The method proved to be rapid, simple, and reliable.

A method for the determination of lactulose in milk powder by high performance liquid chromatography (HPLC) was developed. Lactulose was extracted with water. The analysis was performed on a NH2 column using 80% acetonitrile in water as the mobile phase. The recovery of lactulose spiked into milk powder in the range of 0.3–2.0 g/100 g was 97.4%– 103.0%. The limit of detection was 0.3 g/100 g. The results indicated that this method is accurate, simple and suitable for the analysis of lactulose in milk powder.

A method for detecting thiocyanate in dairy products by high-performance liquid chromatography (HPLC) is described. The proteins in the samples were precipitated by the addition of acetonitrile, then the filtrate was separated on a strong anion exchange (SAX) column using a mobile phase made up of a mixture of sodium dihydrogen phosphate solution and methanol. The target compound was detected with a UV detector at 218 nm. The results showed that the calibration curve displayed a good linear relationship in the range of 0.2–100 mg/kg. The recovery rate of thiocyanate was 98.5%– 113.0%.The method is simple with good accuracy and stability for detecting thiocyanate in dairy products.

A method for the determination of nucleotides in milk powder by high performance liquid chromatography (HPLC) was developed. Nucleotides were extracted with water, deproteinated with 0.5% acetic acid and cleaned up by an SAX solid phase extraction (SPE) column. The analysis was performed on C18 column using 0.1 mol/L phosphate as the mobile phase. The recoveries of spiked samples at three levels ranging from 0.3 to 50 mg/100 g were higher than 90%. The limit of quantification was 0.3 mg/100 g. This method was accurate, simple, reproducible, and suitable for the analysis of nucleotides in milk powder.

A method for the determination of fructooligosaccharides in modified milk by high performance liquid chromatography (HPLC) was developed. Fructooligosaccharides were extracted with water. The analysis was performed on a NH2 column using 70% acetonitrile in water as the mobile phase. The recoveries of fructooligosaccharides at four spiked levels between 20 and 500 mg/100 g ranged from 80.2% to 107.1%. The limit of quantification was 20 mg/100 g. This method is accurate, simple and suitable for the analysis of fructooligosaccharides in modified milk.

A method for determining vitamin C (VC) in dairy products by high performance liquid chromatography (HPLC) is described. Samples were added with metaphosphoric acid to precipitate proteins, filtered through filter paper, separated on a C18 chromatographic column with 0.25% metaphosphoric acid solution as mobile phase, detected with a UV detector, and quantified by an external standard method. The method proved simple and rapid with good accuracy and precision. The recovery of VC ranged between 93.6 % and 103.9% with relative standard deviation of 2.56% to 4.05%. The detection limit was 1 mg/kg.

A method for the determination of vomitoxin in milk powder by high performance liquid chromatography (HPLC) was developed. Samples were precipitated and filtered, and the supernatant was then purified and concentrated by immunoaffinity column chromatography, separated by C18 column chromatography, detected by ultraviolet detector and quantified by calibration curve method. The method proved to have good accuracy and precision. The spiked recovery of vomitoxin in dairy products was 98%–106%, and the relative standard deviations were 0.45%–1.21%. The detection limit of vomitoxin was 0.05 mg/kg.

A method for determining lutein in dairy products by HPLC is described. Samples were extracted with acetone and separated with a mobile phase made up of methanol and methyltert-butyl ether. The analysis was performed by UV detection at 445 nm, and the external standard method was used for quantification. This method has good accuracy and precision. The spiked recoveries in milk and milk powder ranged from 86.9% to 101.2% with a relative standard deviation of 2.56% to 4.05%. The detection limit was 0.02 mg/kg, and a linear range of 0.02 to 4 mg/kg was obtained.

A method for the determination of phosphatidylserine in milk powder by High performance liquid chromatography with evaporative light scattering detection（HPLC-ELSD）was developed. Samples were extracted with a mixture of chloroform and methanol. Chromatographic separation was performed on a Diol column by gradient elution using a binary mobile phase system consisting of hexane- isopropanol-acetic acid triethylamine and isopropanol-water-acetic acid-triethylamine. The recoveries of phosphatidylserine in milk powder at spiked levels between 50 and 150 mg/100 g were greater than 85%, and the limit of quantification was 30 mg/100 g. The proposed method has the advantages of accuracy,

Sodium caseinate is commonly used in the food industry. In its many applications as a food ingredient, significant quantities of salts are simultaneously used. Previous studies have shown that co-existing salts can change physiochemical properties of sodium caseinate, especially rheological properties. NaCl has been shown to be able to dramatically increase viscosity of sodium caseinate solution; however, the mechanism is still debatable. In order to further probe the influence of NaCl on rheological properties of sodium caseinate solution and clarify the mechanism. A rheometer, diffusing wave spectroscopy (DWS) and FTIR were combined to investigate the effect of NaCl on properties of sodium caseinate solution. The results showed that the shape and peak positions of FTIR spectra did not change after addition of NaCl, but the intensity changed. Preliminary analysis suggested that NaCl molecules could compete with sodium caseinate for water and indirectly increased protein concentration, while decreasing diffusion properties of the system, as indicated by the increased characteristic decay time τ. It also indicated that NaCl did not influence the secondary structure of sodium caseinate molecules. Rheological characterization indicated that 3% and 7.5% sodium caseinate solutions were Newtonian fluid while 15% sodium caseinate solution was non-newtonian fluid. Addition of NaCl significantly increased protein solution viscosity, and this phenomenon was more obvious at higher protein concentration. To further investigate the rheological properties of 15% sodium caseinate solutions, time dependence and thixotropy measurements were performed. The results showed that viscosity of all these samples increased in a linear manner with increasing time as thixotropic fluid. Collectively, we concluded that high concentrations of sodium caseinate solutions are negative rheopecticity fluid. All these results could help us better understand interactions of NaCl with sodium caseinate and provide theoretical guidance for using sodium caseinate in the food industry.

A method for determining parabens and natamycin in dairy products by HPLC is described. Samples were extracted with methanol and separated on a C18 column with methanol-acetic acid solution as mobile phase. UV detection was performed at 256 nm and 305 nm. Complete separation of pimaricin and four parabens, methyl 4-hydroxybenzoate, ethyl 4-hydroxybenzoate, propyl 4-hydroxybenzoate and butyl 4-hydroxybenzoate was achieved within 35 min. Under optimized conditions, the linear ranges for the food antiseptics was 1–100 mg/kg with a correlation coefficient greater than 0.9990, and their average recovery rates from blank real samples spiked at three different levels was between 83.7% and 103%. This method was simple, rapid and accurate.