A total of 46 samples from nine types of commercially available foods for special dietary uses were collected for osmolality measurement by a freezing point and a dew point osmometer, and the differences between the two methods were analysed. The results showed that the detection range of the freezing point osmometer was 195–763 mOsmol/kg with relative standard deviation (RSD) of 0.20%–4.08%, and the detection range of the dew point osmometer was 197–649 mmol/kg with RSD of 0.00%–3.66%. It was found that different reconstitution methods had a significant effect on the determination results, and the temperature of the solution also affected the parallelism of the determination results. Statistical analysis using t-test showed that there were significant differences between the results of the two methods for each of 31 samples. It was inferred from the experiments that whether the sample solution reached an ideal dilute solution state was the major factor affecting the significant difference between both methods. This study provides a theoretical basis for further research on the detection of osmolality in foods for special dietary uses, and highlights some key issues that need urgent attention in the design and production of foods for special dietary uses.

In this study, a method based on weak cation exchange (WCX) solid phase extraction (SPE) coupled with ultrahigh performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed for the simultaneous determination of 13 aminoglycoside (apramycin, amikacin, paromomycin, hygromycin B, ribostamycin, kanamycin, streptomycin, gentamicin C₁, dihydrostreptomycin, tobramycin, spectinomycin, neomycin and micronomicin) residues in milk. Samples were extracted using a mixture of ammonium acetate buffer solution and acetonitrile, and purified using a WCX SPE column. Chromatographic separation was achieved using a SILICA SG80 column with gradient elution using a mobile phase made up of 0.1% formic acid aqueous solution and acetonitrile. Detection was accomplished using an electrospray ionization source (EIS) in the positive ion mode, and quantification was carried out using a matrix-matched external standard method. Excellent linear relationships were observed for the 13 aminoglycosides in the concentration range of 5.0-500.0 ng/mL (R² ≥ 0.9983). The limit of detection (LOD) for hygromycin B, ribostamycin, streptomycin, tobramycin, and dihydrostreptomycin were 3 μg/kg, and the limit of quantification (LOQ) were all 10 μg/kg for these aminoglycosides. For apramycin, amikacin, paromomycin, kanamycin, gentamicin C₁, micronomicin, neomycin and spectinomycin, the LODs and LOQs were 15 and 50 μg/kg, respectively. The recovery rates of milk spiked at 1 ×, 2 × and 5 × LOQ levels were 73.8%–107.4%, with relative standard deviation (RSD) of 1.0%-9.8%. This developed method is sensitive, simple, stable, and suitable for the determination of these 13 aminoglycoside residues in milk.

This study established a method for the determination of pyrroloquinoline quinone (PQQ) disodium salt, a newly approved food ingredient in China, in foods using centrifugal ultrafiltration as a novel pretreatment technique combined with high performance liquid chromatography (HPLC). Ethylenediaminetetraacetic acid disodium (EDTA-2Na) solution was used as a stabilizing agent in sample extraction. After purification by centrifugal purification, chromatographic separation was accomplished on a RD-C₁₈ column (4.6 mm × 150 mm, 5 μm) with gradient elution using a mobile phase consisting of tetrabutylammonium bromide-potassium dihydrogen phosphate mixed solution and acetonitrile. Detection was carried out using a photodiode array detector. The calibration curve showed good linearity within the concentration range of 0.0400–10.0 mg/L with a determination coefficient of 0.9998. The limit of quantitation (LOQ) was 1.0 mg/kg for liquid samples and 4.0 mg/kg for soy sauce, semi-solid, and solid samples. The recoveries from spiked samples ranged from 82.1% to 103.3% with a relative standard deviation (RSD) ranging from 0.7% to 2.5%. This method was characterized by high sensitivity, simple operation, rapidity and accurate and reliable quantification, and suitable for the quantitative detection of PQQ disodium salt in various food matrices. This research effectively addresses the shortcomings of existing methods for detecting PQQ disodium salt in foods and provide strong technical support for the routine supervision of PQQ disodium salt in various food matrices.

This study systematically reviewed the Chinese and international laws, regulations and scientific guidelines regarding novel food raw materials. It clarified the basic definition of “novel food raw materials” and related concepts at home and abroad, and elaborated on the changes in the nomenclature and types of novel food raw materials in China. It also gave a brief overview of the categories and scope of novel food raw materials abroad, a general explanation of declaration information and approval management of novel food raw materials, a brief summary of China’s standards for testing novel food raw materials, and a detailed review of various analytical methods for non-microbial novel food raw materials such as liquid chromatography, gas chromatography and mass spectrometry in order to provide reference for the standardization and uniform detection of novel food raw materials in China.