Research and Application of Multi-component Sterol Determination Methods in Pre-prepared Dishes

Ying Ying¹Zhengyan Hu¹Wu Ping gu¹Luo Xian fa²Wang Li yuan^1*Chen Jing^1*

• ¹Zhejiang Center for Disease Control and Prevention (Zhejiang CDC), Hangzhou, China
• ²Hangzhou Medical College, Hangzhou, China

(1) Background: Pre-prepared dishes contain fats/oils, high protein, and complex seasonings, making sterol detection difficult due to multiple components and matrix interference. Given the market's analytical chal-lenges, detecting sterols—key functional components affecting nutritional value—is practically vital. This study aims to develop a sensitive, selective GC-MS method for simultaneous qualitative and quantitative multi-component sterol analysis in pre-prepared dishes and to examine their compositional traits. (2) Methods: After saponification treatment, the sample undergoes ultrapure water-assisted dispersion and n-hexane extraction. The extract is dried and subjected to derivatization reaction. The derivative is redissolved and analyzed by gas chromatography-mass spectrometry (GC-MS) for qualitative identification, with quantification per-formed using the internal standard method. This method optimizes sample pretreatment and chromatographic separation conditions, enhancing detection efficiency and separation effectiveness.(3) Results: The six target sterol compounds exhibited good linearity within the concentration range of 1.0-100.0 μg/mL (correlation coefficients ≥ 0.99). The limits of detection (LODs) and limits of quantification (LOQs) were 0.05-5.0 mg/100g and 0.165-16.5 mg/100g, respectively. At low, medium, and high spiked concentrations, the average recoveries ranged from 87.0% to 106%, with relative standard deviations (RSDs, n=6) of 0.99%-9.00%.Application of this method to analyze actual pre-prepared dish samples revealed significant variations in cholesterol content among different dish categories, with meat ingredients playing a dominant role. The sterol composition exhibited marked diversity: ergosterol was not detected in pre-prepared dishes, while β-sitosterol, campesterol, and stigmasterol constituted the major components. Notable differences in sterol content and composition were observed across different categories of pre-prepared dishes, further confirming the impact of various meat raw materials and processing technologies on sterol levels.(4) Conclusions:The GC-MS analytical method established in this study has been validated to demonstrate excellent reliability and applicability, providing an efficient analytical tool for precise detection of multi-component sterols in pre-prepared dishes. This method supports quality control and nutritional value assessment in the pre-prepared dish industry, facil-itating product labeling standardization and informed consumer choices.