Jingnan Chen

Cooking oil fumes (COFs) are major pollutants generated during thermal food processing, with emissions rising rapidly due to urbanization and the expanding catering industry, posing significant risks to indoor air quality and human health. This review systematically examines the formation mechanisms, physicochemical properties, and environmental and health impacts of COFs. Their formation involves primary processes such as thermal oxidation, cracking, Maillard reactions, and water vaporization, alongside secondary reactions where volatile organic compounds (VOCs) contribute to ozone (O₃) and secondary organic aerosol (SOA) formation. COFs exhibit complex gas–liquid–solid coexistence and contain hazardous components including polycyclic aromatic hydrocarbons (PAHs), benzene compounds, aldehydes, and ultrafine particles (Dp ≤ 0.1 μm). Based on reported data, emission factors under typical cooking conditions range from 17.966 to 71.923 mg/(min·kg oil) for VOCs, 0.016 to 1.710 mg/(min·kg oil) for benzene compounds, and 0.458 to 1.820 mg/(min·kg oil) for formaldehyde. This highlights the variability in cooking fume emissions and associated health risks. Despite growing research attention, challenges remain in emission characterization and health risk assessment. By synthesizing current knowledge, this review provides a scientific basis for developing precise mitigation strategies and guiding future regulatory standards, with implications for improving food processing practices and indoor air quality management.

Phytosterol esters are functional compounds that can effectively reduce plasma cholesterol concentration, and have wide applications in the food industry. In this study, a simple and efficient enzymatic method was successfully applied to synthesize phytosterol oleic acid esters with fatty acids from high-oleic sunflower seed oil. Among the tested lipases, Candida rugosa lipase (CRL) exhibited higher catalytic activity in the esterification of phytosterols with fatty acids (oleic acid 84%) from high-oleic sunflower seed oil. Box–Behnken design and response surface methodology were used to investigate the influence of reaction factors on the conversion of phytosterols. The maximum conversion of phytosterols (96.8%) and yield of phytosterol esters (92%) could be obtained under optimal conditions: reaction temperature 50 °C, a molar ratio of phytosterols to fatty acids at 1 : 2.3, enzyme loading of 5.8%, isooctane volume of 2 mL and reaction time of 2 h. It was noteworthy that this enzymatic esterification method indeed expended a much shorter reaction time (2 h) than that observed in previous reports. In general, the enzymatic preparation of phytosterol oleic acid esters with fatty acids from high-oleic sunflower seed oil will be a simple and rapid method for producing unsaturated fatty acid esters of phytosterol with both higher oil solubility and oxidative stability, which is beneficial as functional food ingredients.

Herein, we have developed a simple chemical method toward efficient preparation of phytosterol linoleic acid esters through esterification at very mild temperature (60 °C) using 4-dodecylbenzenesulfonic acid (DBSA) as the catalyst.

The stability of soybean germ phytosterols (SGPs) in different lipid matrixes, including soybean germ oil, olive oil, and lard, was studied at 120, 150, and 180 °C. Results on the loss rate demonstrated that SGPs were most stable in olive oil, followed by soybean germ oil, and lard in a decreasing order. It is most likely that unsaturated fatty acids could oxidize first, compete with consumption of oxygen, and then spare phytosterols from oxidation. The oxidation products of SGP_S in non-oil and oil systems were also quantified. The results demonstrated that at relatively lower temperatures (120 and 150 °C), SGPs’ oxidation products were produced the most in the non-oil system, followed by lard, soybean germ oil, and olive oil. This was consistent with the loss rate pattern of SGPs. At a relatively higher temperature of 180 °C, the formation of SGPs’ oxidation products in soybean germ oil was quantitatively the same as that in lard, implying that the temperature became a dominative factor rather than the content of unsaturated fatty acids of lipid matrixes in the oxidation of SGPs.

The aim of this study was to characterize the composition of soybean germ and its oil from Northeast (NE-SG) and Shandong Province (SD-SG) of China with a focus on the composition of fatty acids and phytosterols as well as physicochemical properties.

Soybean germ phytosterols (SGP) largely exist in soybean germ oil. Our previous study demonstrated that soybean germ oil was effective in reducing plasma cholesterol. However, it remains unknown if its phytosterols are the active ingredients responsible for the plasma cholesterol-lowering activity. The present study aimed to test the effect of SGP on plasma cholesterol and to investigate its associated underlying mechanisms using hamsters as animal model. Male hamsters (n = 40) were randomly divided into five groups (n = 8/group) and fed one of the five diets: a non-cholesterol diet (NCD), a high cholesterol diet (HCD), a HCD diet containing 0.5% cholestyramine (PC), and two HCD diets containing 0.1% (LP) and 0.2% (HP) SGP, respectively, for six weeks. Results showed that SPG reduced plasma cholesterol level in a dose-dependent manner, whereas it dose-dependently increased the excretion of both fecal neutral and acidic sterols. SGP was also effective in displacing cholesterol from micelles. It was concluded that SGP possessed hypocholesterolemic activity, likely by inhibiting cholesterol absorption in the intestine and promoting fecal sterol excretion.