In this work, electrospun short nanofiber aerogel-templated oleogels (ESNF-ATO) were fabricated by electrospun pullulan nanofibers. Spinning solutions with different concentrations were utilized to maintain fiber diameter, and short nanofibers were homogenized to prepare aerogel templates for oil adsorption. The shape of the templates could be easily controlled, and the fabrication process unchanged the properties of pullulan and the diameter of short nanofibers. Increasing the fiber diameter resulted in more flexible aerogel templates, which exhibited lower compressive strengths but higher recovery rates in 100-cycle fatigue tests. Simple linear fitting further confirmed the above results. Oleogels could be formed by rapid oil adsorption (normally within 100 s), and capillarity mainly induced this procedure. The thinner nanofibers provided the templates a high oil adsorption capacity (up to 69.05 g/g) but a relatively weakened oil holding capacity. ESNF-ATO exhibited good rheological properties, and could effectively realize the sustained-release of free fatty acids or lipo-soluble compounds. The significance of this work lied in the innovativeness of the combination of electrospun short nanofibers and aerogel templates, and the characteristics of fiber-based templates and oleogels were adjustable by modulating the fiber diameter.
Aflatoxin contamination levels vary from crop to crop, suggesting that it is of great significance to explore the effects of different substrates on aflatoxins production. In this study, the effects of corn, wheat, peanut, and soybean on aflatoxin B 1 (AFB 1 ) production by Aspergillus parasiticus were investigated, and the effects of corn germ, wheat germ, soybean, and peanut oils on the production of AFB 1 by A . parasiticus in the corresponding defatted substrates were evaluated at the rates of 2, 5, 10, and 15 g/100 g of substrate. The effects of the combinations of different oils with different defatted substrates on the accumulation of AFB 1 by A . parasiticus were also studied. AFB 1 concentration was determined by HPLC. The results indicated that high-lipid substrates of soybean and peanut had significantly higher AFB 1 production than low-fat substrates of wheat and corn throughout the entire incubation period (15 days) in both autoclaved and non-autoclaved grains. Corn germ, wheat germ, soybean, and peanut oils with different doses could effectively stimulate AFB 1 accumulation, and AFB 1 production was determined by the oil content of the substrates. Our results suggest that the oil content of substrates is one of the factors affecting AFB 1 production by A . parasiticus and that the composition and content of the substrates may also play a role.
The co-occurrence of AFB 1 , AFB 2 , AFG 1 , and AFG 2 in mold-contaminated feed suggests a significant contribution of A. parasiticus to aflatoxin contamination in feed. In contrast to A. flavus , research on the effects of A. parasiticus growth and aflatoxin production is limited. This study aims to investigate the factors influencing the growth and aflatoxin production by A. parasiticus , as well as to analyze the interactions among these factors utilizing response surface methodology. The results will be compared with relevant studies on A. flavus , ultimately contributing to the development of a comprehensive strategy for the prevention of aflatoxin contamination. The findings indicated that both A. parasiticus and A. flavus used sugar as an initial substrate to produce aflatoxins. The substrate preference of A. parasiticus was not changed due to differences in nutrient content in different feeds. The mineral Mn was found to suppress aflatoxin production by both fungi, whereas glucose, sucrose, and Zn stimulated production. Temperature and water activity levels effective against A. flavus may not be equally effective for A. parasiticus . The optimum storage conditions were for temperature and water activity below 10 °C and 0.85 at the same time. Although chemical pesticides may comply with regulatory limits in feed, certain pesticides and their interactions could increase the risk of aflatoxin contamination during feed storage. Hence, a comprehensive evaluation of factors influencing both fungi is imperative to prevent aflatoxin contamination effectively.
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