Significantly enhancing fracture toughness of epoxy composite with promisingγ-FeOOH@Fe_(2)O_(3)hybrid nanoparticles by magnetic field assistance

The toughening of epoxy resin(EP)and the interlaminar toughening of carbon fiber reinforced composite(CF/EP)laminates have been widely concerned.In this work,the needle-likeγ-FeOOH nanoparticles were prepared by liquid phase deposition-air oxidation method,and then were calcined under different conditions to obtainγ-FeOOH andγ-Fe_(2)O_(3) hybrid nanoparticles(γ-FeOOH@Fe_(2)O_(3)).Effect of calcination condition ofγ-FeOOH@-Fe_(2)O_(3) and magnetic field assistance on fracture toughness(KIC)of EP was systematically investigated.Then the selectedγ-FeOOH@Fe_(2)O_(3) with the best toughening effect were used to improve the mode I interlaminar fracture toughness(GIC)of CF/EP laminate.The resultingγ-FeOOH@Fe_(2)O_(3) have a length of around 1μm,a diameter of around 100 nm and the Ms of 8.99–45.96 emu/g.After calcinated at 250℃ for 1 h,theγ-FeOOH@Fe_(2)O_(3) containing 24 wt%FeOOH and 76 wt%Fe_(2)O_(3) achieved the best toughening effect.Under a magnetic field of 0.09 T,the KIC of theγ-FeOOH@Fe_(2)O_(3)/EP composite(2.45 MPa m^(1/2)) is 81.7%and 66.7%higher than that of neat epoxy and the composite without magnetic field induction,respectively.Furthermore,the GIC of theγ-FeOOH@Fe_(2)O_(3)/CF/EP composite(0.914 kJ/m^(2)) is also significantly increased by 88.8%and 51.8%compared to that of CF/EP and the corresponding composite without magnetic field induction,respectively.

Phytosterols in edible oil:Distribution,analysis and variation during processing

Phytosterols,which are naturally occurring in plants,have excellent nutritional and health values on lowering both the blood cholesterol level and the risk of cardiovascular diseases.Edible oils are the main source of daily intake of phytosterols,whereas the properties of phytosterols may vary a lot depending on their sources.During the processing of edible oil including refining and frying,phytosterol's content fluctuates,which influences the properties of the final product.Phytosterols and their derivatives undergo physical migration between different phases and chemical conversion during the processing,which reduces the quality and the commercial value of edible oils.Therein,the loss of phytosterols is the major concern in the process of neutralization and deodorization.In addition,oxidation and thermal degradation of phytosterols occur simultaneously during frying,which also reduces the content of phytosterols.Nevertheless,the oil matrix has a promoting or an inhibitory effect on the thermal oxidation of phytosterols.Therefore,various efforts have been devoted to analyzing and improving the remaining contents of phytosterols in edible oil.Regardless of the processing method,temperature plays an important role in the loss of phytosterols.At present,themain analysismethods of phytosterols include gas chromatography and liquid chromatography,inwhich the pretreatment of different types of phytosterols is also a crucial step.This review focused on the following topics comprehensively:(i)the distribution of phytosterols in the oil-containing plants and edible oils during the refining processing;(ii)the pretreatment and analysis methods of various phytosterols(free phytosterols,phytosteryl fatty acid esters,phytosteryl glycosides and acylated phytosteryl glycosides);(iii)the variation of phytosterols in process of esterification and oxidation,storage and so on.The study also proposed that the investigation in the loss and safety of phytosterols during processing of the vegetable oils should be proceeded further in combination with efficient and accurate chromatography methods.

Adsorption behavior of activated carbon for the elimination of zearalenone during bleaching process of corn oil

Zearalenone is a mycotoxin produced by Fusarium species.It frequently contaminates cereals used for foods or animal feeds,especially deposited in crude corn oil.Certain amounts of zearalenone can be removed during refining processes.In this study,we studied the influence of activated carbon and six industial absorbents(zeolite,diatomite,attapulgite,perlite,montmorillonite and activated clay)on the elimination of zearalenone during bleaching process of corn oil and explored the absorption mechanism of activated carbon.Results showed that activated carbon had an excellent adsorption capacity of zearalenone compared with the other six industrial adsorbents.For activated carbon,a high removal rate of zearalenone(exceeding 83%)from heavily zearalenone-polluted corn oil was achieved and the removal rate of zearalenone was kept above 60%after five regeneration cycles.The research on the adsorption mechanism of activated carbon showed that Freundlich adsorption isotherm model and pseudo-second-order kinetic model could well described the adsorption process.The thermodynamic study demonstrated that adsorption process was spontaneous and exothermic.Fourier transform infrared spectroscopy and Raman spectroscopy further revealed that activated carbon was effectively combined with zearalenone viaπ-πinteraction.Thus,activated carbon is an efficient and suitable adsorbent to control the levels of zearalenone during bleaching process of corn oil.This study not only proposed a systematic research scheme for the mechanism study of activated carbon for the elimination of zearalenone in corn oil,but also provided the scientific basis for developing effective methods to eliminate zearalenone in refined vegetable oils.

Hydrophilic phytosterol derivatives: A short review on structural modifications, cholesterol-lowering activity and safety

Phytosterols have received extensive attention owing to their excellent cholesterol-lowering activity and the role in cardiovascular diseases prevention. However, poor solubility in both oil and water limited the application of free phytosterols in the food industry. Chemical or enzymatic modifications were effective to improve the physicochemical properties as well as the bioavailability and cholesterollowering activity of phytosterols. Higher oil solubility and lower melting point of phytosterols have been achieved by esterification and transesterification with fatty acids and triacylglycerols so as to enhance the bioavailability, reduce formation of precipitates, and improve the sensory quality of products.While the researches on the improvement on its water solubility is a hot topic. Hydrophilic phytosterol derivatives have promising applications in the food industry because most of foods belong to aqueous matrix. Hydrophilic modification is useful and meaningful for phytosterols in both industrial and commercial applications. This review mainly highlights the hydrophilic phytosterol derivatives in the following aspects:(i) hydrophilic modifications of phytosterols by coupling with various polar components;(ii) cholesterol-lowering activity and possible molecular mechanisms of hydrophilic phytosterol derivatives on reducing serum cholesterol level;and(iii) safety evaluation of hydrophilic phytosterol derivatives in cell-culture studies, animal models and clinical trials.

Study on crystallization behavior of Tibet butter

Tibetan butter(TB),generally called butter,is a solid oil product extracted from yak milk in the QinghaiTibet plateau area.However,due to the limitations of raw material sources and production technology,there is a shortage of TB,so it is important to find substitutes of TB.This paper studied the crystallization behavior of six kinds of commercial TB products in Tibet to provide the theoretical basis for the development of TB substitutes for the production of TB lamps and flowers.This study assessed the crystallization behaviors of the TB samples,including isothermal crystallization process and non-isothermal crystallization process.The microstructure,isothermal crystallization of TB were evaluated by polarized light microscopy and low-pulse NMR spectrometry,respectively.The non-isothermal crystallization process of TB under temperature scanning were investigated using Rheometer,and the crystallization behavior under different cooling rates were determined by diferential scanning calorimetry(DSC)procedures.The results showed that the TB was crystallized at a higher supercooling(-10,0 and 10℃).Dimensional growth is dominant;at 20℃,spiral growth dominates.The TB has complex crystallization nucleation behavior.The crystal types of TB are mainlyβ’-crystal form andβ’-like crystal form.The lower the cooling rate,the shorter the crystallization induction time,and the more the number of crystal nuclei.Therefore,during producing TB substitutes in the factory,the cooling rate can be controlled at10℃/min to reduce energy consumption and production costs.

A notable impact of lipid matrices on cholesterol bioaccessibility from phytosterols-loaded nanostructured lipid carriers during in vitro intestinal digestion

Encapsulation of phytosterols in nanostructured lipid carriers(NLCs)is an effective approach to improve their physicochemical properties,but the interaction of phytosterols in NLCs with cholesterol can be affected by lipid matrices.The objective of this study was to screen a desired phytosterols-loaded NLC(PS-NLC)formulation to reduce the absorption of intestinal cholesterol.A series of formulations were prepared using amphipathic glycerol monostearate(GMS)as the solid lipid fraction to increase lipid compatibity with phytosterols.All formulations showed a lowering effect on cholesterol bioaccessibility through in vitro intestinal digestion.And the PS-NLCs with medium chain triglycerides(MCT)as the liquid lipid showed significantly higher inhibition of cholesterol bioaccessibility(accessible fraction for intestinal absorption)than the formulations with long chain triglycerides(LCT),which could due to the solubilization of cholesterol by hydrolysis products of LCT,suggesting a notable impact of lipid type on cholesterol bioaccessibility.Furthermore,the analysis of distribution of phytosterols and cholesterol revealed a cocrystallization mechanism occurred during in vitro digestion.This study provides a certain reference for designing phytosterol-ingredient agents with a better hypocholesterolemic effect in water-dispersible functional foods.