SiBCN ceramics have excellent high-temperature stability and anti-oxidation properties, and they are candidates for materials used at extreme conditions. In this paper, amorphous SiBCN(O) ceramics were obtained through pyrolysis of cross-linked polyborosilazanes. The element content could be readily tuned through adjusting the structures of polymer precursors. The cerminization process and microstructure evolution process were systematically investigated. The SiBCN(O) ceramics remain amorphous below 1400 °C. The carbothermal reduction was suppressed because of the presence of boron. The SiBCN(O) ceramics showed 95.7% and 99.2% carbon residual in argon and air at 1600 °C, indicating high-temperature stability and good anti-oxidation properties. These SiBCN(O) precursors/ceramics could be potentially used in composites or protective coatings for harsh environments.
Fu Xiaona,Su Jiling,Hou Li,Zhu Ping,Hou Ying,Zhang Kai,Li Huowang,Liu Xiangyi,Jia Chengxinzhuo,Xu Juan
Physicochemical and thermal characteristics of Moringa oleifera seed oil were studied. The refractive index of Moringa oleifera seed oil at ambient temperature was 1.46. The acid, peroxide, saponification, and iodine values content of Moringa oleifera seed oil were 2.35 g KOH/kg oil, 7.2 meq O 2 /kg oil, 189.84 g KOH/kg oil, and 66.78 g I 2 /100 g oil, respectively. Moringa oleifera seed oil contains ten fatty acids. Among 10 kinds of fatty acids in Moringa oleifera seed oil, oleic acid is the most abundant fatty acid comprising 70.85% of total oil followed by palmitic acid (8.98%). The unsaturated fatty acids represented by oleic acid are mainly distributed in the Sn-2 position, which is as high as 95.59%. It contains a high level of unsaturated fatty acids. Moringa oleifera seed oil contains 233.29 mg/kg α-tocopherol, 9.04 mg/kg β-tocopherol, and 10.13 mg δ-tocopherol, respectively. Determination of 10 elements in Moringa oleifera seed oil by ICP-MS. Among them, calcium has the highest content. Moringa oleifera seed oil remained stable up to 305 °C with a negligible degradation. Moringa oleifera seed oil has high nutritional value and broad development prospect. This research provides a prospect for the comprehensive development and utilization of Moringa oleifera seed oil. Graphical abstract
The basic physical and chemical properties and structure of Moringa oleifera seed oil was analyzed and characterized
Xin Xu,Jinhang Wang,Huihui Wu,Xuedan Cui,Daibing Hou,Jun Cui,Rui Lu,Aijun Lin
Biofortification is an effective way to increase micronutrient levels in food crops. This study investigated selenium enrichment as a biofortification strategy in soybean sprouts. Chitosan oligosaccharide selenium nanoparticles (COS-Se NPs) were synthesized and used in soybean sprout culture to study their effects on the sprouts. The results showed that the enrichment factor value (EF) was higher when the concentration was 2.36–9.43 mg·L–1 compared with other concentrations, and the enrichment factor (EF) reached a maximum value of 0.9782 at a COS-Se NP concentration of 4.72 mg·L–1. Translocation factors (TFradicle-hypocotyl and TFhypocotyl-cotyledon) reached maximum values of 0.7866 and 0.9723 at 25.15 mg·L–1 and 15.09 mg·L–1, respectively, suggesting the relationship between enrichment of nanoselenium and concentration was not proportional. Most of the organic selenium was present mainly in the protein fraction, and albumin and glutelin were the main protein-bound seleniums. The contents of protein and biomacromolecule selenium reached higher values at a COS-Se NP concentration of 2.36–9.43 mg·L–1. Furthermore, the COS-Se NPs at 2.36–9.43 mg·L–1 concentration significantly affected the nutrient parameters in soybean sprouts. Different concentrations of COS-Se NPs were observed to have different effects on the mineral element content of the bean sprouts. In vitro digestion and dialysis experiments showed that the bioavailability of K, Mg, P, and Se was at a high level, while that of Fe and Ca was at a low level in soybean sprouts. Overall, no significant impact on the bioaccessibility of most elements was observed during the enrichment process compared to the control group. This work shows that the selenium enrichment strategy can be a potential soybean sprout production method and help solve the problem of nutritional deficiencies with selenium and reduce malnutrition.
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