新疆辣椒中辣椒碱超临界CO_2萃取工艺研究

采用超临界CO2萃取技术对新疆辣椒中辣椒碱进行了萃取研究,运用L9(34)正交表系统研究了萃取压力、萃取温度、萃取时间以及夹带剂用量对萃取率的影响。确定了超临界CO2萃取新疆辣椒中辣椒碱的最佳工艺条件为:萃取压力12MPa、萃取温度45℃、分离温度45℃、萃取时间为40min、夹带剂(无水乙醇)料液比为1:2,此条件下辣椒碱提取率为5.0mg/g。超临界萃取法具有提取速度快、节省溶剂、杂质含量低及可实现辣椒碱与辣椒红色素综合开发等优点。     

Identification of the major allergen of Macrobrachium rosenbergii (giant freshwater prawn)

Objective

To characterize the major allergens of Macrobrachium rosenbergii (giant freshwater prawn).

Methods

Raw and cooked extracts of the giant freshwater prawn were prepared. The IgE reactivity pattern was identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting technique with the sera of 20 skin prick test (SPT) positive patients. The major allergen identified was then characterized using the proteomics approach involving a combination of two-dimensional (2-DE) electrophoresis, mass spectrometry and bioinformatics tools.

Results

SDS-PAGE of the raw extract showed 23 protein bands (15–250 kDa) but those ranging from 40 to 100 kDa were not found in the cooked extract. From immunoblotting experiments, raw and cooked extracts demonstrated 11 and 5 IgE-binding proteins, respectively, with a molecular mass ranging from 15 to 155 kDa. A heat-resistant 36 kDa protein was identified as the major allergen of both extracts. In addition, a 42 kDa heat-sensitive protein was shown to be a major allergen of the raw extract. The 2-DE gel fractionated the prawn proteins to more than 50 different protein spots. Of these, 10 spots showed specific IgE reactivity with patients'' sera. Matrix assisted laser desorption/ionization-time of flight (MALDI-TOF) analysis led to identification of 2 important allergens, tropomyosin and arginine kinase.

Conclusions

It can be concluded that the availability of such allergens would help in component-based diagnosis and therapy of prawn allergies.     

Factors Associated with Intention to Donate Hematopoietic Stem Cells among Blood Donors

IntroductionPast studies pay little attention to the intention to donate hematopoietic stem cells (HSC) among blood donors. This study investigated the level of and the influence of socio-demographic characteristics, knowledge, attitude, subjective norm and self-efficacy on the intention to donate HSC among blood donors.MethodsThis cross-sectional study recruited blood donors at selected public hospitals in the Malaysian State of Sarawak in 2019. A structured questionnaire was developed based on the review of relevant literature. It gathered information on socio-demographic characteristics, knowledge, attitude, subjective norm and self-efficacy on the intention to donate HSC. Variables with a p value <0.200 in bivariate analysis were included in the variable selection for regression modeling to examine their associations with the intention to donate HSC.ResultsA total of 569 blood donors participated (94.5% response rate). Overall, 87.1% reported a positive intention to donate HSC. In the regression model, the factor with the greatest association with intention to donate HSC was subjective norms about HSC donation (β = 0.35, 95% CI 0.27–0.42), followed by attitude about regulations of HSC donation (β= 0.21, 95% CI 0.13–0.35), self-efficacy on HSC donation (β = 0.15, 95% CI 0.09–0.32), attitude about the potential side effects of HSC donation (β = 0.14, 95% CI 0.02–0.10) and highest education level (β = 0.10, 95% CI 0.03–0.44).ConclusionsThe findings can be used to formulate a better strategy in promoting HSC donation among blood donors in the region.     

Identification of major allergens of wildflower honey

The aim of this study was to identify the major allergens of wildflower honey in local patients with atopic disease. SDS-PAGE revealed ten protein bands of 25 to 110 kDa, with a heavy cluster in region of 40-75 kDa. Immunoblotting demonstrated seven IgE-binding bands of 39 to 110 kDa. The 60 kDa protein had the highest frequency of IgE-binding (100%) followed by 54 kDa protein (95%), thus identified as the major allergens of wildflowerhoney. Our findings indicate that the allergen extract used for diagnosis of honey allergy contains both the 54 kDa and 60 kDa proteins.     

Carbon Derived from Jatropha Seed Hull as a Potential Green Adsorbent for Cadmium (II) Removal from Wastewater

Carbon from jatropha seed hull (JC) was prepared to study the adsorption of cadmium ions (Cd²⁺) from aqueous solutions under various experimental conditions. Batch equilibrium methods have been used to study the influences of the initial metal ion concentration (0.5–50 ppm), dosage (0.2–1 g), contact time (0–300 min), pH (2–7), and temperature (26–60 °C) on adsorption behavior. It has been found that the amount of cadmium adsorbed increases with the initial metal ion concentration, temperature, pH, contact time, and amount of adsorbent. A kinetic study proved that the mechanism of Cd²⁺ adsorption on JC followed a three steps process, confirmed by an intraparticle diffusion model: rapid adsorption of metal ions, a transition phase, and nearly flat plateau section. The experimental results also showed that the Cd²⁺ adsorption process followed pseudo-second-order kinetics. The Langmuir and Freundlich adsorption isotherm models were used to describe the experimental data, with the former exhibiting a better correlation coefficient than the latter (R² = 0.999). The monolayer adsorption capacity of JC has been compared with the capacities of the other reported agriculturally-based adsorbents. It has been clearly demonstrated that this agricultural waste generated by the biofuel industry can be considered a potential low-cost adsorbent for the removal of Cd²⁺ from industrial effluents.