核桃内种皮黄酮的提取工艺优化及抗氧化性研究

为了优化核桃内种皮黄酮的超声提取工艺并对其进行抗氧化性和主要成分进行初步探究,在单因素实验基础上采用响应面分析法研究乙醇浓度、料液比、提取温度对黄酮得率的影响.同时采用水杨酸比色法和邻苯三酚自氧化测定提取物的抗氧化能力并测定其主要化学组成.结果表明,当乙醇浓度59％,料液比1:52 g/mL,提取温度41 ℃,超声功率...     

Rapid Removal of Toxic Remazol Brilliant Blue-R Dye from Aqueous Solutions Using Juglans nigra Shell Biomass Activated Carbon as Potential Adsorbent: Optimization,Isotherm, Kinetic,and Thermodynamic Investigation

Recently, the treatment of effluent by agricultural waste biomass has significantly attracted wide interest among researchers due to its availability, efficacy, and low cost. The removal of toxic Remazol Brilliant Blue-R (RBBR) from aqueous solutions using HNO₃-treated Juglans nigra (walnut) shell biomass carbon as an adsorbent has been examined under various experimental conditions, such as initial pH, adsorbate concentration, adsorbent dosage, particle size, agitation speed, and type of electrolyte. The experiments are designed to achieve the maximum dye removal efficiency using the response surface methodology (RSM). The optimum pH, adsorbent dosage, and particle size were found to be 1.5, 7 g L⁻¹, and 64 μm, respectively for maximum decolorization efficiency (98.24%). The prepared adsorbent was characterized by particle size, Brunauer–Emmett–Teller (BET) surface area, pore volume, zero-point charge (pH_zpc), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy/energy dispersive X-ray spectroscopy (FE-SEM/EDX), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Based on fitting the experimental data with various models, the isotherm and kinetic mechanism are found to be more appropriate with Langmuir isotherm and pseudo-second-order kinetics. The adsorption mechanism can be described by the intra-particle diffusion model, Bangham, and Boyd plots. The overall rate of adsorption is controlled by the external film diffusion of dye molecules. The maximum monolayer adsorption capacity, (q_max) 54.38 mg g⁻¹ for RBBR dye, was obtained at a temperature of 301 K. From a thermodynamic standpoint, the process is endothermic, spontaneous, and the chemisorption process is favored at high temperatures. Desorption studies were conducted with various desorbing reagents in various runs and the maximum desorption efficiency (61.78% in the third run) was obtained using the solvent methanol. Reusability studies demonstrated that the prepared adsorbent was effective for up to three runs of operation. The investigation outcomes concluded that walnut shell biomass activated carbon (WSBAC) is a cost-effective, eco-friendly, and bio-sustainable material that can be used for synthetic dye decolorization in aqueous media.     

核桃内源性多酚的体外抗氧化能力及对核桃油 氧化稳定性的影响

为促进核桃加工副产物的综合利用,探究副产物中多酚对核桃油氧化稳定性的影响,测定了槲皮素、没食子酸、儿茶素、绿原酸、鞣花酸5种核桃内源性多酚对DPPH和ABTS+自由基的清除能力及氧自由基吸收能力（ORAC）以评价其体外抗氧化能力,并将5种内源性多酚分别加入核桃油中,进行18 d的加速氧化试验,以酸值、过氧化值、共轭二烯值、共轭三烯值、同步荧光光谱、色泽及感官品质（透明度、气味、滋味）作为考察指标,分析其对核桃油氧化稳定性的影响。结果表明：槲皮素、没食子酸和绿原酸的体外抗氧化能力较强;5种多酚均能有效减缓核桃油酸值、过氧化值、共轭二烯值和共轭三烯值的升高,其中没食子酸、绿原酸和儿茶素在维持核桃油感官品质方面优于其他2种多酚。综上,在开发核桃油相关产品时,可以考虑通过添加没食子酸、儿茶素和绿原酸提高产品的氧化稳定性。     

核桃多酚对皮质酮损伤PC12细胞的作用机制

核桃多酚为核桃粕中的生物活性物质,具有重要的开发和应用价值。为探讨核桃多酚的潜在抗抑郁活性,采用皮质酮诱导的大鼠嗜铬瘤(PC12)细胞损伤模型,以细胞活力、细胞凋亡、乳酸脱氢酶(lactate dehydrogenase, LDH)释放量、细胞内钙离子水平评价核桃多酚在皮质酮损伤模型上的作用,并进一步采用蛋白免疫印迹法探讨核桃多酚对皮质酮损伤PC12细胞作用的机制。结果表明:核桃多酚(75、150μg/mL)预处理可显著逆转皮质酮损伤引起PC12细胞活力降低、细胞凋亡、LDH释放量增加和钙超载,发挥细胞保护作用；此外,核桃多酚可显著逆转皮质酮诱导的PC12细胞中cAMP依赖性蛋白激酶A(cAMP-dependent protein kinase A, PKA)活性降低,并下凋cAMP反应原件结合蛋白(cAMP-response element binding protein, CREB)133位丝氨酸的磷酸化和下游靶蛋白脑源性神经营养因子(brain-derived neurotrophic factor, BDNF)的表达量；进一步应用PKA阻断剂H89预处理消除了核桃多酚对皮质酮诱导的PC12细胞的保护作用,说明增加PKA/CREB/BDNF 信号通路活性是核桃多酚发挥抗皮质酮损伤作用必需的。研究结果表明,核桃多酚具有潜在的抗抑郁活性,可能是核桃饮食发挥抗抑郁作用的重要物质基础,其对皮质酮损伤的PC12细胞的保护作用与上调PKA/CREB/BDNF 信号通路有关。研究结果旨在探明核桃多酚的潜在抗抑郁活性及机制,并为核桃粕的高值化利用提供理论参考。     

荟萃分析核桃仁抗2型糖尿病机制

本研究基于荟萃法探讨了核桃仁干预2型糖尿病的作用机制.采用TCMSP数据库筛选核桃仁的主要活性成分及其潜在靶点,通过OMIM、TTD、Genecards等数据库获得2型糖尿病相关靶点,运用R3.6.2软件对活性成分靶点和疾病靶点交集,并用Cystoscope 3.7.2软件构建网络图,通过STRING等平台对交集靶点进...     

核桃衣多酚改性对植物蛋白溶解性和抗氧化活性的影响

为改善植物蛋白的溶解性并提升其抗氧化活性，选择核桃蛋白、小麦蛋白和芝麻蛋白为实验对象，在碱性条件下与核桃衣多酚相互作用，考察了核桃衣多酚改性对3种植物蛋白中性条件下的溶解度和抗氧化活性的影响。此外，通过SDS-PAGE、圆二色光谱和荧光光谱对溶出蛋白质的结构变化进行表征。结果表明：在核桃衣多酚添加量为75 mg/g时，核桃蛋白、小麦蛋白和芝麻蛋白在中性条件下的溶解度分别提升了61.54、 61.23、69.25百分点；同时，添加核桃衣多酚改性后的核桃蛋白、小麦蛋白和芝麻蛋白的DPPH自由基和ABTS自由基清除活性显著升高；3种植物蛋白在核桃衣多酚的作用下均形成了大分子聚集体，总体上蛋白质的α-螺旋和β-转角含量增加，β-折叠含量减少，同时内源性荧光强度降低。综上所述，核桃衣多酚改性可以使蛋白质结构发生改变，显著改善植物蛋白的溶解性并提升其抗氧化活性。     

酶法辅助制备核桃蛋白的工艺优化及超滤回收核桃蛋白

为提高核桃蛋白得率,分别探索了以碱性蛋白酶、纤维素酶和α-淀粉酶为辅助酶,碱溶酸沉法制备核桃蛋白的工艺,采用超滤工艺回收酸沉废液中核桃蛋白,比较醋酸纤维素(CA)膜、聚醚砜树脂(PES)膜和聚偏氟乙烯(PVDF)膜3种不同超滤膜的回收效率。结果表明,酶法辅助碱溶酸沉法制备核桃蛋白的最佳工艺条件为以纤维素酶为辅助酶、酶解时间60 min、酶解pH 3.6、酶添加量0.5%、酶解温度37℃,在最佳工艺条件下核桃蛋白得率为84.11%。CA膜能显著提高核桃蛋白得率,在原料液质量浓度0.363 mg/mL、原料液温度30℃的条件下,CA膜的截留率可达92.33%,核桃蛋白得率可达87.64%。