山苍子精油结合1-MCP处理对杨桃的保鲜效果

以'香蜜'杨桃为试材,使用山苍子精油(熏蒸浓度为400μL/L)、1-甲基环丙烯(1-MCP,熏蒸浓度为0.6μL/L)及两者结合分别处理杨桃果实,通过测定呼吸强度、细胞膜相对渗透率、贮藏品质相关指标,并辅以感官评价比较不同处理对杨桃的保鲜效果。与对照相比,三种处理均能推迟呼吸峰值的出现,并将峰值分别降低21.60%、33.52%和43.92%,降低了细胞膜相对渗透率、失重率和腐烂指数,保持了较高硬度、可溶性固形物、可滴定酸和维生素C含量;其中,结合处理的效果最好,可将杨桃保鲜期延长约8 d。在贮藏20 d时,结合处理的感官分值为74.27分,单一处理的感官分值均低于临界值70.00分。由此表明,精油的抑菌作用和1-MCP的抑制乙烯作用可以产生协同效应,更有效地提高杨桃的保鲜效果,这为易腐果实的保鲜提供了可行思路。     

溶血磷脂制备含沙棘油微乳液的研究

溶血磷脂比磷脂的HLB大,易形成O/W型乳化剂,可制备热力学稳定的微乳化体系.利用溶血磷脂作乳化剂,制备含沙棘油的微乳液,以沙棘油为油相,溶血磷脂为乳化剂,正丙醇为共表面活性剂,制成微乳液.最终产品呈透明、稳定的均相混合物.     

夏枯草水溶性酸性多糖的分离及活性分析

采用水提醇沉法提取夏枯草多糖,然后经非极性吸附树脂HZ-820 脱色和脱蛋白后,再用DEAE-SepharoseFast Flow 阴离子交换柱层析进行分离得到酸性多糖。化学法和红外光谱证明该酸性多糖中半乳糖醛酸和硫酸根含量较高,间羟基联苯- 硫酸和氯化钡- 明胶比浊法测定其半乳糖醛酸和硫酸根含量分别为(58.85 ± 0.46)% 和(7 ± 0.52)%。紫外、红外光谱分析结果发现,该酸性杂多糖为非糖蛋白,可能含半乳糖醛酸、木糖、葡萄糖、鼠李糖和半乳糖等单糖。抗氧化活性研究表明该酸性多糖具有显著的DPPH 自由基和羟自由基清除活性。     

茄未成熟叶与衰老叶叶绿体超微结构比较研究

为揭示叶衰老对茄叶叶绿体超微结构的影响,用透射电子显微技术对茄未成熟叶和衰老叶叶肉细胞叶绿体进行比较研究.结果表明:未成熟叶叶绿体类囊体染色深,基粒柱状,许多基粒类囊体向基质中延伸,基粒之间由基质类囊体连接,基质中有大量淀粉和少量质体小球,小球体积小,直径0.1 μm以下;衰老叶叶绿体类囊体染色较浅,基粒球状,基粒类囊...     

亚太地区玉米质量标准对比分析

通过对亚太地区部分经济体及国际食品法典委员会对玉米质量标准中的质量指标和部分重要安全指标进行对比分析,总结得出,各经济体玉米标准对质量要求的方向是相同的,设置的质量指标大同小异,主要是以容重、不完善粒、杂质、水分、色泽气味等指标进行质量分级,按玉米种皮颜色进行分类;在术语定义、检测仪器、检验方法、感官检验和质量要求等方面均存在不同,相同样品使用不同经济体的标准检测和判定时,质量等级和结果判定会存在差异;重要安全指标如真菌毒素、外来种子等差异较大,尤其是国际公认的外来有害种子。建议启动亚太地区玉米容重、杂质、不完善粒、水分等重要指标测定方法的研究,统一相关测定方法和仪器设备,制作感官检测指标的可视化参照系统;开展多层面检测技术人员研讨和交流,收集玉米样品检测数据,进一步分析不同经济体玉米标准的实际差异;增加国际同行沟通与协调,推动区域玉米质量标准协同一致,形成统一或相似贸易技术标准体系,提高效率,实现区域玉米贸易便利化和一体化。     

Characteristics of Tableted Roselle (Hibiscus sabdariffa Linn.) with Addition of Sodium Starch Glycolate

The focus of this research is to study the characteristics of tablets produced from the binary powder mixture of Roselle (Hibiscus sabdariffa Linn.) and sodium starch glycolate (SSG) powders. The experimental parameters studied were the compaction pressure and the mass composition. The findings indicated that the increase of compaction pressure increased the tensile strength of tablets until a limiting value was reached. On the other hand, as the compaction pressure increased, the porosity of tablets decreased to a minimum value. The elastic recovery of tablets slightly decreased in some results. The increase in compaction pressure also increased the dissolution time of tablets up to a maximum value. The increase of SSG composition decreased the tensile strength of tablets to a certain amount. The dissolution time of tablets also reduced when the percentage of SSG increased. Subsequently, under the same compaction conditions, the increase of SSG composition increased the porosity and the elastic recovery of tablets until the limiting values were achieved.     

大孔树脂对菥蓂总黄酮的静态吸附分离特性研究

采用静态法考察了10种大孔树脂对菥蓂总黄酮的吸附和解吸性能,筛选出较优的3种树脂HPD722、D101和AB-8,并进一步研究这3种树脂的静态吸附和解吸动力学特性,其中HPD722树脂略优于另外2种树脂。HPD722树脂静态吸附行为结果表明,平衡数据符合Langmuir等温吸附方程和Langmuir平衡吸附速率方程。      

3,5-二硝基水杨酸比色法测定芒果的可溶性糖含量

目的 建立3,5-二硝基水杨酸(3,5-dinitrosalicylic acid,DNS)比色法测定芒果可溶性糖含量的分析方法。方法 首先优化不同配方DNS显色剂测定芒果可溶性糖的条件,再以高效液相色谱法(high performance liquid chromatography, HPLC)检测结果作为参考,筛选建立测定芒果可溶性糖含量的最佳DNS试剂和方法。结果 DNS2试剂在优化条件下的测定结果与HPLC检测结果最为接近,平均相对偏差为8.81%,为芒果可溶性糖含量测定的最佳显色剂。优化的测定条件为:最适检测波长530 nm、显色剂添加量6 mL、显色温度80℃以上、显色时间5min,冷水阻断反应,显色后10min内检测。该方法的平均回收率为94.4%～101.0%,相对标准偏差(relative standard deviations, RSDs)为2.71%～4.83%。结论 基于DNS2试剂的比色法具有较高的准确度和精密度,可作为芒果可溶性糖含量快速测定的方法。     

Evaluation of Mucilage of Hibiscus rosasinensis Linn as Rate Controlling Matrix for Sustained Release of Diclofenac

This article reports the exploitation of novel hydrophilic excipient, that is, mucilage from Hibiscus rosasinensis Linn, for the development of sustained release tablet. Swelling ratio and flow properties analyses of dried mucilage powder were carried out. A 3² full factorial design was used. In factorial design, amounts of dried mucilage and dibasic calcium phosphate (DCP) were taken as independent factors and percentage drug release in 60 and 300 min and time for 80% drug release as dependent variables. Matrix tablet containing dried mucilage and diclofenac sodium (DS) was prepared through direct compression techniques. DS tablets were evaluated for hardness, friability, weight variation, in vitro drug release and water uptake, and mass loss study. The dried mucilage powder shows superior swelling capacity and excellent flow properties. Prepared tablets have acceptable hardness, friability, and uniformity in weight. It was found that batch HD8 fulfills all selected criteria. Drug release kinetics from these formulations corresponded best to the zero-order kinetics. Water uptake was independent whereas mass loss was dependent on agitation speed. The concept of similarity factor (f₂) was used to prove similarity of dissolution profile in distilled water and phosphate buffer and was found to be 90.68. It was concluded that mucilage can be used as release-retarding agent for 12 h when the drug–mucilage ratio was 1:1.5. So, matrix tablet containing dried mucilage is most suitable for sustained release of DS.     

毛蕊花挥发油成分分析及其在卷烟中的应用

采用水蒸气蒸馏法,对毛蕊花中挥发油进行提取。测得毛蕊花挥发油得率为0.6%。并用气相色谱/质谱联用技术进行分析鉴定,鉴定出58种化学成分,应用峰面积归一法确定了各成分的相对含量。水蒸气蒸馏法提取的毛蕊花挥发油主要含苧烯(31.28%)、小茴香酮(22.17%)、桉叶素(9.25%)、反式石竹烯(6.63%)、α-艹律草烯(6.4%)、蒎烯(3.24%)、胡椒烯酮醚(3.01%)等。用毛蕊花挥发油进行了卷烟加香试验,结果表明毛蕊花挥发油具有改善卷烟香气、增加清香香韵、降低刺激性的作用,毛蕊花挥发油可用于卷烟加香。