苦味西葫芦果实木脂素类成分研究

采用色谱技术对苦味西葫芦果实的抗炎活性部位的化学成分进行分离,应用1HNMR、13CNMR确定化合物的结构.从正丁醇萃取部位分离得到4个木脂素化合物:Larisiresinol 4'-O-β-D-glucopyranoside(Ⅰ)、( )-5'-Methoxyisolarisiresinol 3α-O-β-D-glucopyranoside(Ⅱ)、Lyoniside(Ⅲ)、Isolariciresinol-9-O-β-D-xylopyranoside(Ⅳ).化合物Ⅰ、Ⅱ、Ⅲ和Ⅳ均为首次从南瓜属植物中分离得到.     

响应面法优化冻干河套蜜瓜工艺的研究

本文以河套蜜瓜为原料,采用响应面(RSM)的实验设计方法对蜜瓜进行干燥工艺研究。以干燥速率作为影响冻干河套蜜瓜品质的指标,在单因素实验基础上,利用响应面优选出一组真空冷冻干燥河套蜜瓜的最佳工艺参数。结果表明,真空冷冻干燥河套蜜瓜的最佳工艺参数为:物料装载量100 g、升华温度为42℃、解析温度为61℃。在此条件下真空冷冻干燥速率为9.23%/h,与理论预测值较接近。说明通过响应面优化后得出的回归方程具有一定的实践指导意义。      

响应面法优化灰枣中黄酮提取工艺研究

以提取时间、提取温度、料液比、乙醇体积分数为实验因素,在单因素基础上,应用Box-Behnken实验设计和响应面分析法优化灰枣中黄酮提取工艺。确定灰枣中黄酮最佳提取工艺条件为:提取时间30 min,提取温度40℃,料液比1∶29（g∶m L）,乙醇体积分数70%,实际提取量为3.266 mg/g。实际提取值与模型预测值之间的RSD为0.38%,实际优化的工艺条件与理论预测拟合程度高。      

香榧籽油对高脂膳食SD大鼠脂质代谢的影响及机理

为推进对香榧籽油生物功效的认知,以高脂膳食大鼠模型评估香榧籽油的降脂、抗氧化功效及其作用机理。将40只SD大鼠随机分为正常对照组（NF组）、2%香榧籽油正常组（NFO组）、高脂对照组（HF组）、2%香榧籽油高脂组（HFO组）。每周记录SD大鼠体重,分别在第4周和第7周检测血清中总胆固醇（TC）、甘油三酯（TG）、高密度脂蛋白胆固醇（HDL-C）、低密度脂蛋白胆固醇（LDL-C）、血糖（Glu）、超氧化物歧化酶（SOD）、丙二醛（MDA）、谷胱甘肽过氧化物酶（GSH-Px）、总抗氧化能力（T-AOC）、C反应蛋白（CRP）、白介素6（IL-6）、白介素4（IL-4）水平。在第7周处死大鼠,解剖取肝脏、十二指肠、脂肪组织,采用油红O、苏木精-伊红（HE）染色观察组织形态,并采用qRT-PCR检测肝脏脂质代谢相关基因的表达。结果表明：实验第4周,与NF组相比,香榧籽油能极显著降低SD大鼠体重（P<0.01）,整个实验周期内HF、HFO组大鼠体重无显著差异;与NF组相比,NFO组大鼠血清TG、Glu、MDA水平显著下降（P<0.05）,HDL-C水平显著提高（P<0.05）;与HF组相比,香榧籽油能显著降低大鼠血清TC、LDL-C和Glu水平（P<0.05）,显著提高SOD、GSH-Px的活性和T-AOC（P<0.01,P<0.05）。实验第7周,与NF组相比,NFO组大鼠血清LDL-C水平极显著上升（P<0.01）,TC、MDA水平显著下降（P<005）;与HF组相比,香榧籽油能显著升高大鼠血清TG、LDL-C、MDA、CRP、IL-4水平（P<0.05,P<001）;长期食用香榧籽油,大鼠肝脏、十二指肠组织中偶有炎性细胞浸润,脂肪组织细胞形态大小不均。NFO组大鼠肝脏AMPKα、SREBP-1c基因表达水平极显著高于NF组（P<0.01）,HFO组大鼠肝脏FAS、ACC、AMPKα基因表达水平极显著低于HF组（P<0.01）。香榧籽油可能通过调节AMPKα/SREBP-1c信号通路实现调节大鼠血脂、提高抗氧化水平的生物功效。     

Analysis of tannins in seeds and skins of Shiraz grapes throughout berry development

The flavan-3-ol and proanthocyanidin composition of both seeds and skin of Vitis vinifera L. cv. Shiraz grapes was determined by reversed-phase HPLC after acetone extraction and acid-catalysis in the presence of excess phloroglucinol. Samples were taken at weekly intervals from fruit-set until commercial harvest. The main period of proanthocyanidin accumulation in grape seeds occurred immediately after fruit-set with maximum levels observed around veraison. Over two seasons there was variation in both the timing and content of proanthocyanidins in seeds. In skin, proanthocyanidin accumulation occurred from fruit set until 1–2 weeks after veraison. Proanthocyanidin subunit composition was different in seeds and skin and changed during berry development but the mean degree of polymerisation of the tannin polymers in skins was higher than in the seeds at all stages of berry development. Proanthocyanidin levels in both seeds and skin decreased between veraison and harvest. Additional proanthocyanidin subunits were released when the residues remaining after acetone extraction were subjected to direct acid-catalysis in the presence of phloroglucinol. In the seeds, these accounted for much of the post-veraison decrease, but not in grape skin. At harvest, 75% of extractable berry proanthocyanidin was in the seeds. Accumulation of proanthocyanidins in the seeds appears to be independent of that in the skins, but in both tissues synthesis occurs early in berry development and maximum levels are reached around veraison.     

Isolation,purification, and antioxidant activities of polysaccharides from Ziziphus Jujuba cv. Muzao

In the present study, crude polysaccharides from Ziziphus Jujuba cv. Muzao were isolated and purified using DEAE cellulose-52 and Sephadex G-100 size-exclusion chromatography; four fractions were collected, namely GZMP-1, GZMP-2, GZMP-3, and GZMP-4. The molecular weights of these four fractions were measured to be 111.2, 95.1, 84.2, and 571.4 kDa, respectively, using high-performance gel permeation chromatography. Gas chromatography analysis of the monosaccharide composition confirmed that GZMP-1 was composed of rhamnose, arabinose, glucose, and galactose. Rhamnose, arabinose, and galactose were the main components present in GZMP-2 and GZMP-3, whereas GZMP-4 was composed of only rhamnose and arabinose. Scanning electron microscopy showed relatively smooth surfaces for GZMP-1 and GZMP-4, whereas GZMP-2 and GZMP-3 had more folds on their surfaces. Fourier transform infrared spectroscopy analyses indicated that GZMP-1 and ZMP mainly had α-type glycosidic linkages. The in vitro antioxidant activities of the polysaccharides revealed that jujube polysaccharides exhibit remarkable antioxidant activity, and can scavenge DPPH radical and OH radical in a concentration-dependent manner. The results of this work suggest that polysaccharides from Z. Jujuba cv. Muzao have potential to be used as functional food and in the development of natural antioxidant drug carriers.     

大久保桃的催熟条件研究

本文研究了冷藏后的大久保桃适宜的催熟方式、温度和时间对桃果实和软白桃罐头感官品质和理化指标的影响,并分析了原料利用率。结果表明:大久保桃采用打孔的PE袋包装,催熟效果较好,此时桃的腐败指数和褐变指数低,风味浓郁;有效冷藏18 d内的大久保桃,30℃催熟3 d后,生产的软白桃罐头感官和理化指标均达到国标要求;原料利用率均保持在83.31%以上。该研究为软白桃罐头加工中的桃催熟处理提供了技术依据。     

白肉番石榴总黄酮提取工艺优化及体外抗氧化活性分析

对白肉番石榴中总黄酮的提取工艺进行优化,并研究其体外的抗氧化活性。以珍珠番石榴(白肉)的叶、皮为原料,在单因素实验的基础上,以总黄酮提取量为指标,采用正交试验优化获得了番石榴叶、皮中总黄酮的提取工艺。在此基础上提取番石榴果肉中的总黄酮,然后比较番石榴叶、皮、果肉中黄酮的体外抗氧化作用。结果表明,番石榴叶、皮的总黄酮的最优提取工艺略有差异。番石榴叶总黄酮的提取最优工艺为:乙醇浓度50%,提取温度65 ℃,料液比1:20 (g/mL),提取时间135 min。番石榴皮总黄酮提取最优工艺为:乙醇浓度60%,提取温度45 ℃,料液比1:7 (g/mL),提取时间105 min。在最优条件下番石榴叶、皮总黄酮的提取量分别为(188.66±0.23)、(48.03±0.16) mg/g。番石榴叶、皮、果肉总黄酮在ABTS自由基及羟基自由基清除实验、铁还原力及总抗氧化力测定分析中显示良好的抗氧化活性,其中番石榴叶总黄酮的体外抗氧化能力最强。由此说明番石榴黄酮有望成为一种良好的天然抗氧化剂。     

黄骅市冬枣和果园土壤中重金属元素分析与膳食暴露风险评估

目的 为了给冬枣的种植生产、流通监管和风险预警提供科学依据,保障其质量安全,参照风险评估模型对黄骅冬枣中的重金属元素对人体健康危害的风险进行评估。方法 采集黄骅市的冬枣产区27个果园的冬枣样品和对应的果园土壤样品,采用电感耦合等离子质谱法(inductively coupled plasma mass spectrometry, ICP-MS)和直接测汞仪对其中的Cr、Cu、Cd、As、Pb和Hg进行测定。根据美国环境保护局（the United States Environmental Protection Agency, USEPA）推荐健康风险模型评价法,对冬枣中的Cr、Cu、Cd、As、Pb的健康风险进行定量评估。结果 所采集样品的果园土壤中Cd、Pb、Cr、Cu、Hg和As含量均低于GB15618-2018中规定的“农用地土壤污染风险筛选值”;不同果园的冬枣中As、Cd、Pb、Cr、Cu、Hg的检出率分别为100%、88.9%、96.3%、96.3%、100%、3.7%;6种元素的THQ<1（目标危害系数法,target hazard quotient）,TTHQ<1（累积目标危害系数,total target hazard quotient）,说明膳食暴露风险均可接受;Pb在土壤和冬枣的样品中呈显著正相关性,其他元素在两者间均没有明显的相关性。冬枣样品中重金属元素As和Cr可能来源于外部投入品。结论 黄骅冬枣的重金属元素的膳食摄入风险处于安全水平,消费者可放心食用。外部投入品可能是冬枣重金属污染的来源之一,应引起密切关注。