Antioxidant effects of gallic acid alkyl esters of various chain lengths in oyster during frying process

The antioxidant effects of gallic acid (GA) and its alkyl esters including methyl gallate, ethyl gallate, propyl gallate, butyl gallate (GA-C4), octyl gallate, lauryl gallate, hexadecyl gallate and octadecyl gallate in frying oil (soybean oil) and oyster during frying were investigated. Rancimat induction period (RIP) assay indicated GA and its alkyl esters effectively improved the oxidative stability of soybean oil according to the ‘polar paradox’; that is, the antioxidant effects of the polyphenols decreased in lipid system with the increasing of hydrophobicity. Results also indicated that GA and its alkyl esters all effectively retarded lipid oxidation in oyster tissue according to parameters including RIP, peroxide value and electron spin resonance assays. Moreover, the antioxidant efficiency in oyster increased with the alkyl chain length until GA-C4, and thereafter, the antioxidant effects decreased, similar to the ‘cut-off effect’. This study provides basic data for improving the oxidative stability of seafood during frying.     

Development and quality evaluation of a cereal-based breakfast product from yellow maize (Zea mays), sesame (Sesamum indicum) and mushroom (Pleurotus ostreatus) flour blends

Composite flours were prepared from blends of yellow maize (Zea mays), sesame seed (Sesamum indicum) and oyster mushroom (Pleurotus ostreatus) powder in the ratio of 80:20:0; 75:20:5; 70:20:10; 65:20:15 and 60:20:20, respectively to produce the cereal-based breakfast product coded as YSB, SMB, TMB, PMB and OMB with YSB as the control. The breakfast cereals were produced by hydration and toasting of yellow maize and sesame to 160°C for 25 min and blended together with oven-dried and packaged oyster mushroom. The developed products were analysed for proximate, vitamins, minerals and sensory properties. The proximate composition (%) of different blends ranged as moisture (4.07–7.08), ash (3.09–2.28), crude fat (16.04–12.83), crude fibre (4.30–8.22), protein (16.14–22.54), carbohydrate (56.34–47.04) and energy (434.34–393.83 Kcal). Vitamin A (7.99–5.98 mg/100 g), vitamin B₁ (0.08–0.42 mg/100 g), vitamin B₂ (0.06–0.15 mg/100 g), vitamin B₃ (1.91–4.52 mg/100 g) and vitamin C (3.55–3.32 mg/100 g) were u while minerals (mg/100 g) were calcium (75.31–58.02), potassium (0.65–4.01), magnesium (12.25–12.62), iron (1.21–4.15) and zinc (0.40–1.32). Sensory scores revealed that the cereal-based breakfast product were acceptable to the panellist with oyster mushroom supplementation up to 10%.     

贝壳填料曝气生物滤池的硝化特性研究

贝壳粗糙的表面及其合有的大量碳酸钙，可作为生物膜的载体及硝化反应的碱度来源。以海产弃物贝壳为生物膜载体，通过改变进水氨氮浓度及pH值，考察了贝壳填料曝气生物滤池的硝化脱氮规律。结果表明：对于氨氮〈120mg／L的原水，贝壳溶解提供的碱度能够满足硝化反应的需要，因此硝化反应进行得比较完全，对氨氮的去除率不受进水氨氮浓度的影响，可达90％以上；而当进水氨氮浓度达240mg／L时，因贝壳溶解提供的碱度不能完全满足硝化反应之所需，硝化反应将停滞，但对氨氮的去除率仍可达65％左右。此外，进水pH值对贝壳填料曝气生物滤池去除氨氮的效果及出水pH值基本没有影响。     

煅烧温度对牡蛎壳陶粒磷吸附效果的影响

研究主要是制备一种牡蛎壳陶粒,并考察煅烧温度对牡蛎壳陶粒除磷性能的影响。结果表明煅烧温度对牡蛎壳载体磷吸附效果的影响较大,当牡蛎壳粉末∶粘土∶九水硅酸钠=7∶2∶1,煅烧温度为450℃时,制备的牡蛎壳陶粒对磷的吸附量为0.155 mg·g-1。牡蛎壳陶粒对磷的吸附符合Langmuir等温吸附模型,且在25℃下最大吸附量为0.432 mg·g-1。最佳条件下制备的牡蛎壳陶粒具有良好的亲水性,吸水率可以达到18.64%、载体的抗压强度可以达到2.15 MPa、空隙率为41.2%、比表面积为5.71 m2·g-1、破碎率与磨损率之和为2.95%、含泥量为0.61%,这些指标均满足《水处理用人工陶粒滤料CJ/T 299-2008》的指标,可以将此牡蛎壳陶粒用到水处理当中。     

利用牡蛎壳制备水处理剂的应用研究

以牡蛎壳为原料制备一种新型牡蛎壳负载壳聚糖水处理剂,研究了水处理剂对水中苯酚的吸附性能。通过单因素试验确定水处理剂去除苯酚的条件,试验分析得出水处理剂去除苯酚最佳工艺条件:壳聚糖/牡蛎壳质量比0.08、pH=3、水处理剂用量0.5g和吸附时间150min。该研究对牡蛎壳为基的水处理剂的开发与利用提供科学依据。     

改性牡蛎壳材料去除Cr（VI）的研究

用牡蛎壳和硅微粉为原料制备可用于废水除Cr（VI）的型体材料。探讨材料制备中不同烧结温度和水热反应时间对其除Cr（VI）效果影响。采用二苯碳酰二肼分光光度计法测试各样品的除Cr（VI）效果,用SEM观察样品的微观结构。实验结果表明：牡蛎壳经硅微粉改性后除Cr（VI）效果明显增加;改性牡蛎壳除Cr（VI）材料650℃为最佳烧结温度,水热时间12h,除Cr（VI）效果最好,除铬率可达到91.2%。     

高效液相色谱-电感耦合等离子体质谱联用测定牡蛎中的有机锡

采用微波辅助萃取结合高效液相色谱 电感耦合等离子体质谱（HPLC-ICP-MS）法测定牡蛎样品中的有机锡。用含有1.0 mol/L冰醋酸和0.5 mol/L醋酸钠的甲醇溶液作为萃取溶剂,在微波功率60 W条件下萃取牡蛎样品20 min,样品经过滤后采用HPLC-ICP-MS法进行分析检测。在优化的条件下,二丁基锡、三丁基锡和三苯基锡3种有机锡的加标回收率分别为104%、99.3%和113%,检出限分别为0.33、0.22、0.48 ng/g。并采用CE 477贻贝标准物质进行方法验证,该方法的测定值与标准值符合。     

广西牡蛎活性肽抑制卵巢癌淋巴结定向高转移细胞增殖及对运动迁移能力的调控作用

目的：研究广西牡蛎活性肽对卵巢癌淋巴结定向高转移细胞（SKOV3-PM4）的增殖及运动迁移能力的抑制作用。方法：采用四甲基偶氮唑蓝（3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide,MTT）法测定广西牡蛎活性肽作用24 h后对细胞增殖的抑制作用。细胞经不同质量浓度的广西牡蛎活性肽处理后,采用细胞计数法和集落形成实验测定细胞增殖能力;细胞划痕实验和Transwell小室测定细胞体外运动和侵袭迁移能力。结果：MTT实验结果显示牡蛎活性肽质量浓度在5～80 mg/L范围内抑制SKOV3-PM4的增殖,24 h的半数抑制浓度（inhibitory concentration 50%,IC50）为35.36 mg/L。细胞划痕实验表明无细胞毒性的质量浓度为4 mg/L的牡蛎活性肽能抑制SKOV3-PM4的增殖能力,牡蛎活性肽作用SKOV3-PM4细胞后其侵袭、迁移能力降低,与空白对照组比较差异显著（P＜0.05）。结论：从牡蛎中分离出的小分子多肽在一定质量浓度下对SKOV3-PM4细胞的生长增殖、运动迁移具有抑制作用。     

牡蛎微波干燥特性及动力学研究

测定不同微波强度下牡蛎干燥水分曲线及失水速率曲线,考察不同微波强度对牡蛎干制品的复水增重率、收缩率、色差等品质方面的影响。结果表明：增大微波干燥强度可提高干燥速率,缩短干燥时间。在实验条件下,采用中等强度的微波干燥(如5、8W/g),牡蛎微波干燥时间在3.5～30min范围内。牡蛎品质较好。用Page方程建立的牡蛎微波干燥模型,与实验测定值的拟合度较高。