米根霉固态发酵橘皮产纤维素酶工艺的优化

以橘皮为原料,以米根霉为生产菌株,采用固态发酵法生产纤维素酶。通过单因子试验分别考察了发酵培养基水分含量、接种量及培养时间三个重要因子对纤维素酶活力的影响,在此基础上,采用Box-Behnken设计对产酶工艺进行优化,利用Design Expert软件对试验数据进行回归拟合和方差分析,最终确定产酶最优工艺条件为:发酵培养基水分含量12.24 mL,接种量10.76%,培养时间72.64 h,在最优条件下所得纤维素酶的酶活力为464.33 U/g。     

贡柑果酒酿造工艺的研究

以贡柑为原料,经打浆、酶解和脱苦等预处理,对贡柑果酒酿造的工艺参数等进行研究;以初始pH值、接种量、SO2添加量和发酵温度为因素,做4因素3水平的正交试验.结果表明,贡柑果汁经0.6％β-环糊精处理80min,酵母接种量为0.06％,二氧化硫添加量为90mg/L,初始pH值为4.5,发酵温度为33℃,发酵周期为7d,可得到浅黄色、澄清透明、风味好、营养丰富的贡柑果酒.     

外源亚精胺对黄果柑果实抗氧化酶活性的影响

为探索亚精胺（spermidine,Spd）与3 种抗氧化酶过氧化氢酶（CAT）、过氧化物酶（POD）和超氧化物歧化酶（SOD）活性变化的关系,以及黄果柑果实成熟过程中抗氧化酶活性的变化趋势。以5 a生黄果柑果树为实验材料,设置3 个不同质量浓度的亚精胺处理,通过叶面、果面喷施亚精胺,研究外源亚精胺对黄果柑果实发育后期抗氧化酶活性的影响。结果表明：外源Spd能显著提高黄果柑果实中Spd和精胺含量,极显著降低腐胺含量;显著提高黄果柑果实转色初期CAT、POD和SOD活性;显著降低成熟后果实丙二醛（malondialdehyde,MDA）含量,推迟MDA含量快速累积的时间。结果显示,外源Spd具有改善黄果柑果实抗氧化保护系统的功能,通过调控黄果柑果实抗氧化酶活性,提高自由基防御系统的防御能力。     

Inhibitory effect of sour orange (Citrus aurantium) juice on Salmonella Typhimurium and Listeria monocytogenes

The sour orange (Citrus aurantium) juice is commonly used as flavoring and acidifying agent for vegetable salads and appetizers in Turkey. It was aimed to determine the survival and growth pattern of Salmonella Typhimurium and Listeria monocytogenes in sour orange juice. Different concentrations of neutralized and un-neutralized juice samples were inoculated with each of the test microorganisms (∼6 log CFU/mL) separately and then incubated at 4 °C and 37 °C for seven days. It was detected both of the test microorganisms could survive and even grow in neutralized juice samples at 37 °C for two days. However, none of them could survive at the end of seventh day of incubation at 37 °C. Low incubation temperature (+4 °C) increased the survival of the tested microorganisms. Also, it was detected that L. monocytogenes were less resistant to the variable conditions than S. Typhimurium. It was concluded that the antimicrobial effect of sour orange juice mainly depends on the low pH value of the product. However, incubation time and temperature are also effective on the survival of the tested pathogens.     

正交法优化超声波提取橘皮果胶的工艺研究

将超声波与酸法结合探究橘皮果胶得率.设置4个影响试验结果的因素:料液比、pH、超声温度、超声时间,每个因素选取5个水平进行单因素试验,通过正交试验优化工艺.结果 表明,最佳提取条件为:料液比1∶15 (g/mL)、pH 1.5、超声温度70℃、超声时间40 min,根据最优方案获得的果胶提取率为22.43％.     

甜橙果肉粉对橙油风味物质的吸附性能研究

为探究柑橘果肉在风味吸附方面的机制,测定了甜橙果肉粉的成分构成、氮气吸附-脱附等温线,采用扫描电子显微镜（scanning electron microscope, SEM）观察了其微观结构,采用气相色谱-质谱法（gas chromatography-mass spectrometry, GC-MS）测试分析了其对橙油风味物质的吸附性能。成分分析结果表明甜橙果肉粉主要由膳食纤维（51.87%±3.12%）、蛋白质（20.47%±0.58%）、脂肪（11.33%±1.60%）、淀粉（4.06%±0.59%）构成。SEM观察结果及氮气吸附-脱附等温线分析结果表明,甜橙果肉粉复合物中存在丰富的褶皱和缝隙等不规则结构,比表面积达2.98 m2/g。GC-MS测试分析结果表明,甜橙果肉粉对橙油典型香气成分例如柠檬烯、γ-萜品烯、β-月桂烯、β-水芹烯、芳樟醇、辛醛、壬醛等有明显的吸附作用,尤其与直链脂肪醛、含氧萜类衍生物的相互作用较明显,而对α-蒎烯、桧烯等双环单萜类成分的吸附作用相对较弱。综上,甜橙果肉粉中各组成成分交联而成的褶皱和缝隙结构是其发挥风味吸附作用的重要基础,研究结果可为进一步开发利用甜橙果肉提供参考。     

高效液相色谱法测定辣椒粉中碱性橙的不确定度评定

为分析高效液相色谱法测定辣椒粉中碱性橙含量的不确定度,采用JJF 1135-2005《化学分析测量不确定度评定》进行评定。依据检测方法建立数学模型,分析不确定度的重要来源,其中标准溶液配制产生的不确定度是0.008 3,最小二乘法拟合标准曲线校准产生的不确定度是0.056,样品称量带来的不确定度是0.002 5,样品定容带来的不确定度是0.005 0,样品处理过程带来的不确定度是0.012,结果的重复性带来的不确定度是0.022。对各不确定度分量进行分析计算和合成不确定度,通过乘以95%概率下的扩展因子2,获得加标辣椒样品中碱性橙含量测定结果是（30±3.73） mg/kg,最小二乘法拟合标准曲线对测定结果的影响最大,其次样品处理过程和结果的重复性带来的不确定度也不容忽略。     

酶法真空间歇处理脱除脐橙果皮和囊衣的研究

为降低柑橘汁胞生产中通常采用的热烫去皮酸碱脱囊衣工艺造成的环境污染和水资源浪费,选用植物酶制 剂结合真空间歇处理作为一种替代方法。根据所选酶的特性选择pH 3.5、处理温度40 ℃的条件下,研究酶添加量、 真空度、间歇方式和浸泡时间等因素对去皮效果的影响。在单因素试验的基础上确定各因素的最佳水平,并采用 L9（34）正交试验优化了各工艺参数。结果表明：在酶制剂添加量2%、真空度10 psi、间歇减压方式（2＋2＋2＋ 2）min的条件下处理50 min后,得到脐橙全果果皮去除完全、囊衣脱除干净的样品。     

Inactivation kinetics of pectin methylesterase in orange juice as a function of pH and temperature/time process conditions

Pasteurisation of orange juice (OJ) is necessary to prevent spoilage due to microorganisms and enzymes, mainly pectin methylesterase (PME). PME has a higher thermal resistance than the bacteria and yeasts existing in OJ and therefore its inactivation is used as a parameter to define the time/temperature combination of the thermal process. The enzyme has isoforms with different activities and thermal resistances. A three‐parameter model can be used to describe the kinetics of PME inactivation, where the more and less thermally resistant fractions are represented. In this study the thermal inactivation kinetics was evaluated at six pH values (3.6, 3.7, 3.8, 3.9, 4.0 and 4.1), three minimal temperatures (82.5, 85.0 and 87.5 °C) and at least six holding times for each condition. It was found that the thermolabile PME fraction (a) was influenced by pH and processing temperature. A slower reaction rate constant (k₁) was found for juices with pH values of 3.8 and 3.9 at the studied temperatures. The highest inactivation levels were obtained in juices with pH values of 3.6 and 3.7. Copyright © 2006 Society of Chemical Industry     

柑橘-胡萝卜复合果肉饮料的研制

以柑橘、胡萝卜为主要原料,研制一种新型的复合果肉饮料,重点解决产品配方和悬浮稳定性问题。采用单因素实验和正交试验,产品最佳配方为柑橘浆12.5%、胡萝卜浆12.5%、蔗糖11%、柠檬酸0.15%;稳定剂的最佳组合为羧甲基纤维素(Carboxymethyl Cellulose,CMC)0.25%、黄原胶0.15%。在此配方下,产品口感好,稳定效果佳。