苹果果肉颜色及褐变多样性研究

为了评价苹果品种在果实鲜切后果肉颜色变化及褐变程度,寻找抗褐变品种,选用40个品种的果实进行了果肉颜色和褐变多样性的研究,并进行差异显著性和聚类分析。结果表明：苹果果肉颜色可分为黄、白、绿3种;初始色泽为黄色的切分1 h后大部分变为黄褐色;初始色泽为绿色和白色的,切分1 h后一般呈灰褐色,也有的呈黄褐色;苹果果实切分后褐变现象普遍发生,表型多样,品种间差异较大,而且成熟期越晚褐变渐轻。苹果品种华红、华冠是优良的抗褐变种质资源。     

碱性木聚糖酶辅助漂白马尾松硫酸盐浆的研究

为了降低邵武纸厂的D1/C段有效氯用量,减轻对环境的污染,在马尾松硫酸盐法纸浆OD1/CEopD2漂白工艺过程中,进行了碱性木聚糖酶辅助漂白(X)的研究试验。结果表明,与原有OD1/CEopD2漂白流程相比,碱性木聚糖酶用量为5.50 IU.g-1,在其它漂白工艺条件相同的情况下,采用OXD1/CEopD2漂白流程,马尾松硫酸盐浆漂后白度由85.3%(ISO)提高至87.3%(ISO);在漂后浆目标白度为85%(ISO)时,与OD1/CEopD2漂序相比,OXD1/CEopD2漂序的D1/C段有效氯用量减少31%,漂白废水中AOX可降低25%。     

猕猴桃果浆中叶绿素和颜色的热降解动力学

为了研究猕猴桃果浆加工中叶绿素和绿色的热降解规律,测定了不同温度(70、80、90℃)和pH值(pH值3.3、6.0、8.0)对猕猴桃果浆叶绿素含量和色差的影响。结果表明,猕猴桃叶绿素a、b和绿色值(-a*)的热降解属一级动力学反应;在相同pH值条件下,随温度升高,叶绿素a、b和绿色值(-a*)的反应速率常数(k)降低,半衰期(t1/2)缩短;随pH值增加,叶绿素a的活化能(Ea)变化范围为14.69～66.02kJ/mol,叶绿素b为40.88～54.64kJ/mol,绿色值(-a*)为48.55～64.14kJ/mol;pH值3.3时叶绿素a、b的降解和绿色值(-a*)相关性较好。猕猴桃果浆加工中适量提高pH值可减少叶绿素和绿色的损失。     

木聚糖酶在稻草浆漂白中的应用

分别采用真菌和细菌木聚糖酶对碱法稻草浆进行漂白处理,结果表明,在细菌木聚糖酶处理时,随着酶用量的增加,白度和强度都相应有所增加,但经过次氯酶盐补漂后,真菌木聚糖酶比细菌木聚糖对白度提高更有效。     

基于超高压处理的猕猴桃原浆制备研究

为优化猕猴桃超高压灭菌条件下原浆制作工艺,对3种不同原浆制作工艺分别进行单因素优化试验,筛选出两种产品色泽和稳定性较好的工艺,并对这两种工艺所制作样品进行4℃储藏40 d的品质对比。结果表明,在最大程度保留猕猴桃原浆绿色,提高其稳定性的条件下,3种工艺的优选次序为：对辊式挤压制浆>胶体磨制浆>高压微射流制浆;与胶体磨工艺相比,对辊式挤压工艺制作的产品在4℃条件下储藏30 d内无明显的自然分层,产品VC损失较少;优化后的制浆工艺为：采用对辊式挤压工艺,挤压次数为1次。按照该工艺制作的猕猴桃原浆色泽相对均一,以青绿色为主,VC含量为40～50 mg/100 g。     

石榴果实香气物质的研究

利用顶空固相微萃取法提取大青皮甜石榴整体果实、石榴皮和石榴籽汁的芳香物质,气相色谱-质谱联机定性定量分析,检测香气组分.石榴香气组分中以醛类和醇类为主,在石榴整体果实中占总峰面积的78.32%和14.52%,在石榴皮中占89.88%和4.70%,在石榴籽汁中占82.15%和9.78%.石榴中共检测出77种香气组分,其中石榴果实、果皮和籽汁中分别检测出42种、39种和43种.香气成分中共有的成分为18种,在果实、果皮和籽汁中分别占总峰面积的94.62%、95.59%和93.76%.2-己烯醛、己醛、3-己烯醛、(E,E)-2,4-己二烯醛为石榴的主要香气成分,在果实、果皮和籽汁分别占78.27%、89.78%和81.79%.结果表明,石榴香气组分以C6醛和醇为主,石榴不同部分香气组分差异也主要表现在C6醛和醇含量的差异上.     

Optimisation of oxygen delignification in production of totally chlorine-free cellulose pulps from oil palm empty fruit bunch fibre

The effects of oxygen delignification on prehydrolysed-soda pulps produced from oil palm (Elaeis guineensis) empty fruit bunch fibre were statistically investigated by employing response surface methodology (RSM). Polynomial estimation models of five response variables namely yield, Kappa number, α-cellulose, viscosity and brightness were developed, each model comprised of four-independent variables: reaction temperature, reaction time, the alkali charge, and initial Kappa number. The calculated optimum condition (95 °C reaction temperature, 60 min reaction time, 2% alkali charge, and initial Kappa number of 6.6) is capable to produce pulp with 98.1% yield, Kappa number 2.4, 97.38% α-cellulose, pulp viscosity 13.8 cPs and ISO brightness 67.1%, which were proven close to the predicted values calculated from estimation models. The results indicated that oxygen delignification which is used as the first stage of bleaching sequence has the ability to both delignify and increase pulp brightness without substantial reduction in viscosity and α-cellulose, that appeared to be beneficial for subsequent TCF bleaching.     

发展竹浆造纸 节约木材资源

随着社会经济水平的发展,中国纸及纸板的现有产品结构已不适应纸张消费市场的变化与发展,加剧了国内市场对进口纸及纸板的依赖性。竹材纤维细长,是制浆造纸的优质原料。竹浆纸的开发有利于节约木材资源,有利于环境保护。中国竹资源丰富,发展竹浆造纸的市场前景非常广阔。因此,在造纸工业中实现以竹代木,建立林纸一体化的竹浆生产基地,将成为节约木材资源,减少纸及纸浆的进口,使制浆造纸工业得以持续发展的有利途径。     

湖北省马尾松纸浆林主伐年龄的确定

利用湖北省马尾松人工林的样地资料,建立了优势高生长方程,林分自然稀疏方程,未疏伐林分直径生长方程,疏伐后林分生长预测方程,直径分布模型、树高曲线方程,根据现场造林资料,建立了材种出材材种材性达到工艺要求的最低年龄,采用现现法（基准贴现率为１２％）进行经济分析,以净现值（ＮＰＶ）最大（适当考虑内部收益率ＩＲＲ）来确定经济成熟。根据“以工艺成熟为基限,重点考虑经济成熟,适当兼顾数量成熟”的原则,确定不     

Inhibition by pulp juice and enhancement by ingestion on germination of bird-dispersedPrunus seeds

To evaluate what prevents seed germination and why ingestion by birds enhances germination, we carried out germination experiments using bird-dispersed seeds of twoPrunus species (Prunus sargentii andP. ssiori) in the laboratory. Germination of seeds with following four treatments was compared: “Ingested seeds” excreted after feeding of fruits to birds; “Extracted seeds” deliberately extracted from the fruit pulp; “Juiced seeds” which were supplemented with the juice of the pulp after seeds had been deliberately extracted from the pulp; and “Intact seeds” in untreated whole fruits. Many ingested (27%, 23% inP. sargentii, 18% inP. ssiori) and extracted seeds (24% inP. sargentii, 17% inP. ssiori) germinated, and difference in germination percentages between ingested and extracted seeds were not significant, for eitherPrunus species. The Juiced seeds rarely germinated (2% inP. sargentii, 6% inP. ssiori), and seeds within intact fruits did not germinate. These results suggest that the fruit pulp and the juice of the pulp inhibit germination and the seeds could germinate without ingestion by birds once they had been manually extracted from pulp. Therefore, it is considered that bird ingestion enahnces germination by removing pulp, especially juice of the pulp, in these twoPrunus species.