北枳椇果渣不溶性膳食纤维的制备及其性能特性研究(英文)

对枳椇果渣不溶性膳食纤维(IDF)的化学法提取工艺、双氧水脱色工艺进行了研究,并对产品的营养成分和功能性质进行分析。通过单因素及正交试验确定最佳的化学法提取工艺为:以液料比为8∶1(mL∶g)、浓度为1.5mol/L的氢氧化钠溶液,在20℃条件下处理40min后过滤,冲洗至中性,然后取滤渣转移至液料比为6∶1(mL∶g)、pH值2的硫酸溶液中,60℃下作用60min,冲洗至中性,干燥。不溶性膳食纤维的提取率为74.02%,质量分数由果渣中的62.62%(干基计)提高到84.97%;双氧水脱色的最佳工艺条件为:5%H2O2、pH值12、45℃、5h,在此条件下不溶性膳食纤维的白度由51.63%增加到60.21%;制备的膳食纤维产品的持水力由果渣中2.4g/g增加到4.3g/g、持油率由2.3mL/g增加到3.9mL/g、结合水力由2.6g/g增加到4.7g/g、膨胀力由2.8mL/g增加到4.6mL/g。     

油橄榄果渣膳食纤维碱法提取工艺优化及其理化性质研究

以油橄榄脱脂果渣为原料,采用碱法提取油橄榄果渣水溶性膳食纤维(SDF)和水不溶性膳食纤维(IDF),并对其理化性质进行研究。在单因素试验基础上采用正交试验优化油橄榄果渣膳食纤维最佳提取工艺条件为:NaOH质量分数8%、提取温度80℃、提取时间80 min、液料比15∶1(m L∶g)。在最佳提取工艺条件下,油橄榄果渣SDF产率为28.74%,IDF产率为52.39%。理化性质研究结果表明:油橄榄果渣IDF的持水力、膨胀力和持油力分别为3.38 g/g、2.20 m L/g、1.91 g/g;油橄榄果渣SDF的持水力、膨胀力和持油力分别为5.05 g/g、4.78 m L/g、4.25 g/g。在透析90 min时,油橄榄果渣SDF、IDF和脱脂果渣的葡萄糖透析延迟指数分别为13.22%、8.55%、4.38%。扫描电镜观察表明,制备的IDF结构疏松,具有较大的空腔和裂缝,而SDF粒径较小,呈堆积状,具有较多的空腔。     

金橘果渣膳食纤维制备工艺研究

为了进一步深度开发和综合利用我国柑橘类水果资源,采用酸碱洗涤剂法制备金橘果渣膳食纤维.通过正交试验确定了金橘果渣水溶性膳食纤维的提取工艺,结果表明:提取水溶性膳食纤维的最佳工艺为:pH值1.0、提取温度85C、提取时间80min、加水量25mL/g,水溶性膳食纤维的提取率为20.76%;将该工艺剩余的残渣提取水不溶性膳食纤维,其提取率为15.42%.合并及脱色后的总膳食纤维产品中总膳食纤维含量为82.42%,水溶性膳食纤维含量为30.26%,其SDF/IDF质量比为0.59,而金橘果渣原料中其比值仪为0.18.金橘果渣膳食纤维具有广阔的市场应用前景.     

红薯膳食纤维提取工艺优化试验

以红薯为原料,对影响红薯可溶性膳食纤维提取的因素(料液比、溶液pH值、温度、纤维素酶添加量和酶解时间5个因素)进行了单因素试验,然后在此基础上进行了正交试验,得到了纤维素酶制备红薯可溶性膳食纤维的最佳条件:料液比1∶12、温度55℃,pH值为6,纤维素酶的添加量20U/g,酶解时间2h。以此条件提取的红薯水溶性膳食纤维的含量高达20.91%,能显著提高红薯水溶性膳食纤维的提取率。     

酶法提取黑加仑果渣花色苷的研究

通过单因素和正交试验,确定了黑加仑果渣花色苷酶法提取的最佳工艺条件为:釆用纤维素酶酶解,温度50℃,时间100min,果渣与酶解液的比1:9(g:mL),酶用量为原料质量的1%,pH值5.0,黑加仑花色苷提取率86.63%.釆用果胶酶酶解,温度50℃,时间120min,果渣与酶解液的比为1:8(g:mL),酶用量为原料质量的1.4%,pH值3.5,黑加仑花色苷提取率91.09%.并确定了使用果胶酶的提取效果好于纤维素酶.     

糠醛渣酶解工艺优化及过程的研究

笔者以糠醛渣为原料,在单因素实验的基础上,应用响应曲面法进行酶解糖化试验,探索了纤维素酶水解反应的最佳工艺条件。在优化条件的基础上进行了发酵罐糖化试验,同步分析了反应过程中糖化率的变化。研究结果表明:糠醛渣酶解的最佳工艺条件为:温度46.8℃,pH 4.32,酶用量35.95FPU/g,底物浓度2.899%,纤维素的平均转化率为92.59%。糖化过程同步分析结果显示,反应初期糖化速度非常快,反应进行3h糖化率达到了55.33%。反应18h时糖化率已达到87.88%,36h酶解反应基本结束,糖化率高达98.1%,比其他纤维原料的糖化时间大大缩短。     

酸碱法提取葛根粉膳食纤维素的工艺优化

为提高葛根的资源利用率,以葛根为原材料,采用化学酸碱法提取了葛根中的膳食纤维素,通过单因素实验和正交实验以获得提取膳食纤维素的最佳工艺条件。结果表明：提取膳食纤维素的最佳工艺是碱处理料液比1∶20、pH值为11、温度60℃、时间120 min,提取率为72.26%;酸处理料液比1∶10、pH值为4、温度50℃、时间80 min,提取率为71.13%。根据各单因素实验和正交实验的各影响因素的关系,碱处理对膳食纤维素的提取影响较大,而酸处理对膳食纤维素的提取影响较小。     

高活性竹笋膳食纤维饼干的研制

高膳食纤维饼干是一种重要的营养保健食品.介绍了以面粉为主要原料,辅以乳酸菌发酵制备的竹笋膳食纤维和可溶性膳食纤维等成分制作高纤维饼干的工艺,并对影响饼干品质的主要因素进行了研究.得出高活性竹笋膳食纤维饼干的最佳配方和工艺参数为:竹笋膳食纤维颗粒度大小为120目、质量分数为6%,可溶性膳食纤维、谷朊粉、白糖和油脂的质量分数分别为6%,0.6%,25%和7%,烘烤温度为190℃,烘烤时间为8 min.该饼干口感松脆、香甜,特别适合于老年人和儿童食用.     

漆酶处理条件对枫香湿法纤维板强度的影响

为消除人造板的游离甲醛污染,开发一种无胶人造板生产工艺,以漆酶和枫香纤维为原料,进行纤维板的工艺研究.以湿法生产纤维板,并检测板材的内结合强度(IB),结果表明:漆酶处理纤维板的IB值高于对照板;处理温度、时间和酶用量对纤维板的IB均有显著影响;最佳处理条件为pH 3.0,50 ℃,2 h,20 U/g纤维.     

葵花籽壳制取活性炭的工艺研究

以葵花籽壳为原料,比较了水蒸气物理法、磷酸转炉法和磷酸微波法制取的活性炭,以磷酸微波法制取的活性炭各项性能较优.在微波功率为700 W的条件下,采用正交试验法对磷酸微波法制取活性炭性能的影响因素如:活化剂浓度、处理时间及催化剂用量进行系统研究,得到磷酸微波法制备活性炭的最佳工艺.亚甲基蓝吸附值的最佳工艺条件为磷酸浓度30 °Be′、活化时间25 min、催化剂1用量4 %、催化剂2用量2 %;碘吸附值的最佳工艺条件为磷酸浓度35 °Be′、活化时间25 min、催化剂1用量4 %、催化剂2用量2 %;焦糖脱色率的最佳工艺条件为磷酸浓度30 °Be′、活化时间35 min、催化剂1用量2 %、催化剂2用量2 %.     

Browsing Damage on Pine (Pinus sylvestris and P. contorta) by a migrating moose (Alces alces) Population in Winter: Relation to Habitat Composition and Road Barriers

In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads.     

Effects of Root Freezing on the Physiology and Growth of Picea glauca,Picea mariana and Pinus banksiana Seedlings Under Different Soil Moisture Regimes

The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage.     

Decomposition and nutrient loss from prunings of different contour hedgerow species in tea plantations in the sloping highlands of Sri Lanka

Contour hedgerows of multipurpose tree species in the sloping tea lands of Sri Lanka are expected to reduce soil erosion and also add significant amounts of plant nutrients to the soil via periodic prunings. The objective of this experiment was to characterize the biomass decomposition pattern and quantify the amount of nutrients added through prunings of six tree species (Calliandra calothyrsus, Senna spectabilis, Euphatorium innulifolium, Flemingia congesta, Gliricidia sepium and Tithonia diversifolia) currently being used in hedgerows associated with tea. Withered leaf and stem prunings (50 g) were enclosed in 2-mm litter bags, placed at 5-cm depth and retrieved after one, three, six, nine and 12 weeks. Loss of initial dry weight, N, P and K was measured. Single exponential decay function adequately described both dry weight and nutrient loss. Tree species differed significantly in their rate of breakdown with decomposition constants (k) varying from 0.0299 to 0.2006 week⁻¹ for leaves and from 0.0225 to 0.0633 week⁻¹ for stems. Gliricidia showed the highest k for leaves with the rest in the following descending order: Senna > Tithonia ≥ Euphatorium > Calliandra > Flemingia. A similar pattern was observed for loss of all nutrients with Calliandra and Flemingia always having lower k values than the rest. Although N immobilization was not observed, immobilization of P and K was observed during the first week of incubation in some species, particularly in stem prunings. Annual biomass of prunings differed significantly between tree species in the following descending order: Calliandra > Senna > Flemingia > Tithonia > Gliricidia > Euphatorium. Calliandra added the greatest amount of nutrients annually to the soil with Euphatorium adding the least. Calliandra prunings provided the annual total K requirement and 49% of the N requirement of mature tea. However, none of the species provided more than 5% of the P requirement. It is concluded that among the tree species tested, Calliandra and Flemingia are the most suitable for contour hedgerows in tea plantations of this agroclimatic region because of their higher soil nutrient enrichment capacity and slower decomposition rates which would minimize leaching losses. This revised version was published online in June 2006 with corrections to the Cover Date.     

Growth of Phlebiopsis gigantea in wood of seven conifer species

Heterobasidion parviporum and Heterobasidion annosum are widely distributed root‐rot fungi that infect conifers throughout Europe. Infection of conifer stumps by spores of these pathogens can be controlled by treating fresh stumps with a competing non‐pathogenic fungus, Phlebiopsis gigantea. In this study, growth of three Latvian strains of P. gigantea and the biological control agent ‘Rotstop’ strain was evaluated in stem pieces of Norway spruce, Scots pine, lodgepole pine, Douglas‐fir, Weymouth pine, Siberian larch and Sitka spruce. The growth rates of one H. parviporum and one H. annosum isolate were also measured in the same stem pieces. The growth rate of P. gigantea varied greatly in wood of different conifer species. It was higher in the three pine species, lower in Norway spruce and lowest in Sitka spruce and Siberian larch, and in Douglas‐fir, this fungus did not grow. The largest area of wood occupied by P. gigantea was in lodgepole pine. Growth of Latvian isolates of P. gigantea in the wood of Pinus and Picea species was comparable to that of the Rotstop isolate. Consequently, stump treatment with local P. gigantea isolates should be recommended. However, our results suggest that Douglas‐fir stump treatment against Heterobasidion by P. gigantea may be ineffective and other stump treatment methods should be considered.     

Effects of Seed Weight and Seed Type on Early Seedling Growth of Pinus sylvestris under Harsh and Optimal Conditions

The effects of seed weight and seed type on seedling growth of Pinus sylvestris (L.) were studied by seeding individually weighed orchard and stand seed in different mixtures under harsh (direct seeding in field) and optimal (seeding in nursery) conditions. In the nursery experiment an increase in the seed weight from 3 to 7 mg increased the seedling height by 10-27% and total weight by 27-113%, and decreased the height/diameter ratio by 5-6% after 2 yrs. With elimination of seed weight effects, orchard seedlings were 2% taller than stand seedlings in year 2. Without elimination of seed weight effects, orchard seedlings were 7-13% taller. In the field experiment an increase in the seed weight from 3 to 7 mg increased seedling height by 18-65%, stem volume by 81-274% and the number of top-buds by 23-34% in year 5. After elimination of seed weight effects, orchard seedlings were 7-13% taller than stand seedlings and without elimination of seed weight effects 20-21% taller after 5 yrs. Even after elimination of both seed weight and genetic effects orchard seedlings were 3-9% larger than stand seedlings in the field experiment. In conclusion, the influence of seed weight and seed type on growth traits and slenderness is highly significant and the influence seems to be greater in harsh conditions.     

Stand Structure in Pine,Spruce and Deciduous Forests: A Comparison Between Finnish and Russian Karelia

This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland.     

Growth and Terminal Bud Formation in Picea abies Seedlings Grown with Alternating Diurnal Temperature and Different Light Qualities

The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions.     

CAD与建筑设计的关系

本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。     

Growth of Mixed Birch-Coniferous Stands in Relation to Pure Coniferous Stands at Similar Sites in South-eastern Norway

Mean age, mean and top heights and yield were studied in 20 mixed stands of birch ( Betula pubescens Ehrh. and B. pendula Roth) and Picea abies (L.) Karst. and nine mixed stands of birch and Pinus sylvestris L. in south-eastern Norway. Each mixed stand and the adjacent pure coniferous stand (control) were growing under the same site conditions and had not been commercially thinned. There were no significant differences in mean age at breast height or in top heights between birch and conifers in the mixed stands, while mean height was significantly higher for birch than for spruce. A growth index was calculated based on total volume and age at breast height. For the spruce sites the growth in young mixed stands (birch < 17 m) was superior to that of pure spruce, while the difference was insignificant in older stands. The growth index correlated positively with the ratio between generatively and vegetatively regenerated birch trees, and negatively with the age of the oldest species in the mixture and with site quality. For the pine sites there was no significant difference in the growth index between mixed birch-pine and pure pine stands. A mixture effect of birch on the volume yield of spruce or pine could not be demonstrated.     

Defoliation by the Needle-shortening Pine Gall Midge,Thecodiplosis brachyntera,on Pines in Central Sweden

An outbreak of the needle-shortening pine gall midge, Thecodiplosis brachyntera , occurred on Scots pine, Pinus sylvestris (L.) and lodgepole pine, P. contorta (Dougl.) in central Sweden during 1995-1998. The larval feeding of T. brachyntera kills current-year needles and heavy infestation causes severe defoliation. A pattern of fluctuating defoliation among years and sites was found on both pine species. Defoliation was evenly distributed in the crown of P. sylvestris during years of high as well as low infestation; apical whorls had as much defoliation as basal whorls. In P. contorta , however, there was a tendency for defoliation to be concentrated on branches in the most apical whorls. Growth ring increments on P. sylvestris with high levels of defoliation (71%) did not differ from trees with moderate levels (26%) of defoliation. Shoot lengths were significantly shorter, however, on heavily infested trees the year after defoliation.