响应面法优化残次枣中不溶性膳食纤维提取工艺

以残次哈密大枣为原料,采用酶重量法提取不溶性膳食纤维,在单因素试验的基础上,根据Box-Behnken中心组合实验设计原理,以不溶性膳食纤维得率为响应值,设计三因素三水平响应面分析试验,优化残次枣中不溶性膳食纤维的提取工艺参数,同时建立并分析各个因素与对应变量的数学模型。结果表明,提取残次枣不溶性膳食纤维的最佳工艺条件为:α-淀粉酶添加量0.5%,中性蛋白酶添加量0.6%,液料比27∶1,酶解温度50℃,酶解40 min。在此条件下,残次枣中不溶性膳食纤维得率可达13.04%。     

菠萝皮渣可溶性膳食纤维的提取及物化特性研究

以干菠萝皮渣为原料,运用纤维素酶解法提取菠萝皮渣中的可溶性膳食纤维,通过单因素试验和正交试验,确定最优的提取工艺为纤维素酶添加量0.9%,料液比1∶35(g∶m L),酶解液pH值6.0,酶解时间75 min。在此工艺条件下,菠萝皮渣中可溶性膳食纤维的提取率可达10.03%,样品的持水力、持油力和溶胀性分别为8.698 g/g,5.07 g/g,12.02 m L/g,同时对胆固醇也具有一定的吸附能力。     

木聚糖酶结合微粉法改性米糠膳食纤维

用木聚糖酶对经过超微粉碎处理后的DRBDF水解使其改性,增加其中可溶性膳食纤维的含量。以可溶性膳食纤维的得率为指标,通过单因素试验和正交试验对改性条件进行优化,以确定最佳的改性工艺。结果表明,在木聚糖酶添加量30 FXU/g,酶解p H值4.5,酶解温度50℃,酶解时间3 h,粒径范围100~150μm时,可溶性膳食纤维的得率最高,达到7.13%。经过改性后的米糠膳食纤维,其持水力、持油力分别为改性前的1.18倍和2.04倍,溶胀力降低为原来的79%。     

超声波辅助酶法提取红豆中的膳食纤维

采用超声波辅助酶解法提取红豆中的膳食纤维(DF),用木瓜蛋白酶和α-淀粉酶对已经干燥并且脱脂后的红豆粉进行酶解。酶解过程以木瓜蛋白酶添加量、α-淀粉酶添加量、酶解溶液pH值、酶解温度和酶解时间为单因素,研究各单因素对膳食纤维(DF)得率和其中可溶性膳食纤维(SDF)所占百分比的影响,用正交法对试验工艺进行优化。试验结果表明,木瓜蛋白酶添加量0.9%,酶解溶液pH值4.5,酶解温度70℃,酶解时间60 min时,膳食纤维(DF)得率最高,为43.68%;可溶性膳食纤维(SDF)所占百分比为14.66%。     

铜藻膳食纤维的提取及其理化特性研究

铜藻经复合酶解、化学处理、脱色、过滤等工艺流程,提取水溶性和水不溶性膳食纤维,研究蛋白酶种类、蛋白酶用量、复合酶比、料液比等因素对产率的影响,确立最佳工艺条件,并分析了提取的水不溶性膳食纤维的理化特性。结果表明,铜藻膳食纤维最佳提取条件为：蛋白酶加酶量2%,中性蛋白酶与纤维素酶比例30∶1,料液比1∶20（g/mL）,提取温度50 ℃,酶解时间2 h;最佳脱色条件为：料液比1∶20（g/mL）,过氧化氢浓度6%,脱色温度80 ℃,脱色时间1 h。水不溶性膳食纤维产率为32.14%,呈浅绿色;水溶性膳食纤维产率为2.26%,呈淡黄色。按照上述条件制备的水不溶性膳食纤维的膨胀力为(14.99±0.23) mL/g,持水力为1 255.50%±0.15%,吸附不饱和脂肪量为170.84%±0.18%,吸附饱和脂肪量为238.87%±0.37%。研究表明,铜藻的水不溶性膳食纤维具有较好的水合能力、吸附油脂等功能特性,可以作为原料开发多元化产品。     

挤压膨化胡萝卜粉理化特性的研究

以脱水胡萝卜为原料,采用双螺杆挤压膨化机进行膨化,并对挤压膨化胡萝卜粉的理化特性进行研究。结果表明,经挤压膨化后脱水胡萝卜粉的蛋白质、粗脂肪含量基本上没有改变,可溶性膳食纤维、乳化性、黏度、流动性、水溶性、吸油性有所提高,持水力、持油力有所降低。     

响应曲面法优化可溶性膳食纤维提取工艺条件

以香蕉皮为原料,采用超声波辅助酸水解法提取可溶性膳食纤维,并通过单因素试验和响应曲面设计分析,建立二次回归模型,考查了超声时间、酸解温度、酸解时间、磷酸体积分数、料液比对可溶性膳食纤维得率的影响。结果表明,最优工艺条件以磷酸为提取液,超声时间10 min,酸解温度80℃,酸解时间90 min,磷酸体积分数8%,料液比1∶15(g∶m L);在此条件下所获样品得率20.75%,持水力4.93,持油力2.83,膨胀力9.76 m L/g。     

白萝卜不溶性膳食纤维提取方法的比较及其对饼干消化的影响

以烘干和冻干白萝卜粉为原料,采用酶法、酸法和碱法提取不溶性膳食纤维(IDF),测定IDF的持水力、持油力、膨胀力,并用性质最佳的IDF制作韧性饼干,研究其对饼干消化的影响。结果表明,从冻干粉提取的IDF理化性质总体优于烘干粉。其中,以酶法从冻干粉提取的IDF最优,其持水力为17.19 g/g,持油力为2.11 g/g,膨胀力为18.2 m L/g。添加10%的白萝卜膳食纤维不影响饼干的风味和口感,但可降低淀粉的消化速率。     

沙果渣膳食纤维酶法制备工艺研究

制备高品质的沙果渣膳食纤维,以沙果渣为原料,通过单因素试验和正交试验,研究纤维素酶酶解法制备高活性沙果渣膳食纤维的最佳工艺条件,并对优化后沙果渣膳食纤维的持水力、持油力和膨胀力等理化性质进行了分析。结果表明,最佳工艺条件为纤维素酶用量50 U/g,酶解时间80 min,酶解温度45℃,pH值4.6,此时测得SDF/TDF为18.86%。该条件下所得的膳食纤维呈淡黄色,其持水力为6.87 g/g,持油力为7.36 g/g,膨胀力为6.54 mL/g。     

双酶法提取大蒜水溶性膳食纤维及其抗氧化活性分析

以大蒜为原料,采用双酶法提取大蒜水溶性膳食纤维,研究纤维素酶加酶量、木瓜蛋白酶加酶量、酶解时间、酶解温度对大蒜水溶性膳食纤维得率的影响,并对其抗氧化活性进行分析。结果表明,大蒜水溶性膳食纤维最佳提取条件为纤维素酶添加量2.2%,木瓜蛋白酶添加量2.2%,酶解时间180 min,酶解温度55℃,大蒜水溶性膳食纤维得率32.06%。大蒜水溶性膳食纤维对对O_2~-自由基和DPPH自由基均表现出较强的清除能力,且随其质量浓度的增加清除率增大,呈良好的量效关系。因此,大蒜水溶性膳食纤维是一种优质的食物纤维,可作为食品添加剂应用。     

A note on the origin of Kalanchoë x vadensis Boom & Zeilinga (Crassulaceae)

Summary K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes.     

Mechanisms and diversity of resistance to sorghum shoot fly,Atherigona soccata

Sorghum shoot fly, Atherigona soccata, is one of the important pests of postrainy season sorghums. Of the 90 sorghum genotypes evaluated for resistance to this pest, RHRB 12, ICSV 713, 25026, 93046 and 25027, IS 33844‐5, Giddi Maldandi and RVRT 3 exhibited resistance in postrainy season, while ICSB 463, Phule Anuradha, RHRB 19, Parbhani Moti, ICSV 705, PS 35805, IS 5480, 5622, 17726, 18368 and 34722, RVRT 1, ICSR 93031 and Dagidi Solapur showed resistance in rainy season, suggesting season‐specific expression of resistance to A. soccata. ICSB 461, ICSB 463, Phule Yasodha, M 35‐1, ICSV 700, 711, 25010, 25019 and 93089, IS 18662, Phule Vasudha, IS 18551 and 33844‐5 and Barsizoot had fewer deadhearts than plants with eggs across seasons, suggesting antibiosis as one of the resistance mechanism. Five genotypes exhibited resistance with high grain yield across seasons. Correlation, path and stepwise regression analyses indicated that leaf glossiness, seedling vigour, trichome density, oviposition and leaf sheath pigmentation were associated with the expression of resistance/susceptibility to shoot fly, and these can be used as marker traits to select and develop shoot fly‐resistant sorghums.     

Reaction of tritordeum to Fusarium culmorum and Septoria nodorum

Summary Hordeum chilense is a wild barley extensively used in wide crosses in the Triticeae. It could be a valuable source of resistance to Fusarium culmorum and Septoria nodorum. Some H. chilense x Triticum spp. amphiploids, named tritordeums, were more resistant than the parental wheat line to these diseases, others were not. Average contents of ergosterol and deoxynivalenol (DON) suggested that resistance to colonization by Fusarium was the highest for Hordeum chilense, followed by tritordeum and wheat in decreasing order. In particular, the H. chilense genotypes H7 and H17 enhanced the wheat resistance to F. culmorum in its tritordeum offsprings. Resistance to S. nodorum in tritordeum was not associated with tall plant height. There is sufficient genetic variation for resistance to F. culmorum and S. nodorum among tritordeum to allow the breeding of lines combining short straw and resistance to both diseases.     

Disease resistance in protected crops and mushrooms

Summary Cultivars of tomatoes, cucumbers, lettuce and peppers have been bred for resistance to one or more pathogens. Some tomato and cucumber cultivars have resistance to a wide range of diseases. Resistance has been transient in many cases and a succession of cultivars with new genes or new combinations of resistance genes has been necessary to maintain control. There has been a number of notable exceptions and these have included durable resistance to such pathogens asFulvia fulva and tomato mosaic virus. With lettuce the resistance situation is complicated by the occurrence of fungicide resistant pathotypes. There are no strains ofAgaricus bisporus purposely bred for disease resistance.In protected flower crops only resistance to Fusarium wilt in carnations has been purposely bred but differences in disease resistance are apparent in cultivars of many ornamental crops. This is particularly so in chrysanthemums where there are cultivars with resistance to many of the major pathogens. Similar situations occur with other flower crops and pot plants. Cultivars of some species have not been systematically investigated for resistance.The need for genetic resistance will increase with the further reduction, in the limits on pesticide use and an increasing public awareness and importance of pesticide pollution.ADAS is an executive agency of the Ministry of Agiculture, Fisheries and Food and the Welsh Office.     

Genetic constitution and diversity in four narrow endemic redwoods from the family Cupressaceae

The genetic constitution and diversity of four relictual redwoods are discussed in this review. These include monotypic genera of the family Cupressaceae: coast redwood (Sequoia sempervirens), giant sequoia (Sequoiadendron giganteum), dawn redwood (Metasequoia glyptostroboides), and alerce (Fitzroya cupressoides). All four species are narrow endemics, share a number of common phenotypic traits, including red wood, and are threatened species. Fossil history suggests that the ancestors of redwoods probably originated during the Cretaceous and Tertiary periods and flourished thereafter for millions of years. Towards the end of the Tertiary period began their decline and struggle for existence that continued during the subsequent geologic upheavals and climate changes, until the survival of the present-day redwoods in the current restricted locations in the world (USA, China, and South America). Although two species, Sequoiadendron and Metasequoia, are diploids (2n = 22), and the other two are polyploids: Fitzroya a tetraploid (2n = 4x = 44), and Sequoia a hexaploid (2n = 6x = 66); they all share the same basic chromosome number x = 11. The genome size in the hexaploid Sequoia is one of the largest (31,500 MB) in the conifers, while the genome sizes of diploid Metasequoia and Sequoiadendron are about one-third (~10,000 MB) of Sequoia. Genetic diversity in the redwoods is lower than most other gymnosperms, except in Sequoia, which seems to rank near the upper quarter of the coniferous forest trees. Genomic research is sparse in the redwoods, and should be pursued for a better understanding of their genome structure, function, and adaptive genetic diversity.     

The induction in vitro of adventitious shoots in Rosa

Summary Adventitious shoots were formed on excised leaves, roots and callus of Rosa persica x xanthina and on excised leaves of R. laevigata and R. wichuraiana on culture media that included BAP and NAA as growth regulators. Shoots formed freely on freshly cultured callus of R. persica x xanthina but their production declined in successive cultures and ceased after twelve weeks. Transplantation to soil was improved by rooting plantlets in cellulose plugs in vitro and transferring plantlets to soil while still in the plugs.     

Distribution,ecology and reproductive biology of wild tomatoes and related nightshades from the Atacama Desert region of northern Chile

Over the past 20 years, several expeditions were made to northern Chile to collect populations of wild tomatoes (Solanum chilense, S. peruvianum) and allied nightshades (S. lycopersicoides, S. sitiens), and obtain information about their geographic distribution, ecology and reproductive biology. Restricted mainly to drainages of the Andean and the coastal cordillera, populations are geographically fragmented. The two nightshade species are rare and threatened by human activities. Adaptation to extreme aridity and soil salinity are evident in S. chilense and S. sitiens (the latter exhibits several xerophytic traits not seen in the tomatoes) and to low temperatures in S. lycopersicoides and S. chilense. All tested accessions are self-incompatible, with the exception of one S. peruvianum population collected at the southern limit of its distribution. Several distinguishing reproductive traits—anther color, attachment, and dehiscence, pollen size, and flower scent—suggest S. sitiens and S. lycopersicoides attract different pollinators than S. chilense and S. peruvianum. The four Solanum spp. native or endemic to Chile provide a variety of novel traits which, through hybridization and introgression with cultivated tomato, could facilitate development of improved varieties, as well as research on a variety of basic topics, including plant-pollinator interactions, abiotic stress responses, and evolution of reproductive barriers.     

The exploration of genetic resources of Portuguese cabbage and kale for resistance to several Brassica diseases

Summary Twenty three accessions of nine Portuguese cabbage and kale land races from different geographic origins were tested at the seedling stage for resistance to several important brassica diseases. Resistance to downy mildew (Peronospora parasitica), expressed as necrosis of the cotyledon mesophyll, was found in all the accessions. Type A resistance to cabbage yellows (Fusarium oxysporum f. sp. conglutinans race 1) was present in most of the landraces. Resistance to clubroot (Plasmodiophora brassicae race 6) was found in one accession of the Portuguese tree kale. High resistance to blackleg (Leptosphaeria maculans) and white rust (Albuco candida) was not detected, although several accessions showed 20 to 30% of plants with intermediate expression of resistance. All Portuguese cole accessions were susceptible to blackrot (Xanthomonas campestris pv. campestris).     

Production and characterization of intergeneric diploid cybrids derived from symmetric fusion between Microcitrus papuana Swingle and sour orange (Citrus aurantium)

Plants were regenerated from intergeneric somatic hybridization between embryogenic protoplasts of Microcitrus papuana Swingle and leaf-derived protoplasts of sour orange (Citrus aurantium L.) via electrofusion. The regenerated plants were morphologically similar to the leaf parent in growth vigor, leaf and branch structure. FCM analysis showed that they were diploids. Simple-sequence-repeat (SSR) and cleaved-amplified-polymorphic-sequence(CAPS) were employed for hybridity characterization. SSR banding patterns of the regenerated plants were identical to the leaf parent, sour orange, indicating that they possessed nuclear component derived from sour orange. DNA amplification with chloroplast and mitochondrial universal primers, followed by restriction endonuclease digestion, revealed polymorphism between the fusion parents. Therefore, this method was used to determine the cytoplasmic compositions of the regenerated plants. Banding patterns for all the polymorphic primer/enzyme combinations of the regenerated plants were similar to those of the embryogenic parent, M. papuana, suggesting that only the cytoplasmic components derived from the embryogenic parent were present in the regenerated plants. FCM, SSR and CAPS demonstrated that intergeneric diploid cybrids have been successfully obtained by symmetric fusion. Related results concerning nuclear and cytoplasmic composition of previous diploid somatic hybrids and potential mechanism for regeneration of such kind of plants are discussed herein. This revised version was published online in July 2006 with corrections to the Cover Date.     

Breeding barriers between the cultivated strawberry, Fragaria × ananassa, and related wild germplasm

Five-hundred interspecific and intergeneric crosses were performed among accessions of the wild strawberries Fragaria vesca(2x), Duchesnea indica (8x), Potentilla tucumanensis (2x) and 9 genotypes of the cultivated strawberry, Fragaria×ananassa (8x), following an incomplete diallele mating design. Crosses between D. indica and F.×ananassa produced many putative hybrids when D. indica was used as female but a few achenes and plants when used as male; therefore, pollen-pistil compatibility relations were analyzed by fluorescence microscopy in this direction of the cross. Of the genotypic combinations, 78.6% were incompatible at the stigma level and 17.2% at the first third of the style. Only 3.6% were pollen-pistil compatible and produced fruits with achenes (seven did not germinate or originated short-lived plants and nine produced normal plants). F.vesca×F.×ananassa crosses produced 35 hybrid achenes but only 14% germinated, yielding short-lived plants; histological analyses revealed that inviable seeds had less developed (or collapsed) endosperms and smaller embryos than control plump F. vesca seeds. P.tucumanensis was only used as male, with negative results. These species and genera are partially isolated by a complex system of pre- and post-zygotic barriers. Knowledge of their nature would allow the breeder to devise strategies to put the genetic variability available in the group into a useful form. This revised version was published online in July 2006 with corrections to the Cover Date.