黑木耳果胶中半乳糖醛酸含量的测定

据测黑木耳的碳水化合物中半乳糖醛酸是果胶的主要组成成份。而黑木耳中果胶含量的多少与黑木耳的医疗、保健和食用价值关系很大,可作为衡量木耳品质好坏的重要质量指标。     

江西豆腐柴的开发与利用

豆腐柴干叶中果胶含量16—20%，蛋白质含量13%以上。不同生长期叶内果胶含量有明显差异，从12%，18%到20．04%，以7、8、19三个月摘叶为宜。同一月份不同地区的豆腐柴叶果胶含量差异也很明显，其中以11号地区含量最高，选22．16%，7号地区次之为20．87%。对豆腐柴果胶的胶凝度、酯化度、干燥失重、灰分，pH等指标的测定表明，这些指标与讪头香料厂和丹麦哥本哈根工厂生产的果胶各项指标大致相同。豆腐柴果胶属高酯果胶；半乳搪醛酸含量为74%。经毒理试验和卫生检验证明，豆腐柴果胶属无毒物质．徽核实验阴性，卫生检验符合国家食品卫生标准．用豆腐柴果腱制果酱，其色、香、嗥俱佳、经济效益明显。     

河北果胶资源及其开发利用前景

果胶,是一种天然高分子化合物,是植物细胞间质的重要成分,主要由半乳糖醛酸及其甲酯、多缩半乳糖、多缩阿拉伯糖等缩合而成.果胶在酸性溶液中能凝结成冻.把糖浆加热至沸再冷却时,加1%果胶就可使糖浆变成为胶冻.人们利用它的这一性质,作为胶凝剂、乳化剂、稳定剂、脱水剂广泛用于食品、化妆、医药等工业.果胶用于食品工     

狐臭柴叶片中果胶提取条件的初步研究

以狐臭柴叶为原料、柠檬酸为酸解液提取果胶,采用单因素实验、正交实验对酸浓度、提取温度、料液比和提取时间等条件进行探索,并以响应面实验设计方法进行工艺优化。结果表明:酸浓度和料液比是影响果胶酸解的主要因子;一定范围内,酸浓度与果胶粗产率(Y1)呈线性正相关,料液比与果胶粗产率(Y1)呈线性负相关,二者与粗果胶半乳糖醛酸含量(Y2)的关系符合二元二次多项式方程模型,但随着酸浓度的增加和料液比的降低,半乳糖醛酸含量有下降趋势;半乳糖醛酸提取率(果胶有效提取率Y3)的拟合效果是一个平均值模型,即Y3=8.86%。在提取温度、提取时间分别为90℃和120 min,响应面的优化条件为酸浓度3.91%、料液比1∶44.09时,果胶粗产率、半乳糖醛酸含量和果胶有效提取率分别为36.72%、32.09%和11.78%。     

果胶的提取与应用

果胶是从农副产品中提取出来的天然高聚物 ,具有优良的胶凝化和乳化作用 ,早已被广泛用于食品工业、化妆品和医药等方面。我国生产果胶的资源丰富 ,需求量大 ,因此发展果胶生产是很有前途的。１果胶的结构与性质果胶广泛存在于植物的根、茎、叶、果实中 ,是细胞壁的一种组成成分。一般人们所说的果胶系指原果胶、果胶酯酸和果胶酸的总称 ,是一种高分子聚合物 ,分子量介于２００００～４０００００之间。其基本结构是Ｄ—吡喃半乳糖醛酸 ,以１ ,４甙链连接成的长链 ,通常以部分甲酯化状态存在。果胶为白色或淡黄色粉末 ,溶于水形成粘性液体。…     

果胶对山楂加工的影响

果胶是一种天然高分子化合物，广泛存在于各种水果中，具有凝胶、粘韧、增稠乳化等作用。山楂中果胶含量达6．4％，居所有水果之首。丰富的果胶物质决定着山楂特有的加工性能和特有的加工产品，从而使其加工产品丰富多彩。     

天仙果果胶提取条件及含量测定

以天仙果果实为原料采取盐酸溶液萃取、酒精沉析制取果胶;确定最佳提取工艺条件为提取温度87~90℃、pH 0.5~1.0、萃取时间2h、料液比1∶20。研究了亚硫酸氢钠对天仙果果胶得率的影响;用咔唑比色法对其含量进行了准确测定。     

银杏型果胶的提取及开发应用前景

银杏型果胶是以银杏外种皮为原料提取的果胶多糖,含半乳糖醛酸大干66.5%,符合QB2484——2000《食品添加剂——果胶》国家行业标准的半乳糖醛酸量的要求。银杏型果胶既可与柑桔型等果胶一样,用于食品、医药、化妆品、化工等行业,具有增倜、增粘、乳化、稳定等作用;还具有抗癌、抗衰老、抗过敏、降血脂、降血压、降血糖、止咳被被祛痰、提高免疫力等功能,因此可以为疗效型果胶使用,配制药物和保健品。     

半乳糖醛酸-木质素复合体结构的研究

以果胶前驱物α-D-半乳糖醛酸和木质素前驱物松柏醇-β-D-葡萄糖苷为起始物,在复合酶(β-葡萄糖苷酶、葡萄糖氧化酶、漆酶和辣根过氧化物酶)的协同作用下,合成出半乳糖醛酸-DHP复合体(GDHPC).通过FT-IR及13C NMR测试,发现产物中DHP的主要结构单元为β-O-4、β-β、β-5和β-1结构.另外,还含有较多的松柏醇/醛和少量的香草醛结构,以及Ar-Cα H2-和醚化5-5’结构.产物GDHPC中,木质素结构单元主要通过α碳与α-D-半乳糖醛酸以酯键、缩醛键和苯甲醚键的方式结合.     

辽宁地区不同种源地欧李果实品质分析

以辽宁地区5个不同种源地的欧李(辽欧1号、辽欧2号、辽欧3号、辽欧4号、辽欧5号)果实为研究对象,测定、比较其营养成分及矿质元素含量。结果表明:不同种源地的欧李果实的功能营养成分存在显著的差异,但其可溶性糖和果胶的含量均较低;5种欧李果实中,果肉的可溶性糖含量最高为1.80%,而果皮中的可溶性糖含量最高为1.25%;果肉中的果胶含量最高达到0.33%,而果皮中的果胶含量最高为0.40%。与其它水果相比,单宁、维生素C以及多种矿质元素,尤其是钙元素的含量较高,其中辽欧1号果肉、果皮中的钙含量分别高达986、1673 mg·kg~(-1)。综合比较结果表明,辽欧1号的综合性状优于其它品种,可作为欧李育种、品质改良及欧李资源开发利用的原材料。     

马尾松苗木小分子有机化合物动态监测

对马尾松1、2年生苗木中松醇、肌醇、可溶性糖等小分子有机化合物进行动态监测。结果表明:1年生马尾松苗木针叶内松醇含量随着苗木的生长而逐渐增加,并在木质化期达到最高;2年生苗木针叶内松醇含量随着苗木生长反而下降,只在木质化期有所增加。肌醇、半乳糖和麦芽糖含量的变化较为复杂,均没有规律性。葡萄糖含量的变化比较平稳,2年生苗木在8月份时其葡萄糖含量明显高于1年生苗木的。     

沙棘果胶提取工艺研究

以沙棘果实为原料，利用酒精沉析法系统研究了萃取时间、萃取温度、萃取pH值、果胶酶活性和水质等对果胶产量的影响，探讨了酒精沉析法提取沙棘果实中果胶的工艺条件。为工业化生产提供了理论依据。     

不同沉淀方法提取柚皮果胶的研究

柚皮经盐酸溶液提取而得果胶提取液,分别以醇沉法和盐析法从提取液中沉淀果胶.研究并获得了两种沉淀方法的最佳沉淀条件,比较了不同沉淀方法的乙醇消耗量,探索了不同沉淀方法对果胶沉淀得率和品质的影响.结果表明:醇沉法所消耗的乙醇量几乎为盐析法乙醇消耗量的两倍.盐析法能大大降低乙醇使用量,省去稀酸提取液浓缩工序和减少乙醇回收量,节省能耗,降低生产成本,并能保证较高的沉淀得率和果胶品质.     

白梭梭同化枝对干旱胁迫的生理生态响应

对白梭梭同化枝自然水分胁迫下的季节抗旱特征进行研究。结果表明:自然干旱胁迫条件下,不同生长发育时期同化枝的主导抗旱生理因子不同。5月31日至6月29日盛花期间,同化枝内源ABA含量甚微,气孔导度值与光合强度处于生长发育过程的最高水平,可溶性糖含量呈现下降趋势,而脯氨酸含量略有增加,植物通过渗透调节作用适应此阶段轻度干旱胁迫;6月29日至7月26日盛夏期间,ABA迅速积累,气孔导度值降为生长发育过程的最低值,叶绿素分解,可溶性糖与脯氨酸均呈现快速积累趋势,且可溶性糖积累强度大于脯氨酸;8月9日至8月22日同化枝生长发育后期,ABA急剧积累为生长发育过程的最高浓度,气孔导度值有所增大,脯氨酸和可溶性糖保持在高水平平稳变化。此阶段高浓度ABA调节植物生理过程适应干旱的效应受CTK、IAA两种内源激素的抑制,进而抑制脯氨酸和可溶性糖的继续积累。     

Seasonal fluctuations of low‐molecular‐weight sugars,starch and nitrogen in sapwood of Pinus sylvestris L.

The content of water‐soluble substances and starch in the living tree stem at the time of felling influences wood durability during further utilization. The aim of the study was to describe the annual and seasonal fluctuations in the contents of stored carbohydrates and nitrogenous compounds. The contents of soluble sugars, starch, and nitrogen were measured in the outer sapwood (0–15 mm from cambium) of 65‐yr‐old Scots pine {Pinus sylvestris L.) trees during an annual cycle. To study the influence of growth conditions, samples were taken from different stands in Sweden, in one stand from a control and a fertilized block. The effect of the age of the trees on the content of stored substances was also considered by comparing young (10–15 yrs old) and older trees (40–65 yrs old). Determination of the carbohydrates was carried out using enzymatic analysis. The outer pine sapwood contained a higher content of low‐molecular weight sugars during autumn and winter than during spring and summer. Starch content rose at the beginning of the growth period and decreased in autumn. The content of soluble sugars increased towards the cambium on all sampling occasions. Fructose and glucose were dominant sugars in all the stands studied. Seasonal changes of sucrose were different from those of glucose and fructose, in that the sucrose content was already decreasing in February. The variations in the nitrogen content of the sapwood were far smaller than those of the soluble sugars. No significant differences were found between the stands with regard to glucose, fructose and the sum of all three sugars. The fertilized block showed low content of sucrose and nitrogen. It is concluded that seasonal fluctuations are more important with regard to the sugar content than the effect of growth conditions. Data indicate a lower content of soluble sugars and nitrogen in the outermost sapwood of young trees as compared with older trees.     

Epigallocatechin gallate content change of the fresh tea leaf homogenates extracted by different methods in extraction and preservation

Introduction Tea polyphenols, extracted from tea leaves, is a hydroxyl phenol compound. Of the components of green tea (Camellia sinensis), the content of (?)-epigallocatechin gallate (EGCG) is high, and this catechin has been extensively studied (Harold …     

低温胁迫对蓝靛果忍冬渗透调节物质的影响

为了探究低温胁迫过程中蓝靛果忍冬渗透调节物质与抗寒性的关系,设6个温度胁迫梯度(-15、-20、-25、-30、-35、-40℃),处理9个蓝靛果忍冬品种的1年生枝条(蓝鸟、伊利亚特、炭火、谢丽娜、加洛奇卡、落火炭、别列里、蓝纺锤及阿索里),研究品种间在不同温度下生理指标的变化趋势。结果表明:在气温降至-15~-25℃时,蓝纺锤和落火炭的可溶性糖含量最高,加洛奇卡和落火炭可溶性蛋白质含量最高,落火炭游离脯氨酸含量最高;在气温降至-30~-40℃时,落火炭、谢丽娜和别列里可溶性糖含量最高,伊利亚特、加洛奇卡和落火炭可溶性蛋白质含量最高,蓝纺锤、伊利亚特和落火炭游离脯氨酸含量最高;在新疆最低气温条件下(北疆气温在-33~-41℃,南疆气温在-19.4~-32.9℃),落火炭更适宜种植于新疆地区。     

Physio-ecological response of Haloxylon persicum photosynthetic shoots to drought stress

This paper studied the seasonal characteristics to resist the drought stress of Haloxylon persicum Bge. Ex Boiss. et Buhse photosynthetic shoots at habitat. The results showed that the predominant drought resistance factors were varied at the different stage from growth to development. In the blooming season (from May 31 to June 29), endogenous ABA contents were rare; stomatal conductance and photosynthesis intensity were the highest at the whole stage from growth to development; soluble sugars contents had a decreasing trend and proline contents increased a little that made proline become the predominant factor to resist the drought under this light water stress. In the hot summer (from June 29 to July 26), ABA contents accumulated rapidly; stomatal conductance dropped to the lowest level of the growth and development; chlorophyll was also decomposed; both soluble sugars and proline contents showed the trend of quickly accumulating, but the former was faster than the latter. It was due to stomatal limitation and osmotic organic molecules accumulation that would affect the photosynthetic shoots to resist severe drought stress. At the late period of the development (from Aug 9 to Aug 22), ABA rapidly accumulated, its contents got to the highest level of whole life-span; stomatal conductance increased a little; proline and soluble sugars contents changed little at high level; while the ratios of ABA to CTK content and ABA to IAA content got up obviously, the effect to resist drought stress on high content ABA was inhibited by endogenous plant hormone CTK and IAA, then the continuing accumulation of proline and soluble sugars would be prevented. Osmosis of organic molecules was the most important factor to adjust leaves to severe water stress at this period. __________ Translated from Scientia Silvae Sinicae, 2005, 41(5) [译自, 林业科学 2005, 41(5)]     

不同肥料配比对红富士苹果果实品质的影响

为探讨肥料配比对红富士苹果果实品质的影响，以盛果期红富士苹果为试材，进行了施肥种类试验。结果表明，增施有机肥(烘干鸡粪)，果实中可溶性固形物、蔗糖和总糖含量显著高于对照。其中综合表现以株施烘干鸡粪40kg最好，其单果重、果实着色面积、产量、可溶性固形物、葡萄糖、还原糖、总糖含量和糖酸比均最高。表明增施烘干鸡粪有利于提高果实品质。     

柚木石油醚抽提物成分及其对心边材颜色的影响

为探究国产柚木抽提物对心材和边材颜色差异的影响,采用3种沸程的石油醚溶液分别对国产柚木的心材与边材进行抽提处理,利用气相色谱-质谱法分析抽提液的成分和含量,并以差异较大的抽提物溶液处理柚木边材,通过色度学参数表征柚木边材的变色情况,从而验证影响柚木心材和边材颜色的主要抽提物成分。结果表明:在3种沸程的石油醚抽提液中,柚木心材抽提物在成分种类数量和含量上均显著高于边材;不同沸程的石油醚对柚木心、边材中抽提物成分有一定的影响,其中30~60℃(低沸程)和60~90℃(中沸程)石油醚抽提物成分和含量的差异较小,而90~120℃(高沸程)石油醚抽提物的含量较高,约为中、低沸程抽提物含量的2倍;柚木心材抽提液中酚类、醌类、烯烃类物质的含量较多,但这些物质在边材中含量极低;4-叔丁基-2-苯基苯酚、2-甲基蒽醌(柚木醌)、全反式三十碳六烯(角鲨烯)是柚木心、边材抽提物含量差异最明显的物质。经角鲨烯溶液处理后的柚木边材表面颜色变黄,更接近心材颜色,因此,角鲨烯是导致柚木心边材颜色差异的重要抽提物成分。