共查询到19条相似文献,搜索用时 62 毫秒
1.
2.
3.
4.
5.
低聚木糖的酶法生产 总被引:2,自引:0,他引:2
确立了玉米芯经稀酸预处理后加水蒸煮提取木聚糖 ,然后再加酶水解提取液的生产低聚木糖的工艺路线 .玉米芯在质量分数为 0 .1%的H2 SO4 溶液中于 6 0℃下浸泡 12h后 ,滤去浸泡液并水洗至 pH 6左右 ,然后采用液固比 10∶1,150℃ ,30min的蒸煮条件进行蒸煮 .结果表明 ,可溶性木聚糖的提取得率达 17% (按玉米芯计 ) ,提取液的RS/TS小于 33% .提取液和渣一起用木聚糖酶进行水解 ,可获得阿拉伯糖 /葡萄糖 /木糖 /木二糖 /木三糖之比为 7.7∶6 .8∶11.5∶54.1∶19.8的高纯度低聚木糖产品 .低聚木糖的质量分数大于 70 % (对总糖 ) ,且产品的可溶性总糖得率达2 6 .4 % (对玉米芯 ) . 相似文献
6.
为研究碱法提取玉米芯中水不溶性木聚糖的优化条件及产物组成,用单因素试验评价预处理温度、NaOH浓度、料液比、提取温度与时间对提取率的影响之后,通过正交试验L16(45)确定最佳提取条件是:40℃预煮,15%NaOH溶液,固液比1∶15,100℃提取4 h,过滤,调节滤液pH值至7.0,静置过夜后离心得沉淀,洗涤沉淀,烘干后即得水不溶性木聚糖。在上述条件下玉米芯水不溶性木聚糖提取率为20.86%。对碱法提取的玉米芯水不溶性木聚糖进行木聚糖酶水解及产物分析,结果几种木聚糖酶均能使水不溶性木聚糖产生木二糖、木三糖及木四糖含量较高的低聚糖。 相似文献
7.
《食品与生物技术学报》1998,17(4)
通过对几种不同的木聚糖提取方法的比较,确立了酸预处理后加水蒸煮的方法提取低聚木糖生产用木聚糖的工艺路线。首先将玉米芯用质量浓度为1g/L的H2SO4在60℃下浸泡12h,滤去浸泡液,然后加水至固液比为1∶10,在150℃蒸煮30min.采用此工艺木聚糖的提取得率可达到17%(按玉米芯计),提取液的还原糖与总糖质量之比小于33%.该法得到的提取液(和渣一起)用自制的木聚糖酶水解,可获得m(木糖)∶m(木二糖)∶m(木三糖)=1∶5∶2.7的高纯度低聚木糖产品,产品总糖的得率达到26.4%(按玉米芯计)。 相似文献
8.
本文以棉籽壳为原料制备低聚木糖。以超声温度、超声时间,料液比和Na OH浓度为单因素,采用正交实验设计确定了超声波预处理提取木聚糖的最优条件,即超声温度60℃,超声时间30 min,料液比为1∶15,Na OH浓度为8%,此时木聚糖得率为33.66%。在单因素料液比、加酶量、酶解时间、酶解温度的实验基础上,根据Box-Benhnken中心组合实验设计原理,采用4因素3水平的响应面分析法,以低聚木糖含量为响应值建立数学模型,确定了最佳酶解工艺条件:料液比1∶20,加酶量4%,酶解时间3.5 h,酶解温度64℃,此时低聚木糖含量为3.35 mg/m L。 相似文献
9.
本文以棉籽壳为原料制备低聚木糖。以超声温度、超声时间,料液比和Na OH浓度为单因素,采用正交实验设计确定了超声波预处理提取木聚糖的最优条件,即超声温度60℃,超声时间30 min,料液比为1∶15,Na OH浓度为8%,此时木聚糖得率为33.66%。在单因素料液比、加酶量、酶解时间、酶解温度的实验基础上,根据Box-Benhnken中心组合实验设计原理,采用4因素3水平的响应面分析法,以低聚木糖含量为响应值建立数学模型,确定了最佳酶解工艺条件:料液比1∶20,加酶量4%,酶解时间3.5 h,酶解温度64℃,此时低聚木糖含量为3.35 mg/m L。 相似文献
10.
以Bacillus pumlis.木聚糖酶水解玉米芯制备木寡糖 总被引:4,自引:0,他引:4
木聚糖酶对 Birch wood,Oat spelt和自制玉米芯木聚糖的水解结果表明,不同来源的木聚糖对木聚糖酶水解的影响非常明显,硬本属的 Birch wood的水解效果较好,自制玉米芯木聚糖的水解效果优于同属于禾本科的 Oat Spelt。自制玉米芯木聚糖的水解结果表明,可溶性木聚糖能够被木聚糖酶有效水解而不溶性木聚糖几乎不被水解,长链木聚糖比短链木聚糖更容易被木聚糖酶水解。采用HPLC对自制玉米芯木聚糖水解液的组成进行分析,结果表明,水解液中低聚木糖的主要成分为木二糖、木三糖和木四糖,占水解液中总糖的80%以上。 相似文献
11.
12.
假丝酵母发酵玉米芯半纤维素水解液生产木糖醇 总被引:3,自引:0,他引:3
玉米芯是廉价的可再生资源,利用玉米芯半纤维素水解液发酵生产木糖醇,具有工艺简单、能耗小、产品质量好等特点。假丝酵母(Candida tropicalis)菌株经驯化后显著地提高了对水解液中发酵抑制物的耐受力,从而提高了木糖醇得率。确定发酵温度、初糖浓度、pH值、接种量、通气量等因素对发酵生产木糖醇的影响,并对其进行优化,优化结果为接种量10%(v/v),种子龄24h,温度为30%,起始pH值为5.5,并且在发酵过程中补加适量氮源,木糖醇得率达61%。该方法大大降低了预处理的成本,有良好的应用前景。 相似文献
13.
Velmurugan P Hur H Balachandar V Kamala-Kannan S Lee KJ Lee SM Chae JC Shea PJ Oh BT 《Journal of Bioscience and Bioengineering》2011,112(6):590-594
Natural pigments are an important alternative to potentially harmful synthetic dyes. We investigated the feasibility of corn cob powder as a substrate for production of pigments by Monascus purpureus KACC 42430 in solid-state fermentation. A pigment yield of 25.42 OD Units/gram of dry fermented substrate was achieved with corn cob powder and optimized process parameters, including 60% (w/w) initial moisture content, incubation at 30°C, inoculation with 4 mL of spores/gram of dry substrate, and an incubation period of 7 days. Pigment yield using corn cobs greatly exceeded those of most other agricultural waste substrates. The pigments were stable at acidic pH, high temperatures, and in salt solutions; all important considerations for industrial applications. Our results indicate the viability of corn cob substrate in combination with M. purpureus for industrial applications. 相似文献
14.
Bruna da Silva Menezes Daniele Misturini Rossi Fabio Squina Marco Antônio Záchia Ayub 《International Journal of Food Science & Technology》2018,53(9):2110-2118
We investigated the simultaneous production of xylanase and the liberation of xylooligosaccharides in rice husk solid‐state cultivations of Aspergillus brasiliensis BLf1 and by the recombinant Aspergillus nidulans XynC A773 strain. The bioprocess was optimised by experimental fractional design and response surface analysis. Results show that both fungi strains produced xylanases and their activities were dependent on the addition of basal medium, moisture content and the interactions between particle size and inoculum size, producing maximum xylanase activities of 230.7 U g?1 substrate for A. brasiliensis, and 187.9 U g?1 substrate for A. nidulans XynC. Xylooligosaccharides were liberated in the same cultures, with concentrations up to 17.6 mg g?1 and 23.9 mg g?1 of substrate for A. brasiliensis and A. nidulans XynC, respectively, both strains presenting similar profiles, with xylose residues varying from X3 to X6. These results suggest the possibility of lowering production costs of enzymes for food applications and oligosaccharides. 相似文献
15.
Jian-Yi Sun Ming-Qi Liu Xiao-Yan Weng Li-Chun Qian Sai-Hong Gu 《Food chemistry》2007,104(3):1055-1064
The mature peptide of Thermomonospora fusca xylanase A (TfxA) was successfully expressed in Pichia pastoris under the control of AOX1 promoter. The activity of recombinant T. fusca xylanase A (reTfxA) in culture supernatant was 117.3 ± 2.4 U/mg, which is 3 times higher than that of the native TfxA. The optimal temperature and pH for reTfxA were 60 °C and 6.0, respectively. When treated at 70 °C and pH 6.0 for 2 min, the residual activity of the reTfxA was 70%. The reTfxA was very stable over a wide pH range (5.0–9.0). After incubation over pH 5.0–9.0 at 25 °C for 1 h, all the residual activity of reTfxA was over 80%. The Km and kcat values for reTfxA were 2.45 mg/ml and 139 s−1, respectively. HPLC analysis revealed that xylobiose (X2) was the main hydrolysis product released from birchwood xylan and wheat bran insoluble xylan by reTfxA. Hydrolysis results of xylooligosaccharides showed that reTfxA was an endo-acting xylanase and xylobiose, xylotriose (X3), xylotetraose (X4), xylopentaose (X5), and xylohexaose (X6) could be hydrolysed. This is the first report on the expression of reTfxA in yeast and on the determining and quantifying of the hydrolysis products released from xylans and xylooligosaccharides by reTfxA. 相似文献
16.
17.
18.
以玉米芯为原料,采用酸碱结合法提取不溶性膳食纤维,对提取过程中酸、碱用量和反应时间进行优化。结果表明:玉米芯在料液比1∶10(g∶mL),反应温度95 ℃,硫酸体积分数2.0%条件下提取40 min,漂洗后,再于料液比1∶10(g∶mL),反应温度95 ℃,NaOH质量浓度2.0 g/100 mL条件下提取60 min,可制得膨胀力为4.1 mL/g,持水力为5.1 g/g的终产品。产物的蛋白质、淀粉含量显著降低,分别为0.7 g/100 g、7.4 g/100 g,吸油性能有显著提升,为2.3 g/100 g,还原能力略有下降,A700 nm为0.327。 相似文献
19.
利用玉米芯制备对香豆酸和低聚木糖的研究 总被引:1,自引:1,他引:0
采用氢氧化钙代替氢氧化钠从玉米芯中提取对香豆酸,而后采用酶法水解残渣制备低聚木糖。提取对香豆酸的最佳工艺为:料液比(玉米芯∶提取液)1∶10,氢氧化钙用量0.1g/g玉米芯,室温下提取24h。在此条件下,对香豆酸提取率为10.66mg/g。提取对香豆酸后的残渣用清水洗至中性,在料液比1∶15(玉米芯∶提取液)的条件下,用木聚糖酶酶解,经响应面实验得其最佳工艺条件:酶添加量8g/L、温度55℃、pH5.0、时间8h。在此条件下,酶解产生的还原糖含量为155.84mg/g,可溶性总糖含量为379.61mg/g,平均聚合度为2.43。 相似文献