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为了获得富硒黑木耳菌丝,提高黑木耳菌丝的产量,改善黑木耳菌丝的品质,以亚硒酸钠作为硒源,用不同碳源有机物和氮源有机物进行黑木耳的深层发酵,研究pH值和温度对黑木耳深层发酵的影响。实验结果表明,黑木耳菌丝生长的最佳条件为:葡萄糖作碳源,豆饼粉作氮源,pH5.3,温度28℃。在此最佳条件下加入不同浓度的亚硒酸钠溶液进行培养,通过测定黑木耳菌丝的生物量,粗多糖含量和硒吸收率,表明亚硒酸钠浓度在60mg/kg以下时可提高黑木耳菌丝产量;在60~100mg/kg之间时会降低黑木耳菌丝产量;而在60mg/kg时,硒的吸收率达到最高。 相似文献
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黑木耳多糖提取工艺条件的研究 总被引:1,自引:0,他引:1
黑木耳多糖是黑木耳子实体中的重要活性物质,除具有一般的生化性质外,还具有调节免疫功能、抗血栓、抑菌、降血糖、抗溃疡、抗肝炎和抗突变、降血脂和促进血清蛋白生物合成等多种功效。为优化黑木耳多糖的提取工艺,本文在单因素试验结果的基础上,选择料液比、提取温度、提取时间为自变量,黑木耳多糖的得率为响应值,研究各自变量交互作用及其对黑木耳多糖得率的影响,确定了黑木耳多糖提取的最佳条件为:提取温度60℃、料液比为1∶40、提取时间为2.5h,在此最佳提取条件下,黑木耳多糖的得率达到5.12%。对提取的黑木耳多糖的营养成分进行了分析,所制备的多糖以大分子多糖为主,还含有一定量的蛋白质、水分、还原糖及灰分,为一种粗多糖。 相似文献
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以黑木耳为原料,采用RVA和质构仪分别测定了黑木耳全粉、黑木耳多糖及黑木耳胶质对豌豆淀粉糊化黏度和质构的影响,发现黑木耳胶质对豌豆淀粉的影响效果明显好于黑木耳全粉和黑木耳多糖;然后与卡拉胶和明胶进行了比较并测定了溶解度和溶胀度.研究结果表明:添加8%黑木耳胶质的淀粉糊峰值黏度、谷值黏度、末值黏度和衰减值均显著提高,分别达到819、568、861、250 RVU,约是原淀粉的3倍;与添加卡拉胶和明胶相比,添加黑木耳胶质对提高豌豆淀粉糊黏度效果更明显,且添加黑木耳胶质的豌豆淀粉凝胶硬度、回复力和内聚力均较高;黑木耳胶质的添加使得豌豆淀粉的溶解度降低,并显著提高了豌豆淀粉的溶胀度. 相似文献
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目的 优化黑木耳多糖酸奶的生产工艺。方法 采用超声波辅助酶法提取黑木耳多糖,以黑木耳多糖和生牛乳为原料,保加利亚乳杆菌、嗜热链球菌为发酵剂,进行黑木耳多糖酸奶最佳工艺的研究,以感官评价为指标,采用单因素实验探究黑木耳多糖添加量、接种量及发酵时间对黑木耳多糖酸奶的影响,进一步通过响应面实验对黑木耳多糖酸奶工艺进行优化,并对酸奶品质进行评价。结果 确定了黑木耳多糖酸奶的最佳工艺条件:黑木耳多糖添加量0.15%,接种量3%,发酵时间4 h。在最优工艺条件下生产出的黑木耳多糖酸奶的感官评分达(91.26±0.05)分,与预测值接近,最终产品感官指标、理化指标及微生物指标均符合国家标准要求。结论 本研究开发出了一种比普通酸奶具有更高营养价值和保健功效的新型酸奶产品。 相似文献
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黑木耳超微粉多糖相对分子质量分布及降血脂功能研究 总被引:4,自引:1,他引:3
采用酸法对黑木耳粗粉和超微粉多糖进行分离提取。研究了超微粉粗多糖DEAE-Cellul ose52离子交换层析的分离纯化工艺。样品分出两个峰,将超微粉与两个组分收集后浓缩,采用HPLC法分析多糖组成及相对分子质量分布,并做黑木耳超微粉多糖与粗粉多糖的降血脂功能动物试验。结果表明,最佳分离条件为:洗脱液浓度0.25mol/L,流速200s/mL,上样质量浓度3.5mg/mL。黑木耳经超微粉碎后多糖相对分子质量降低明显;相对于未经超微粉碎获得的粗多糖,超微粉碎后得到的多糖具有更明显的降血脂作用。 相似文献
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壳聚糖、果胶和海藻酸钠是天然多糖,具有良好的生物相容性和生物可降解性等优点。以CaCl_2为交联剂制备壳聚糖-海藻酸钠水凝胶和果胶-海藻酸钠水凝胶,研究Ca Cl2浓度、多糖质量比(壳聚糖与海藻酸钠、果胶与海藻酸钠)和交联温度对水凝胶在模拟人体胃肠道环境(pH 1.2胃、pH 6.8小肠、pH 7.4结肠缓冲溶液)中溶胀性能的影响。当壳聚糖或果胶和海藻酸钠质量比为1.25∶1、CaCl_2浓度为0.09 mol/L、温度为60℃时,制备的水凝胶在pH 1.2溶液中溶胀率最小,在pH 6.8和pH 7.4溶液中溶胀率较大;结果表明所制备水凝胶具有pH值敏感性。此外,在优化条件下水凝胶具有较好的质构性能。 相似文献
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《Food chemistry》1999,66(2):201-208
Potato french fries were coated with a combination of calcium chloride and either pectin or sodium alginate at different levels. The best treatment was selected for the second coating with different hydrocolloids. Qualities of single- and double-coated french fries were evaluated. Potato french fries coated with sodium alginate as a first coating had less oil reduction and less quality than those coated with pectin. Single-coated french fries with a combination of 0.5% calcium chloride and 5% pectin had the highest reduction of oil content as well as the highest moisture content. Also, coated french fries at these levels exhibited higher red and yellow colours and were firmer than the control. Coated french fries with 0.5% calcium chloride and 5% pectin had higher sensory scores for all attributes compared to the control. French fries coated with carboxy methyl cellulose (CMC) as a second layer were more effective than those coated with pectin or sodium alginate in reducing the oil content. The incorporation of CMC at 1.5% level as a second layer reduced the oil content by 54%; however, the single coating with 0.5% calcium chloride and 5% pectin reduced the oil content by 40%. Double-coated french fries had higher moisture contents and firmer structures than the single coated french fries. Increasing the level of the hydrocolloid forming the second coating up to 1.5% resulted in non-significant differences in the sensory scores for all attributes. Scanning electron microscope photographs indicated that the single- or double-coating process was effective in protecting the cellular structure of potato tissues from the damage produced during deep-fat frying. © 相似文献
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目的优化海藻酸钠和CaCl_2对硝基还原假单胞菌SP.001细胞的固定化条件。方法以海藻酸钠为载体,通过包埋法固定化谷氨酰胺酶,通过单因素实验和正交实验对固定化细胞制备条件进行优化。结果单因素实验中,当海藻酸钠和CaCl_2的浓度分别为4%和3%、酶液量与海藻酸钠的体积比为1:2、固定化时间为3 h时,包埋效果最好,测得固定化细胞回收率较高,可达80.5%。通过正交实验得出最佳组合为:酶液量与海藻酸钠体积比1:3,固定化时间3 h,海藻酸钠浓度4%,CaCl_2浓度3%,固定化细胞回收率达到85.78%。结论本研究优化了海藻酸钠包埋法固定硝基还原假单胞菌的条件,并对固定化细胞的性质进行探讨,为硝基还原假单胞菌所产的谷氨酰胺酶的固定化和应用提供参考。 相似文献
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Interactions in Protein/Polysaccharide/Calcium Gels 总被引:9,自引:0,他引:9
Protein-polysaccharide-calcium gels were prepared using combinations of crude myofibrillar protein, whey protein concentrate, sodium alginate, methylcellulose, low methoxyl pectin, carrageenan and CaCl. The nature of the interactions taking place in the gels and the effect of freezing or heating on viscosities and water losses were investigated. In most cases the stability of the gels was increased by freezing and lowered by heating. Myofibrillar protein with added whey protein concentrate formed stronger gels with the polysaccharide gums than did the myofibrillar protein extract alone. With the exception of methylcellulose gels, electrostatic interactions seemed to be the main forces involved in the formation and stability of the gels. 相似文献
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Graziela Brusch BrinquesMarco Antônio Záchia Ayub 《Journal of food engineering》2011,103(2):123-128
In the present research the survival of free and microencapsulated cells of a new strain of Lactobacillus plantarum BL011 under stress conditions was tested in sodium alginate or pectin, coated with sodium alginate or chitosan. Results for the simulated gastrointestinal medium (SGT) showed no change in viability of cells in relation to the control. However, the simulated gastric medium (GM) drastically reduced the viability under the tested conditions, with no significant differences between free and immobilized cells. Under refrigerated storage viability of immobilized cells were greatly enhanced compared to the free microorganisms, and the treatments showing the lowest loss of viability were those of 4% (w/v) pectin, 3% (w/v) sodium alginate coated with chitosan and a mixture of 2% (w/v) sodium alginate and 2% (w/v) pectin, respectively. Loss of viability of immobilized L. plantarum in 3% alginate coated with chitosan in yogurt was of 0.55 log cycles during 38 days of storage. The results of this study suggest the efficiency of immobilization techniques to increase the survival of lactobacilli in yogurt under refrigerated storage. 相似文献
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海藻酸-聚乙烯醇二元膜的结构表征与性能研究 总被引:1,自引:0,他引:1
由海藻酸钠和聚乙烯醇的水溶液共混,在3%的CaCl2水溶液中凝固,然后用1%的HCl水溶液处理,成功制得海藻酸/聚乙烯醇共混膜.采用红外光谱、X-射线衍射、原子吸收光谱和扣描电镜对共混膜进行了结构表征,并对共混膜的透光率、吸水率、保水率、力学性能、水蒸气透过率等方面进行了测试.结果表明,共混膜中海藻酸与聚乙烯醇分子间存在着强的相互作用及良好的相容性,其中Ca2+交联作用和海藻酸与聚乙烯醇分子间作用力、氢键等强的相互作用使共混膜理化性能得到了显著改善. 相似文献