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甲壳素和壳聚糖不仅可被甲壳素酶、壳聚糖酶和溶菌酶水解 ,还可以被一些包括蛋白酶、脂肪酶和其它糖酶的非专一性酶水解 ,这些酶对甲壳素和壳聚糖解聚的作用机理和动力学 ,对于开发甲壳素和壳聚糖在食品、化工、医药、农业等领域中的应用具有重要意义 .为此 ,介绍了近年来国外的研究进展 . 相似文献
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壳聚糖被水解生成的甲壳低聚糖(chitooligosaccharides)是水溶性产物,可被人体、动物和植物吸收,有很高的免疫调节功能及抗肿瘤、抗菌等生理活性。甲壳低聚糖的制备中酶法水解由于其条件温和,易控制而受到广泛关注。据报道,甲壳素和壳聚糖除被甲壳素酶、壳聚糖酶和溶菌酶降解外,还能被葡萄糖酶、蛋白酶、脂肪酶、纤维素酶、淀粉酶、半纤维素酶和果胶酶等非专一性酶有效地水解,非专一性酶由于价格便宜、易制得等优点而倍受关注,而且有些非专一性酶甚至比专一性酶更加有效,例如脂酶。Pantaleone等研究了脂酶的非专一性作用,发现来自猪胰腺的脂肪酶对壳聚糖有强烈的水解作用。国内夏文水教授等 相似文献
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甲壳素是存在于自然界中惟一能被生物降解的带正电荷高分子材料,近年研究表明,它在调节机体免疫功能,降血脂、血糖、血压,保护胃肠道等方面发挥着巨大的作用.壳聚糖是甲壳素的N-脱乙酰基衍生物,具有组织相容性好、生物学活性多样、可生物降解、无毒、易于吸收等特点.本文介绍了甲壳素、壳聚糖的保健功能特性,以及甲壳素和壳聚糖在食品工业中的应用,对于甲壳素的应用前景以及新产品的开发具有一定的指导意义. 相似文献
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壳聚糖及其衍生物在食品工业中的应用 总被引:6,自引:0,他引:6
壳聚糖是甲壳素最重要的一类衍生物,它是甲壳素糖基上的乙酰基用强碱水解或酶解脱去一部分或90%以上而得到的一种多糖,这种多糖就叫壳聚糖或壳多糖(chitosan),也叫脱乙酰甲壳素.甲壳素(Chitin)又称甲壳质、几丁、几丁质、蟹壳素、壳多糖等,它在地球上天然有机化合物中,除纤维素外,是数量最大的亦是地球上除蛋白质外数量最大的含氮天然有机化合物.自然界中,甲壳素广泛存在于低等植物菌类、藻类的细胞,节肢动物虾、蟹、蝇蛆和昆虫的外壳、贝类、软体动物(如鱿鱼、乌贼)的外壳和软骨,高等植物的细胞壁等,据估计,自然界每年生物合成的甲壳素近100亿吨,因此壳聚糖的资源是相当丰富的. 相似文献
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壳聚糖的生理活性及其在保健食品中的应用 总被引:22,自引:1,他引:22
本文在介绍壳聚糖结构与理化性质的基础上,重点讨论了壳聚糖在体内的水解、消化吸收及其生理活性和疗效作用,提出了壳聚糖在保健食品中的应用和质量控制指标。 相似文献
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介绍了甲壳素、壳聚糖作为载体的酶的固定化条件及固定化方法,并介绍其活力回收率及稳定性。甲壳素、壳聚糖来源丰富,可以通过多种方法进行处理用作固定化酶载体。 相似文献
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PREPARATION OF CHITIN AND CHITOSAN OLIGOMERS AND THEIR APPLICATIONS IN PHYSIOLOGICAL FUNCTIONAL FOODS 总被引:3,自引:0,他引:3
Chitin and chitosan are known to possess multiple functional properties. Chitin is insoluble in any common solvent containing organic or mineral acid as well as water. Chitosan is water-insoluble and highly viscous in dilute acidic solutions. These solubility problems may restrict their use in physiological functional foods. However, chitin and chitosan oligomers are not only water-soluble and their solutions have low viscosity values, but they may also be absorbed in the human intestine. They may have much physiological functionality in the in vivo systems. This review demonstrates that chitin and chitosan oligomers can be prepared by chemical and enzymatic hydrolyses and that the oligomers with high degrees of polymerization, especially those with six residues or more, show strong physiological activities. 相似文献
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鲜切果蔬酶促褐变关键酶研究进展 总被引:2,自引:0,他引:2
机械伤使得鲜切果蔬在生理生化方面出现各种变化,导致果蔬贮藏期间品质下降,其中酶促褐变是导致鲜切果蔬贮藏品质下降的重要原因之一。本文主要介绍了鲜切果蔬酶促褐变过程中4个关键酶,即多酚氧化酶(PPO)、苯丙氨酸解氨酶(PAL)、脂肪氧合酶(LOX)和过氧化物酶(POD)的特性、作用机理以及影响酶活性的因素,以期为进一步研究鲜切果蔬酶促褐变的机理及酶促褐变的控制方法提供理论基础。 相似文献
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该研究从连云港海域海泥中筛选产右旋糖酐酶菌株,对其进行形态学观察、生理生化试验及分子生物学鉴定,并对其产右旋糖酐酶的酶学性质、酶解产物组分及抗氧化活性进行研究。结果表明,筛选得到一株产右旋糖酐酶菌株GN02,其被鉴定为芽孢杆菌(Bacillus sp.)。菌株GN02产右旋糖酐酶的最适温度和pH分别为20 ℃和7.0,在25~40 ℃、pH 5.0~9.0范围具有良好的稳定性。酶解1 h的主要产物为异麦芽四糖(85.6%)和异麦芽三糖(14.3%)。酶解产物清除羟基自由基、1,1-二苯基-2-三硝基苯肼(DPPH)和超氧阴离子自由基的半抑制浓度(IC50值)分别为0.42 mg/mL、2.98 mg/mL和11.54 mg/mL。 相似文献
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我国海藻资源极其丰富,但目前其利用主要集中于食品、饲料和保健品生产等少数方面,海藻资源的高值化利用途径有待进一步开发。海藻多糖是海藻细胞壁重要组分,具有多种生物活性功能,但因其聚合度高、黏度大、溶解性差,很难被机体吸收利用。海藻多糖经物理、化学、生物等方法可降解为海藻寡糖,其溶解性和生理学活性显著提升,更适合应用于食品、保健品、饲料、农业等诸多领域。基于酶法开发海藻寡糖绿色制备技术,具有传统方法不可比拟的优势,效率高、成本低、污染少。作者综述了褐藻寡糖、琼胶寡糖、卡拉胶寡糖、岩藻寡糖等海洋寡糖的生理活性及酶法转化的研究进展,为海藻资源的高值化利用提供新思路。 相似文献
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Cheng Tao Wang Chang Tao Wang Yan Ping Cao M. J. Robert Nout Bao Guo Sun Liu Liu 《European Food Research and Technology》2011,232(5):851-860
To quantify the effect of oxygen concentrations on the quality and antioxidant enzyme system of stored golden needle mushroom,
modified atmosphere packaging (MAP) with low and initial superatmospheric oxygen was applied during mushroom storage, and
physiological changes associated with postharvest deterioration, activities of antioxidant enzymes, and of cellulase, were
monitored during subsequent storage for 0–34 days. Golden needle mushrooms stored in MAP without oxygen or 20–50% oxygen rate
had a poorer sensory quality because of chilling injury and physiological injury. These injuries included increased levels
of malondialdehyde and superoxide anion whereas some extent of browning was observed. The antioxidant enzyme system, including
superoxide dismutase, catalase, peroxidase, and polyphenol oxidase, was activated, to scavenge the reactive oxygen species
to reduce injury during the initial storage period. However, these injuries also induced senescence of the stored golden needle
mushroom during later storage, followed by a decrease in activities of the antioxidant enzymatic system. The activities of
the antioxidant enzymatic system of the mushroom stored in MAP with 80% oxygen rate were the most favorable to delay the senescence
process in the later period of storage, and the mushrooms had the best quality until the end of storage. MAP with high oxygen
concentrations (e.g., 80% oxygen rate) can induce relatively high antioxidant capacity, significantly decrease postharvest
quality loss and improve shelf life of fresh mushrooms. 相似文献