果胶酶在果蔬加工中的应用

果胶酶是指分解果胶类物质的多种酶的总称。通常包括原果胶酶、果胶甲酯水解酶、果胶酸酶。果胶酶普遍存在于细菌、真菌和植物中,在果蔬加工、饲料、纺织和造纸业中应用非常广泛。本文对果胶酶的来源、分类、作用机制及其在果蔬加工中的应用等方面进行综述。     

果胶甲酯酶的作用机理及在食品加工中的应用

该文综述食品加工中应用较为广泛的果胶酶的一个分类——果胶甲酯酶的作用机理及目前在果蔬汁澄清、果蔬制品改善、低酯果胶制备等食品相关行业中的应用现状,并进行总结,为果胶甲酯酶在食品加工中的深入研究开发及未来应用前景预测提供参考。     

果胶酶在果蔬汁加工中的应用

果胶作为细胞结构的一部分,是一种高分子的多糖化合物,存在于植物及微生物细胞中。果胶酶是分解果胶物质的酶的总称,广布分布在自然界当中。如今,通过对果胶酶应用的相关研究,果胶酶已充分应用到食品加工领域,尤其是在果蔬汁加工中起着重要的作用。本文就果胶酶在果蔬汁加工过程中的应用加以概述及研究,希望对食品加工领域有一定的借鉴作用。     

微生物果胶酶的研究进展

果胶酶是一类分解果胶质的酶的总称。果胶酶分布很广，主要存在于高等植物和微生物中。在果胶酶中，原果胶酶、聚半乳糖醛酸酶、裂解酶和果胶酯酶得到了广泛深入的研究。果胶酶在当前的生物工程领域中起着非常重要的作用。主要论述了果胶酶的分类、结构、检测方法以及物理化学和生物学特性，并且简要概述了其在工业生产中的应用。     

果胶酶制剂及其在果浆出汁和果汁澄清方面的应用

果胶类物质是存在于高等植物初生壁和细胞间隙中的一组多糖,果胶是一种杂多糖.果胶酶是分解果胶质的多种酶的总称,是一种在食品工业上广泛使用的酶.本文对果胶类物质及果胶酶的类型和性质进行了详细分析和说明.在此基础上,文章重点分析了果胶酶制剂在果浆出汁和果汁澄清方面的应用,对其在应用过程中的一些关键性问题进行了详细说明,最后对其应用前景进行了一个简要的概述,其目的皆在为食品行业（特别是果蔬加工及果酒生产行业）果胶酶的应用提供依据和参考.     

微生物果胶酶的应用研究

针对微生物果胶酶的不同用途,介绍了其分为原果胶酶、多聚半乳糖醛酸酶、裂解酶和果胶酯酶,并着重介绍了利用果胶酶分解植物细胞的细胞壁、分解细胞间质中的果胶物质和生产果胶低聚糖上的应用.     

微生物果胶酶的研究进展

果胶酶(pectinases)是指能协同分解果胶质的一组酶的总称,主要包括聚半乳糖醛酸酶(PG)、果胶裂解酶(PL)和果胶酯酶(PE)等,广泛应用于食品工业、饲料工业、造纸工业和纺织工业.近年来,随着我国国家政策和产业结构的调整,果汁和果酒行业得到迅猛发展.果胶酶作为果汁加工的重要酶制剂,市场需求量巨大.果胶酶生产普遍采用微生物发酵法,本文主要概述并比较了国内外微生物发酵法生产果胶酶的研究和应用情况.对国内果胶酶生产菌种的选育、微生物产果胶酶的发酵工艺及培养条件等进行了重点阐述,并简要介绍了微生物果胶酶的酶学性质和果胶酶的固定化情况.旨在发现当前我国果胶酶研究和开发中存在的问题,明确今后我国果胶酶研究中的前进方向,为研究和开发出同国际接轨的新型、高效果胶酶提供参考.     

碱性果胶酶的应用进展

碱性果胶酶分解复杂的果胶成小分子如半乳糖醛酸。碱性果胶酶在茶和咖啡发酵、纺织和植物纤维加工、油提取、含果胶工业废水处理等领域具有广泛应用。最近有些有关碱性果胶酶应用于造纸、植物病毒纯化、诱导植物抗病、家禽饲料、洗涤剂等领域的报道。综述了碱性果胶酶在各个领域中的应用。     

果胶酶产生菌的筛选鉴定和酶学性质研究

以果胶为唯一碳源,从海南采集的土样中筛选出一株能够利用果胶生长并产生果胶酶的菌株,采用3,5-二硝基水杨酸定糖法测定果胶酶酶活,通过生理、生化特性以及16S rRNA基因序列分析比对对菌株进行鉴定,并对其所产果胶酶的酶学性质进行研究。结果表明,分离筛选出一株果胶酶产生菌,编号为YY01,被鉴定为Bacillus niabensis。菌株YY01所产果胶酶的最适pH值为7.0,最适反应温度为45 ℃;在pH 10.0孵育12 h,仍有52.5%残余酶活力,50 ℃孵育6 h,仍有64%的残余酶活力。结果显示该酶有较好的耐碱性及较高的热稳定性,具有应用于果汁加工和胡椒脱皮的应用前景。     

果胶酶在果蔬汁加工中的应用研究进展

果胶酶是一种能够分解果胶物质的复合酶。作为世界四大酶制剂之一,果胶酶已被广泛应用于果蔬汁加工、酿酒以及天然产物的提取等食品行业中。在收集和整理相关资料的基础上,介绍了果胶的组成和结构,论述了果胶酶的分类及其作用机理,着重对近年来果胶酶在果蔬汁加工中的应用研究进展作了较为全面的综述,并对国内果胶酶的生产存在的问题以及未来的研究方向进行了讨论,以期为今后的研究以及实践提供参考。     

超声加工技术对果蔬汁品质影响及其作用机制研究进展

传统热加工虽然能有效灭酶和灭菌,但会对果蔬汁的色泽、营养物质及风味等品质造成严重破坏。超声技术作为一种新型的非热加工技术,能够改善果蔬汁的稳定性、安全性、感官特性和营养特性,已广泛用于果蔬汁加工的研究中;但由于受到复杂因素的影响,超声波处理也可能对果蔬汁产生不利影响。本文综述了国内外有关超声技术应用于果蔬汁加工的最新研究进展,从果蔬汁内源酶、微生物（发酵微生物、致腐和致病微生物）、理化特性和营养成分（如抗坏血酸、多酚和类胡萝卜素）等不同视角深入分析了超声波处理对它们的影响及作用机制,并总结了现阶段超声技术所存在的问题及研究趋势,为超声技术在果蔬汁加工中的应用提供一定的理论基础。     

粥化酶及其在果蔬加工中的应用研究

研究了粥化酶的粗酶特性及其在果蔬加工中的应用，并比较了粥化酶与其它果蔬加工用酶在苹果加工中的应用效果。研究结果表明粥化酶作用的最佳条件符合果蔬加工的要求，它能够不同程度的提高果蔬的出汁率及其澄清度；与其它果蔬加工用酶相比粥化酶具有作用效果好，价格便宜的优点     

COMBINED EFFECTS OF ENZYME DOSAGE AND REACTION TIME ON PAPAYA JUICE EXTRACTION WITH THE AID OF PECTIC ENZYMES – A PRELIMINARY REPORT

Pectic enzymes are widely used in the food industry for fruit juice extraction as well as in the clarification of cloudy juices. Our laboratory has been using pectic enzymes produced from a strain of Saccharomyces cerevisiae (ATCC 52712) in different applications including fruit juice extraction. The enzyme was produced in the laboratory by culturing the yeast in papaya juice supplemented with 1% pectin for 6 days. Known amounts of enzyme preparation (0–40 mg protein) were added to a measured weight of papaya mash for varying reaction periods (30–90 min) and the amount of free‐run juice obtained in each treatment compared with a control sample. Treatment of 200 g of papaya mash with different dosages of the pectic enzyme extract resulted in rapid increases in flow rate of free‐run juice. Mash treated with 32 mg of total protein extract with a 30‐min reaction time was the optimum for a maximum rate of juice flow (25 mL/min) when initial rates were measured. There was no significant difference (P > 0.05) between the red‐ and yellow‐fleshed varieties of the papaya used. When juice flow was monitored over 6 min, the treated samples gave a flow rate that was more than twice those of the untreated samples. This biotechnological approach could be adopted to enhance papaya‐juice production by local fruit juice processors when parameters for scale‐up processes are established.     

微生物与柑桔汁脱苦

对用于柑桔汁脱苦的微生物种类及其脱苦机理进行了综述,同时介绍了与脱苦有关的酶及微生物细胞的固定化在柑桔汁脱苦中的应用。     

EFFECT OF PECTINOLYTIC AND AMYLOLYTIC ENZYMES ON APPLE JUICE TURBIDITY

The mechanisms governing the enzymatic clarification of apple juice were studied by electron microscopy techniques. Full ripe and unripe apple juice samples (Granny Smith) were treated with commercial pectinase (Solvay 5XLHA) and amylase (Röhalase HT) enzymes, respectively. Scanning electron microscopy studies revealed that commercial amylolytic enzymes quickly reduced starch content in unripe apple juice to undetectable values. It was also observed that after pasteurization of this juice (90C, 5 min) all starch granules gelatinized. Using transmission electron microscopy, it was possible to observe pectin bonded to ripe apple juice particles. This protective colloid is known to be responsible for cloudy juice stability. The effect of pectic enzyme to destroy the protective pectin colloid was also detected with this technique. As a result of the enzymatic treatment, average particle size initially increased from 1000 to 1500 nm and decreased thereafter to ≈1100 nm, and Z‐potential increased in absolute values from ?9.6 to ?11.4 mV. It was speculated that the destruction of the weak pectin net by the action of the specific enzyme caused particle aggregation, followed by the collapse of aggregates, increasing the number of particles <500 nm.     

PHYSICOCHEMICAL AND SENSORY PROPERTIES OF MUSCADINE GRAPE JUICE AND CONCENTRATES

Juices from bronze and red muscadines were concentrated by low-temperature vacuum evaporation. Half of each of the lots was treated with a mixture of pectinolytic and cellulolytic enzymes and the other half untreated. Red juice was higher in soluble solids and Brix-to-acid (BTA) than bronze, but pH, acid, and viscosity were similar. When concentrated to 68° Brix, the BTA was the same regardless of juice type. Enzyme treated samples were not different from their nontreated counterparts, except for slightly higher pH of treated red juice. Hue angle for bronze concentrate shifted from about 100 to 78 while chroma increased. Hue for the red juice shifted from about 40 to 95, while chroma remained constant. Fructose and glucose were the major sugars with sucrose averaging less than 1%. Panelists rated the bronze reconstituted juices lower in color intensity, aroma intensity, sweetness, acidity, and flavor than the single-strength juice. However, the red reconstituted juices were rated higher in color intensity than their single-strength counterparts. Panelists rated reconstituted juices higher when reconstituted with essence recovered plus water than with water only.     

A review on pectinase properties,application in juice clarification,and membranes as immobilization support

Pectic substances cause haziness and high viscosity of fruit juices. Pectinase enzymes are biological compounds that degrade pectic compounds. Nontoxicity and ecofriendly nature make pectinases excellent biocatalysts for juice clarification. However, the poor stability and nonreusability of pectinases trim down the effectiveness of the operation. The immobilization techniques have gained the attention of researchers as it augments the properties of the enzymes. Literature has reported the stability improvement of enzymes like lipase, laccase, hydrogen peroxidase, and cellulase upon immobilization on the membrane. However, only a few research articles divulge pectinase immobilization using a membrane. The catalysis-separation synergy of membrane-reactor has put indelible imprints in industrial applications. Immobilization of pectinase on the membrane can enhance its performance in juice processing. This review delineates the importance of physicochemical and kinematic properties of pectinases relating to the juice processing parameters. It also includes the influence of metal-ion cofactors on enzymes’ activity. Considering the support and catalytic-separation facets of the membrane, the prediction of the membrane as support for pectinase immobilization has also been carried out.     

GENERATION AND APPLICATION OF IMMUNOLOGICAL PROBES FOR THE STUDY OF MEMBRANE-BOUND PROTEINS AND ENZYMES—A REVIEW

Immunological techniques are widely used for the detection of enzymes in food systems and for elucidating protein structure and function. The generation of anti-bodies recognizing membrane-bound proteins is difficult due to their hydrophobic nature, and reduced antigenicity. This review summarizes strategies for the production and purification of polyclonal antibodies recognizing membrane proteins. Applications such as enzyme immunoprecipitation, use of site-specific anti-peptide. antibodies for determination of the topology of membrane-embedded proteins, immunocytochemistry, and expression vector cloning are described.     

酶技术在果菜汁饮料生产中的应用

讨论了果胶酶、纤维素酶、溶菌酶等十几种酶在水果汁、蔬菜汁饮料加工和储藏中的应用；讨论了酶技术对果菜汁饮料稳定性、营养成分、色泽和风味的影响。     

α-葡聚糖酶在蔗汁澄清工艺中的应用研究

使用细丽毛壳菌发酵生产的α-葡聚糖酶粗酶液在蔗汁中进行试验,试验结果表明,在混合汁中添加粗酶液,用常规的亚硫酸法工艺进行澄清处理,过滤速度与沉降速度均提高了40%,葡聚糖除去率为20%,清汁混浊度降低60%,色值降低10%。在混合汁、清汁与糖浆中添加粗酶液,葡聚糖含量分别减少20%、15%与5%。葡聚糖酶的加入对蔗糖无影响。