响应面法在黑莓渣汁酶解工艺中的应用

选取果胶酶酶解黑莓浆加酶量、酶解温度和酶解时间三个因素进行中心组合设计,利用响应面法对其提取工艺进行优化研究。利用DesignExpert软件,对酶解花色苷含量的二次多项数学模型解逆矩阵分析表明:在加酶量为0.1%、酶解时间1.4h、酶解温度54(C的工艺条件下,酶解黑莓汁里花色苷含量最高,其最大提取产量预测值为650mg.g-1,与实测值相符。     

响应面法优化果胶酶酶解提取黑莓花色苷的工艺参数

选取果胶酶酶解黑莓浆加酶量、酶解温度和酶解时间3 个因素进行Box-Behnken 设计,利用响应面法对其提取工艺进行优化研究。利用Design Expert 软件,对酶解花色苷产量的二次多项数学模型解逆矩阵分析表明：在加酶量0.21%、酶解时间1.46h、酶解温度42.7℃工艺条件下,酶解黑莓汁里花色苷产量最高,其最大提取产量预测值为0.645mg/g,与实测值相符。对花色苷含量、Hunter 颜色值(L*、C*、h)进行两两线性相关分析,相关程度表明,C* 值可在一定程度上表征花色苷含量。     

酶法加工黑莓混汁工艺的研究

冷冻黑莓经解冻、蒸汽热烫及破碎后,采用果胶酶处理果浆,显著提高了黑莓混汁的出汁率,并且提高了黑莓汁的悬浮稳定性。通过单因素和正交试验确定了果胶酶加工黑莓混汁的最佳工艺条件:酶解温度45℃,果胶酶添加量为0.007%,酶解时间90min。     

果胶酶澄清香梨汁的工艺优化

此次试验优化了果胶酶澄清香梨汁工艺。以库尔勒香梨为原料,以酶添加量、酶解时间及酶解温度三个单因素试验为基础,以香梨汁的透光率为响应值,进行试验分析,通过响应面分析法对香梨汁澄清工艺条件进行优化。结果表明,优化后的澄清条件为果胶酶添加量0.06%、酶解温度40℃、酶解时间120 min,透光率平均值可以达到95.27%,澄清效果最好,与模型预测值相符。同时,对酶解前后的香梨汁进行部分基本营养物质含量比较,发现果胶酶的使用对可溶性固形物、总酚、维生素C的含量没有明显的影响。     

酶法生产紫马铃薯饮料的工艺研究

研究以紫马铃薯为原料的新型饮料。以淀粉酶用量、果胶酶用量、酶解温度和时间为工艺参数,通过单因素试验和正交试验相结合的方法,确定紫马铃薯饮料的最佳酶解工艺条件和配方。经烫漂的紫马铃薯加1倍水打浆后,加入0.03%淀粉酶和0.05%果胶酶,在50℃条件下作用3h,获得出汁率、澄清度和花色苷含量均较理想的紫马铃薯汁。对此条件下获得的紫薯汁按300mL/L原汁加入2g/L柠檬酸、120g/L蔗糖和9g/L蜂蜜,可以获得色泽和风味俱佳的紫马铃薯饮料。     

果胶酶澄清柚子汁工艺条件研究

通过单因素试验和正交试验,研究了果胶酶对柚子汁的澄清工艺.单因素试验结果表明,果胶酶用量为0.08～0.10 g/L,pH值为3.0～4.0,温度为25～35℃,酶解时间为1.5～2.5h条件下,果胶酶对柚子汁澄清处理的效果较好,果汁中的可溶性固形物含量基本不变.正交试验得到的果胶酶澄清柚子汁的最佳工艺条件为果胶酶用量0.09 g/L,最适pH值为3.5,酶解温度25℃,酶解时间1.5 h.     

超声辅助酶解制备黑莓清汁工艺及其协同效应

针对黑莓果汁加工过程中存在的出汁率低、品质不稳定等问题,运用响应面法研究超声波辅助复合酶（果胶酶＋果浆酶）制备黑莓清汁的优化工艺条件,并对超声波辅助酶解提高黑莓果汁品质的协同效应进行解析。结果显示,超声辅助酶解制备黑莓清汁的最佳工艺条件为超声功率200 W、加酶量0.3%、酶解时间1.5 h、酶解温度45 ℃,在此优化条件下制备的黑莓清汁具有较高的出汁率（80.89%）和透光率（68.21%）,对其品质和色泽稳定性分析得出,其花色苷含量和总酚含量明显高于单一酶解组,且色泽呈红色,在贮藏过程中具有较好的稳定性。采用扫描电子显微镜对处理后原料进行观察,结果表明,超声与酶产生协同效应,加速原料组织结构的破坏,提高黑莓清汁的制备效率。     

黑莓汁树脂降酸工艺研究及其复合果汁制备

基于紫薯糖液可提供一定糖分及其酰基化花色苷可提高花色苷稳定性,研究不同阴离子交换树脂和流速对黑莓汁降酸效果及紫薯糖液对黑莓汁口感的影响,比较黑莓紫薯复合果汁、黑莓汁和紫薯汁在加速贮藏期间花色苷含量的变化,探究紫薯糖液对黑莓汁花色苷稳定性的影响。结果表明,8种树脂对黑莓汁均有不同程度的降酸效果和花色苷、可溶性固形物吸附作用,其中LXZ-67树脂最适于黑莓汁降酸,脱酸率为55.6%,花色苷和可溶性固形物保留率分别为81.4%、87.1%,综合考虑生产效率和花色苷保留率,适宜生产流速为20 BV/h。黑莓汁与紫薯糖液的最佳调配比例为4∶1,此时复合果汁酸甜适口、香气浓郁。加速贮藏期间花色苷降解速率由大到小为黑莓汁复合果汁紫薯汁,表明紫薯糖液可提高黑莓汁花色苷稳定性。     

超声辅助果胶酶法提取红树莓花色苷及其成分测定

本研究利用超声辅助果胶酶法来提取制备红树莓花色苷,通过单因素实验,研究花色苷提取工艺中果胶酶浓度、料液比、酶解pH、酶解温度、超声时间和超声功率对提取液中花色苷含量的影响,结合响应面实验对提取工艺进行了优化,对比超声辅助果胶酶法和单一提取法所得的花色苷含量,并利用超高效液相色谱仪串联四级杆/飞行时间质谱(UPLC-Q/TOF)对树莓花色苷进行结构鉴定。结果表明:红树莓花色苷最佳提取条件为:果胶酶浓度5 mg/g、料液比1:15(g/mL)、酶解pH3、酶解温度50℃、酶解时间60 min、超声时间20 min和超声功率450 W,此时所得花色苷含量为127.51 mg/100 g。超声辅助酶法所得到花色苷含量较酶法提高了24.58 mg/100 g,较超声法提高40.40 mg/100 g,较单一提取法,超声辅助酶法具有更好的提取效果。经过超高效液相色谱三重四级杆飞行质谱分离中主要花色苷为:芍药素-3-葡萄糖苷、矢车菊素-3-葡萄糖苷、矢车菊素-3-阿拉伯糖苷和矢车菊素-3-芸香糖苷。     

酶法澄清枣汁的研究

采用果胶酶、纤维素酶、中性蛋白酶等多种酶制剂对枣汁进行澄清处理，并采用正交实验研究了联合使用酶制剂对枣汁澄清度稳定性和营养成分的影响。结果表明，适于澄清枣汁的最佳工艺条件为：每百克枣汁需用果胶酶2000U，纤维素酶1200U，中性蛋白酶500U，酶解温度50～60℃，酶解时间180min，pH值为5．0。     

Effects of different maceration enzymes on yield,clarity and anthocyanin and other polyphenol contents in blackberry juice

Enzymatic maceration of blackberries was conducted with eight different pectinolytic enzyme preparations. Juice yields were increased greatly when macerated blackberries were treated with enzyme preparations (P < 0.05), but no significant difference in yield was found among different enzymes (P > 0.05). The amounts of anthocyanins and polyphenols in the juices as well as clarity of the juices were greatly varied because of different enzyme treatment. Juice prepared with Klerzyme 150 showed better clarity and greater amount of anthocyanins than the juices prepared with other enzyme preparations (P < 0.05). Studies on the uniform design for Klerzyme 150 enzyme revealed that the optimum conditions were 0.063% (v/w), 44 °C and 110 min for enzyme dosage, reaction temperature and reaction time, respectively.     

Effect of pectinolytic juice production on the extractability and fate of bilberry and black currant anthocyanins

Bilberries (Vaccinium myrtillus L.) and black currants (Ribes nigrum L.), dark blue berries rich in anthocyanins, were processed with an aid of commercial pectinolytic enzyme preparations, and the effect of processing on berry anthocyanins was investigated. The enzyme preparations were dosed based on their polygalacturonase activity from 1 to 100 nkat/g of berry mash. The juice yields were determined by weighing, and anthocyanin analyses were performed with HPLC. The bilberry and black currant juice yields increased significantly in enzyme-aided treatments with comparison to control, even with the lowest (1 nkat/g) polygalacturonase dosage. The anthocyanin yield increased by up to 83% for bilberries and up to 58% for black currants in enzyme-aided treatments as compared to control. The results showed that higher polygalacturonase dosage was needed for black currant to achieve the maximal juice and anthocyanin yields than for bilberries. The stability and the profile of extracted anthocyanins were greatly affected by the glycosidase side activities present in the enzyme preparations, which were able to hydrolyze certain anthocyanins to the corresponding aglycones. In addition, the data indicate that anthocyanidin rutinosides were more easily extracted than those of glucosides, which prevailed over the arabinosides and galactosides. Thus, prior to processing it is important to know the intact anthocyanin structures of the raw material, and the activity profile of the enzyme preparation to obtain optimal anthocyanin extractability and enzyme dosage.     

Statistically designed two step response surface optimization of enzymatic prepress treatment to increase juice yield and lower turbidity of elderberry juice

This study examined the effects of different, statistically designed, enzymatic maceration treatments on juice yield, turbidity, and phenol yield (total phenols and total anthocyanins) in experimentally produced elderberry juice. Increased pectinolytic enzyme dose, longer maceration time, and elevated reaction temperature all had significantly positive effects on the juice yield. Increased enzyme dose and maceration temperature also increased the yields of anthocyanins in the elderberry juice, while none of the reaction parameters affected the juice turbidity. The juice yield was optimized further in a new experimental template, made by using the statistical steepest ascent optimization method. In the new response surface design template an optimal maceration treatment giving maximal juice yield and anthocyanin yields and low turbidity was identified. With the optimal treatment with a pectinolytic enzyme preparation, Pectinex BE 3L, produced by a cloned Aspergillus strain, a maximal juice yield of 77% w/w of the berry mash, an anthocyanin yield of 2380 mg/kg fresh berry mash, and a turbidity level of 128 formazin nephelometric units (FNU) were obtained. Enzymatic prepress treatment generally decreased turbidity levels by 30% as compared to pressing without prior enzymatic treatment. A comparison of the responses obtained after the optimal enzymatic treatment with five different pectinolytic enzyme preparations showed that the Aspergillus niger preparation Pectinex BE Color gave slightly better juice and phenol yields, and lower turbidity levels than the other enzyme preparations tested. In conclusion, the results demonstrated that juice yields and phenolic yields in elderberry juice could be improved with enzyme treatment and that the optimal reaction conditions for obtaining the best juice yield, highest phenolics, and lowest turbidity levels could be rationally identified via statistical factor level optimization.Industrial relevanceThis paper describes an optimization study on enzymatic pre-press treatment of elderberries for elderberry juice production. The aim is to increase juice yield, lower juice turbidity, and enhance the release of anthocyanins and other co-existing phenolics into the juice via enzyme catalyzed degradation of the cell wall polysaccharides in the elderberries. The work defines an optimal enzymatic treatment for increased elderberry juice yield, anthocyanin yield, and lowered juice turbidity, and also demonstrates how to shift a statistical design template to obtain improved results on selected parameters. Although the work is focused on elderberry juice the enzymatic as well as the statistical design strategy can easily be adapted for other fruit juice and food processes.     

Impact of enzyme on quality of blackcurrant and plum juices

The aim of work was optimization of technology of cloudy blackcurrant and plum juices production. The major concern was the increase of product cloudiness and its stability. Red fruit were processed with commercial pectinolytic preparations (Pectinex BE Colour, Pectinex BE XXL, and mixture of Rohapect PTE with Rohament PL). The effect of enzyme dose, maceration time and addition of ascorbic acid (in case of plum) on juices quality was investigated. Using single enzyme, either polygalacturonase or pectin lyase did not allow obtaining juices with high enough turbidity, however appropriate enzyme mixture allowed to obtain cloudy juice with the turbidity of at least 230 NTU for blackcurrant and above 500 NTU for plum juice. The best pressing-yield for blackcurrant was achieved with polygalacturonase and pectin lyase, 65 g/100 g after 1 h and 74 g/100 g after 4 h of pectinolysis. The macerating mixture gave about 58÷59 g/100 g yield, irrespectively of enzymation time. Pressing-yield of plum juices was in the range of 94÷97 g/100 g due to the fact that practically only skins were retained on pressing cloth. Addition of ascorbic acid (AA) during plum juice processing in quantity of 500 mg/kg had protective effect on anthocyanins. In control plum juices range of anthocyanins contents were 12.1÷16.5 mg/100 ml while in juice with AA addition even 21.4÷24.5 mg/100 ml.     

Effects of different enzymatic maceration treatments on enhancement of anthocyanins and other phenolics in black currant juice

Pre-press maceration treatments with 10 different pectinolytic enzyme preparations were investigated in experimental black currant juice production using response surface design templates. Enzyme dosage, maceration time, reaction temperature, and degree of berry crushing were varied, and the juice yields, anthocyanins, total phenols, and turbidity in the resulting juices were compared for a total of 250 different enzymatic treatments. The yields of anthocyanins and total phenols in the juices ranged from 900 to 2200 and 3050 to 5100 mg/kg wet weight black currant mash, respectively. Juice yields ranged from 66.4% to 78.9% by wet weight of mash. Turbidity levels ranged from 25 to 916 formazan nephelometric units (FNU). The reaction parameters induced larger variations in the responses than the different enzyme preparations, but the cloned Aspergillus niger/Aspergillus aculeatus preparation Pectinex BE® consistently tended to be among those giving the best responses regarding anthocyanin yields, phenols, and low juice turbidity. The optimal maceration was achieved using an enzyme dosage of 0.18% by wet weight of berries with a reaction at 60 °C for 30 min on the most finely crushed berry mash. This treatment gave similar profiles of anthocyanins in the juices with all the 10 enzyme preparations. The same 10 juices all exhibited antioxidant activity against human low-density lipoprotein oxidation in vitro, but the antioxidant potency varied depending on the enzyme preparation used in the pre-press maceration.     

Effect of ultrafiltration on concentrated apple juice colour and turbidity

Colour and turbidity of conventional bentonite-gelatin clarified apple juice was compared with 30,000–50,000 and 100,000DA hollow fibre ultrafiltered apple juice, with and without pectinolytic enzyme treatment. Results indicated that objective quality of ultrafiltered apple juice compared favourably with conventionally clarified apple juice over 30 weeks of storage at 37.5°C. However, treatment with pectinolytic enzymes before ultrafiltration increased both the initial colour and the browning rate. No significant differences were found in the values of the transmission haze after storage.     

Effect of enzyme‐aided pressing on anthocyanin yield and profiles in bilberry and blackcurrant juices

Bilberries (Vaccinium myrtillus) and blackcurrants (Ribes nigrum) were treated with extensive dosages of commercial cell wall degrading enzyme preparations, i.e. Econase CE, Pectinex Ultra SP‐L, Pectinex Smash, Pectinex BE 3‐L and Biopectinase CCM. The enzymes were dosed based on the polygalacturonase activity. The juice yield was improved in both berries as a result of the enzymatic treatment. The improvement was more pronounced with blackcurrants owing to their thicker cell walls. The impact of the enzymatic treatment on anthocyanins present in the juices was investigated using HPLC‐DAD. The enzyme preparations affected the contents and composition of anthocyanins in the juices. Pectinex Ultra SP‐L, Pectinex Smash, Pectinex BE 3‐L and Biopectinase CCM increased the total content of anthocyanins by 13–41% in the bilberry juices and by 18–29% in the blackcurrant juices. Econase CE, however, produced a dramatic decrease in the total anthocyanin content in the bilberry juice due to its enzyme profile, whereas no such effect was observed with the blackcurrant juice. All the enzyme mixtures tested produced a total or extensive loss of anthocyanidin galactosides in bilberry juice. Commercial enzyme preparations used in the production of berry juices can improve extraction of anthocyanins into the juice. However, they may effectively hydrolyse certain glycosides and thus affect the profile of extracted anthocyanins. Copyright © 2005 Society of Chemical Industry     

加工工艺对蓝莓汁和蓝莓酒中花色苷及类黄酮的影响

为了优化保留蓝莓中活性成分的加工工艺参数,考察了制汁、不同发酵工艺条件对蓝莓汁和蓝莓酒中花色苷和类黄酮物质的影响。结果表明,添加3‰果浆酶在60 ℃条件酶解2.0 h制得的蓝莓汁出汁率提高至72.50%,可溶性固形物含量为14.5%,花色苷及类黄酮含量分别为250.36 mg/100 mL和408.10 mg/100 mL。选择蓝莓原果浆在接菌量4%、25 ℃的条件下不加糖发酵的蓝莓酒花色苷及类黄酮含量分别为111.50 mg/100 mL和523.87 mg/100 mL。研究结果为提升蓝莓汁及蓝莓酒的营养品质提供一定的理论依据。     

Optimization of enzymatic clarification of green asparagus juice using response surface methodology

Enzymatic clarification conditions for green asparagus juice were optimized by using response surface methodology (RSM). The asparagus juice was treated with pectinase at different temperatures (35 °C-45 °C), pH values (4.00-5.00), and enzyme concentrations (0.6-1.8 v/v%). The effects of enzymatic treatment on juice clarity and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging capacity were investigated by employing a 3-factor central composite design coupled with RSM. According to response surface analysis, the optimal enzymatic treatment condition was pectinase concentration of 1.45%, incubation temperature of 40.56 °C and pH of 4.43. The clarity, juice yield, and soluble solid contents in asparagus juice were significantly increased by enzymatic treatment at the optimal conditions. DPPH radical-scavenging capacity was maintained at the level close to that of raw asparagus juice. These results indicated that enzymatic treatment could be a useful technique for producing green asparagus juice with high clarity and high-antioxidant activity. PRACTICAL APPLICATION: Treatment with 1.45% pectinase at 40.56 ° C, pH 4.43, significantly increased the clarity and yield of asparagus juice. In addition, enzymatic treatment maintained antioxidant activity. Thus, enzymatic treatment has the potential for industrial asparagus juice clarification.     

Effect of macerate enzymes on the yield,quality, volatile compounds and rheological property of prickly pear juice

Pectinase and cellulase enzymes were used to investigate efficacy for improving juice yield, stability and quality from prickly pear fruit. Pectinase improved the yield, stable color, color-assayed as release of anthocyanins or carotinoids and clarity of the juice. A significant increase in the effectiveness of pectinase was observed as the concentration was increased from 0.05 to 0.50% v/w. However, at concentration > 0.25% v/w they tended to impart a bitter flavor in the juice. Among three concentrations of pectinase and cellulase, pectinase at 0.50% v/w produced higher yield, a sediment-free clear juice and high-quality juice. The results indicated that depectinated clarified prickly pear juice behaves as a Newtonian fluid. It was found that the activation energy (Ea) for viscous flow was in the range of 5.02 x 10(3)-20.06 x 10(3) kJ/mol depending on the concentrations of pectinase and cellulase enzyme treatment of prickly pear juice, in contrast to 22.15 x 10(3) kJ/mol in untreated juice. Volatile compound concentrations of twelve compounds were not affected by pectinase and cellulase treatment. Overall the quality of prickly pear juice was better in pectinase-treated juice compared with untreated and cellulase-treated juice.