Effects of different enzymatic pre-press maceration treatments on the release of phenols into blackcurrant juice

The effects of different pectinolytic enzyme treatments on the release of phenolic compounds from blackcurrant berry mash into juice in experimental blackcurrant juice production were examined. The influence of enzyme dose (0–0.1% by weight), degree of berry crushing, maceration time, and temperature on the total phenol concentration, the juice yield, and on polysaccharide degradation were evaluated for four commercial, fungal enzyme preparations in statistically designed experimental templates. In optimal experimental conditions, treatments with Macer8 [FJ] and Pectinex Ultra SP-L released ~6500 and 6650 mg gallic acid equivalents/L of total phenols, respectively. These levels correspond to increases of 14–15% compared to the juice extracted without enzymes, and were significantly higher than those achieved with Rapidase BE Super and Grindamyl pectinase treatments. Increased enzyme dosage gave larger juice yields and higher phenol concentrations. There was a positive, linear correlation between degradation of the substrate polysaccharides and the amount of phenols released. The juice samples inhibited the oxidation of human low-density lipoproteins in vitro in a dose-dependent matter. The non-enzyme-treated sample exhibited higher antioxidant activity than the enzyme-treated juices at equimolar test levels of phenols, presumably because of differences in their phenolic profiles.     

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.     

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。     

Effects of pectolytic enzyme treatments on anthocyanins in raspberry juice

Raspberry juices treated with two commercial pectinase preparations lost almost 20% of their total anthocyanin pigments; losses were related to both concentration of enzyme and time of treatment. Analysis of individual anthocyanins showed differences between the enzymes. Ultrazyme reduced all components in similar proportions, whereas Pectinex apparently also converted cyanidin-3-sophoroside and cyanidin-3-glucosylrutinoside into cyanidin-3-glucoside and cyanidin-3-rutinoside respectively, presumably by hydrolysis of β1–2 glucosidic bonds by glucosidase present in the Pectinex.     

白萝卜澄清汁的酶解工艺

以白萝卜为原料,采用双酶法酶解工艺,在单因素实验的基础上,采用正交实验设计,研究白萝卜澄清汁的酶解工艺。结果表明,白萝卜澄清汁的最佳酶解工艺为:果胶酶添加量0.2g/kg,纤维素酶添加量0.6g/kg,pH5.0,酶解温度45℃,酶解时间80min。在此工艺条件下生产的白萝卜澄清汁的出汁率为80.13%,透光率为89.2%。      

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.     

Impact of various factors on the composition and stability of black currant anthocyanins

Nine black currant varieties cultivated in Lithuania were studied. The highest amount of ascorbic acid was established in fresh berries from cv Minaj Smyriov and Kupoliniai: these varieties contained 220.5 and 186.7 mg 100 g⁻¹ of ascorbic acid in berries. The highest amount of anthocyanins was found in cake produced from berries cv Kupoliniai and Kriviai: 14.65 and 15.42 mg g⁻¹, respectively. The major pigment determined in Kupoliniai variety was delphinidin-3-rutinoside; in Ben Lomond, Minaj Smyriov, Kriviai and Gagatai cultivars, cyanidin-3-rutinoside. The composition of the identified pigments was the following: cyanidin-3-rutinoside (33–38%), delphinidin-3-rutinoside (27–34%), cyanidin-3-glucoside (8–10%) and delphinidin-3-glucoside (8–10%). Impact of storage, thermal treatment and addition of sweeteners were studied. Cyanidin-3-rutinoside was the most stable to the effect of thermal treatment at 95 °C, while cyanidin and delphinidin rutinosides were the most stable during storage for 12 months at 8 °C. Fructose has a greater effect on anthocyanin degradation compared with glucose and aspartame.     

均匀设计在黑莓澄清汁酶解工艺中的应用

研究了均匀实验设计法在黑莓澄清汁酶解条件优化中的应用,结果表明:较少的实验次数可以获得良好的实验结果。利用SAS数据处理软件对实验结果进行回归分析,得到了具有很好拟合度的回归方程;通过分析加酶量、温度、时间等酶解条件对果汁的影响,得出最优酶解参数为加酶量0.063%(v/w)、酶解时间110min、酶解温度44℃。     

酶法生产橄榄混浊汁

确定了酶法生产橄榄混浊汁的最佳工艺条件，研究了果胶酶对橄榄果汁的产量和提取率的影响。当果胶酶的含量大于0．01％时，果汁的提取率提高但产量下降，果汁颜色不理想；温度30“C时。产率最高；酶解时间1h，产率和提取效率都最好。由于橄榄中含有大量的果胶，果胶酶的加入，使果汁的产率提高了20％～30％，提取率提高了5％～7％，改善了果汁的颜色。     

天然抗菌活性物质在黑加仑果汁加工中的应用研究

研究了天然抗菌活性物质-新疆家蚕抗菌肽的耐热性及其对部分微生物的最小抑菌浓度,和其在不同pH条件下的溶解度及抑菌效果,并在此基础上进行正交实验,得到将其应用于黑加仑果汁加工中的最佳工艺条件。抗菌肽的添加可降低黑加仑果汁的杀菌强度,提高产品品质,为工业化生产应用提供科学依据。     

Optimising enzymatic maceration in pretreatment of carrot juice concentrate by response surface methodology

In this paper, enzyme preparation for carrot pulp maceration was screened out and enzymatic maceration processing condition of the carrot pulp was optimised by response surface methodology for carrot juice concentrate. Pectinex Smash XXL was the best commercial enzyme preparation than Pectinex Ultra SP‐L, Pectinase FNP‐1 and cellulose FNC‐1 employed in the carrot juice processing in the study. The effect of enzyme concentration and incubation time and their complex interaction on juice β‐carotene content, juice yield and viscosity in the maceration process was studied by using experiments of central composite rotatable design. The results indicated that under the optimal conditions that the enzyme concentration was 100 mL t^?1 and incubation time was 80 min, the juice β‐carotene content was ≥54.2 mg kg^?1, the juice yield ≥63.5% and the juice viscosity ≤2.1 mPa S.     

不同酶制剂对银杏浊汁品质的影响

以银杏为原料，通过酶法制备银杏混浊汁，考察不同的淀粉酶和蛋白酶对银杏浊汁品质的影响。结果表明：不同的酶制剂对银杏浊汁的品质有不同的影响，采用组合酶系较使用单一酶制剂效果更好，其中，使用中温α-淀粉酶和Alcalase蛋白酶制备的银杏浊汁悬浮稳定性最好，品质较佳。     

杀菌处理对发酵红枣汁品质的影响

目的:对比不同杀菌方式对发酵红枣汁品质的影响。方法:红枣汁发酵前,采用低温等离子体杀菌(CPS)和脉冲强光杀菌(PLS)对发酵前后红枣汁品质的影响,以高压杀菌(SA)红枣汁为对照。结果:采用CPS处理,红枣汁发酵前后总糖、还原糖和可溶性固形物含量均显著高于另外两种杀菌方式,发酵后红枣汁的总糖、还原糖和可溶性固形物含量分别为1.7 mg/L、1.64 mg/L和12.4%;采用SA处理,红枣汁发酵前后总酚含量均为最低,发酵后红枣汁的总酚含量仅为2.19 mg/L;采用PLS处理,红枣汁发酵前后的色差值变化最小。经CPS、PLS和SA处理后的红枣汁,接种植物乳杆菌发酵48 h后,其活菌数均>6.48 lg(CFU/mL),其中,PLS处理后植物乳杆菌活菌总数最高[6.63 lg (CFU/mL)]。结论:非热杀菌处理(特别是PLS)对发酵红枣汁的品质影响较小,可作为发酵红枣汁加工中的杀菌处理技术。     

Optimisation of extraction of phenolics and antioxidants from black currant leaves and buds and of stability during storage

Health benefits of a diet rich in fruits and vegetables are attributed in part to their contents of phenolics and other antioxidant compounds. In this research, the extraction of phenolics and antioxidant compounds from black currant was optimised for different plant organs. The extraction solvent affected yield: aqueous acetone was better than methanol and acetate or glycine buffer. In aqueous buffer, maximum yields of total phenolics and antioxidant activities were obtained at pH 3. Extraction from lyophilised materials yielded extracts with higher phenolic contents and antioxidant activities.     

Effects of combining ultraviolet and mild heat treatments on enzymatic activities and total phenolic contents in pineapple juice

Ultraviolet (UV) is able to inactivate most microorganisms in fruit juices with a low absorption coefficient but its effect is limited in inactivating undesired enzymes. The aim of this study was to overcome limitation of ultraviolet light (UV) by combining mild heat with UV. Pineapple juice was treated with mild heat (temperature: 50, 55 and 60 °C; holding time: 10, 20 and 30 min) and subsequently exposed to UV (5.61, 7.55 and 11.23 mJ·cm^− 2). The effects of these combined treatments on pectin methylesterase (PME), bromelain activities and total phenolic content (TPC) were determined. Both enzymatic activities were reduced by mild heat but not by UV treatment. Increasing holding time and UV dosage led to higher depletion of TPC. Treating pineapple juice with mild heat at 55 °C for 10 min and UV at 5.61 mJ·cm^− 2 decreased PME by 60.53% whilst retaining 61.57 ± 0.21% and 72.80 ± 0.33% of bromelain and TPC, respectively.Industrial relevanceAs opposed to traditional heat pasteurisation, ultraviolet (UV) treatment has the potential to produce pineapple juice with added value, such as high amount of health benefiting phenols and bromelain. Despite being known for being economically feasible, this technology is not widely adapted by the industry due to its inability to inactivate pectin methylesterase (PME). To overcome the limitation of UV, mild heat (MH) is introduced as hurdle technology. This study demonstrates that combining UV and MH could be able to effectively inactivate the PME in pineapple juice whilst preserving relatively high amount of bromelain and phenols.     

Changes in strawberry phenolics, anthocyanins, and antioxidant capacity in response to high oxygen treatments

Changes in fruit quality, decay, phenolic and anthocyanin content, and antioxidant capacity of strawberries (Fragaria × ananassa Duch. cv. Allstar) stored under air and high oxygen atmospheres at 5 °C were investigated. Freshly harvested strawberries were placed in jars and ventilated continuously with air or with 40, 60, 80, or 100 kPa O₂ at 5 °C for up to 14 days. Samples were taken initially, and after 3, 7, 10 and 14 days of storage. While fruit quality parameters such as titratable acidity, total soluble solids and surface color were only slightly affected by differing levels of O₂, the higher oxygen concentration treatments significantly reduced decay. Oxygen concentrations higher than 60 kPa also promoted increases in ORAC values, total phenolics and total anthocyanins as well as individual phenolic compounds analysed by HPLC during the initial 7 days of storage. However, this effect diminished with prolonged storage. No significant differences in ORAC values, total phenolics, total anthocyanins, or the individual phenolic compounds were observed among the high O₂ and air-stored fruits after 14 days of storage. These results indicate that high oxygen treatments exert the most effects on fruit quality and antioxidant capacity of strawberry fruit in the first 7 days of storage.     

几种浸渍方式对葡萄酒酒质影响探讨

研究了冷浸渍、传统浸渍、冷浸渍结合热浸提3种不同浸渍方法在红葡萄酒酿造中应用.结果显示,发酵前冷浸渍与发酵后期热浸提相结合的浸提方式适宜嘉峪关地域气候特点、耗能低,适宜嘉峪关地域气候特点、耗能低,有利于葡萄果皮中酚类物质的浸出,且能够增强其葡萄酒果香,改善口感和色泽稳定性,有利于酿造陈酿型红葡萄酒.     

Comparative study of juice production by pulsed electric field treatment and enzymatic maceration of apple mash

The application of pulsed electric fields (PEF) to apple mash as an alternative to enzymatic mash maceration (EM) was investigated on a pilot plant scale. Chemical composition of the juices obtained by different processes was similar, except for phenolic content and antioxidative capacity, thus proving substantial equivalence of the juices. However, PEF led to an enhanced release of nutritionally valuable phenolics into the juice. Sensory properties of the juices did not significantly differ when PEF pre-treatment was applied. Total juice yield amounting to approx. 85% was not increased by PEF treatment and was irrespective of the different mash pre-treatments, however, juice release was delayed after PEF application (W = 10 kJ/kg), whereas EM enhanced the de-juicing process. In contrast to EM, genuine pectin quality was retained by PEF processing, which allows sustainable pomace utilisation and additional commercial benefit through its commercialisation. Within a storage time of 40 weeks juice composition remained unchanged.     

黑豆皮花色苷的降血糖作用及其机理的研究

目的:观察黑豆皮花色苷(Black Soybean Anthocyanins,BSA)的降血糖效果,并对其机理进行初步研究。方法:对不同组的正常小鼠和利用四氧嘧啶造模的实验性糖尿病小鼠分别进行相应浓度的黑豆皮花色苷腹腔注射,并测定血糖、超氧化物歧化酶(SOD)、丙二醛(MDA)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-PX)以及胰岛素含量。结果:黑豆皮花色苷可以降低糖尿病小鼠的血糖和血清中MDA与CAT的含量,提高血清中SOD和GSH-PX的含量,同时提高了血清中胰岛素的含量。结论:黑豆皮花色苷具有降低糖尿病小鼠高血糖的作用,而它的作用机理可能是通过促进胰岛素分泌和清除自由基及抗脂质过氧化过程实现的。