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℃。     

低温果浆酶处理对黑莓出汁率和几个理化指标的影响

用低温果浆酶处理黑莓浆液,探讨酶处理对黑莓出汁率、还原糖含量和色泽等的变化规律。在pH、酶作用时间、加酶量和反应温度单因素实验的基础上进行正交实验。结果表明,pH为3.5、低温果浆酶用量为0.2%,反应温度为30℃,作用时间为1.5h时,黑莓的出汁率最高。      

黑莓原汁加工工艺及贮藏稳定性研究

目的 研究黑莓原汁的加工工艺及贮藏稳定性.方法 通过对黑莓原汁澄清、灭菌和贮藏过程中透光率、色度、色调、花色苷、多酚、可溶性固形物、总酸含量变化的考察,优化加工工艺,并了解其贮藏稳定性.结果 离心澄清(10000 r/min,5 min)的方法能在保持果汁各项指标稳定的前提下将原汁的透光率提高至44.0％～77.2％,...     

The effects of six phenolic acids and tannic acid on colour stability and the anthocyanin content of mulberry juice during refrigerated storage

Six phenolic acids and tannic acid are added to fresh mulberry juice to enhance the colour. Effects of these copigments on colour stability and the anthocyanin content of mulberry juice are investigated while being stored at 4 °C for 30 days. Results suggest that the addition of the copigments markedly increases the maximum absorbance of mulberry juice. Cyanidin-3-glucoside is the major anthocyanin, followed by cyanidin-3-rutinoside. Furthermore, the retention rate of the total anthocyanin, cyanidin-3-rutinoside and cyanidin-3-rutinoside increases after the addition of all copigments. The effect of ferulic acid on the stability of total anthocyanin, cyanidin-3-glucoside and cyanidin-3-rutinoside in mulberry juice is the best, 89.52%, 86.90% and 94.46% respectively (66.56%, 62.58% and 73.60% in the control group). Researchers recommend the addition of ferulic acid, p-coumaric acid and caffeic acid – all of which belong to the hydroxycinnamic acid group, to the mulberry juice to enhance the colour stability and anthocyanin content.     

复合酶在苹果汁加工中的应用研究

将纤维素酶与α-淀粉酶结合果胶酶用于苹果汁加工过程中的液化与澄清,弥补现行果胶酶在酶系上的不足。通过正交实验获得了液化与澄清工艺的最佳组合参数,对于苹果汁的加工生产具有实际指导意义。     

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 enzymatic macerate treatment on rutin content, antioxidant activity, yield, and physical properties of asparagus juice

ABSTRACT:  Asparagus is a vegetable with high antioxidant activity. In this research, asparagus juice was produced from fresh asparagus macerate treated with a carbohydrases mixture (Viscozyme) at 37 °C for up to 8 h. Rutin content, antioxidant activity, yield, soluble solid content, and color of the produced asparagus juice were determined. The results showed that Viscozyme significantly increased the yield of asparagus juice, especially in the 1st hour, which was higher than control (without Viscozyme treatment), but the juice had significantly less rutin content than control and had higher antioxidant activity than control only in the 1st 2 h. Juice with Viscozyme treatment had significantly higher soluble solid content than control. The greenness of asparagus juice deteriorates quickly for both the Viscozyme group and control. Viscozyme had advantage in producing juice with high yield, antioxidant activity, and soluble solid content in shorter time (2 h) of treatment compared to control.     

不同取汁工艺对青竹梅出汁率及品质的影响

目的 探讨不同取汁工艺对青竹梅出汁率及品质的影响。方法 以新鲜青竹梅为实验材料, 研究水浴提取法、超声波辅助提取法和复合酶法对青竹梅出汁率的影响, 对比分析3种方法在最优条件下的出汁率、可溶性固形物、可滴定酸、总糖、类黄酮和总酚等指标差异。结果 水浴提取法最优工艺料液比1?4(g:mL), 水浴温度80 ℃, 水浴时间60 min, 出汁率52.4%; 超声波辅助提取法最优工艺: 料液比1?4(g:mL), 超声波功率140 W, 提取温度60 ℃, 提取时间20 min, 出汁率53.2%; 复合酶解法最优工艺: 果胶酶添加量为0.6%, 纤维素酶添加量为0.2%, 酶解温度40 ℃, 酶解时间90 min, 出汁率66.6%。结论 3种方法均可有效提高青竹梅出汁率, 但复合酶法出汁率最高且综合营养成分提取效果最好。     

亲水性胶体对橙汁饮料稳定性的影响

目的以30%橙汁饮料为对象,研究结冷胶、黄原胶、海藻酸钠等亲水性胶体对橙汁稳定性的影响。方法采用U8(88)均匀设计筛选出对橙汁稳定性影响最为显著的因素,再通过L9(34)正交设计进一步验证优化橙汁饮料中的胶体最佳复配方案。结果对橙汁沉淀影响最为显著的胶体是海藻酸钠、结冷胶、果胶、黄原胶,而瓜尔胶、阿拉伯胶和羧甲基纤维素钠(CMC)的影响不显著,其中结冷胶和黄原胶有利于橙汁的混浊稳定性,但是黄原胶和CMC的加入会促进橙汁的絮凝产生。海藻酸钠和结冷胶是影响橙汁稳定性的重要因素,一定用量的海藻酸钠和结冷胶复配能很好抑制产品沉淀,维持体系的混浊稳定性;黄原胶是引起产品絮凝的主要因素,适量的果胶和海藻酸钠可以防止絮凝形成。结论在海藻酸钠、结冷胶和果胶添加量分别为1.2‰、0.32‰和0.8‰时,橙汁具有最佳稳定性,产品的沉淀量最少,混浊稳定性最高,同时可最大程度防止絮凝。经过验证,在最优胶体复配条件下,其沉淀稳定性为98.52%,混浊稳定性达94.89%,产品无明显絮凝。     

酶液化法对果蔬汁加工的影响概述

综述了运用酶液化法处理不同果蔬浆，研究其对果蔬浆液化效果、出汁率、澄清度、营养成分等因素造成的影响，并比较了与传统制汁工艺的差异。综合表明酶液化法对果蔬汁加工有积极的作用和贡献。     

Impact of maceration enzymes on skin softening and relationship with anthocyanin extraction in wine grapes with different anthocyanin profiles

The impact of an enzyme preparation on the extraction of grape skin anthocyanins into a wine-like solution was evaluated during maceration (25 °C, 8 days). The study was performed on Vitis vinifera L. cv. Cabernet Sauvignon and Nebbiolo because of their different anthocyanin profiles, which are mainly composed of tri- and disubstituted forms, respectively. Maceration enzymes enhanced the skin releasing capacity for anthocyanins between 8% and 15% more, depending on the enzyme dose and variety, and shortened the time required to reach the maximum extraction yield by about 40 h, when compared to the control samples. The effect of enzymes on the profile and total content of anthocyanins during maceration was significant only for Cabernet Sauvignon. Therefore, a variety effect was found. In particular, the relative amount of malvidin glucosides increased up to 9% more whereas that of delphinidin, cyanidin and peonidin glucosides decreased up to 5%, 2% and 3% more, respectively, with the addition of the enzyme preparation. The results also showed lower anthocyanin degradation at maceration times longer than 72 h with the use of enzymes. Furthermore, the relationship between this enzyme effect and the instrumental skin hardness was assessed for the first time, as no previous study deals with the variation in the mechanical properties of the berry skin after using maceration enzymes. Significant positive relationships were found between the skin softening and the anthocyanin extraction yield (R > 0.69, p < 0.01), which confirmed that the skin degradation by enzymes facilitates the anthocyanin release.     

外源添加物质对黑莓清汁花色苷稳定性和抗氧化活性的影响

本文研究了咖啡酸、阿魏酸、单宁酸、黄芩素、茶多酚、没食子酸、原儿茶酸、芦丁等8种外源辅色素对黑莓清汁花色苷辅色效果、热稳定性、光稳定性和体外抗氧化活性的影响。结果表明:咖啡酸、原儿茶酸、茶多酚、没食子酸、单宁酸对黑莓清汁花色苷的辅色效果影响较显著(p<0.05),最适浓度为0.1 mmol/L,而芦丁的最佳辅色浓度为0.4 mmol/L;实验所选辅色素能够在一定程度上提高黑莓清汁花色苷的热稳定性,其中没食子酸、阿魏酸、咖啡酸对其影响效果显著(p<0.05),分别使黑莓清汁花色苷的热降解半衰期延长了6.06、2.07和1.39倍。此外,原儿茶酸、阿魏酸、芦丁能够显著提高黑莓清汁花色苷的光稳定性、DPPH自由基清除能力和总还原力(p<0.05);没食子酸和单宁酸的辅色作用降低了黑莓清汁花色苷的光稳定性。黄芩素、阿魏酸、咖啡酸、芦丁等外源物质可作为黑莓清汁花色苷有效的辅色素。     

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 the time of cold maceration on the evolution of phenolic compounds and colour of Syrah wines elaborated in warm climate

The effect of different cold maceration times on Syrah red wines from warm climate has been evaluated. Differential colorimetry and tristimulus colorimetry were applied to colour data at different points of the vinification stage. Virtually, all the phenolic compounds showed significantly higher content in cold macerated wines, even more when longer contact time was used. Long cold macerated (LCM) wines had the significantly (P < 0.05) highest chroma values (C*_ab) and lowest of lightness (L*) and hue (h_ab). Unexpectedly, wines submitted to short‐time cold maceration (SCM) presented the lowest chroma values, even significantly inferior to that observed in traditional macerated (TM) wines. Moreover, colour changes (ΔE*_ab) between TM and SCM were mainly quantitative (%Δ²L and %Δ²C), whereas they were also qualitative when compared TM with LCM (%Δ²C and %Δ²H). Cold maceration in warm climates characterised by common colour losses must be carefully employed because undesirable consequences on colour may occur.     

不同乳酸菌对发酵桑葚汁酚类物质含量及抗氧化能力的影响

为提高桑葚(Morus alba L.)精深加工潜力,以嗜热链球菌(Streptococcus thermophilus)(ST)、保加利亚乳杆菌(Lactobacillus bulgaricus)(LB)、干酪乳杆菌(Lactobacillus casei)(LC)、植物乳杆菌(Lactobacillus plantarum)(LP)为发酵菌种,比较不同乳酸菌发酵桑葚汁的理化性质、单体酚类物质含量及抗氧化能力。结果表明,桑葚汁是四种乳酸菌优良的生长基质,发酵结束添加不同乳酸菌发酵的桑葚汁中活菌数皆超过11 lg(CFU/mL)。发酵过程总糖及还原糖含量明显下降,总酚及总黄酮含量显著提高。综合比较四种菌种的发酵能力,菌株LP的发酵性能最佳,发酵后桑葚汁中活菌数为12.5 lg(CFU/mL),总酚、总黄酮含量分别为7.4 mg没食子酸当量(GAE)/mL、4.5 mg芦丁当量(RE)/mL,1,1-二苯基-2-三硝基苯肼(DPPH)自由基清除率为65.3%,铁离子还原力(FRAP)为25.3 mg抗坏血酸当量(AAE)/mL,其抗氧化能力最强,菌株LP可作为桑葚发酵的最佳菌种应用于实际生产。     

Inactivation kinetics of peroxidase and polyphenol oxidase in peach juice treated with gaseous ozone

The effectiveness of gaseous ozone for inactivating peroxidase (POD) and polyphenoloxidase (PPO) in peach juice was investigated. The suitability of first‐order and Weibull models to describe inactivation kinetics was also analysed. Peach juice was exposed to ozone (0.11 and 0.20 mg O₃ min^?1 mL^?1) in a bubble column up to 12 min at 20 ± 1 °C. Enzyme activities were reduced due to treatments. The magnitude of the inactivation increased with ozone level and exposure time. Reductions in activity after 12 min of treatment ranged between 99.5% and 99.8% for POD and between 93.9% and 97.3% for PPO, depending on ozone concentration. Inactivation curves were successfully fitted with the first‐order and Weibull models; although, based on the root‐mean‐square error, the corrected Akaike and the Bayesian Schwarz criterion, the Weibull model showed stronger capability in all cases.     

不同乳酸菌对发酵桑葚汁酚类物质含量及抗氧化能力的影响

为提高桑葚（Morus alba L.）精深加工潜力,以嗜热链球菌（Streptococcus thermophilus）（ST）、保加利亚乳杆菌（Lactobacillus bulgaricus）（LB）、干酪乳杆菌（Lactobacillus casei）（LC）、植物乳杆菌（Lactobacillus plantarum）（LP）为发酵菌种,比较不同乳酸菌发酵桑葚汁的理化性质、单体酚类物质含量及抗氧化能力。结果表明,桑葚汁是四种乳酸菌优良的生长基质,发酵结束添加不同乳酸菌发酵的桑葚汁中活菌数皆超过11 lg（CFU/mL）。发酵过程总糖及还原糖含量明显下降,总酚及总黄酮含量显著提高。综合比较四种菌种的发酵能力,菌株LP的发酵性能最佳,发酵后桑葚汁中活菌数为12.5 lg（CFU/mL）,总酚、总黄酮含量分别为7.4 mg没食子酸当量（GAE）/mL、4.5 mg芦丁当量（RE）/mL,1,1-二苯基-2-三硝基苯肼（DPPH）自由基清除率为65.3%,铁离子还原力（FRAP）为25.3 mg抗坏血酸当量（AAE）/mL,其抗氧化能力最强,菌株LP可作为桑葚发酵的最佳菌种应用于实际生产。     

Influence of processing on the antioxidant capacity and bioactive compounds in jellies from different blackberry cultivars

The effect of thermal processing and the berry cultivar has been the subject of several studies, to serve as a basis for the least possible loss of bioactive compounds and antioxidant capacity. In Brazil, there are numerous blackberry cultivars under cultivation, and in this context, the aim of this work was to study how the bioactive compound contents and antioxidant capacity of blackberry jelly were influenced by the cultivars (Guarani, Brazos, Comanche, Tupy, Cherokee, Caingangue and Choctaw). Analysis was made of 7 fresh blackberry cultivars and 7 blackberry jelly formulations. Analysis of antioxidant activity, total phenolics, total anthocyanins and ascorbic acid was performed. It was verified that the contribution of the heat sensitive antioxidants compounds is considerable in all blackberry cultivars, and the degradation of these compounds was significantly different between the different blackberry cultivars. The Brazos and Caingangue cultivars stand out as undergoing the lowest losses in processing, resulting in jellies richer in bioactive compounds and higher antioxidant capacity.