Effects of juice processing on cranberry antioxidant properties

The effects of the industrial juice process on the antioxidant capacities of cranberry samples and of three phenolic extracts (polar phenolics (E1), apolar phenolics (E2) and anthocyanins (E3)) adjusted at pH 2.5 and 7.0 were investigated. The free radical-scavenging (FRS) and the lipid peroxidation inhibition (LPI) activities of each sample and extract, were studied using a N,N-diethyl-p-phenylenediamine discoloration test and the thiobarbituric acid reactive substances assay, respectively. The FRS and the LPI results, expressed in mM Trolox® equivalent (TE)/mg phenol and mg TE/mL/mg phenol, respectively, showed a negative effect of the juice process steps on E1. The E2 and E3 extracts were also affected by the process but not as much. The milling step increased the FRS capacity of E2 and E3 extracts, but decreased their LPI capacity. The evaporation of the juice did not have a significant effect on the FRS capacity, but lowered the LPI capacity. Before and after each step of the juice process, the FRS capacity of the cranberry extracts was greater than the LPI capacity. The results were consistent in classifying the FRS capacity of the extracts in the following order of polarity: E1 > E3 > E2; and their total phenolic (TP) content in the following order: E3 > E2 > E1. In general, the neutralization of the pH of the extracts did not significantly influence the changes observed during the juice process in the FRS and LPI capacity, except for E3 for which a decrease in the LPI capacity was observed.     

Antioxidant and antiradical properties of cranberry juice and extracts

The antioxidant capacities of cranberry juice and three extracts isolated from frozen cranberries containing anthocyanins, water-soluble and apolar phenolic compounds, were evaluated at pH 2.5 and 7, respectively. The free radical-scavenging (FRS) and the lipid peroxidation inhibition (LPI) activities of each samples, and extracts, were studied using the N,N-diethyl-p-phenylenediamine (DPD) decoloration test and the thiobarbituric acid reactive substances (TBARS) assay, respectively. The cranberry phenols displayed good free radical-scavenging properties, but were less efficient at inhibiting the peroxidation of lipids. Of all the samples tested, the water-soluble phenolic compounds showed the greatest free radical-scavenging (68.2 mmol TE/mg phenol) and antioxidant (13.4 mmol TE phenol) activities. The polarity of the phenols, the pH of the medium and the juice process had a great influence on the antioxidant activities. The phenols isolated from cranberries with an aqueous solvent have greater antioxidant properties than those extracted with an organic solvent mixture. The antioxidant activity of the cranberry samples adjusted at pH 2.5 was greater than those adjusted at pH 7. Compared to the cranberry extracts, the juice exhibited a much lower antioxidant activity, especially when compared with the extract containing water-soluble compounds which the extraction conditions were similar to those used to obtain the juice.     

甘蔗汁酒精废液色素抗氧化活性的研究

对以甘蔗汁酒精废液为原料提取得到的色素的抗氧化活性进行了研究。结果表明,甘蔗汁酒精废液色素中多酚类含量为17.53mg没食子酸当量/g色素;该色素具有自由基清除能力,10mg/mL时的还原力、.OH清除能力及1,1-二苯基-2-苦基-肼(DPPH.)清除能力分别是1mg/mL茶多酚的34.58%、59.27%和92.31%;Fe3+、Cu2+、Al3+和紫外光能够增加其DPPH.清除能力,Zn2+、Ca2+和山梨酸钾使其DPPH.清除能力降低,而温度和Mg2+对色素DPPH.清除能力影响不明显。     

Effect of gamma irradiation on microbial analysis, antioxidant activity, sugar content and color of ready-to-use tamarind juice during storage

Gamma irradiation is highly effective in inactivating microorganisms in various foods and it offers a safe alternative method of food decontamination. In the present study, the effect of gamma irradiation on microbial analysis, antioxidant activity, sugar content, color and sensory evaluation of ready-to-use tamarind juice was investigated during storage. A fresh tamarind juice was prepared by dissolving 5 g of pulp/100 ml of deionized distilled water and irradiated at 0, 1, 3 and 5 kGy at room temperature. Microbiological assay of the fresh and stored ready-to-use tamarind juice showed better quality after gamma irradiation. Antioxidant ability was studied by using 1,1-diphenyl-2-picrylhydrazyl (DPPH), FRAP (ferric reducing/antioxidant power) and total phenolic contents, and gamma irradiation had a significant increase or maintenance on the antioxidant potential of the ready-to-use tamarind juice. Contents of glucose and fructose also showed minimal alterations both in the fresh and stored samples. There was a significant improvement in the Hunter color value in both the fresh and stored tamarind juice. To conclude, gamma irradiation improves the microbial decontamination and the antioxidants as well as the color of the ready-to-use tamarind juice without any adverse change in sensory qualities.     

Shelf life extension of minimally processed cabbage and cucumber through gamma irradiation

The influence of irradiation of minimally processed cabbage and cucumber on microbial safety, texture, and sensory quality was investigated. Minimally processed, polyethylene-packed, and irradiated cabbage and cucumber were stored at refrigeration temperature (5 degrees C) for 2 weeks. The firmness values ranged from 3.23 kg (control) to 2.82 kg (3.0-kGy irradiated samples) for cucumbers, with a gradual decrease in firmness with increasing radiation dose (0 to 3 kGy). Cucumbers softened just after irradiation with a dose of 3.0 kGy and after 14 days storage, whereas the texture remained within acceptable limits up to a radiation dose of 2.5 kGy. The radiation treatment had no effect on the appearance scores of cabbage; however, scores decreased from 7.0 to 6.7 during storage. The appearance and flavor scores of cucumbers decreased with increasing radiation dose, and overall acceptability was better after radiation doses of 2.5 and 3.0 kGy. The aerobic plate counts per gram for cabbage increased from 3 to 5 log CFU (control), from 1.85 to 2.93 log CFU (2.5 kGy), and from a few colonies to 2.6 log CFU (3.0 kGy) after 14 days of storage at 5 degrees C. A similar trend was noted for cucumber samples. No coliform bacteria were detected at radiation doses greater than 2.0 kGy in either cabbage or cucumber samples. Total fungal counts per gram of sample were within acceptable limits for cucumbers irradiated at 3.0 kGy, and for cabbage no fungi were detected after 2.0-kGy irradiation. The D-values for Escherichia coli in cucumber and cabbage were 0.19 and 0.17 kGy, and those for Salmonella Paratyphi A were 0.25 and 0.29 kGy for cucumber and cabbage, respectively.     

黑花生衣色素抗氧化作用的研究

为研究黑花生衣色素的抗氧化能力,对黑花生衣色素溶液进行紫外-可见光谱扫描,并分别测定黑花生衣色素的还原能力,清除羟自由基、超氧阴离子自由基、DPPH自由基的能力以及抗脂质过氧化功能。结果表明:黑花生衣色素的紫外光谱图显示在223nm和278nm处有两个最大吸收峰,与可可色素和高粱红色素等天然抗氧化物质的紫外吸收图谱相似;对羟自由基、超氧阴离子自由基、DPPH自由基的半抑制能力IC50分别为0.601、0.496、0.208mg/mL,对脂质过氧化有很强的抑制作用,是一种效果较好的天然抗氧化剂。      

贻贝蒸煮液体外抗氧化及阻断N-亚硝胺合成的研究

为了研究贻贝蒸煮液的抗氧化活性和阻断亚硝胺合成能力,采用DPPH.法测定了试样的抗氧化活性,并模拟胃液在体外进行亚硝胺合成阻断实验,测定了试样对亚硝酸根离子的清除率和N-亚硝胺合成的阻断率。结果表明,在DPPH.清除实验中,贻贝蒸煮液(以可溶性固形物计)的IC50为3.80μg/mL,对照品TBHQ的IC50为7.55μg/mL。另外,贻贝蒸煮液清除亚硝酸根离子与阻断N-亚硝胺合成的最佳剂量水平(以可溶性固形物计)为64μg/mL,此时,清除率和阻断率分别达到84.08%和71.04%,相同浓度下,对照品VC的清除率和阻断率分别为30.90%和29.27%。     

黑莓原果汁及其果汁饮料加工

根据黑莓果实的组织结构及理化性状特点，比较了原果汁不同提取方法对所含成分的影响，提出了保持黑莓原有色泽、风味和营养成分的原果汁及其饮料生产工艺流程和技术条件。     

Shelf life extension of fresh fruit and vegetables by chitosan treatment

Among alternatives that are currently under investigation to replace the use of synthetic fungicides to control postharvest diseases in fresh produce and to extend their shelf life, chitosan application has shown promising disease control, at both preharvest and postharvest stages. Chitosan shows a dual mode of action, on the pathogen and on the plant, as it reduces the growth of decay-causing fungi and foodborne pathogens and induces resistance responses in the host tissues. Chitosan coating forms a semipermeable film on the surface of fruit and vegetables, thereby delaying the rate of respiration, decreasing weight loss, maintaining the overall quality, and prolonging the shelf life. Moreover, the coating can provide a substrate for incorporation of other functional food additives, such as minerals, vitamins, or other drugs or nutraceutical compounds that can be used to enhance the beneficial properties of fresh commodities, or in some cases the antimicrobial activity of chitosan. Chitosan coating has been approved as GRAS substance by USFDA, and its application is safe for the consumer and the environment. This review summarizes the most relevant and recent knowledge in the application of chitosan in postharvest disease control and maintenance of overall fruit and vegetable quality during postharvest storage.     

Possible nutritional and health‐related value promotion in orange juice preserved by high‐pressure treatment

Effects of high‐pressure treatment on the orange juice carotenoids (β‐carotene, α‐carotene, zeaxanthin, lutein and β‐cryptoxanthin) associated with nutritional (vitamin A) and health‐related (radical‐scavenging capacity) values were investigated. Various high‐pressure treatments (50–350 MPa) combined with different temperatures (30 and 60 °C) and times (2.5, 5 and 15 min) of treatment were assayed. The carotenoid content of the orange juice was analysed by HPLC‐UV, the vitamin A value was determined as retinol equivalents (RE) and the free radical‐scavenging capacity was evaluated using the DPPH (2,2‐diphenyl‐1,1‐picrylhydrazyl) radical model system. A storage study was carried out at refrigeration temperature (4 °C). High‐pressure treatments at 350 MPa produced significant increases of 20–43% in the carotenoid content of fresh orange juice (from 3.99 to 4.78–5.70 mg l^?1). A non‐uniform behaviour of high‐pressure treatments was detected. An increase in time (beyond 5 min) or temperature (above 30 °C) of treatment did not improve the amount of carotenoids extracted. Owing to better extraction of carotenoids, an increase in vitamin A value from 164 to 238 RE l^?1 (45%) was achieved with the 350 MPa/30 °C/5 min treatment. No correlation was found between the increase in carotenoid amount extracted and the free radical‐scavenging activity. © 2002 Society of Chemical Industry     

果胶酶在果蔬汁生产中的应用

介绍了果胶酶的组成与结构，讨论了果胶酶在果蔬汁的出汁率、澄清、超滤等方面的应用。     

The effects of areca catechu L extract on anti-inflammation and anti-melanogenesis

Ethanolic extract (CC-516) from Areca catechu L was prepared and its various biological activities were evaluated, CC-516 showed potent anti-oxidative, free radical scavenging, and anti-hyaluronidase activity. Anti-oxidative effect of CC-516 (IC _ 50: 45.4 mug/ml) was lower than butylated hydroxytoluene (IC _ 50: 5mug ml), but similar to tocopherol and higher than ascorbic acid. Especially, CC-516 exhibited relatively high free radical scavenging activity (IC _ 50: 10.2 mug/ml) compared to control. CC-516 inhibited effectively hyaluronidase activity (IC _ 50: 416 mug/ml), showed inhibition in vivo on delayed hypersensitivity as well as croton-oil induced ear edema in mice when it was topically applied. These results strongly suggest that CC-516 may reduce immunoregulatory/inflammatory skin trouble. Also, from the results, we have elucidated that CC-516 showed anti-allergic and anti-cytotoxicity activity. The whitening effect of CC-516 shown by the inhibition of mushroom tyrosinase activity with IC _ 50 of 0.48 mg/ml and of melanin synthesis in B16 melanoma cells. This study indicates that CC-516 is effective on anti-inflammatory/anti-melanogenesis, and can be used as a new agent for cosmetics.     

辐照处理对混浊苹果汁有机磷农药降解的影响

研究了辐照处理对混浊苹果汁的品质和降解有机磷农药（毒死蜱、敌敌畏、乙酰甲胺磷、氧化乐果）的作用,并对果汁颜色、V C含量和总酚含量等的变化进行了研究。有机磷农药的测定参考农业部标准（NY/Y761-2004）,并略作改进。结果表明,辐照降解有机磷农药效果较好,降解率从大到小依次为毒死蜱、敌敌畏、乙酰甲胺磷、氧化乐果。辐照剂量小于6kGy时对混浊苹果汁品质无显著负面影响。      

Effect of temperature and PH value on the stability of bioactive compounds and antioxidative activity of juice from colour-fleshed potatoes

The colour-fleshed potatoes represent a good raw material for the extraction of juices with a high content of biologically active compounds and a high antioxidant activity. The blue-fleshed potatoes turned out to be a rich source of total polyphenols, as they had approximately 3.5 times higher content of identified anthocyanidins. Regardless of anthocyanin composition, all juices made of colour-fleshed potatoes were highly stable. Both, high temperature, exposure time to these temperatures, and medium pH had no significant effect on changes in total polyphenols content of potato juices. The juices examined, especially these made of blue-fleshed potatoes, demonstrated a higher ABTS+ stability during their heating than during pH changes. In addition, a higher antioxidant activity of juices was determined at neutral and alkaline than at acidic pH value of the medium.     

Effect of fruit blanching on phenolics and radical scavenging activity of highbush blueberry juice

Frozen highbush blueberries (Vaccinium corymbosum L.) were processed into juice, and the influence was studied of a steam blanching step, applied to fruit before milling, on the recovery of anthocyanin pigments and total cinnamates, in relation to the radical-scavenging properties of blueberry juices. Inactivation of PPO induced a significant recovery increase of anthocyanin and cinnamate contents. Furthermore juice from blanched fruits was more blue and less red than that obtained in the traditional way, due to the positive effect of the thermal treatment on the extraction of the most soluble anthocyanin pigments, which are also the most intense blue. Blanching of fruit greatly increased the radical-scavenging activity of the juice, in relation to the higher recovery of anthocyanin pigments and total cinnamates.     

Simulation and analysis of a sugarcane juice evaporation system

The production of sugar and alcohol is the main objective of the sugarcane processing industry. The evaporation of sugarcane juice has a high energetic cost and is usually performed in multiple-effect evaporators. The loss of performance during operation due to fouling makes the process more complex. In this study, modeling, simulation, validation, and analysis were performed for a sugarcane juice industrial evaporation system (IES) composed of a falling film evaporator followed by three short vertical-tube evaporators arranged in parallel. The IES model was developed using a commercial process simulator and validated with data from the plant. The IES had marked performance losses in the first 14 days of operation, mainly due to fouling in the first effect, with a 30% decrease in the evaporation rate.     

高压均质技术在果汁加工中的应用

果汁产品感官、营养品质提升及其安全性保障是其加工领域近年来亟待解决的关键难题和研究热点,而非热加工技术在杀菌的同时能最大限度地保留果汁原汁原味,其有望替代热加工技术.其中,高压均质技术从一种传统的均质化工艺逐渐发展成为非热加工技术而备受关注.基于前期的研究成果,该文从高压均质技术的发展历史和设备原理出发,对高压均质处理...