Antioxidant activity of commercial ready-to-drink orange juice and nectar

Total antioxidant activity (TAA), total phenolic compounds (TPC), and physicochemical characteristics of ready-to-drink orange juice and nectar from the most consumed brands available in Brazil were evaluated. TPC ranged from 18.7 to 54.2 mg of gallic acid/100 mL, and TAA varied from 57.88 to 349.32 μmol TEAC/100 mL ready-to-drink orange juice and nectar. The ascorbic acid content was the only physicochemical parameter that showed strong variation among packages and brands. Correlation of TPC with TAA showed that the higher the level of TPC the higher the TAA. Correlation of ascorbic acid content with TAA is higher for ready-to-drink orange juice than nectar. The same was found for the correlation of ascorbic acid content with TPC. The results confirm the contribution of the TPC to TAA.     

不同冷冻浓缩橙汁质量比较

对进口和国产的5个冷冻浓缩橙汁样品进行了分析,结果表明,国产橙汁的苦味重,酸度大,香气淡,而进口橙汁苦味淡,酸度适宜,香气较浓,因此进口橙汁的质量较好,但是国产橙汁Vc含量较高,两者的颜色差异不大。     

Effect of thermal pasteurization and concentration on carotenoid composition of Brazilian Valencia orange juice

Changes in carotenoid pigment content of Brazilian Valencia orange juices due to thermal pasteurization and concentration were studied. Total carotenoid pigment content loss was not significant after thermal pasteurization and concentration. However, thermal effects on carotenoid pigment contents, especially violaxanthin and lutein, were clearly observed and significant (P < 0.05). Pasteurization reduced the content of violaxanthin by 38% and lutein by 20%. The concentration process resulted in loss of lutein (17%). With the loss of lutein, β-cryptoxanthin became the major carotenoid in the pasteurized and concentrated juices. The provitamin A content of the juice (β-carotene, -carotene and β-cryptoxanthin) and the amount of zeaxanthin, which are considered to be active against age-related macular degeneration and cataracts, did not significantly decrease after pasteurization and concentration.     

橙汁的杀菌条件与橙汁稳定性的关系研究

通过采用高温短时杀菌（９５℃１５″）和水浴低温长时间杀菌（７５℃５’）两种方法对橙汁进行杀菌，对杀菌后的橙汁进行测定，发现橙汁中的几种沉淀前体物的含量变化有较大差异，并且得到了低温长时间杀菌（７５℃５’）优于高温短时（９５℃１５″）杀菌的结论。     

Degradation of anthocyanins from blood orange juices

Summary The degradation of anthocyanic pigments of fresh and industrial juices from blood oranges were studied during storage periods of a few days at −18 °C and 12 months at 4 °C in nitrogen. The change of anthocyanin pigments was followed by HPLC at 520 nm while the coloured polymeric pigments were fractionated by chromatography and characterized by their transformation indices and their reactivity with NaHSO₃. The results show that the process of polymerization is accompanied by production of chemical indicators of sugar and ascorbic acid degradation (furfural and hydroxymethylfurfural). It seems that the resulting polymeric compounds have structures different from those of the compounds formed during wine processing. Reactions between anthocyanic pigments and the intermediates of degradation of sugar and ascorbic acid in an acidic environment are the main causes of formation of these polymers.     

橙汁饮料中橙与橘成分双重实时荧光定量PCR检测技术

目的：建立双重实时荧光定量PCR检测橙汁饮料中橙与橘成分的方法。方法：通过设计和筛选橙、橘成分的引物和探针,检测水果寻找橙和橘的荧光扩增规律,利用橙和橘在FAM/VIC两个荧光通道上的比值差异来判定橙、橘成分。采用模拟橙汁掺杂柑橘汁试验验证方法检测的最低掺杂比例,对市售橙汁饮料进行检验来验证方法可行性。结果：纯橙水果在FAM和VIC两通道均有荧光扩增曲线,FAM/VIC通道荧光比值在0.5±0.2的范围内,而纯橘水果仅在FAM通道有很强的荧光扩增曲线。模拟掺杂试验中,可以检测出橙汁中掺有10%及以上的柑橘汁。结论：该方法能够检测橙汁饮料中的橙和橘成分,可用于市售橙汁饮料的鉴伪。     

Quantitative bioactive compounds assessment and their relative contribution to the antioxidant capacity of commercial orange juices

Dietary recommendations for healthy eating include the consumption of fruit juices whose health effects are ascribed, in part, to carotenoids, phenolic compounds and vitamin C. These bioactive compounds have been implicated in the reduction of degenerative human diseases, mainly due to their antioxidant potential. Orange juice is characterized by substantial accumulation (apart from ascorbic acid) of flavonoids and carotenoids. Commercial orange juice is the main human dietary source of antioxidant compounds in developed countries. The qualitative and quantitative determination of carotenoid, flavonoid and vitamin C content of Spanish commercial orange juices was achieved by high‐performance liquid chromatography. The health‐related properties of bioactive compounds contained in orange juice are based on their antioxidant activity. The antioxidant capacity of these juices was assessed by 2,2‐diphenyl‐1‐picrylhydrazyl stable radical scavenging and was compared with a freshly squeezed orange juice. In addition, the relative contribution of the different bioactive compounds to the antioxidant activity of orange juices was calculated. Total vitamin C was found to be the major contributor to the antioxidant potential of the orange juices studied, followed by flavonoid and carotenoid compounds. Ascorbic acid, total vitamin C and β‐cryptoxanthin content correlated positively with the free‐radical scavenging parameters. No significant differences, in terms of antioxidant capacity, were found between commercial traditional pasteurized orange juices and freshly squeezed orange juice. Copyright © 2003 Society of Chemical Industry     

Discriminant and principal component analyses to classify commercial orange juices based on relative amounts of volatile juice constituents†

Pasteurised orange juices and two types of commercial orange juice from frozen concentrate were differentiated based on the combined levels of 15–25 volatile constituents monitored in each of 44 juice samples. Multivariate analysis programs were used to calculate discriminant and principal component analyses and to display the results graphically. Since this group of samples was part of a nutritional database study, other parameters were included in an effort to improve discrimination of the types of juice samples monitored. Addition of °Brix and acid values improved the separation by principal component analysis of the three types of juice studied. Discriminant analysis provided better separation of juice types than did principal component analysis.     

Pectin methylesterase activity in juices from mandarins, oranges and hybrids

The pectin methylesterase (PME) activity of fresh and processed juices obtained from Valencia-late oranges, Clementine mandarins (cultivar Nules) and citrus hybrids (Ortanique) was studied. The PME activity was measured using a modification of the traditional method of Rouse and Atkins [1], based on the titration of carboxylic groups generated by PME during the hydrolysis of a commercial pectin solution. Instead of maintaining the pH at a given value by addition of NaOH, the maximum rate of pH decrease is used as measurement of the PME activity. An exponential decay function accurately represents the evolution of pH with time from a starting value of pH = 7.8 (optimum pH of PME activity for all assayed cultivars). This function allows an easy calculation of the PME activity. The total PME activity measured was similar in Clementine and Valencia-late juices, and approximately twice that of Ortanique juices. Ratios between thermostable and total PME activity were 4.0–8.4% for Clementine, 12.6–12.7% for Valencia-late and 24.2–34.2% for Ortanique juices. Soft heat treatments (70 °C, 30 s or 74 °C, 10 s) were enough to reduce the total PME activity of Clementine juices under the maximum residual level (10%) for commercial life of refrigerated juices, according to Irwe and Olson [2]. An erratum to this article can be found at     

市售橙汁抗氧化活性物质的研究

利用1,1-二苯基-2-三硝基苯肼（1,1-Diphenyl-2-picrylhydrazyl radical,DPPH）法和铁离子还原能力（Ferric reducing antioxidant power,FRAP）法、福林酚法以及超高效液相-四极杆飞行时间串联质谱（Ultra-high performance liquid chromatography-quadruple time-of-flight-mass spectrometry,UPLC-QTOF-MS）法,分别对市售橙汁的抗氧化活性、总酚含量以及抗氧化活性物质种类进行了研究,以达到明确橙汁的抗氧化活性有无,以及研究其主要抗氧化活性物质种类的目的。实验结果表明橙汁甲醇提取液具有清除DPPH自由基的能力[（1023±9.56）μg/m L,VCEAC（Vitamin cequivalent antioxidant capaciy）]和还原铁离子能力[（804.49±7.57）μg/m L,VCEAC],并且总酚含量丰富[（601.57±9.92）μg/m L,阿魏酸当量]。橙汁中鉴定出的主要的酚类化合物为柚皮素和橙皮苷,其中柚皮素是主要的抗氧化活性物质之一。      

基于UPLC-QTOF-MS代谢组学技术的NFC和FC橙汁差异成分比较

以橙汁为研究对象,利用顶空固相微萃取-气相色谱-质谱联用技术（headspace solid-phase microextraction-gas chromatography-mass spectrometry,HS-SPME-GC-MS）对不同橙油添加量的橙汁样品中的挥发性化合物进行定性定量分析,并利用感官测试对橙汁品质进行感官评价。同时对橙汁样品的稳定性进行快速分析。结果表明,添加橙油后的橙汁的香气化合物种类由19种增加至71种,主要包括萜类、醇类、酯类、醛类和酮类,且随着橙油添加量的增加,明显增加的化合物依次为D-柠檬烯、β-月桂烯、α-蒎烯、芳樟醇、侧柏烯和癸醛,其中橙油的关键性香气物质为萜类、醇类和醛类。当添加0.10%的橙油时,橙汁的滋味和整体风味最优。此外,添加不同比例的橙油显著地影响橙汁的稳定性,当橙油添加比例大于0.10%时,橙汁逐渐出现上浮下沉以及上浮严重的现象。本研究揭示了橙油对橙汁风味和稳定性的影响效果,可为今后橙汁加工和橙汁饮料开发提供参考依据。

     

Antioxidant activity and total phenolic,organic acid and sugar content in commercial pomegranate juices

Pomegranate fruit and pomegranate juices (PJs) have taken great attention for their health benefits in the last years. The purpose of this study is to analyse the antioxidant activities, along with the organic acid and sugar contents of pomegranate juices sold in the Turkish markets. In the present study, we evaluated total phenolics (TPs), free radical scavenging capacity by 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing capacity of seven commercial PJs. Organic acid and sugar contents of juices were determined by capillary zone electrophoresis. The results showed that commercial pomegranate juices had markedly high total phenolic contents and antioxidant capacity. Fructose (F) and glucose (G) were found as the major sugars. The major acids were citric and malic. From the F/G ratio, organic acid profiles, TPs, and antioxidant capacity values, a possible adulteration was detected in one of the juices.     

Cryostability of frozen concentrated orange juices produced by enzymatic process

The cryostability of frozen concentrated orange juices (FCOJ) produced by an enzymatic process (enzymatic juice) and a squeezing process (squeezed juice) was investigated. The results showed that after thawing the enzymatic juice was superior in colour stability and cloud stability to the squeezed juice. The influence of glass transition temperature and viscosity of juices on the cryostability was examined and the data showed that some physico-chemical changes/reactions in juices during storage were controlled by diffusion. The composition of carbohydrates in juices was determined by high performance liquid chromatography (HPLC). Results obtained showed that the dominant solutes (low molecular weight compounds) of FCOJ governed the glass transition temperature of juices while the smaller fractions (high molecular weight carbohydrates) of the total solids of FCOJ had significant effects on the viscosity of FCOJ.     

Effects of β‐cyclodextrin addition and farming type on vitamin C,antioxidant activity,carotenoids profile,and sensory analysis in pasteurised orange juices

The effects of organic farming, pasteurisation and addition of β‐cyclodextrin on the content of vitamin C, colour, carotenoids and antioxidant capacity of orange juices were studied. After pasteurisation at 98 °C (20 s) and subsequently storage along 145 days at room temperature (20–25 °C), the loss of vitamin C content was around 30%. The effects of the thermal process on carotenoid were clearly observed in lutein (loss of 16% for organic and traditional 8%) and especially β‐cryptoxanthin (loss of 30%). The colour changes were noticeable after the pasteurisation of orange juice and subsequent storage, with significant decreases being observed in lightness and the coordinate a*, while increases were found for coordinates b*, Hue* and chroma. The antioxidant capacity was 0.075 ± 0.01 and 0.053 ± 0.01 mMT mL^?1 for organic and conventional, respectively, with losses around 40% being found at the end of the storage period. The addition of β‐cyclodextrin caused no significant effects on the parameters under analysis. These data showed that strong thermal treatments, such as pasteurisation, adversely affect the nutritional and sensory quality of orange juices.     

Approaches to understanding the contribution of anthocyanins to the antioxidant capacity of pasteurized pomegranate juices

Influence of processing and storage conditions on anthocyanin stability and antioxidant activity of clarified and cloudy juices from arils of the ‘Mollar’ pomegranate variety was studied. Clarification process reduced the content of total monomeric and individual anthocyanins, and increased the antioxidant activity of pomegranate juice. Thermal treatments (65 and 90 °C for 30 or 5 s) decreased the percentage of polymeric anthocyanin form, increasing on the contrary the monomeric one. In any case, storage temperature was the main factor affecting all the parameters tested. Cyanidin 3-O-glucoside (Cy3G) was more instable than delphinidin 3,5-di (Dp3,5dG) and cyaniding 3,5-diglucosides (Cy3,5dG). A linear relationship was observed between oxygen radical absorbance capacity (ORAC) and total monomeric anthocyanins, suggesting that they contributed strongly to the antioxidant capacity. Results presented in this study show that hurdle technology (heating plus refrigeration) may help to reduce anthocyanin degradation in pasteurized pomegranate juice, avoiding a dramatic impact on its colour and preserving the beneficial effects of this specific bioactive compounds on human health.     

橙汁的果汁含量测定及与其6种特征指标相关性的比较

测定了19个橙汁样品的果汁含量,并比较了GB/T16771-1997《橙、柑、桔汁及其饮料中果汁含量的测定》中所规定的6个特征指标(钾、总磷、氨基酸态氮、L-脯氨酸、D-异柠檬酸、总黄酮)含量与果汁含量的相关性。结果表明,6个特征指标的含量和果汁含量都具有不同程度的相关性,其中钾含量与果汁含量相关性最大,相关系数达0.6873;氨基酸态氮含量与果汁含量相关性最小,相关系数为0.3768,但均未达到显著相关水平。     

芦荟果粒橙汁复合饮料的研制

以芦荟和橙子为主要原料,甜味、酸味剂等为辅料,采用正交实验设计,确定了芦荟果粒橙汁符合饮料的最佳配比,制成酸甜适度,口感爽滑的悬浮饮料。结果表明,当芦荟果粒6%、橙汁15%、白砂糖4%、柠檬酸0·16%时,生产出的产品感官评定结果好,芦荟果粒悬浮均匀。      

Determination of phenolic composition and antioxidant capacity of blood orange juices obtained from cvs. Moro and Sanguinello (Citrus sinensis (L.) Osbeck) grown in Turkey

The phenolic compounds and antioxidant capacities of orange juices obtained from cvs. Moro and Sanguinello (Citrus sinensis (L.) Osbeck) were determined. A high-performance liquid chromatographic method coupled with diode-array detection was used to identify and quantify phenolic compounds of the orange juices. A total of 18 phenolic compounds were identified and quantified in Moro and Sanguinello orange juices, including hydroxybenzoic acids (2), hydroxycinnamic acids (5), flavanones (5), and anthocyanins (6). It was observed that total phenolic content of Moro juice was higher than that of Sanguinello juice. Ferulic acid was the most dominant hydroxycinnamic acid and cyanidin 3-(6″-malonyl glucoside) and cyanidin 3-glucoside were the most dominant anthocyanins in both cultivars. Antioxidant activities of orange juices were measured using the DPPH^· (2,2-diphenyl-1-picrylhydrazyl) method. According to DPPH^· assays, the antioxidant capacity of Moro juice was found to be higher than that of Sanguinello juice.