The effect of iron, tin, aluminium, and chromium on fading, discoloration, and precipitation in berry and red beet juices.

The effect of iron(II), tin(II), aluminium(III), and chromium(III) on the properties of red whortleberry, blackcurrant, and red beet juices was followed during storage for 10 months at 5 degrees C. The colour and pH changes were studied, and the precipitates formed were weighed and their metal contents assayed. Of the metals tested, only tin caused bluish discoloration in the berry juices. In the case of iron, aluminium, and chromium the low pH prevented this type of discoloration. In berry juices, some increases in colour intensity took place with the lowering of pH value, whereas in red beet juice the opposite change occurred. The colour changes due to storage appear to take place irrespective of the metals. Precipitation is enhanced in red whortleberry juice only by tin, and in blackcurrant juice by tin and iron. In red beet juice, precipitation is increased by the lowering of pH resulting from metal salt addition. In general, increase in the amount of metal added increased the metal content of the precipitate. Iron showed the greatest tendency to become bound in the precipitate, particularly in blackcurrant and red beet juice. The suitabilities of the metals for canning purposes are considered. Chromium, in particular, has interesting possibilities in view of the low degree of colour change associated with it.     

The role of iron and tin in discoloration of berry and red beet juices

Summary The color changes and precipitation induced by iron(III), iron(II), and tin(II) ions in juices from five northern berries containing different anthocyanins and from red beets were studied. Each series of juices, containing progressively increasing amounts of metal ions, was analyzed by spectra and TLC before and after storage for five weeks at 5° C. Iron (III) and tin(II) ions caused considerable discoloration and precipitation: the strong blue color in berry juices was due to tin (II) complexes with cyanidin and delphinidin glycosides, whereas iron (III) proved more harmful to red beet juices.

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Zusammenfassung Die Wirkung von Eisen(III)-, Eisen(II)- und Zinn(II)-ionen auf die Farbe und Bodensatzbildung von Säften aus 5 nordischen Beeren, mit verschiedenen Anthocyanfarbenkompositionen, sowie von Saft der roten Reete wurde untersucht. Jede Serie von Säften mit Zusätzen von Metallionen in ansteigenden Mengen wurde analysiert mit Hilfe der Spektren und durch Dünnschichtchromatographie am Anfang und nach 5wöchiger Lagerung bei 5° C. Eisen(III)-und Zinn(II)-ionen verursachten merkliche Mißfärbung und Bodensatzbildung. Die starke blaue Farbe in den Beerensäften war durch Komplexe von Zinn(II) mit den Cyanidin- und Delphinidin-Glycosiden hervorgerufen. Bei den Säften der roten Beete war Eisen(III)-ionen gefährlicher für die Farbe als Zinn(II)-ionen.

     

Lead, chromium, tin, iron and cadmium in foods in welded cans

The levels of lead, chromium, tin, iron and cadmium in fruit and vegetables in welded tinplate cans were determined by atomic absorption spectrophotometry. The levels found were compared with those in foods in soldered tinplate cans and fresh foods. The results show that the lead levels in foods in welded cans were much lower than those in similar foods in soldered cans. Foods in unlacquered welded cans contain much more lead, chromium and tin than foods in lacquered welded cans. The cadmium and iron levels in canned fruit and vegetables in welded cans were similar to those found in the corresponding fresh foods.     

The effect of high hydrostatic pressure processing on the extraction,retention and stability of anthocyanins and flavonols contents of berry fruits and berry juices

Anthocyanins and flavonols are types of phenolic compounds. Previous researches showed that phenolic compounds are relevant to the quality of plant‐derived foods and beverages. Any food‐processing technologies, which can preserve phenolic compounds after processing, should be taken into account for increasing the food quality. High hydrostatic pressure processing (HHPP) is a novel nonthermal process. There are some researches about the effect of HHPP on total phenolic content, total monomeric anthocyanins, kaempferol, myricetin and quercetin contents of berry fruits and berry juices in the literature. These studies showed that HHPP could possibly have a success potential in increasing the extraction, retention and stability of anthocyanins and flavonols contents of berry fruits and berry juices by preserving phenolic compounds after food processing. The aim of this review is to put forward how high hydrostatic pressure processing affects extraction, retention and stability of anthocyanins and flavonols of berry fruits and juices.     

The stability properties of golden beet and red beet pigments: influence of pH, temperature, and some stabilizers.

Golden beet (Beta vulgaris var. lutea) color was found to contain 8 components, of which the most important seemed to be vulgaxanthin-I and -II. Purified vulgazanthin -I solutions are easily degraded at high temperatures. The stability is, however, strongly dependent on pH: the stability is best at pH values between 5 and 6, the poorest at low pH values, but at pH 7 the stability is better than that of betanin. Vulgaxanthin-I is more stable in the raw extract than in a purified solution. EDTA, even in ppm amounts, was found to improve the stability of betanin. The effect was dependent on pH value, being most efficient at pH 2.0 and 5.0. Stability of vulgaxanthin-I was not improved by EDTA. Tannin did not show stabilizing influence. Ascorbic acid was found to have an unfavorable influence on stability, especially in the case of betanin.     

1997 UK Total Diet Study dietary exposures to aluminium, arsenic, cadmium, chromium, copper, lead, mercury, nickel, selenium, tin and zinc

Concentrations of aluminium, arsenic, cadmium, chromium, copper, lead, mercury, nickel, selenium, tin and zinc were determined in samples from the 1997 UK Total Diet Study and used to estimate dietary exposures of the general UK population. Population average dietary exposures to aluminium (3.4mg/day), arsenic (0.065mg/day), cadmium (0.012mg/day), chromium (0.10mg/day), copper (1.2mg/day), mercury (0.003mg/day), nickel (0.13mg/day), tin (1.8mg/ day) and zinc (8.4mg/day) are similar to those from previous UK Total Diet Studies and are below the appropriate PTWIs, PMTDIs and TDIs. Dietary exposure of the UK population (0.026 mg/day) to lead is falling as a result of measures taken to reduce lead contamination of the environment and food and is well below the PTWI. There has been little change in UK estimates of selenium exposure since the 1994 Total Diet Study but current estimates (0.039mg/day) are lower than those derived from earlier Total Diet Studies.     

冷冻对柑橘汁过滤性能的影响

过滤是果汁生产中固液分离的重要手段。冷冻至 - 2 2℃的柑橘汁的粘度从原来的 16 .5 m· Pa/s降低至 2 .80 m·Pa/s,室温下自然解冻后出现固液分离现象 ,经离心分离后 ,平均过滤速度是未冷冻过的柑橘汁过滤速度的 3倍 ,但冷冻温度对可溶性固形物含量基本没有影响     

澄清剂和酶对梅鹿辄葡萄酒澄清和脱色的影响

用明胶、蛋清、甘草、硅藻土、果胶酶、木瓜蛋白酶等对梅鹿辄红葡萄酒进行澄清。结果表明，这几种澄清剂和酶对葡萄酒都有一定程度的澄清和脱色作用，且随着澄清效果的提高，脱色渐趋严重。兼顾澄清和脱色两方面的因素得出，明胶和木瓜蛋白酶澄清效果好，脱色轻，两者的最佳用量分别为400～500mg／L和50～100mg／L。     

维生素K5对果汁防腐作用的研究

本文研究了维生素K5在果汁中的防腐抑菌作用。发现在较低的浓度下，维生素K5就具有很高的防腐抑菌效果；对经过巴氏杀菌处理的果汁，所需的浓度更低。与苯甲酸钠和山梨酸钾相比，其具有用量少、效果好，且不影响果汁风味的特点。对果汁颜色也不会造成明显影响，是极具发展前景的新型防腐剂。     

The effect of bunch shading on berry development and flavonoid accumulation in Shiraz grapes

Opaque boxes were applied to bunches of Shiraz grapes prior to flowering to determine the effect of sunlight on berry development and accumulation of flavonoids. The boxes were designed to maintain airflow while excluding light and thus to minimise changes in temperature and humidity. There was no significant effect of shading on sugar accumulation and in two of the three seasons studied there was no effect on berry weight. Chlorophyll concentration was much lower in the shaded fruit, which appeared pale yellow until veraison. The fruit coloured normally in the shaded bunches and in two of the three seasons there was no significant change in anthocyanin content. Expression of the gene encoding UDP-glucose flavonoid-3-O-glucosyl transferase (UFGT), a key gene in anthocyanin synthesis, increased after veraison and was similar in both shaded and exposed fruit. Anthocyanin composition was altered in the shaded fruit, which had a greater proportion of the dioxygenated anthocyanins, the glucosides of cyanidin and peonidin. Shading had no significant effect on the levels of condensed tannins in the skin or seeds of ripe fruit. Shading significantly reduced the levels of flavonols in the grape skin. In the exposed fruit, flavonol concentration was highest around flowering then declined as the berries grew, but there was an increase in flavonols per berry during ripening. When the boxes were applied before flowering, shaded fruit had much lower levels of flavonols throughout berry development and at harvest the level of flavonols were less than 10% of that in exposed fruit. A gene encoding flavonol synthase (FLS) was expressed at flowering and during ripening in exposed grapes but its expression was greatly reduced in shaded fruit. The results indicate that shading had little effect on berry development and ripening, including accumulation of anthocyanins and tannins, but significantly decreased flavonol synthesis.     

甜菜红色素提取工艺及其稳定性研究

目的:优化出甜菜红色素的提取工艺,并对甜菜红色素的稳定性进行研究。方法:首先研究影响提取甜菜红色素的几个因素,包括最佳提取液、料液比、提取时间、提取温度、提取p H,并通过正交试验设计与分析优化最佳工艺参数;然后研究了甜菜红色素在光照、温度、护色剂和各金属离子下的稳定性。结果:甜菜红色素提取的最佳工艺条件:在常温下,以水作为提取溶剂、提取料液比为1∶5(g/m L),时间为5h,p H为4.5,并进行二次提取;其中溶剂p H是影响提取效果的主要因素。甜菜红色素的稳定性研究结果表明:光照和温度对甜菜红色素稳定性影响较大;护色剂苯甲酸钠对甜菜红色素有保护作用,1‰苯甲酸钠护色效果最好。各金属离子对甜菜红色素色泽无明显影响,Ca2+对甜菜红色素稳定性影响最小、Fe3+和Cu2+对色素稳定性影响最大,同时Fe3+和Cu2+还可降低甜菜红色素的色调。结论:利用该工艺提取甜菜红色素简单可行,光照和温度对其稳定性影响较大,金属离子影响较小,此研究可为甜菜红分离提取提供理论指导和参考依据。     

The effect of red beet (Beta vulgaris var. rubra) fiber on alimentary hypercholesterolemia and chemically induced colon carcinogenesis in rats

The effect of diet supplemented with 5% and 15% cellulose or with 15% fiber isolated from red beet (Beta vulgaris var. rubra) on the development of alimentary hypercholesterolemia and chemically induced colon carcinoma was studied in male Wistar rats. Hypercholesterolemia was induced by a diet containing 0.3% of cholesterol and colon carcinoma was induced by treatment with dimethylhydrazine (20 mg/kg, 12 doses applied s.c. in one-week intervals). Fibrous matter isolated from red beet contained 89% fiber, of which 9% was in water soluble form. Animals were killed 14 weeks after the application of dimethylhydrazine (i.e. 26 weeks after starting on the diets). Red beet fiber diet (and not the increased cellulose intake) caused a reduction of serum cholesterol and triacylglycerol levels (by 30 and 40%, respectively) and a significant increase in the fraction of cholesterol carried in HDL. This diet induced also a significant decrease (almost by 30%) of cholesterol content in aorta. Higher cellulose content in the diet and even more so the administration of red beet fiber caused a significant reduction of conjugated dienes content in plasma, erythrocytes and in liver. Also observed were increases in the activities of superoxide dismutase and catalase in erythrocytes and in colon and activities of glutathione peroxidase and glutathione-S-transferase in liver. The presence of both higher cellulose content and red beet fiber in the diet significantly reduced the incidence of precancerous lesions--aberrant crypt foci--in the colon. The diet containing red beet fiber did not affect significantly the incidence of colon tumours although the number of animals bearing tumours was reduced by 30%.     

KT30与GA3对葡萄果粒增大的效应

１９９３￣１９９６年，用ＧＡ３，ＫＴ３０（ＣＰＰＵ）等激素对藤稔葡萄花后１０日进行增大处理，以ＫＴ３０的效果为好，ＧＡ３有增大作用，同时可提早上色。生产用ＫＴ３０ ５－１０ｐｐｍ＋ＧＡ３２５ｐｐｍ进行一次增大处理即可。     

Interaction between beet vinasse and iron fertilisers in the prevention of iron deficiency in lupins

BACKGROUND: Recycling of organic byproducts for use as soil amendments or fertilisers may enhance the productivity of soils. The aim of this study was to investigate the potential of sugar beet vinasse to correct iron chlorosis in crops when applied in conjunction with Fe fertilisers such as vivianite and ferrous sulfate (FS). An experiment involving two factors (Fe source and dialysed sugar beet vinasse (DBV) rate) was performed using white lupin (Lupinus albus L.) and calcareous sand as growing medium. RESULTS: Although vivianite provided lower chlorophyll contents than Fe‐chelate, dry matter production was not significantly different between the two Fe sources. Vivianite was more effective than FS in preventing iron chlorosis in white lupin, but not when DBV was applied. DBV significantly increased chlorophyll content in plants treated with FS after 3 weeks of growth. CONCLUSION: DBV increased the effect of FS in preventing iron deficiency chlorosis in white lupin. This was due, at least in part, to the inhibition of the precipitation of Fe oxides by organic compounds and to the increase in the content of Fe complexed by organic compounds in the growing medium, as revealed by sequential Fe fractionation. Copyright © 2010 Society of Chemical Industry     

茶叶中铝、铅、砷、汞、铬、镉含量的分析及危害评价

目的研究福建省市售茶叶中金属元素含量情况,通过分析茶叶中重金属含量情况,评估其对人体的健康风险情况。方法在福建省市场随机抽取不同品种茶叶98份,用微波消解法处理茶叶,电感耦合等离子体质谱法(inductively coupled plasma mass spectrometry,ICP-MS)检测茶叶中铝、铅、砷、汞、铬、镉的含量。结果98批市售茶叶中的铅、砷、汞、铬、镉5种重金属元素含量都在国家标准范围之内,目前暂无茶叶中铝含量相关限量标准,但其危害作用有限。98份市售茶叶中铅、砷、铬、铝检出率均为100%,铬、汞的检出率分别为95.9%、37.8%。各元素靶标危害系数(target hazard quotient,THQ)排名依次为铝>铬>砷>铅>镉>汞,危害指数(hazard Index,HI)为0.2589,铝对危害指数的贡献率为45.2%。按照不同茶叶种类进行分类,其危害指数排名依次为黑茶>乌龙茶>绿茶>红茶。按照茶叶产地进行分类,其危害指数排名依次为云南>福建>浙江。结论福建省市售茶叶中这6种金属元素存在一定程度的污染,但危害指数为0.2589,小于1,对人们的健康风险较低,但仍应持续监测茶叶中金属元素的含量情况。     

Impact of processing of red beet on betalain content and antioxidant activity

Red beet has high concentration betalains that are used as food colorants and food additives due to their health promoting properties. Redbeet is generally processed before consumption which influences the stability of betalains in turn which affects the acceptability and health properties. The objective of the study was to investigate the influence of processing techniques as microwaving, boiling, roasting and vacuuming on the red beet. The impact of processing was evaluated on the basis of belatains content and antioxidant activity of the processed samples. With spectrophotometric results betalains content were found to add up to 20% with vacuum treatment and also with microwave treatment of 900 W and 1800 W for 30 s up to7% and 19% respectively, however there was decrease in boiling and roasting treatments. With HPLC analyses the content of betanin seems to increase in microwave treatments with 450 W and 900 W but reduced with 1800 W. In the case of antioxidant activity there was 2 to 3 fold increase in boiling, roasting and microwave treatments as compared to the control.     

Heat stability of betacyanins in red beet juice and in betanin solutions

Summary The losses of red pigments during heating and their regeneration after heating were investigated in red beet juice and pure betanin solutions. The experiments were carried out with equal access of oxygen and a similar level of the initial content of the pigment. The presence of heavy metal ions in trace amounts had a great destructive influence on the pigment in solutions of pure betanin. In red beet juice compounds which decrease and compounds which increase the retention of betanin both occured during heating and regeneration. The group of compounds that decrease betanin stability included some metal ions, e.g. Cu(II) and Fe(III), along with certain amino acids. The negative influence of the metal ions in beet juice decreased probably due to the presence of metal-complexing agents.

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Stabilität der Betacyane während der Erhitzung des Rote-Beete-Saftes und der Betanin-Lösungen

Zusammenfassung Es wurden die Verluste an rotem Farbstoff im Rote-Beete-Saft und in Betanin-Lösungen während der Erhitzung mit der Regeneration des Farbstoffes in den erhitzten Proben verglichen. Die Versuche wurden bei gleichem Sauerstoffdruck und bei vergleichbarer Menge des Farbstoffes zu Beginn durchgeführt. Die Anwesenheit von Spuren an Schwermetallen in den Lösungen von reinem Betanin wirkt zerstörend auf den Farbstoff. Im Rote-Beete-Saft treten sowohl Verbindungen auf, die die Betanin-Retention während der Erhitzung und die Regeneration vermehren, wie auch solche, die sie vermindern. Zur Gruppe der Verbindungen, die die Stabilität von Betanin verringern, gehören die Ionen einiger Schwermetalle wie Cu(II) und Fe(III) und einige Aminosäuren. Die negative Wirkung der Metallionen im Saft wird wahrscheinlich durch Anwesenheit metallkomplexierender Verbindungen vermindert.