Conjugated triene oxidation products of alpha-farnesene induce symptoms of superficial scald on stored apples.

The sesquiterpene alpha-farnesene (1) and its conjugated triene oxidation products accumulate in the skin of apples after harvest and are implicated as the causal agents of superficial scald. Conjugated triene oxidation products and analogues were synthesized and applied to the surface of Granny Smith apples either as vapors or in squalane. Farnesyl hydroperoxide (2a), trienol (2b), endoperoxide (3a), dehydronerolidol (5), and cumyl hydroperoxide (4) all produced the symptoms of superficial scald when applied at nanomolar doses. Scald-inducing activity was dependent on the mode of application. Farnesyl hydroperoxide (2a) was the most active conjugated triene when applied directly to the apple skin. Trienol (2b) also induced scald symptoms and partially reversed the inhibition of scald caused by diphenylamine.     

Relationship of superficial scald development and alpha-farnesene oxidation to reactions of diphenylamine and diphenylamine derivatives in Cv. Granny Smith apple peel

Cv. Granny Smith apple fruit, treated at harvest with aqueous emulsions containing diphenylamine (DPA) and DPA derivatives, were evaluated for the peel disorder superficial scald (scald) after 6 months of cold storage at 1 degrees C plus 0 or 7 days at 20 degrees C. Metabolism of these derivatives and alpha-farnesene oxidation were also evaluated after 6 months. Derivatives substituted at the para position prevented scald, but scald developed on fruit treated with derivatives substituted in the amino, ortho, or meta positions. The extent of scald control was also dependent on the chemical nature of the functional group used to derivatize DPA. Hydroxylation of DPA and DPA derivatives during storage was not associated with scald control. Methoxylated DPA derivatives produced during storage resulted from O-methylation of C-hydroxylated derivatives rather than C-methoxylation of DPA. N-Nitrosodiphenylamine provided partial scald control, possibly resulting from its degradation to DPA, indicating that the amino hydrogen of DPA may be crucial for scald control. Results suggest that functional group position and chemical properties both contribute to the efficacy of DPA derivatives for scald control.     

Peroxidase activity and superficial scald development in apple fruit

The relationship between soluble peroxidase (EC 1.11.1.7; POX) activity and the development of a chilling-related disorder, superficial scald, was studied in three apple fruit (Malus x domestica Borkh.) systems: a White Angel x Rome Beauty population with progeny with different scald susceptibilities; Delicious from three harvests with progressively declining scald susceptibility; and the scald-resistant Idared and the scald-susceptible Law Rome. Differences in incidence and severity of scald in progeny from White Angel x Rome Beauty progeny tended to show relationships with POX activity at harvest, but, overall, associations were not consistent. However, greater scald incidence and lower POX activity were found in less mature Delicious fruit than in later harvested fruit. Also, the scald-resistant Iotadared had a much higher POX activity compared with the scald-susceptible Law Rome. A general hypothesis that POX activity is related to scald susceptibility was generally supported, but exceptions were observed.     

Temperature-dependent autoxidation of conjugated trienols from apple peel yields 6-methyl-5-hepten-2-one, a volatile implicated in induction of scald

Conjugated triene (CT) oxidation products of alpha-farnesene have long been thought to be involved in development of superficial scald in apple fruit. Early studies found that CT hydroperoxides and the volatile 6-methyl-5-hepten-2-one (MHO) are major in vitro autoxidation products of alpha-farnesene. However, it was recently shown that > or =99% of the oxidation products of alpha-farnesene that accumulate in apple peel are conjugated trienols (CTols), isomers of 2,6,10-trimethyldodeca-2,7,9,11-tetraene-6-ol. HPLC-purified CTols from fruit of two scald-susceptible cultivars, Granny Smith (GS) and Red Delicious (RD), were used to study autoxidation of these compounds in vitro. Incubation of CTols in sealed glass vials under air resulted in accumulation of MHO. Oxygen enrichment did not increase the amount of MHO produced. Regardless of which cultivar CTols were derived from, at 0 degrees C autoxidation yielding MHO was quite slow and linear, whereas at 20 degrees C MHO production was much more rapid, and after several hours the rate increased abruptly. However, CTols isolated from GS and RD fruit differed in the duration of the initial lag phase and the overall level of MHO generated at 20 degrees C. The sharp increase in MHO production occurred after 3 h with GS CTols and at about 12 h with RD CTols. Also, the yield of MHO from GS CTols after 6 h at 20 degrees C was nearly 6-fold greater than that from RD CTols after 20 h at 20 degrees C. The antioxidants butylated hydroxytoluene and diphenyamine reduced the yield of MHO by about 97%. Recent work has shown that MHO can induce scald-like symptoms in apple peel and that tissue sensitivity increases with time in storage. This may explain the correlation between high CTol levels and scald development, and why symptoms rapidly intensify when fruits are removed from cold storage.     

Multivariate analysis of superficial scald susceptibility on Granny Smith apples dipped with different postharvest treatments

Multivariate methods were used to present the results of different postharvest treatments applied to control superficial scald disorder in Granny Smith apples. In a two-season study, the treatments applied by dips were diphenylamine (DPA), Semperfresh (a sucrose ester coating) formulated alone or with either ascorbyl palmitate or n-propyl gallate, and CaCl(2). DPA correlated negatively with scald, whereas the rest of the treatments showed no clear relationship with the disorder. By means of partial least squares, the incidence of superficial scald after cold storage was shown to correlate with quality parameters (firmness and acidity), measured at the end of storage. In contrast, ethylene production did not appear as a relevant factor in the incidence of scald.     

喷硼对梨果硼、钙含量及石细胞形成相关酶活性的影响

以黄花梨为试验材料,分别于幼果期、膨大期和成熟期进行叶面喷施硼酸,研究外源硼对梨果实硼和钙含量、石细胞含量及相关酶活性的影响。结果表明:1）从叶面喷硼对果实吸收硼的短期效果来看,果实发育的不同时期叶面喷施硼酸均促进果实对硼的吸收,其各处理的促进效果顺序为幼果期果实膨大期果实成熟期,不同时期叶面喷施硼酸均提高了果肉中水溶态硼、半束缚态硼和束缚态硼的含量; 2）幼果期喷硼提高了梨果实的钙含量,而果实膨大期和成熟期喷硼降低了果实内的钙含量,但各时期喷硼处理均提高梨果肉细胞壁内的钙含量; 3）不同时期叶面喷施硼酸降低了梨果石细胞含量,果实过氧化物酶、多酚氧化酶和苯丙氨酸解氨酶活性也低于对照,且幼果期处理效果最佳。     

1-Methylcyclopropene interactions with diphenylamine on diphenylamine degradation, alpha-farnesene and conjugated trienol concentrations, and polyphenol oxidase and peroxidase activities in apple fruit

1-Methylcyclopropene (1-MCP) is a new technology that is applied commercially to inhibit ethylene action in apple fruit, but its interactions with existing technologies such as diphenylamine (DPA) for control of superficial scald development in fruit during and after storage is unknown. To investigate possible interactions between 1-MCP and DPA, Delicious apples were untreated or treated with 2 g L(-1) DPA, and then with or without 1 microL L(-1) 1-MCP. Ethylene production and respiration rates of fruit were measured immediately following treatment, and fruit was stored at 0.5 degrees C for 12 weeks. Internal ethylene concentrations (IEC), alpha-farnesene and conjugated trienol (CTol) concentrations, activities of peroxidase and polyphenol oxidase (PPO), and DPA levels in the skin of the fruit were measured at intervals during storage. 1-MCP reduced the rate of DPA loss from peel tissue so that by 12 weeks of storage concentrations of the chemical were 25% higher than in untreated fruit. 1-MCP, with and without DPA, markedly inhibited ethylene production and respiration rates, maintained low IEC and alpha-farnesene and CTol concentrations, while DPA had little effect on these factors except inhibition of CTol accumulation. Treatment effects on peroxidase and PPO activities were inconsistent.     

梨花粉和柱头发育与温度关系研究

考察环境温度对梨花发育的影响是引进蜜蜂为梨树授粉的前提。本研究以主栽品种‘砀山酥梨’及其授粉品种‘鸭梨’为试验材料,设置了8℃、12℃、20℃3种温度条件,考察‘砀山酥梨’开花动态、柱头可授性及‘鸭梨’散粉、花粉萌发、花粉管生长等指标,旨在为梨树合理利用蜜蜂授粉提供理论依据。结果表明:在8℃下,‘砀山酥梨’花朵全部开放所需时间达到144 h以上,柱头具有较强可授性出现时间为112 h,且可授期持续时间短,‘鸭梨’全部散粉时间为230 h,花粉萌发率显著低于20℃(P0.05),培养96 h到达花柱上部、中部、基部的花粉管数量分别为84根、55根、43根;12℃下,花朵全部开放时间为114 h,柱头出现较强可授性时间为88 h之后,‘鸭梨’全部散粉时间为158 h,花粉萌发速度较8℃快,但萌发率显著低于20℃(P0.05),培养96 h到达花柱上部、中部、基部的花粉管数量分别为111根、105根、92根;20℃时,‘砀山酥梨’开花所需时间为44 h,柱头可授性强,且可授期持续时间可达120 h,‘鸭梨’全部散粉所需时间为64 h,花粉萌发速度快,萌发率高,培养96 h到达花柱上部、中部、基部的花粉管数量分别为121根、120根、119根。20℃较12℃和8℃更适合梨花发育和蜜蜂采集。本试验结果为不同温度下梨花的开花生物学特性研究提供了科学依据,也为梨树蜜蜂授粉技术的应用奠定了基础。     

五九香梨贮藏期间挥发性化合物和理化性状的变化(英)

利用高效液相色谱法测定贮藏期间五九香梨的糖和有机酸的组成及变化,采用固相微萃取方式（SPME）进行萃取,并结合气相色谱和质谱（GC/MS）分析检测梨果实中的挥发性香气成分。得出以下主要结论：果糖是五九香梨的主要糖类,其次是葡萄糖和蔗糖。随着贮藏期的延长,果糖先有增加的趋势,在贮藏的第三个月内,果糖含量处于最高,而蔗糖和葡萄糖减少趋势不明显。五九香梨果实中的主要有机酸是苹果酸和柠檬酸,整个贮藏期间,柠檬酸和酒石酸含量处于上升趋势,苹果酸和奎宁酸含量在第一、二月贮藏期间增加,而后开始下降;莽草酸含量在贮藏期第一到第三阶段上升,而后略下降;琥珀酸含量在第一到第二阶段变化不明显,接着有上升的趋势,在第三阶段含量达到最高,第四和第五阶段略低于第三阶段;乙酸含量变化不明显。梨果实的硬度略有下降,贮藏的前3个月,可溶性固形物含量有上升的趋势,随后开始缓慢下降。五九香梨的主要香气成分化合物有乙酸己酯 (49.35%),乙酸丁酯 (19.56%),己酸乙酯 (5.16%),丁酸乙酯 (4.92%),乙酸乙酯 (1.08%),(E,Z)-2,4-癸二烯酸乙酯 (0.84%)等。在整个贮藏期间,部分香气成分随着贮藏期的延长而略有增加,尤其是酯类化合物。结果显示：果实硬度、可溶性固形物、糖、有机酸和香气的组成与变化对五九香梨果实的品质都有一定的影响。     

Toxicity symptoms and tissue levels associated with excess boron in pear trees

Abstract

High levels of B were applied to the soil around ‘Bartlett’ and ‘d'Anjou’ pear trees in a non‐irrigated orchard. B levels in the soil profile and in the flowers, leaves and fruit were monitored for 6 years. Levels of B in the soil dropped to below 2 ppm within 5 years following the application. By then all visible symptoms of toxicity had disappeared. The B content of ‘Bartlett’ tissues was always higher than that of ‘d'Anjou’ and the symptoms of toxicity were more severe. Under conditions of this research, full bloom blossom cluster levels and levels in the fruit at harvest time were better indicators of toxicity than were the levels in leaves. Boron levels in blossom clusters above 90 and 115 ppm and in fruit above 55 and 45 ppm for ‘d'Anjou’ and ‘Bartlett’ pears respectively were considered to be toxic.     

Evaluation of auraptene content in citrus fruits and their products

Auraptene quantities in Tanaka's 77 Citrus species (including 14 varieties and cultivars), 5 Fortunella species, one Poncirus species, 27 hybrids between Citrus species, and 51 intergeneric hybrids between Citrus and Poncirus have been evaluated. The genus Citrus has been divided into eight groups. Auraptene is found in all of the species of Cephalocitrus group, a part of the species of Aurantium group, and most of the species of Osmocitrus group. The Citrus species contain a small amount of auraptene in the juice sacs compared with in the peels except for Henka mikan (C. pseudo-aurantium), Ichang lemon (C. wilsonii), and a Hassaku (C. hassaku)-pummelo hybrid (Okitsu No. 39), which contain large quantities of auraptene in their juice sacs (0.23, 0.52, and 0.14 mg/g, respectively). The Hong Kong wild kumquat (F. hindusii) alone contains auraptene in Fortunella species. All of the Citrus-trifoliate orange (P. trifoliata) hybrids as well as the trifoliate orange contain a large quantity of auraptene in both the peel (16.57-0.51 mg/g) and the juice sac (10.32-0.15 mg/g). These hybrids are almost inedible. The Iyo (C. iyo)-trifoliate orange hybrid (IyP269) is edible and contains auraptene in the peel (1.49 mg/g) and in the juice sac (1.73 mg/g). Citrus fruit products, for example, brand-named grapefruit juice and marmalade, retain about 0. 1 mg and 0.3 mg/100 g of auraptene, respectively.     

Distribution of conjugated and free phenols in fruits: antioxidant activity and cultivar variations

Total and free phenolic contents of 16 commonly consumed fruits (comprising 9 apples, 4 pears, and one each of peach, plum, and kiwi fruit cultivars) were measured by Folin-Ciocalteu assay. Total phenol contents varied from 272 to 475 mg of CtE/100 g of fresh weight. Of the apple cultivars studied, Braeburn and Empire had the highest and lowest total phenol content, respectively. The apple cultivars ranked in the following decreasing order: Braeburn > Red Delicious > Crisp Pink > Granny Smith > Royal Gala > Bramley > Golden Delicious > Fuji > Empire. Among pear cultivars, the order was Forelle > Taylor's > Peckham's > Conference. Peach and plum equally had high contents. The percentage of conjugated phenolics ranged between 3 (Red Delicious) and 77% (Empire) of the total phenols. Comparison of different cultivars of the same fruit and between different fruits showed broad variations in both phenolic content and in vitro antioxidant activity; a weak correlation (R(2) = 0.58) was observed between the phenolic content of the fruits and the total antioxidant activity, as estimated by the FRAP assay. The calculated dietary intake of total, free, and conjugated phenols from average per capita consumption of apples and pears in different regions of the U.K. varied between 104-126, 53-64, and 51-62 mg of CtE/day, respectively.     

Cultivars of apple fruits that are not marketed with potential for anthocyanin production

The red coloration of apple skin is mainly due to anthocyanins that are reported to possess health benefits. The aim of the present study was to determine the anthocyanin content in three underutilized Malus pumila Mill cultivars, Cranberry, Kerr, and Niedzwetzkyana, and confirm their anti-inflammatory and antioxidant activities. Our analysis revealed that the three cultivars studied contained primarily cyanidin-3-O-glucosyl rutinoside (1) at >99%. The anthocyanin was purified by C-18 medium pressure liquid chromatography and characterized by NMR spectral methods. The quantification of anthocyanins in M. pumila cultivars revealed that Cranberry, Kerr, and Niedzwetzkyana contained 1.12, 0.55, and 0.36 mg/g of fresh weight of 1, respectively. The lipid peroxidation (LPO) and cyclooxygenase enzyme (COX) inhibitory activities of 1 in water were compared with the activities of cyanidin-3-O-rutinoside (2) and cyanidin-3-O-glucoside (3) found in cherries and berries. There is a significant increase in LPO and COX enzyme-inhibitory activities of anthocyanin when tested in water compared to using dimethylsulfoxide as the carrier. The LPO inhibition of anthocyanins 1, 2, and 3 were 53.3, 68.3, and 87.9, respectively, at a 0.25 microM concentration. They inhibited the COX-1 enzyme by 42.7, 45.2, and 50.4 and COX-2 by 52.7, 61.5, and 68.5, respectively, at 5 microM. The LPO inhibitory values for commercial standards, BHA, BHT, and TBHQ, were 85, 89, and 94%, respectively at 1 microM. Similarly, positive controls aspirin, celecoxib, and robecoxib inhibited COX-1 and -2 enzymes by 68.6, 40.7, and 0% and 26.6, 72.2, and 92.4%, respectively, at 60, 26, and 32 nM.     

Study of the polyphenolic composition and antioxidant activity of new sherry vinegar-derived products by maceration with fruits

Several experiments of maceration of a sherry wine vinegar with different fruits (orange, lemon, strawberry, grapefruit, and lime) have been carried out. After optimization (only peel, no heating and seven days as maximum time of maceration), parameters such as polyphenolic content, superoxide anion scavenging ability (related to antioxidant activity) and ascorbic acid content were determined in sherry wine vinegars macerated with two amounts of peel and for two maceration times (3 and 7 days). The analysis of variance pointed to a clear relationship (p<0.01) between type of fruit and amount of peel and polyphenolic content. The factor "time" was practically not significant for any polyphenol. Sherry wine vinegars macerated with different fruits exhibited higher superoxide anion scavenger ability, with the maximum values found for the vinegar macerated with lemon peel. The correlation analysis showed that the superoxide anion scavenger ability of the vinegars macerated, and thus their antioxidant activity, was highly correlated (p<0.01) with several polyphenols, especially with naringin, hesperidin, neohesperidin and gentisic acid and not with the ascorbic acid content.     

Effects of conjugated linoleic acid (CLA) isomers on oxygen diffusion-concentration products in liposomes and phospholipid solutions

Conjugated linoleic acids (CLAs) are a group of octadecadienoic acids (18:2) that are naturally present in food products and may have beneficial health effects. Liposomes and ethanol solutions were prepared by mixing synthetic phosphatidylcholines (PCs) with c9,t11-CLA, t10,c12-CLA, and linoleic acid (LA) in the sn-2 position into natural PCs from soybean, egg yolk, rat brain, and rat heart at 5 mol %. The oxygen diffusion-concentration products were measured using electron spin resonance spin-label oximetry methods. Individual synthetic PCs, the phospholipid matrix, and the tested lipid systems all exhibited influence on oxygen diffusion-concentration products during lipid peroxidation. Incorporating 5 mol % PC(c9,t11-CLA) into soy and egg yolk PC increased oxygen consumption in liposome suspensions while it was decreased in rat heart and brain PCs. On the other hand, PC(t10,c12-CLA) increased oxygen consumption in mixtures with egg yolk and rat heart PC but decreased it in soybean and rat brain PC. By comparison, PC(LA) decreased oxygen consumption in every case. In ethanol solutions, all of the synthetic PCs suppressed the capacity to generate peroxide radicals in the order of LA > c9,t11-CLA > t10,c12-CLA. In addition, PCs containing individual CLA isomers and LA differed in their capacities to react with and quench DPPH radicals in both ethanol solution and liposome, suggesting differences between CLA isomers and LA in DPPH radical-fatty acid interactions. Incorporation of CLA isomers and LA into dimyristyl-PC reduced the phase transition temperature from 23.6 to 23.1 and 23.3 degrees C, respectively. The results of this study provide evidence that the behavior of CLA isomers differs in the microenvironment of membranes possibly due to structural differences that affect the permeability of membranes to oxygen and lipid peroxidation.     

四季柚生育期叶片和果实中矿质元素含量变化的研究

本研究以四季柚为试材,定期测定果实发育周期内叶片与果实的矿质元素含量,研究四季柚叶片和果实矿质养分需求特征与相关性,为树体营养科学调控,优质高效施肥提供理论依据。结果显示,叶片生长过程中N、 P元素含量呈逐渐下降趋势,K、 Ca、 Mg、 B、 Zn含量呈先增后降趋势,S含量总体保持上升趋势,Fe含量呈现先降后稳再上升趋势,Cu含量总体较稳定,Mn含量呈现出先上升后下降再上升趋势; 果实生长过程中,N、 P、 K、 Ca、 S含量呈下降趋势,Mg含量呈现先升后降的趋势,微量元素中Fe、 Mn元素含量变化幅度较小,B、 Zn、 Cu元素含量变化趋势略有不同。叶片与果实之间矿质元素协同吸收作用较弱,而果实与果皮之间作用较强。研究表明,萌芽前应适当增施氮、 磷肥,6月中旬增施钙肥,7月中旬增施钾肥和镁肥,以及重视微量元素肥料的应用。     

Socio-economic status and health awareness are associated with choice of cooking oil in Costa Rica

OBJECTIVE: To examine the socio-economic and lifestyle determinants of cooking oil choice in Costa Rica during the last decade (1994-2004). DESIGN: Cross-sectional study. Subjects (total n = 2274) belonged to the control population of a large case-control study; they were recruited yearly. Data about type of oil used for cooking, dietary intake, socio-economic and demographic characteristics were collected. SETTING: A dietitian visited all subjects and conducted the interviews at their homes; all subjects lived in the Costa Rican central valley region. SUBJECTS: Adult, free-living, rural and urban Costa Ricans with no history of myocardial infarction and physical or mental disability. RESULTS: The odds of choosing soybean over palm oil increased significantly each year (P < 0.05) and was determined by high socio-economic status (SES) and variables that suggest health awareness (self-reported history of hypertension, high cholesterol, multivitamin use and intake of green leafy vegetables). The odds of choosing other unsaturated oils, namely corn and sunflower, over soybean oil also increased yearly (P < 0.05) and was associated with the same two factors (high SES and health awareness). Palm oil users remained in the lowest SES tertile and were more likely to live in rural areas. Across all SES tertiles, high health awareness determined the odds of choosing other unsaturated oils over palm oil, and soybean oil (P < 0.05).CONCLUSION: These data show that, in addition to SES, health awareness is associated with the selection of unsaturated oils over palm oil in a developing country undergoing transition. These data should be considered when targeting nutrition messages and policies that promote better dietary choices.     

Potential mechanisms of soil nitrogen content heterogeneity associated with biocrust development in drylands

Biological soil crusts (biocrusts) are complex communities of micro- and macro-organisms dwelling at the soil surface in dryland regions worldwide, which contribute to important ecological functions in these areas. Biocrusts may reach different developmental stages, associated to autogenic succession of specific phototrophic organisms. However, notwithstanding the large amount of existing literature, little is known regarding the relationship between biocrust stages of development and soil nutrient dynamics. In this opinion paper, we specifically focused on soil nitrogen, and compared the total nitrogen content and potential nitrogenase activity of different developmental types of biocrust (-covered) soils. Based on published reports, we looked at a possible relationship between nitrogen content at the soil surface and biocrust development, discussing the potential mechanisms leading to the observed soil nitrogen content heterogeneity. The results showed that a higher nitrogen content remained associated to the presence of moss-dominated biocrusts, and this biocrust morphotype was characterized by a lower potential nitrogenase activity compared to the cyanobacteria- and/or lichen-dominated biocrusts. We hypothesized that these seemingly contradictory findings might be attributed to three potential mechanisms: nitrogen inheritance, nutrient retention and nutrient transfer, which we hereby examined one by one. Altogether, our opinion supports the theory of biocrust succession from incipient cyanobacteria-dominated stages to more ‘mature’ stages dominated by mosses. We stress how the heterogeneous distribution of soil nitrogen, which is closely related with biocrust development and community types, eventually affects regional and even global nitrogen dynamic and storage.     

Distribution of betalain pigments in red blood cells after consumption of cactus pear fruits and increased resistance of the cells to ex vivo induced oxidative hemolysis in humans

Betalain pigments are bioavailable phytochemicals recently acknowledged as natural radical scavengers. This work, which extends previous research on the postabsorbitive fate of dietary betalains, investigated the distribution of betanin and indicaxanthin in red blood cells (RBCs) isolated from healthy volunteers (n = 8), before and during the 1-8 h interval after a cactus pear fruit meal, and the potential antioxidative activity of the pigments in these cells. A peak concentration of indicaxanthin (1.03 +/- 0.2 microM) was observed in RBCs isolated at 3 h after fruit feeding, whereas the concentration at 5 h was about half, and even smaller amounts were measured at 8 h. Indicaxanthin was not detected at 1 h. Betanin (30.0 +/- 5.2 nM) was found only in RBCs isolated at 3 h from fruit feeding. In comparison with homologous RBCs before fruit ingestion, a significant delay (P < 0.05) of the onset of an ex vivo cumene hydroperoxide (cumOOH)-induced hemolysis was evident in the RBCs isolated at 3 h (33.0 +/- 4.5 min) and at 5 h (16.0 +/- 2.0 min). Neither vitamins C and E nor GSH was modified in the RBCs at any time point. Blood collected from the same volunteers after a 12-h fasting was incubated with the purified betalains in the range of 5-25 microM, to enrich the erythrocytes with either betanin or indicaxanthin, and then the cells were exposed to cumOOH. When compared to the relevant nonenriched cells, the betalain-enriched erythrocytes exhibited an enhanced resistance to the cumOOH-induced hemolysis, which was positively correlated (r (2) = 0.99) to the amount of the incorporated compound. On a micromolar basis, betanin and indicaxanthin showed a comparable effectiveness. Taken together, these findings provide evidence that human RBCs incorporate dietary betalains and support the concept that these phytochemicals may offer antioxidative protection to the cells.