The antioxidant profile of three different peaches cultivars (Prunus persica) and their short-term effect on antioxidant status in human

Total polyphenols, carotenoids and vitamin C were assessed in three different peaches cultivars (Prunus persica): ‘Luisa Berselli’ (LB), ‘Stark Earlyglo’ (SE) and ‘Maria Serena’ (MS). Total antioxidant capacity of fruits and plasma antioxidant activity after ingestion of fruits were determined as Trolox equivalent antioxidant capacity (TEAC) and as plasma total radical-trapping potential (TRAP) respectively. The amount of polyphenols, carotenoids and vitamin C resulted to be generally similar in the three cultivars. TEAC, measured from harvest to 7 days postharvest, resulted to be influenced mainly by vitamin C content, whereas polyphenols and carotenoids seemed to play a secondary role. Although TEAC was similar in the three cultivars, only LB significantly increased the TRAP in human plasma at 1, 2 and 4 h after ingestion of peaches. Sugar moiety, condensed and glycoside phenols are suggested to be involved in the higher effect on plasma TRAP of LB.     

Effect of rosehip (Rosa canina L.) phytochemicals on stable free radicals and human cancer cells

BACKGROUND: The commercial development of plants as sources of antioxidants that can be used to enhance the properties of foods, for nutritional purposes and preservation as well as for prevention of oxidation‐related diseases, is currently of major interest. Rosehip (Rosa canina L.) is a rich source of vitamin C and polyphenols. RESULTS: Phytochemicals in rosehip tea were separated into three fractions: Fr1 (vitamin C, 39.17 mg kg^?1), Fr2 (flavonoids, 451.05 µg kg^?1) and Fr3 (phenolic acids, 504.69 µg kg^?1). Quercetin and ellagic acid were the most abundant polyphenolic compounds. Rosehip fractions, primarily rosehip flavonoids (EC₅₀ = 49 mg L^?1), showed high antioxidant activity towards 2,2‐diphenyl‐1‐picrylhydrazyl radicals (DPPH^?). Cell growth effects of rosehip fractions were assessed in HeLa, MCF7 and HT‐29 cell lines, with the lowest IC₅₀ values being determined for rosehip flavonoids, (80.63, 248.03 and 363.95 mg L^?1 respectively). However, the vitamin C fraction did not inhibit the growth of tested tumour cells. CONCLUSION: The results of this study confirm that vitamin C and flavonoids are responsible for the antioxidant activity of rosehip tea, while only polyphenols contribute to its antiproliferative activity. Copyright © 2011 Society of Chemical Industry     

Effect of chitosan and chitooligosaccharide on vitamin C and polyphenols contents in cherries and strawberries during refrigerated storage

The objective of this research was to investigate the effect of treatment with chitosan and chitooligosaccharide on vitamin C and polyphenols contents in cherries and strawberries during refrigerated storage. Chitosans and chitooligosaccharides, as well as vitamin C and polyphenols are associated with reduced risk of cardiovascular diseases and cancer. Synthesis of vitamin C in strawberries and loss of vitamin C in cherries were observed during refrigerated storage. The treatment with chitosan and chitooligosaccharides inhibits vitamin C synthesis in strawberries and promotes vitamin C synthesis in cherries. Lower values of anthocyanin content for strawberries and higher values of anthocyanin content for cherries treated with chitosan and chitooligosaccharide compared with anthocyanin content in control strawberries and cherries were found after 7 days storage at 4 °C. Total phenols content in strawberries decreased and in cherries increased after storage 7 days at 4 °C and more pronounced changes observed for samples treated with high molecular weight chitosan. The correlation between moisture content in treated and non-treated strawberries and contents of vitamin C, anthocyanin and total phenols was shown. No correlation between moisture content and content of vitamin C, anthocyanins and total phenols was found for cherries.     

Chemical composition and in vitro digestibility of some Spanish browse plant species

Samples of leaves, flowers and fruits of four browse species were collected from uplands in the province of León (northwestern Spain) at different sampling times (from spring till autumn). The browse species were Erica australis (Spanish heath), Cistus laurifolius (laurel‐leaved rock rose), Quercus pyrenaica (hoary oak) and Rosa canina (wild dog rose). A large variability in chemical composition and in vitro digestibility and gas production kinetics was observed among species and among sampling times within each species. The ranking order of the browse plants according to their in vitro digestibility and gas production kinetics was R canina > Q pyrenaica > C laurifolius > E australis. In the leaves of R canina and Q pyrenaica, crude protein content, digestibility and parameters of gas production tended to decrease throughout the growing season (P < 0.05 in most cases), whereas cell wall contents followed the opposite trend. Seasonal variations were less pronounced in the other browse species. There were significant (P < 0.05) correlations between in vitro digestibility and chemical composition of the browse plants, positive with the crude protein content and negative with the fibre fractions. Copyright © 2004 Society of Chemical Industry     

PHENOLIC COMPOUNDS AND ANTIOXIDANT POWER IN MINIMALLY PROCESSED SALAD

ABSTRACT

Phenolic content and antioxidant power of Lactuca sativa var. capitata (L.), Cichorium indivia var. latifolium (L.) and Eruca sativa (Mill.) were determined in fresh‐cut products during storage at 4C. In fresh‐cut leaves, storage did not affect the antioxidant power in escarole, whereas after 24 h, lettuce exhibited a transient rise in ferric‐reducing antioxidant power value (+50%), which was associated with increased phenol content. In rocket salad, the antioxidant power increased significantly just 1 h after cutting. The major phenols determined in escarole and lettuce hydroxycinnamic derivatives were chlorogenic acid, di‐caffeoylquinic and caffeoyltartaric acids, which increased significantly in fresh‐cut products of both species during storage. In rocket salad, only hydroxycinnamic and kaempferol derivates were found, and their content was not influenced by processing and storage even if it is probably related to the higher antioxidant power found for this species.

PRACTICAL APPLICATIONS

Many phenolic compounds are antioxidants that may contribute to reduce human diseases (e.g., cancer and heart diseases). The beneficial effects of a diet rich in vegetables have been partially attributed to an increased consumption of phenols with high antioxidant capacity. Processing vegetables (e.g., salad) for minimally processed products influences the antioxidant capacity of the tissues with different effects in relation to the species used.     

Assessment of Nutritional and Antioxidant Potential of Selected Vitality Strengthening Himalayan Medicinal Plants

Three Himalayan medicinal plants (Habenaria intermedia, H. edgeworthii, and Roscoea procera), widely used in vitality strengthening Ayurvedic formulations in India, were assessed for nutritional phytochemical constituents, and antioxidant activity. These target species emerged as a good source of minerals and possessed important micro elements. Individually, H. intermedia contained a high content of total phenols, thiamins, tannins, and calcium; R. procera was rich in potassium and iron content; and H. edgeworthii emerged as a good source of sodium. While various antioxidant assays provided evidences on the antioxidant potential of target species, greater antioxidant potential of H. intermedia as compared to the other two species was revealing. This study, therefore, highlighted the possibilities of harnessing nutritional and antioxidant potential of these species.     

Antioxidant activity of prebiotic ginseng polysaccharides combined with potential probiotic Lactobacillus plantarum C88

The potential prebiotic properties of Panax ginseng polysaccharides were studied using ten strains of Lactobacillus plantarum isolated from traditional Chinese fermented foods. These probiotics showed different growth characteristics depending on the extract and strain specificity. L. plantarum C88 showed higher cell densities and growth rate when cultured on P. ginseng polysaccharides. In the in vitro antioxidant assay, P. ginseng polysaccharides combined with L. plantarum C88 were found to possess significant DPPH, ABTS and superoxide anion radicals scavenging activities, and acidic polysaccharides showed better antioxidant activity than neutral polysaccharides. Furthermore, we evaluated the antioxidant effect of acidic P. ginseng polysaccharide combined with L. plantarum C88 strain in natural ageing mice in vivo. Acidic P. ginseng polysaccharide and L. plantarum C88 together inhibited the formation of malondialdehyde (MDA) and increased the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH‐Px), catalase (CAT) and total antioxidant capacities (T‐AOC) in a dose‐dependent manner.     

Probiotic fermented milk with high content of polyphenols: Study of viability and bioaccessibility after simulated digestion

This research evaluated the functional potential of a fermented milk made with Streptococcus thermophilus, a probiotic (Bifidobacterium animalis subsp. lactis) and pomegranate juice. Ferric‐reducing antioxidant potential, Trolox equivalent antioxidant capacity, scavenging effect on 1,1‐diphenyl‐2‐picrylhydrazyl free radical, oxygen radical absorbance capacity and Folin–Ciocalteu assays were used to estimate antioxidant activity and phenolic content. Probiotic survival, release and absorption of polyphenols were evaluated using in vitro gastrointestinal digestion. The concentration of polyphenols increased during digestion from 608 mg to 1417  gallic acid equivalents (GAE) /L. About 14% of polyphenols were found on the dialysate portion. The beverage presented high viability of probiotics with high survival rate after digestion (above 7 log cfu/mL).     

Antioxidant capacity and the relationship with polyphenol and Vitamin C in Actinidia fruits

Fruit of eight Actinidia genotypes were evaluated for antioxidant potential by several assays (DPPH, ABTS, ORAC, FRAP, SASR and MCC) and tested for their polyphenol composition and vitamin C contents. The significance analysis demonstrated that the antioxidant capacity of Actinidia eriantha and Actinidia latifolia fruits were significantly higher than that of other genotypes, which was about 3.3–8.7-fold higher than the Actinidia deliciosa cv. Hayward assayed in ABTS, DPPH, ORAC and FRAP methods. The total polyphenols and vitamin C contents showed a great variety amongst Actinidia genotypes and highly correlation with the total antioxidant capacity. It is concluded that significant genotypic difference exists in the total antioxidant capacity of Actinidia fruits. The wild A. eriantha and A. latifolia species have significantly higher antioxidant capacity than the cultivars of A. chinensis and A. deliciosa. Both total polyphenols and vitamin C are major contributors to the total antioxidant capacity in Actinidia fruit.     

天然抗氧化剂对斑点叉尾鮰内脏精炼鱼油的抗氧化效果研究

以过氧化值(POV)为指标,采用Schaal烘箱法研究了D-异抗坏血酸钠、迷迭香、茶多酚对斑点叉尾鮰内脏精炼鱼油的抗氧化效果,结果表明当抗氧化剂的添加浓度为0.02%时,抗氧化性能由大到小顺序为茶多酚>迷迭香>D-异抗坏血酸钠,茶多酚的抗氧化效果与其浓度呈剂量效应关系。添加维生素C和柠檬酸对茶多酚的抗氧化效果均有协同增效作用,但维生素C对茶多酚抗氧化能力的增效略大于柠檬酸。     

Bioactive compounds vs. organoleptic assessment of ‘smoothies’‐type products prepared from selected fruit species

The aim of this study was to determine the usability of fruits of selected species growing in Europe for the smoothies production. The organoleptic assessment, analysis of polyphenols and vitamin C content and antioxidant activity of products were determined. The panellists were most in favour of the smoothies containing cranberry, black currant and bilberry purees as well as juice from dog rose. Polymerised proanthocyanidins were found to predominate in most of the products, except for the black currant smoothies (B3) where the main group of polyphenols were anthocyanins. The content of proanthocyanidins was higher in the smoothies containing dog rose juice. The analysed products differed significantly in the content of vitamin C, as the highest content of ascorbic acid was determined in black currant smoothies with dog rose juice and bilberry puree (168.98 mg/100 g).     

Control of antioxidant beer activity by the mashing process

Beer is considered to be a good source of antioxidants. The composition and the quantity of the antioxidant compounds depend not only on the qualities of the raw materials, but also on the technology processes. Barley and malt represent the main source of antioxidant compounds in beer and the contribution of the hop antioxidants is lower. The influence of the mashing process on the antioxidant activity and polyphenol concentration is crucial. The antioxidant state of the sweet wort and the hopped wort are dependent on the technology processes and the raw materials used. The spontaneous sorption of polyphenols onto wort dregs and the polymerization of catechin and epicatechin lead to decreasing concentrations of individual polyphenols in the final beer. Two methods, based on electron spin resonance were used to determine antioxidant activity. These were the DPPH (2,2‐diphenyl‐1‐picryl‐hydrazyl) assay and the ‘lag time’ assay using free radical spin‐trapping agent PBN (N‐tert‐butyl‐α‐phenylnitrone). HPLC with CoulArray detection was used to measure the concentration of the individual polyphenols. This study focused on the antioxidant compounds and on the correlation of their concentrations with the values of total antioxidant activity depending on the mashing process. A good correlation was found between the decline in the concentrations of DPPH (expressed as ARA2) and concentrations of catechin and epicatechin (in sweet wort samples R² = 0.970, R² = 0.961, respectively, and in hopped wort samples R² = 0.949, R² = 0.956 respectively). Copyright © 2012 The Institute of Brewing & Distilling     

核桃多酚与蛋白质的作用方式及其抗氧化活性

以核桃为研究对象,将核桃碱提蛋白和酸提蛋白经溶剂作用后超滤,通过破坏核桃多酚-蛋白复合体间的作用力得到不同结合态多酚,测定多酚含量及其抗氧化活性,以期探究核桃酚类物质与核桃蛋白化学键结合机制。研究结果表明,在pH3.5和pH11条件下,游离态多酚含量分别为6.46、6.27 mg/g,占总酚含量的25.15%、29.77%,非共价结合态多酚含量分别为11.31、7.74 mg/g,占总酚含量的44.02%、36.75%,共价结合态含量7.92、7.05 mg/g,占总酚含量的30.83%、33.48%。由此可知,非共价结合为核桃多酚与核桃蛋白质的主要结合方式。在pH3.5和pH11条件下,游离态多酚对DPPH自由基的清除率分别为82.34%、43.68%,Fe²⁺螯合率分别为71.88%、49.96%,还原力吸光度值分别为1.157、0.857,脂质抗过氧化能力分别为47.71%、32.69%。在5种不同结合态多酚中,游离态多酚的抗氧化活性显著高于其他结合态多酚(p<0.05)。     

几种天然抗氧化剂在大豆油脂中的应用

以迷迭香、茶多酚和维生素E作为大豆油脂抗氧化剂,采用Schall烘箱法研究了三种天然抗氧化剂在大豆油脂中的抗氧化效果。结果表明当抗氧化剂的添加浓度均为0.01%时,茶多酚的抗氧化效果优于迷迭香和维生素E,茶多酚的抗氧化效果与其浓度呈剂量效应关系,但抗氧化效应的增加幅度在浓度为0.01%-0.04%范围内没有显著差异(P<0.05)。添加维生素E、维生素C或柠檬酸作为抗氧化助剂均能提高茶多酚的抗氧化效果,然而在添加浓度为0.01%时,其增加幅度之间也没有显著差异(P<0.05)。     

Tocopherols in rose hips (Rosa spp.) during ripening

BACKGROUND: Rose hips are used as a food ingredient and in health products. They are rich in various bioactive compounds such as carotenoids and vitamin C, but data on their vitamin E content (tocopherols and tocotrienols) are limited. In this study, four different species ofRosa were analysed for tocopherol and tocotrienol content during ripening in three different years. RESULTS: Only α‐ and γ‐tocopherol were found in the fleshy parts of the rose hips, and the tocopherol content and vitamin E activity varied depending on date of harvesting, species and year. The amount of vitamin E activity differed between species of Rosa and years, whereas the changes during ripening were relatively small. CONCLUSION: The choice of species must be considered if tocopherol content is to be optimised when rose hips are used as a food ingredient. Copyright © 2012 Society of Chemical Industry     

Level of Vitamin C,Polyphenols, and Antioxidant and Enzymatic Activity in Three Varieties of Kale (Brassica Oleracea L. Var. Acephala) at Different Stages of Maturity

The aim of this present study was to determine the level of vitamin C, L-ascorbic acid, polyphenols, antioxidant activity, peroxidase, polyphenol oxidase, and catalase in the leaves of three varieties of kale at different stages of maturity. Average values per 100 g of fresh matter were 102 mg of vitamin C (of which L-ascorbic acid constituted 97%) and 359 mg polyphenols; antioxidant activity was measured at 48.9% RSA (17.6 μM Trolox/g kale). Redbor₁ c.v. variety contained the highest levels of the analyzed constituents. Compared with the first stage of maturity, plants at the second stage showed increases of 6% in vitamin C; 28% in polyphenols; and 12% in antioxidant activity, whereas plants at the third stage showed 5, 48, and 22% increased values, respectively. Average POD activity was 7.58 ΔA/min/g, PPO 1.64 ΔA/min/g, and CAT 7.93 mg H₂O₂/min/g. PPO activity increased with the age of the plant. No consistent correlation was found between the stage of growth and the other enzymes.     

The intake of dietary fiber from grape seeds modifies the antioxidant status in rat cecum

The aim of this study was to measure the antioxidant activity and polyphenolic compounds in cecum and feces of rats fed with a grape seed concentrate. The grape concentrate was rich in indigestible compounds (dietary fiber, polyphenols and other associated compounds) which presented significant antioxidant activity. Polyphenols extracted by aqueous–organic solvents (extractable polyphenols, EPs) and non‐extractable polyphenols (NEPs) exhibited high antioxidant capacity as measured by the ABTS method. High correlations were found between antioxidant capacity values and EP (r² = 0.9608) and NEP content (r² = 0.9179). EPs and NEPs exhibited considerable antioxidant activity within the large intestine. Significant antioxidant activity was also found in feces derived from excreted EPs and NEPs. The grape fiber concentrate enhanced the antioxidant status in the large intestine. The antioxidant activity in the intestinal content should be considered when assessing the effects of dietary components on bowel diseases. Copyright © 2005 Society of Chemical Industry     

Germination as a process to improve the antioxidant capacity of Lupinus angustifolius L. var. Zapaton

Antioxidant capacity, measured by glutathione (GSH), superoxide dismutase-like activity (SOD-like activity), peroxyl radical-trapping capacity (PRTC), trolox equivalent antioxidant capacity (TEAC) and inhibition of lipid peroxidation in unilamellar liposomes of egg yolk phosphatidylcholine (PC) has been evaluated in raw and germinated lupin seeds (Lupinus angustifolius L. var. Zapaton) for 2, 3, 4, 5, 6 and 9 days. The content of antioxidant vitamins E and C has been also studied. The tripeptide GSH kept invariable for the first 5 days of germination and suffered a decrease of 20 and 78% after 6 and 9 days, respectively. During lupin germination, SOD-like activity increased slightly whilst PRTC doubled the amount after 9 days. TEAC values changed slightly up to 5 days of germination but after 6 and 9 days a significant increase (25 and 28%, respectively) was found. The oxidation of PC was inhibited by germinated lupin extracts and 9-day germination seeds provided the highest inhibition. Furthermore, germinated lupins provided more vitamin C, vitamin E activity and polyphenols than raw seeds, and the largest amounts of these bioactive compounds were found after 6 days of germination. Therefore, germination of lupin seeds (Lupinus angustifolius L. var. Zapaton) seems to be a good process to enhance their antioxidant capacity.     

Changes in ascorbic acid,polyphenol content and antioxidant activity in minimally processed cactus pear fruits

Cactus pear fruits (Opuntia ficus indica Mill, cv. ‘Gialla’) were manually peeled, then placed in plastic boxes sealed with a film with high permeability to gases, and kept at 4°C for 9 days. After 3, 6 and 9 days, chemical, physical, microbiological and sensorial parameters, total phenols, vitamin C and antioxidant capacity were determined. In-package gas concentrations were measured almost daily. Vitamin C and antioxidant capacity remained unchanged, while polyphenols decreased after 6 days in storage. Of the chemical parameters, only pH and acidity changed significantly, without however, adversely affecting sensorial properties. Microbiological growth was limited and fungal colonies were never visually detected.     

The antioxidant activity of selected cruciferous vegetables subjected to aquathermal processing

Kale (Brassica oleracea var. Acephala), broccoli (Brassica oleracea var. botrytis italica), Brussels sprouts (Brassica oleracea L. var. gemmifera) and green and white cauliflower (Brassica oleracea var. botrytis) were used to determine their contents of antioxidising agents: vitamin C, carotenoids and polyphenols. The examined vegetables were found to contain between 40.6 and 107 mg/100 g FW of vitamin C, from 0.04 to 2.7 mg/100 g FW of carotenoids, and from 144 to 773 mg/100 g FW of polyphenols. Cauliflower was found to contain the smallest amount of these compounds and kale the largest. The antioxidant activity of the vegetables was determined on the basis of their ability to extinguish the ABTS free radical. The aquathermal processes to which the vegetables were subsequently subjected reduced their antioxidant activity, mainly due to escape of vitamin C and polyphenols into the water environment. These losses were largest in the case of leafy or highly fragmented vegetables.