A comparison of some chemical and physical properties of alkali lignins from grass and lucerne hays before and after digestion by sheep

The chemical and physical properties of alkali lignins from a grass hay and a lucerne hay were studied, before and after digestion by sheep. A greater proportion of the total grass lignins was dissolved by alkali than with the lucerne lignins but digestion increased this proportion with both species. Of the lignin dissolved by alkali, less of it was precipitated on acidification when faeces (50–70%) were compared with the undigested hays (86–92%). Extraction of lignins with boiling alkali produced a lignin with the smallest amount of amino acids but considerably altered the chemical structure as revealed by nuclear magnetic resonance (n.m.r.). Trypsin treatment of a cooler alkali extract was less effective in reducing amino acid contamination but did not alter the structure. Compared with the grass alkali lignins, the lucerne lignins had more total but fewer aromatic protons, fewer groups reacting with N-2,6-trichloro-p-benzoquinone imine, ionisable hydroxyl groups and fewer methoxyl groups. On Sephadex G-200 gel chromatography, three peaks were apparent with the lucerne, but only two with grass lignins. Both plant lignins showed large amounts of highly shielded n.m.r. protons but there were more with lucerne. Infrared spectra suggested that they were probably due to methyl groups. Digestion had very little effect on the n.m.r., ultraviolet or infrared spectra or the molecular weight distribution of the isolated lignins. It may have reduced the numbers of groups, reacting with N-2,6-trichloro-p-benzoquinone imine with the grass and two maize samples examined, but appeared to have the opposite effect with the lucerne.     

Roles of structural phenylpropanoids in forage cell wall digestion

Phenolic constituents (lignins and phenolic acids) and carbohydrates are assembled in a tight architecture which differs according to the plant species. During cell wall digestion, the hydrolysis kinetics differ between carbohydrates and seem to depend chiefly on the content and organisation of tissue phenolics. Among the phenylpropanoids, ferulic acid is released more quickly than p-coumaric acid. Lignins remain largely in the cell walls. They also undergo transformations, chiefly solubilisation as lignin-carbohydrate complexes. The limiting effect of lignins on cell wall degradation increases with increasing content. However, their effect on degradation might also depend on qualitative factors such as lignin structure and polymer organisation in walls and tissues. When various grasses (normal and selected genotypes), or grasses and legumes are compared, correlations between certain factors such as lignin uncondensed fraction, syringyl units or phenolic acids contents and cell wall degradation emerge but not clear causal relationship has been shown. Nonetheless, other structural characteristics, related to the alkali reactivity of lignins, seem to have a stronger influence on cell wall degradation. Phenylpropanoids seem to act mainly as a physical and (bio)chemical barrier to the action of the microbial enzymes. In addition, their reactivity as phenolic compounds and their hydrophobicity seem to play a role. Digestion is not limited only by phenolics. The factors that limit glycanolysis—the accessibility, crystallinity and capillary structure of cellulose and the branching of hemicelluloses—seem to have little or no effect on cell wall degradation in vivo. In contrast, other antiquality substances (tannins, cutin and silica), plant antomy, environmental factors, factors modulating microbial growth and animal physiology influence cell wall utilisation. Future research in this field should focus on the effects of phenolic structure and of cell wall and tissue organisation on carbohydrate degradation.     

Changes on Content,Structure and Surface Distribution of Lignin in Jute Fibers After Laccase Treatment

Effect of laccase treatment on the content, structure, and surface distribution of lignin in jute fibers were fundamentally investigated. Four percent lignin was removed from jute fibers via the laccase treatment. The residual lignin in the laccase-treated jute fibers showed increased molecular weights, which indicated polymerization between lignins on jute fibers. Meanwhile, the phenolic hydroxyl content in lignin decreased during the laccase oxidation accompanied by demethylation of methoxyl groups and generation of carbonyl groups. Due to the degradation and subsequent polymerization of lignin by laccase, the bulgy lignins on jute fiber surfaces were redistributed, which made the surface neat and glossy.     

The comparison of chemical and structural differences of Caribean pine (Pinus caribea L.) wood and bark lignin

The presented paper deals with some chemical properties of Caribean pine wood and bark lignin. In order to obtain necessary data, the following operations and analyses were performed: dioxane lignin isolations, determination of Klason lignin, determination of methoxyl, carboxyl and phenolic hydroxyl groups in dioxane lignins and the nitrobenzene oxidation of both compared lignins and of the risidues remaining after dioxane lignins extraction. The oxidation products were analysed by GLC. The experimental data show that there are moderate differences between compared lignins.     

Biological variability in lignification of maize: Expression of the brown midrib bm2 mutation

The cell wall phenolic components in the internodes of three maize genotypes, namely normal, bm2 and bm3 maize, were determined. The bm2 and bm3 brown midrib mutations lowered the lignin content of the bottom, middle and top internodes to a similar extent. However, unlike bm3, the bm2 trait did not induce a sharp reduction of the level of ester-bound p-coumaric acid in maize internodes. The other main alkali labile phenolic acid, ferulic acid, reached similar levels in the three genotypes. The main difference between bm2 and bm3 mutations occurred in the alkyl aryl ether linked structures of the lignin component. In contrast to bm3 lignins, which are characterised by a low syringyl content, the bm2 lignin had a lower content of guaiacyl units than lignin of normal maize internode. Consequently, the syringyl/guaiacyl molar ratio of bm2 lignin gave higher values (2.7–3.2) than those from either normal (0.9–1.5) or bm3 lignins (0.3). The alkali solubility of lignin was also compared between the three genotypes. Incorporation of the bm3 trait in maize led to a high recovery of alkali soluble lignin whereas the bm2 lignin had a similar solubility to the normal one in 2 M NaOH. The monomeric composition of the alkali soluble lignins was consistent with the non-condensed structures of the in-situ polymer. Although the bm3 and bm2 mutations had different effects on lignification, the modification of the cell wall phenolic level was also found in the bm2 maize stem as previously studied.     

Combining quality and antioxidant attributes in the strawberry: The role of genotype

The nutritional value of fruit has been widely studied and is demanded by consumers, especially for protection against cardiovascular disorder, cancer and other diseases, as well as for general health benefits. These benefits can also be ascribed to the total antioxidant capacity (TAC) of fruit.Fruit nutritional quality can be described by a standard quality parameter and the analyses of nutritional parameters, such as antioxidant capacity (and specific related compounds). In this study, firmness, colour, soluble solids content and titratable acidity were considered as quality parameters and TAC and total phenolic content as nutritional parameters. All these attributes were screened in 20 strawberry genotypes (cultivars and selections) for the selection of new improved genetic material (offspring) originating from different cross combinations, including an F1 Fragaria virginiana spp. glauca among parents.Results indicate that the effect of the genotype on strawberry nutritional quality is stronger than that of the cultivation conditions. However, commercial cultivation did not show a high range of variation of fruit nutritional quality, particularly for the nutritional parameters.The study of offspring originating from different cross combinations showed that fruit nutritional quality can be considered an inheritable trait and that the variability of fruit nutritional quality among commercial cultivars can be improved by breeding.Finally, results demonstrate the role of F. virginiana spp. glauca as an important genetic source of the fruit nutritional quality.     

Effects of Accelerated Storage on the Quality of Kenaf Seed Oil in Chitosan‐Coated High Methoxyl Pectin‐Alginate Microcapsules

The objective of this research was to study the oxidative stability and antioxidant properties of microencapsulated kenaf (Hibiscus cannabinus L.) seed oil (MKSO) produced by co‐extrusion technology upon accelerated storage. The combination of sodium alginate, high methoxyl pectin, and chitosan were used as shell materials. The oxidative stability of the kenaf seed oil was determined by iodine value, peroxide value, p‐Anisidine value, total oxidation (TOTOX), thiobarbituric acid reactive substances assay, and free fatty acid content. Total phenolic content, 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulphonic acid) cation radical‐scavenging assay and 2,2‐diphenyl‐1‐picrylhydrazyl radical scavenging assay were used to examine the antioxidant properties of oils. Oxidative stability tests showed that bulk kenaf seed oil (BKSO) was oxidized significantly higher (P < 0.05) than MKSO. The total increment of TOTOX value of BKSO was 165.93% significantly higher (P < 0.05) than MKSO. Co‐extrusion technology has shown to be able to protect kenaf seed oil against lipid oxidation and delay the degradation of natural antioxidants that present in oil during storage.     

Selected bioactivities of Vaccinium berries and other fruit crops in relation to their phenolic contents

Antioxidant activity, urinary tract protective activity, and cardioprotective anti‐platelet effects are among the bioactivities associated with dietary phenolics. These bioactivities were measured in vitro in fruit extracts from seven Vaccinium species and five non‐Vaccinium species to determine their relationship to total phenolic content and to anthocyanin and proanthocyanidin content. Berries belonging to the genus Vaccinium were particularly high in antioxidant activity and urinary tract protective anti‐adhesion activity, while anti‐platelet activity varied among species. There was a positive relationship between antioxidant activity (using the oxygen radical absorbing capacity (ORAC) assay) and both the total phenolic (R² = 0.76) and anthocyanin content (R² = 0.43) of the fruit, although there was no relationship between ORAC and proanthocyanidin content. There were no relationships between anti‐adhesion activity and total phenolic content, anthocyanin content, or proanthocyanidin content. Likewise, no relationships were observed between anti‐platelet activity and total phenolic content, anthocyanin content, or proanthocyanidin content. These results suggest that while antioxidant properties are characteristic of all fruit phenolics, in vitro anti‐adhesion and anti‐platelet bioactivities may be due to less abundant phenolic subgroups. Copyright © 2007 Crown in the right of Canada and Society of Chemical Industry     

Tannin levels in leaves of some oak species at different stages of maturity

Total phenolics, condensed tannins, degree of polymerisation, protein precipitation capacity, protein precipitable phenolics and specific activity (protein bound per unit tannins) were determined in the leaves of four oak species at different stages of maturation (4 days old to 1 year old). The content of total extractable phenols was higher in younger leaves in Quercus ilex Linn, Quercus semecarpifolia Sm and Quercus serrata Roxb, whereas in Quercus glauca Thumb the content was higher in the mature leaves. In all species studied, condensed tannins increased with maturation. Protein precipitation capacity had a trend similar to that of total phenols. In Q serrate and Q semecarpifolia the apparent degree of polymerisation increased, and the content of protein precipitable phenolics and specific activity decreased as the leaves matured. The decrease in protein precipitation capacity with maturation in these two species may be explained by both the decrease in the content and the change in the nature of phenols capable of binding proteins. Protein precipitation capacity was not detectable in Q ilex leaves. Protein precipitation capacity in the mature leaves decreased in the order of Q serrata > Q semecarpifolia > Q glauca > Q ilex.     

Chemical Composition and Antioxidant Capacity of Brazilian Passiflora Seed Oils

The seed oils of different varieties of 4 Passiflora species cultivated in Brazil were analyzed and compared regarding their physicochemical parameters, fatty acid composition and the presence of minor components, such as phytosterols, tocopherols, total carotenoids, and phenolic compounds. The antioxidant capacities of the oil extracts were determined using the 2,2'azinobis [3‐ethylbenzothiazoline‐6‐sulfonic acid] and oxygen radical absorbance capacity methods. The results revealed that all studied Passiflora seed oils possessed similar physicochemical characteristics, except for color, and predominantly contained polyunsaturated fatty acids with a high percentage of linolenic acid (68.75% to 71.54%). Other than the total phytosterol content, the extracted oil from Passiflora setacea BRS Pérola do Cerrado seeds had higher quantities (% times higher than the average of all samples), of carotenoids (44%), phenolic compounds (282%) and vitamin E (215%, 56%, 398%, and 100% for the α‐tocopherol, β‐tocopherol, γ‐tocopherol, and δ‐tocopherol isomers, respectively). The methanolic extracts from Passiflora setacea BRS Pérola do Cerrado seed oil also showed higher antioxidant activity, which was positively correlated with the total phenolic, δ‐tocopherol, and vitamin E contents. For the first time, these results indicate that Passiflora species have strong potential regarding the use of their seeds for oil extraction. Due to their interesting composition, the seed oils may be used as a raw material in manufacturing industries in addition to other widely used vegetable oils.     

Phenolic acids and flavonoids profiles of extracts from edible wild fruits and their antioxidant properties

In this study, the total phenolic, total flavonoids, phenolic compounds, the mineral content, and antioxidant activity of fruit extracts of seven wild species (Crataegus monogyna Jacq., Prunus spinosa L., Rosa canina L., Hippophaë rhamnoides L., Rubus fruticosus L., Prunus padus, Cornus mas L.) were investigated. The results indicated significant differences (p < 0.05) in the total phenolics and total flavonoids content, between the seven analyzed species. These ranged from 184.69 to 727.29 mg GAE/100 g FW and 17.27 to –165.55 mg QE/100 g FW, respectively. The antioxidant activity found in fruits was not directly affected by the total phenolic content (TPC). This activity was linked to a larger extent to the type of individual phenolic compounds and to a lesser extent to the TPC, because fruits with higher TPC have not always presented the highest values of antioxidant activity. HPLC analysis of methanolic extract showed the presence of phenolic acids (i.e. gallic, vanillic, chlorogenic, caffeic, syringic, p-coumaric, ferulic, sinapic, salycilic, elagic, and trans-cinnamic) and flavonoids (i.e. catechin, epicatechin, rutin, myricetin, and quercetin). Significant differences (p < 0.05) were observed in each individual mineral between fruits from wild flora. The fruits tissues of wild species turned out to be a good source of calcium (Ca), magnesium (Mg), sodium (Na), iron (Fe), manganese (Mn), copper (Cu), chromium (Cr), zinc (Zn), and boron (B). The results demonstrated that wild species possessed great potential for food production as sources of bioactive compounds such as phenolic compounds and minerals, for food supplements or functional foods.     

Comparative characterisation of dioxane-soluble lignins released by ball milling and by sheep digestion from forage grasses

Faecal soluble lignin (FSL), extracted from the faeces of sheep that received orchardgrass and timothy, were compared with 90% dioxane-soluble lignins released by ball milling (MHL) and by subsequent enzymatic hydrolysis (EHL) from the same grasses. FSL contained much less carbohydrate and esterified p-coumaric and ferulic acids than MHL and EHL. Although no considerable differences were found in the yields of vanillin and syringaldehyde produced by nitrobenzene oxidation, the molar ratio of syringaldehyde to vanillin was higher for FSL than for MHL and EHL. Such differences in chemical properties among the lignin preparations were confirmed by ¹³C-NMR spectroscopy. FSL had a lower molecular size compared with MHL and EHL. Results indicated that syringyl-rich lignin fragments with less phenolic acid esters, probably depolymerisation products of the grass lignins, were released by digestion in sheep from the forage grasses.     

Phenolic Content and Antioxidant Activity of Germinated and Cooked Pulses

Five commonly consumed pulses, Mah (Vigna mungo), Green mung (Vigna radiata), Arhar (Cajanas cajan), Masur (Lens esculantus), and Moth (Vigna aconitifolia), were studied for their total phenolic content and antioxidant activity after germination (12 and 24 h) and pressure cooking. Arhar had the highest total phenolic content (6.71 mg ferulic acid/g flour) whereas Moth had the least (1.54 mg/g). All pulses, except Moth, showed a significant decrease in total phenolic content after germination. The antioxidant activity of the pulses varied from 10.61 to 36.38% (DPPH radical scavenging activity), which significantly decreased with germination in all pulses except Moth. The total phenolic content highly correlated with the antioxidant activity in the pulses. Cooking lowered the total phenolic content by 10–45% and antioxidant activity by 27–68% in the control and germinated pulses.     

Characterisation of dragon fruit peel pectin extracted with natural deep eutectic solvent and sequential microwave-ultrasound-assisted approach

In this research, the physicochemical characteristics (proximate and chemical compositions, monosaccharides profiles, chemical structures, antioxidant activities and rheological properties) of dragon fruit peel pectin extracted with the solvent system of choline chloride-glucose-water (5:2:5) and sequential microwave-ultrasound-assisted approach (PC-MUAE), were evaluated, and then compared with those of the commercial pectin and other products from various extraction methods. No remarkable differences in the FTIR spectra of the commercial and extracted samples were observed, leading to the fact that the derived polysaccharides were pectin. The commercial pectin possessed a bright-yellow colour, while extracted pectin was yellow to brownish. Moreover, the facade of the latter under SEM was rough with miniature heterogeneous fragments. PC-MUAE was categorised as high methoxyl pectin with the degree of esterification of 59.76% and as a pseudoplastic substance with neutral pH (6.42), average level of solubility (73.90%), high equivalent weight (680.6 g mol⁻¹), high molecular weight (5.05 × 10⁵ Da), high antioxidant activities (total phenolic content of 8.14 mg of gallic acid equivalent/g pectin and 2,2-Diphenyl-1-picrylhydrazyl free radical scavenging capacity of 2.41 µmol Trolox equivalent/g pectin) and high viscosity at all tested domains of shear rate as compared with those of the commercial product and others from various methods. The anhydrouronic acid content of PC-MUAE was 64.28%, approximately to the minimum level (65%) proposed by FAO and EU. There were arabinose, galactose, glucose, mannose, rhamnose and xylose detected in extracted pectin. Consequently, PC-MUAE has the potential characteristics of high methoxyl pectin for the food industries.     

Fruit Phenolic Composition of Different Elderberry Species and Hybrids

The aim of this study was to investigate a detailed composition and content of phenolic compounds in fruits of 4 elderberry species (Sambucus nigra, S. cerulea, S. ebulus, and S racemosa) and 8 interspecific hybrids. Hydroxycinnamic acids (HCAs) represented the major share of phenolics in analyzed elderberries; caffeoylquinic and p‐coumaroylquinic acids were most abundant. Flavanols (catechin, epicatechin, and different procyanidins) were the second major phenolic group detected in range from 2% to 30% of total analyzed phenolics. From the group of flavonols, 13 different quercetin glycosides, 7 kaempferol glycosides, and 8 isorhamnetin glycosides have been quantified. Rutin was the major flavonol in all studied genotypes. S. ebulus was characterized by the highest level of total HCAs, catechin, epicatechin, and most flavonols. Some elderberry hybrids, for example JA × RAC, CER × NI, and JA × (JA × NI), are perspective for further studies because they have high content of phenolic compounds. The results of research could contribute to breed cultivars, which may prove interesting for food‐processing industries.     

The texture of low calorie grape juice jelly

 In this work the production of grape juice jellies with a low methoxyl pectin was studied. Availability of this kind of jelly will increase the range of dietetic products and is a promising alternative use for grapes surplus to the needs of the enological industry. The formulation of the jellies was optimized by response surface methodology (RSM), using as independent variables total sugar content (20 – 50°Brix), low methoxyl pectin content (0.5 – 1.5%) and processing temperature (55 – 90°C) at five levels. The dependent variable was the overall balance (B), a response obtained from sensory analysis. B was chosen from a series of sensory attributes evaluated by a test panel and the data treated by principal component analysis (PCA). The resulting polynomial equation (R ² = 0.92) showed the maximum value for B to occur for a jelly produced with 38°Brix of total sugar, 1.2% of low methoxyl pectin and a processing temperature of 69°C. The sensory-optimized jelly was objectively characterized for texture and dynamic rheological behaviour. Received: 2 October 1996 / Revised version: 7 January 1997     

Fresh from the Ornamental Garden: Hips of Selected Rose Cultivars Rich in Phytonutrients

Morphological parameters (size, weight, color), the content of sugars, organic acids, lycopene, β‐carotene, and phenolics were determined in hips of Rosa canina (RCA), Rosa sweginzowii (RSW), Rosa rugosa (RUG), and selected ornamental Rosa cultivars Fru Dagmar Hastrup (FDH), Repandia (REP), Veilchenblau (RVB), Aloha (RAL), Bonica (BON), and Golden Gate (RGG). Although traditionally used RCA hips contained the highest amount of cyanidin‐3‐glucoside (83 μg/g DW) and were the reddest (h° = 17.5), they did not stand out in other analyzed parameters. RGG climber had the biggest hips (8.86 g), which also contained highest sugar levels (50.9 g/100 g DW). RAL stood out as the cultivar rich in organic acids (33.9 g/100 g DW), mainly because of high quinic acid content (17.6 g/100g DW). FDH and RSW hips were characterized by particularly high ascorbic acid levels (4325 mg/100 g DW and 4711 mg/100 g DW). Other ornamental cultivars contained low amounts of ascorbic acid compared to the analyzed species. The phenolic profile was species/cultivars‐specific. The greatest diversity of phenolic compounds was detected in RUG and FDH hips (55 and 54 different tentatively identified compounds with HPLC/MS). Flavanols represented the main phenolic class in most of the investigated species/cultivars and RGG hips contained the highest amount of catechin and proanthocyandin derivatives (15855 μg/g DW). Altogether RAL hips contained the highest quantity of phenolics (44746 μg/g DW) mainly due to high levels of hydrolysable tannins compared to other species/cultivars. Although small, hips of BON and REP were most abundant regarding β‐carotene and lycopene content, respectively.     

Purine alkaloids in seeds ofTheobroma species from the Amazon

Summary The content of purine alkaloids in seeds of fourTheobroma species from the Amazon basin was analized by a reversed phase high-performance liquid chromatographic method.Theobroma grandiflorum was found to contain 0.38% of 1,3,7,9-tetramethyluric acidT. subincanum 0.07% 1,3,7,9-tetramethyluric acid,T. speciosum 0.01% theobromine and 0.04% 1,3,7,9-tetramethyluric acid and finallyT. mariae 2.35% theobromine and 0.12% caffeine. Theophylline could not be detected in any of these species. The results were confirmed qualitatively by thin-layer chromatography.

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Purinalkaloide in Samen vonTheobroma-Arten aus dem Amazonas-Becken

Zusammenfassung Das Vorkommen von Purin-Alkaloiden in Samen von vierTheobroma-Arten des Amazonasbeckens wurde mit Hilfe einer RP-HPLC-Methode untersucht. In Samen vonTheobroma grandiflorum wurden 0,38% 1,3,7,9-Tetramethylharnsäure (TMU), vonT. subincanum 0,07% TMU, vonT. speciosum 0,01% Theobromin und 0,04% TMU sowie schließlich vonT. mariae 2,35% Theobromin und 0,12% Coffein gefunden. Die Ergebnisse wurden qualitativ dünnschichtchromatographisch bestätigt.

     

Chemical Composition Analysis,Sensory, and Feasibility Study of Tree Peony Seed

Eight wild species in Sect. Moutan DC (tree peony) of the genus Paeonia grown in natural habitats and 1 cultivated specie were investigated to analyze their fatty acid and bioactive phenolic compound profiles. For fatty acid composition, P. ludlowii contained the lowest α‐linolenic acid (27.68%) and P. jishanensis contained the highest (51.96 %) content of the 9 species. For phenolic compounds, P. qiui contained the highest resveratrol (2.12 mg/g), P. delavayi contained the highest β‐gentiobiosylpaeoniflorin (26.23 mg/g), and P. ostii contained the highest paeoniflorin (23.66 mg/g). P. ostii was selected to perform a feasibility study because of its relatively high level of α‐linolenic acid 46.53%, low in ω‐6 to ω‐3 ratio of 1:2, and high level of the preferred bioactive phenolic compounds l including paeoniflorin and resveratrol. Physical pressing and refining process were conducted to obtain P. ostii seed oil. It exhibited bland sensory attributes described as slight grassy, very slight nutty, no painty or fishy aroma and slight grassy, slight nutty flavor with a very slight throat catch. Tocol results reported high level in tree peony seed oil 223.5 ± 13.65 mg/100 g with γ‐tocopherol 70.1 ± 2.14 mg/100 g, and γ‐tocotrienol 149.6 ± 15.83 mg/g. Because of the high total tocol, γ‐tocopherol and γ‐tocotrienol levels, and tree peony seed oil exhibited better oxidation stability than flaxseed oil even with similar α‐linolenic acid levels. In addition, high levels of γ‐tocopherol and γ‐tocotrienol can introduce therapeutic effects such as antiinflammation and antioxidation. Therefore, this study showed that tree peony seed oil has a great potential to be used in edible oil, nutraceutical supplement, and other health care products.     

Chemical composition of rosehips from different Rosa species: an alternative source of antioxidants for the food industry

ABSTRACT

It is important to explore new sources of natural additives because the demand for these compounds by consumers is increasing. These products also provide health benefits and help in food preservation. An unexplored source of nutrients and antioxidant compounds is rosehip, the fleshy fruit of roses. This work compares the antioxidant compound (vitamin C, neutral phenols and acidic phenols) content of four Rosa species rosehips: R. pouzinii, R. corymbifera, R. glauca and R. canina from different geographical zones. Results show quantitative variability in ascorbic acids and neutral phenols content, and quantitative and qualitative differences in acidic phenol content, depending on species. Vitamin C concentration was highly variable depending on species, R. canina being the one with the highest concentration and R. pouzinii the one with the lowest content. Variability was found in total neutral polyphenols concentration and a correlation between freshness of the rosehips and concentration of neutral polyphenols was also found. Significant differences were found in the acidic phenols content among the studied species. Generally antioxidant activity was higher in the vitamin C fraction.