首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
Natural mycoflora and fumonisins were analysed in 490 samples of freshly harvested corn (Zea mays L.) (2003 and 2004 crops) collected at three points in the producing chain from the Northern region of Paraná State, Brazil, and correlated to the time interval between the harvesting and the pre-drying step. The two crops showed a similar profile concerning the fungal frequency, and Fusarium sp. was the prevalent genera (100%) for the sampling sites from both crops. Fumonisins were detected in all samples from the three points of the producing chain (2003 and 2004 crops). The levels ranged from 0.11 to 15.32 µg g?1in field samples, from 0.16 to 15.90 µg g?1in reception samples, and from 0.02 to 18.78 µg g?1in pre-drying samples (2003 crop). Samples from the 2004 crop showed lower contamination and fumonisin levels ranged from 0.07 to 4.78 µg g?1in field samples, from 0.03 to 4.09 µg g?1in reception samples, and from 0.11 to 11.21 µg g?1in pre-drying samples. The mean fumonisin level increased gradually from ≤ 5.0 to 19.0 µg g?1as the time interval between the harvesting and the pre-drying step increased from 3.22 to 8.89 h (2003 crop). The same profile was observed for samples from the 2004 crop. Fumonisin levels and the time interval (ρ = 0.96) showed positive correlation (p ≤ 0.05), indicating that delay in the drying process can increase fumonisin levels.  相似文献   

2.
A direct comparison of two pre-treatments was undertaken to test their effect on the recovery of phenolic acids (PA) from three forage species. Samples of lucerne (Medicago sativa L), reed canarygrass (Phalaris arundinacea L), and switchgrass (Panicum virgatum L) were refluxed with 95% ethanol (EtOH) or neutral detergent solution (NDS). Subsequently, the resulting ethanol insoluble residue (EIR) and neutral detergent fibre (NDF) were treated with 1 M NaOH, and the extract was assayed for concentrations of p-coumaric acid (PCA) and ferulic acid (FA). In lucerne, the concentration of PCA was 9 times greater in the EIR than in the NDF (0·90 vs 0·11 mg g?1 dry matter, DM), and the FA concentration was 27 times greater in forage treated with EtOH than with NDS (1·89 vs 0·07 mg g?1 DM). In reed canarygrass (RCG), the concentrations of PCA and FA were slightly though significantly higher when the forage was pre-treated with EtOH. No significant differences in PA yield were detected between pre-treatments in switchgrass (SG). Extraction of EIR with hot EDTA (0·025 M , pH = 6·8) removed 80 to 90% of the total PA in EIR in lucerne but less than 5% of the PCA and FA in the grasses. These results indicate that almost all the PA in lucerne, in direct contrast to the grasses, are present in a fraction of the plant that is soluble in NDS. The relatively high PA concentration in the NDS soluble fraction suggests that the structure and composition of the fraction to which PA is esterified influence the degree to which PA affects digestibility.  相似文献   

3.
Based on fungal and fumonisin contamination of 870 freshly harvested samples, the quality of corn used by processing industries in the Northern region of Paraná State, Brazil (2003 and 2004 crop-year) was evaluated. Sampling was carried out for each crop at two points in the production chain, i.e. at reception by the processors and at the pre-drying step. Corn samples were more frequently contaminated with Fusarium sp. (100%) and Penicillium sp. (84.1–95.3%) than Aspergillus sp. (5.6–19.8%). Fumonisin B1 (FB1) was detected in all samples from the two points in both crop-years. FB1 levels ranged 0.02–11.83 µg g?1 in the reception and 0.02–10.98 µg g?1 in the pre-drying samples of the 2003 crop. Samples from the 2004 crop showed FB1 levels ranging 0.03–12.04 µg g?1 in the reception and 0.06–7.74 µg g?1 in the pre-drying samples. FB2 levels ranged 0.02–5.25 µg g?1 in the reception and 0.01–7.89 µg g?1 in the pre-drying samples (2003 crop-year). In samples from the 2004 crop, FB2 levels ranged 0.02–6.12 µg g?1 in the reception and 0.05–3.47 µg g?1 in the pre-drying samples. Low fumonisin levels were detected in most corn samples used by processors in the Northern region of Paraná State, showing a decreasing trend in fumonisin contamination over the years.  相似文献   

4.
Lycopene, a carotenoid, has antioxidant properties that may reduce the incidence of certain cancers. Watermelon (Citrullus lanatus (Thunb) Matsum & Nakai) is a natural source of lycopene, with a reported average content of 48.7 µg g?1 fresh weight based on samples taken from retail produce. This study demonstrated the variability of lycopene content in 11 red‐fleshed watermelon cultivars grown at one location, representing seedless, open‐pollinated and hybrid types, and in commercially shipped hybrid and seedless melons, representing seasonal production periods. Tristimulus colorimeter a* and chroma values were positively correlated with lycopene values, but linear or quadratic regressions of colorimeter data against lycopene values were not significant. Tristimulus colorimeter readings from cut melons were compared to amounts of lycopene extracted from the same melons. Lycopene content varied widely among cultivars, with four cultivars having mean values greater than 65.0 µg g?1 fresh weight. Seedless types sampled tended to have higher amounts of lycopene (>50.0 µg g?1 fresh weight) than seeded types. Watermelon lycopene content changed for some cultivars with production season. Published in 2001 for SCI by John Wiley & Sons, Ltd  相似文献   

5.
The principal aim of this study was to estimate the formation of fumonisins (FB1 and FB2), moniliformin (MON), and ergosterol (ERG) by Fusarium oxysporum and Fusarium proliferatum, while the formation of beauvericin (BEA) was estimated by the latter Fusarium species only. Moreover, the effect of temperature on the biosynthesis of mycotoxins was also evaluated. Fumonisins were formed by F. proliferatum, with the highest yield at 18°C (720.0–1976.6 µg g?1 for FB1, 74.2–670.8 µg g?1 for FB2) and only by three of four F. oxysporum strains at a very low level (0.02–4.77 µg g?1 for FB1, 0.02–2.15 µg g?1 for FB2). The amount of MON formed by F. proliferatum was the highest (p < 0.001) at 32°C (3056.87 µg g?1), while MON biosynthesis by F. oxysporum was lower 227.54 µg g?1 (p < 0.001). BEA was produced by F. proliferatum with the highest level at 25°C (p < 0.001). ERG–recognized as an indicator of fungal biomass development and as a consequence of mycotoxin formation–was found at the highest concentration at a biosynthesis temperature of 25°C for F. proliferatum and F. oxysporum (p < 0.001).  相似文献   

6.
Seventeen commonly consumed exotic fruits from Mauritius were analysed for their antioxidant capacity, total phenolics, proanthocyanidins, flavonoids and vitamin C content. Two independent methods were used to evaluate the antioxidant potential of total fruit extracts. The antioxidant activities of the fruits ranged from 1 to 47 µmol Trolox equivalent antioxidant capacity (TEAC) g?1 fresh weight and from 0.3 to 34 micro/mol g fresh weight (FRAP) g?1 fresh weight. Total phenolics in the fruits ranged from 118 to 5638 µg g?1 fresh weight, proanthocyanidins from 7 to 2561 µg g?1 fresh weight, flavonoids from 21 to 712 µg g?1 fresh weight and vitamin C content from 8 to 1426 µg g?1 fresh weight. There were strong correlations between antioxidant activity (assessed by both TEAC and FRAP) and total phenolics and proanthocyanidins. Flavonoids seemed to contribute less to the antioxidant potential of the fruits, while very poor correlations were observed between ascorbate content and antioxidant activity. The highest antioxidant capacities were observed in red and yellow Psidium cattleianum Sabine ‘Chinese guava’, sweet and acid Averrhoa carambola L ‘starfruit’, Syzygium cumini L Skeels ‘jamblon’ and white Psidium guajava L ‘guava’. These fruits were also characterised by high levels of total phenolics. Mauritian exotic fruits are thus a significant source of phenolic antioxidants, which may have potential beneficial effects on health. Copyright © 2003 Society of Chemical Industry  相似文献   

7.
Field and retail collections of bivalves from the Pacific Northwest, Canada, were analysed for cadmium concentrations by atomic absorption spectrophotometry (AAS). Both collections of varnish (Nuttallia obscurata) and manila (Venerupis philippinarum) clams contained cadmium concentrations of less than 0.5 µg g?1, well below international safety guidelines of 1 and 2 µg g?1 wet weight cadmium for the European and Hong Kong markets, respectively, as well as the 2 µg g?1 safety guideline set by the Codex Alimentarius Commission (CAC). Cadmium concentrations in retail collections of the Pacific oyster, Crassostrea gigas, were generally above 2 µg g?1 wet weight (range = 1.5–3.56 µg g?1). Retail collections of the mussel, Mytilus spp., contained cadmium concentrations below the 2 µg g?1 wet weight guideline, but not always the 1 µg g?1 limit (range = 0.15?1.8 µg g?1). However, field collections of Mytilus spp. contained cadmium concentrations between 0.35 and 4.00 µg g?1 wet weight, and depending on sampling location, concentrations exceeded the CAC guidelines by more than two-fold. Locations where mussels had high cadmium concentrations correlated with regions that had previously reported high values for cadmium in Pacific oysters (r = 0.65; p < 0.05). Of the various shellfish analysed, the four species of scallops, Chlamys hastata, C. rubida, Crassadoma gigantea, and Patinopecten yessoensis, contained the greatest concentrations of cadmium, in excess of 5 µg g?1 wet weight (range = 4.97–8.98 µg g?1) with the greatest concentrations determined for C. gigantea. Cadmium concentrations in shellfish from the Pacific Northwest are greater than values reported for shellfish from other regions of the world and consumers need be aware of Health Canada consumption guidelines for shellfish from this region.  相似文献   

8.
Vitamin A deficiency is a disorder of public health importance in Sri Lanka. A recent national survey revealed that 36% of preschool children in Sri Lanka have vitamin A deficiency (serum retinol <0.2 µg ml?1). In view of its well‐established association with child morbidity and mortality, this is a reason for concern. One of the main fruits which has been recommended for prevention of vitamin A deficiency in Sri Lanka is papaya (Carica papaya L). In this study the carotenoid profiles of yellow‐ and red‐fleshed papaya were analysed by medium‐pressure liquid chromatography (MPLC) and UV‐vis spectrophotometry. A section of yellow‐fleshed papaya showed small carotenoid globules dispersed all over the cell, whereas in red‐fleshed papaya the carotenoids were accumulated in one large globule. The major carotenoids of yellow‐fleshed papaya were the provitamin A carotenoids β‐carotene (1.4 ± 0.4 µg g?1 dry weight (DW)) and β‐cryptoxanthin (15.4 ± 3.3 µg g?1 DW) and the non‐provitamin A carotenoid ζ‐carotene (15.1 ± 3.4 µg g?1 DW), corresponding theoretically to 1516 ± 342 µg kg?1 DW mean retinol equivalent (RE). Red‐fleshed papaya contained the provitamin A carotenoids β‐carotene (7.0 ± 0.7 µg g?1 DW), β‐cryptoxanthin (16.9 ± 2.9 µg g?1 DW) and β‐carotene‐5,6‐epoxide (2.9 ± 0.6 µg g?1 DW), and the non‐provitamin A carotenoids lycopene (11.5 ± 1.8 µg g?1 DW) and ζ‐carotene (9.9 ± 1.1 µg g?1 DW), corresponding theoretically to 2815 ± 305 µg kg?1 DW mean RE. Thus the carotenoid profile and organisation of carotenoids in the cell differ in the two varieties of papaya. This study demonstrates that carotenoids can be successfully separated, identified and quantified using the novel technique of MPLC. Copyright © 2003 Society of Chemical Industry  相似文献   

9.
BACKGROUND: In this study, 18 kinds of medicinal plants were collected together with their soils from different regions of Turkey and their macro‐ and micro‐element and heavy metal contents were determined by inductively coupled plasma atomic emission spectrometry (ICP‐AES). In soils, pH, electrical conductivity, carbonate (lime), organic matter, texture, P, K, Ca, Mg, Fe, Cu, Mn, Zn and B were analysed. In plants and extracts, P, K, Ca, Mg, Fe, Cu, Mn, Zn, B, Na, Al, Li, Pb, Ni, Cd, Co and Cr contents were determined. Also, correlations between soil and plant and between plant and extract were established. RESULTS: Element concentrations ranged between 0.11 and 5160 µg g?1 in soil samples, between 0.14 and 54400 µg g?1 in plant samples and between 0.039 and 22033 µg g?1 in extract samples. While sage was rich in Fe (981.3 µg g?1), basil was abundant in P (9.8 mg g?1), K (54.4 mg g?1), Ca (22.6 mg g?1), Mg (3.1 mg g?1) and Zn (46.05 µg g?1) and mint was rich in Li (23.50 µg g?1). Moreover, while high levels of P (4100.9 µg g?1), K (22033 µg g?1) and Mg (529.15 µg g?1) were found in basil extract, Ca (5979.3 µg g?1) was present at high concentration in marjoram leaf extract. Also, Fe (4.25 µg g?1) and Zn (17.51 µg g?1) were detected at high levels in lime flower and mint extracts respectively. CONCLUSION: It was concluded that aromatic plants are important sources of nutrients and essential elements. Copyright © 2007 Society of Chemical Industry  相似文献   

10.
This study compares the susceptibility of winter wheat (Triticum aestivum L.) cultivars to Fusarium head blight (FHB) and accumulation of mycotoxins in kernels and chaff under different climatic conditions in two locations–Cerekwica near Poznan (Central West Poland) and Sitaniec, near Zamosc, Lublin region (South East Poland). Very high variations were found in the concentrations of mycotoxins (zearalenone, ZEA; nivalenol, NIV; deoxynivalenol, DON; moniliformin, MON) in examined fractions: Fusarium-damaged kernels (FDK) and healthy looking kernels (HLK) and in chaff for individual cultivars in both locations. In most cases, significantly higher concentrations of investigated toxins were recorded in wheat from the area of Lublin than from Poznan (p < 0.05). The highest Fusarium infection rates and mycotoxin biosynthesis levels were observed in the Lublin location, with the percentage of the FDK fraction ranging 8.1–81.6. In this region, ZEA concentration (µg g?1) after inoculation with F. culmorum and F. graminearum ranged from 0.02–0.48 and 0.32–1.04, respectively. In the Poznan area, the toxin concentrations were considerably lower, ranging 0.01–0.10 and 0.03–0.13 µg g?1 for both isolates, respectively. The concentration of DON was significantly higher than ZEA or NIV levels. The levels of MON accumulation (µg g?1) in the FDK fraction were between 0.14 and 1.73 (Poznan area) and ND (not detected) to 2.51 (Lublin area). F. avenaceum infection rate ranged 7–35% in samples where the toxin was detected.  相似文献   

11.
Ten Mauritian vegetables, broccoli, cauliflower, white cabbage, lettuce, Chinese cabbage, mugwort, carrot, onion, tomato and chilli pepper, were analysed for their total phenol, flavonoid, proanthocyanidin and vitamin C contents and antioxidant capacity. Antioxidant activities of the vegetables ranged from 0.43 to 3.68 µmol g?1 fresh weight Trolox equivalent antioxidant capacity (TEAC) and from 0.60 to 8.47 µmol g?1 fresh weight ferric reducing antioxidant power (FRAP). Levels of total phenols in the vegetables varied between 132 and 1189 µg g?1 fresh weight and those of total flavonoids between 45 and 944 µg g?1 fresh weight, while proanthocyanidins were detected at very low levels in only a few vegetables. Vitamin C contents varied between 25 and 748 µg g?1 fresh weight. Quercetin was the dominant flavonoid aglycone in the hydrolysed vegetable extracts, with values in the range of 15–390 µg g?1 fresh weight. There were strong correlations between antioxidant capacity and total phenols (TEAC, r = 0.91; FRAP, r = 0.83) and total flavonoids (TEAC, r = 0.89; FRAP, r = 0.82). Vitamin C contents showed poor correlation with TEAC values (r = 0.33), while no correlation was observed with FRAP values. Highest antioxidant capacities were observed in Chinese cabbage (Brassica chinensis L), onion (Allium cepa L), mugwort (Artemisia vulgaris Cantley) and broccoli (Brassica oleracea L var botrytis L subvar cymosa). Mauritian vegetables therefore represent a significant source of phenolic antioxidants, with quercetin derivatives being most abundant, and this may contribute to their potential health benefits. Copyright © 2004 Society of Chemical Industry  相似文献   

12.
A whole‐body radioassay procedure was used to assess the bioavailability to rats of zinc (Zn) in seeds of 18 genotypes of beans (Phaseolus vulgaris L) that were grown hydroponically. Dry beans that were labelled intrinsically with 65Zn were added to test meals fed to rats that were marginally Zn‐deficient. The amount of Zn in the seeds varied between genotypes and ranged from 26.7 to 62.4 µg g?1 (from 0.41 to 0.95 µmol g?1) dry weight (DW). Similarly, the amount of iron (Fe) in the beans varied nearly twofold (from 52.3 to 96.3 µg g?1 DW), and Zn and Fe concentrations were positively correlated. Concentrations of myo‐inositolhexaphosphate (IP6) plus myo‐inositolpentaphosphate (IP5) varied from 18.1 to 27.3 µmol g?1 DW. Cultivars with white‐coloured seeds contained relatively small amounts of tannins varying from 0.12 to 0.16 mg g?1 DW (determined as catechin equivalents) compared to those with coloured seed coats (up to 2.58 mg g?1 DW). All rats readily ate the test meals so that Zn intake varied directly with seed‐Zn concentration. As indicated by 65Zn absorption, the bioavailability to rats of Zn in the seeds varied between genotypes and ranged from about 78 to 95% of the total Zn in the seeds. The bioavailability of Zn to marginally Zn‐deficient rats was not affected markedly by either IP5 + IP6 or tannin in the dry beans. These results demonstrate that the concentration of Zn in dry beans can be increased through traditional plant‐breeding techniques and that this may result in significant increases in the amount of bioavailable Zn in the beans. Increasing the amount of Zn in beans may contribute significantly to improving the Zn status of individuals dependent on beans as a staple food. © 2002 Society of Chemical Industry  相似文献   

13.
Commercial tomato canning yields two different byproducts. One is the material that results from peeling tomatoes, while the other results from removing the seeds. The peel byproduct contained 100.8 g protein, 256.4 g ash and 299.4 g acid detergent fiber kg?1. Ash content was high because the peel byproduct contained 83.8 g kg?1 sodium as a result of using a sodium hydroxide solution to peel the tomatoes. The seed byproduct contained 202.3 g protein, 51.8 g ash, and 537.9 g acid detergent fiber kg?1. An amino acid analysis of seeds indicated that approximately 60% of the protein results from amino acids. Both byproducts were analyzed for carotenoid content. The lycopene content of peel byproduct was 734 µg g?1 of dry material. Significant amounts of lutein, β‐carotene, and cis‐β‐carotene were also present. Seed byproduct contained 130 µg lycopene kg?1 of dry matter. The content of other carotenoids was approximately half of that present in the peels. Peel and seed byproducts were included at 75 g kg?1 in hen diets to determine the transfer of carotenoids to the yolk. When fed at this concentration, the lycopene content of dry egg yolk was approximately 0.9 µg g?1. Approximately 0.1% of the lycopene in peel byproduct and approximately 0.7% of the lycopene in the seed byproduct was transferred from the feed to the yolk. Lycopene appears more similar to carotene than to oxycarotenoids in its transfer to the yolk. Copyright © 2005 Society of Chemical Industry  相似文献   

14.
Total concentrations of essential (Cu, Zn, Se and Cr) and non-essential (Hg, Cd, Pb and As) trace elements were measured in the flesh and hepatopancreas of Octopodidae (Eledone moschata, Eledone cirrhosa, Octopus salutii), Sepiidae (Sepia elegans, Sepia orbignyana) and Loliginidae (Illex coindeti, Loligo vulgaris) from the Mediterranean Sea. As expected, the hepatopancreas showed higher metal concentrations than flesh; the only exceptions were Hg and As, which were equally distributed in the two tissues. Regarding the edible portion, the highest toxic metal concentrations were in Octopodidae (Hg: 0.44, Cd: 0.49, Pb: 0.10 µg g?1 wet weight) and Sepiidae (Hg: 0.27, Cd: 0.50, Pb: 0.12 µg g?1 wet weight), while Loliginidae tended to accumulate less metal, especially Hg (Hg: 0.11, Cd: 0.30, Pb: 0.05 µg g?1 wet weight). The other elements showed a heterogeneous distribution among the different cephalopod families. Loliginidae showed the highest Se concentrations (1.18 µg g?1 wet weight), Octopodidae of Cu (37.37 µg g?1 wet weight) and Zn (42.00 µg g?1 wet weight) and Sepiidae of As (61.43 µg g?1 wet weight), while Cr was uniformly distributed among the various families (0.38–0.43 µg g?1 wet weight). In these seafoods, the concentrations of essential and non-essential elements were within the prescribed limits set by various authorities, except for Cu and As. Health risks posed by toxic elements to humans via dietary intake of these mollusks were assessed on the basis on Provisional Tolerable Weekly Intake (PTWI), while the estimated intakes of essential elements were compared to Dietary Reference Intakes (RDIs). A 70-g serving of these mollusks was shown to provide a large contribution to Cd intake (0.89 µg kg?1 body weight), corresponding to 35.6% of PTWI. Concerning the essential elements, the consumption of these mollusks made an important contribution to daily dietary intake of Se, Cu and Zn.  相似文献   

15.
Fusarium is the agent causing endosepsis (internal rot) in fig fruits and it is widespread in fig orchards in the Aegean region. This research was conducted to determine the natural occurrence of fumonisin B1 (FB1) and B2 (FB2) on dried fig fruits of Sarilop (syn. Calimyrna) variety which are mainly grown in the Big and Small Meander Basins in the Aegean region, representing 60% of world dried fig production. A total of 262 samples belonging to two quality classes, Class A and Class cull, were collected from 12 different locations during the two crop years in 2004 and 2005. The fumonisin detection method is based on extraction with methanol–acetonitrile–water, derivatization with o-phthaldehyde and quantification by reversed-phase high-performance liquid chromatography with fluorescence detection. The mean concentrations of FB1 and FB2 in fumonisin-positive samples were 0.080?±?0.047?µg?g?1 and 0.055?±?0.031?µg?g?1 and ranged from LOD to 0.332?µg?g?1 and from LOD to 0.198?µg?g?1, respectively. The incidence of fumonisins significantly differed between the two crop years. This difference can be attributed to the alteration in the rainfall regime from mid-May to mid-August (7.2?mm in 2004, 90.9?mm in 2005) and number of humid wind currents from a westerly direction (183 in 2004, 492 in 2005) from the end of July and mid-August that may have triggered a higher incidence of Fusarium spp. and thus fumonisin production.  相似文献   

16.
Soybean (Glycine max (L) Merr) seeds contain isoflavones that have positive impacts on human health. The objective of this study was to determine isoflavone concentrations of early maturing soybean cultivars grown in different environments and to determine their relation to other important seed characteristics. Twenty soybean cultivars were grown in replicated trials at two sites in Montreal, Canada in 2002/2003 and their total and individual isoflavone concentrations were determined by high‐performance liquid chromatography. Seed yield, 100‐seed weight and oil, crude protein and crude fiber concentrations were concurrently determined. Total and individual isoflavone concentrations were significantly affected by cultivar, site and year. Total isoflavone concentration ranged from 360 to 2241 µg g?1 and averaged 851 µg g?1 across environments and cultivars. Variation across environments ranged from 20 to 100% for specific cultivars. Total isoflavone concentration was, on average, 40% greater in 2003 than 2002, which was characterized by above average temperatures and severe drought. Despite significant cultivar × year × site interactions, cultivars with consistently high and low isoflavone concentrations across environments were identified. Weak but significant positive correlations were observed between total isoflavone concentration and seed yield, 100‐seed weight and crude fiber, indicating that isoflavone concentration is positively associated with other desirable seed characteristics. Copyright © 2004 Society of Chemical Industry  相似文献   

17.
Syzygium cumini, widely known as Jamun, is a tropical tree that yields purple ovoid fleshy fruit. Its seed has traditionally been used in India for the treatment of diabetes. Based on the available ethno‐pharmacological knowledge, further studies were extended to understand the chemical composition and antioxidant activities of three anatomically distinct parts of fruit: the pulp, kernel and seed coat. Fruit parts, their corresponding ethanol extracts and residues were evaluated for chemical composition. The alcoholic extract was evaluated for its antioxidant potential against DPPH?, OH?, O2?? and lipid peroxidation. The whole fruit consisted of 666.0 ± 111.0 g kg?1 pulp, 290.0 ± 40.0 g kg?1 kernel and 50.0 ± 15.0 g kg?1 seed coat. Fresh pulp was rich in carbohydrates, protein and minerals. Total fatty matter was not significant in all three parts of fruit. Detailed mineral analysis showed calcium was abundant in all fruit parts and extracts. Total phenolics, anthocyanins and flavonoid contents of pulp were 3.9 ± 0.5, 1.34 ± 0.2 and 0.07 ± 0.04 g kg?1, respectively. Kernel and seed coat contained 9.0 ± 0.7 and 8.1 ± 0.8 g kg?1 total phenolics respectively. Jamun pulp ethanol extract (PEE), kernel ethanol extract (KEE) and seed coat ethanol extract (SCEE) showed a high degree of phenolic enrichment. DPPH radical scavenging activity of the samples and standards in descending order was: gallic acid > quercetin > Trolox > KEE > BHT > SCEE > PEE. Superoxide radical scavenging activity (IC50) of KEE was six times higher (85.0 ± 5.0 µg mL?1) compared to Trolox (540.0 ± 5.0 µg mL?1) and three times compared to catechin (296.0 ± 11.0 µg mL?1). Hydroxyl radical scavenging activity (IC50) of KEE was 151.0 ± 5.0 µg mL?1 which was comparable with catechin (188.0 ± 6.0 µg mL?1). Inhibition of lipid peroxidation of the extracts was also studied and their activity against peroxide radicals were lower than that of standard compounds (BHT, 79.0 ± 4.0 µg mL?1; quercetin, 166.0 ± 13.0 µg mL?1; Trolox, 175.0 ± 4.0 µg mL?1; PEE, 342.0 ± 17.0 µg mL?1; KEE, 202.0 ± 13.0 µg mL?1 and SCEE, 268.0 ± 13.0 µg mL?1. Copyright © 2007 Society of Chemical Industry  相似文献   

18.
Twenty-seven rice samples from Brazil, four parboiled brown, seventeen white and six parboiled white were analysed by ICP-MS for trace element determination. Concentrations of arsenic varied from 58.8 to 216.9?ng?g?1, for cadmium from 6.0 to 20.2?ng?g?1, for antimony from 0.12 to 1.28?ng?g?1, and for uranium from 0.025 to 1.28?ng?g?1. The estimated daily intake through rice consumption was 9.5?µg for As, 2.4?µg for Cd, 0.029?µg for Sb, 0.013?µg for U, 3.1?µg for Co, 0.2?µg for Cu, 85.6?mg for Mg, 1.9?mg for Mn, 333?mg for P, 3.0?µg for Se, 1.6?mg for Zn, 0.9?mg for Rb, and 0.3?µg for V. Found values represent a considerable percentage of the dietary reference intakes and provisional tolerable daily intake for essential and toxic elements, respectively.  相似文献   

19.
A sensitive LC–MS/MS method for the simultaneous determination of type A, B and D trichothecenes in cereals is presented. The limits of detection ranged between 0.1 and 0.7 µg kg?1 for all analytes. The method was applied to 289 representatively drawn samples of wheat, rye and oat products. Ninety-four percent of the wheat samples (n = 130), 95% of the rye samples (n = 61) and 100% of the oat samples (n = 98) were contaminated with the type A trichothecenes T-2 and HT-2 toxin. Median levels of T-2/HT-2 (sum of the toxins) were 0.91, 0.53 and 8.2 µg kg?1, respectively. Highest levels were found in wheat bran (24 µg kg?1), rye kernels (3.1 µg kg?1) and oat flakes (85 µg kg?1). All wheat and rye samples and 75% of the oat samples were contaminated with the type B trichothecene deoxynivalenol. Median levels of this toxin were 23, 15 and 0.53 µg kg?1, respectively. Highest levels were found in wheat bran (1160 µg kg?1), rye kernels (288 µg kg?1) and oat flakes (55 µg kg?1). The type B trichothecene nivalenol was detected in 67% of the wheat samples, in 3% of the rye samples and in 24% of the oat samples with highest levels in wheat bran (96 µg kg?1), rye kernels (1.8 µg kg?1) and in oat flakes (17 µg kg?1), respectively. Levels of other type A and B trichothecenes played a minor role, although the rates of contamination were often high. Neither macrocyclic type D trichothecenes (satratoxin G and H, verrucarin A, roridin A) nor diacetylverrucarol and verrucarol (type A trichothecenes), were detected in any of the samples.  相似文献   

20.
Four species of edible tubers endemic to and domesticated in the Andes, native potato (Solanum sp.), mashua (Tropaeolum tuberosum Ruiz & Pavón), oca (Oxalis tuberosa Molina) and ulluco (Ullucus tuberosus Caldas), were studied for their antioxidant capacity and associated secondary metabolites. The antioxidant capacity was measured using ABTS? radicals and total phenolics, carotenoids, anthocyanin, betaxanthin and betacyanin content were also characterized. The antioxidant capacity found in the crops studied ranged from 483 to 9800 µg trolox equiv. g?1, phenolics ranged from 0.41 to 3.37 mg chlorogenic acid equiv. g?1, anthocyanins ranged from 0.08 to 2.05 mg cyanidin 3‐glucoside g?1 and carotenoids ranged from 1 to 25 µg β‐carotene g?1. The content of bioactive compounds was high and variable between crops and within the genotypes studied. In general, mashua tubers showed the highest antioxidant capacity and phenolic, anthocyanin and carotenoid content compared with other crops. Ulluco was the only crop that contained betalains in the acid form of betaxanthins (22–96 µg g?1) and betacyanins (64 µg g?1) with no presence of carotenoids or anthocyanins. This is the first publication regarding the antioxidant capacity of and associated secondary metabolites in Andean tubers. This information can be useful in the identification of Andean tubers species and genotypes with potential value as a novel dietary source of antioxidants for food, and also for medicinal use. Copyright © 2006 Society of Chemical Industry  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号