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1.
The qualitative and quantitative composition of flavonoids from the Huétor-Tájar population variety of asparagus (commonly known as " triguero") was investigated. Flavonoids were analyzed by reversed-phase high-performance liquid chromatography-diode array detection (HPLC-DAD). Liquid chromatography-mass spectrometry (LC-MS) under identical HPLC conditions was used to verify the identities of the flavonoid glycosides from triguero asparagus. The quantities of asparagus flavonoids were calculated according to concentration curves constructed with authentic standards. Total flavonoid contents, calculated as the sum of individual compounds, were determined and ranged from 400 to 700 mg/kg fresh weight. The most abundant was rutin, which represented 55-98% of the total flavonoid complement. Triguero asparagus were revealed to be an important source of not only quercetin derivatives but also kaempferol and isorhamnetin glycosides. Significant differences (p < 0.05) in the content and relative composition of flavonoids were found among the spears of the distinct asparagus genotypes from the Huétor-Tájar population variety.  相似文献   

2.
Commercial pectolytic enzymes were investigated for their influence on phenolics and antioxidant activities of asparagus juice. The antioxidant activity of asparagus juice was analyzed according to 2,2'-diphenyl-l-picrylhydrazyl and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) methods. The enzymes, with the exception of pectinase from Rhizopus sp., contained rutinase, which hydrolyzed rutin to quercetin. Asparagus juice treated with Viscozyme had the highest quercetin content without exhibiting a significant increase in the antioxidant activity. For a pectinase from Aspergillus niger, the antioxidant activity of asparagus juice was markedly reduced. Caution should be paid in the selection of pectolytic enzyme preparations for production of antioxidant activity-rich juice.  相似文献   

3.
TiO 2 photocatalytic decomposition and detoxification of phytotoxic compounds released by the roots of asparagus ( Asparagus officinalis L.) were investigated from the viewpoint of conservation-oriented cultivation. The phytotoxically active fraction was extracted either from dried asparagus roots or from the recycled nutrient solution of an asparagus hydroponic cultivation system. We found that the phytotoxic activity gradually decreased in the fraction with TiO 2 powder under irradiation with ultraviolet (UV) light at an intensity of 1.0 mW/cm (2). The growth of asparagus plants under actual cultivation conditions was also investigated by comparing asparagus grown in a hydroponic system where recycled waste nutrient solution was photocatalytically treated with solar light and a system with untreated recycled waste nutrient solution. The results showed, as measured by growth indices such as stem length and stem thickness, that asparagus growth in the photocatalytically treated system was superior to the untreated one. Furthermore, the yield of asparagus spears was 1.6-fold greater in the photocatalytically treated system, demonstrating the detoxification effect on the phytotoxic compounds and also the killing effect on pathogenic microorganisms.  相似文献   

4.
Nuclear magnetic resonance imaging (MRI) and complementary analytical techniques were used to address the question whether white asparagus (Asparagus officinalis L.) from different cultivation sites in Germany can be distinguished on the basis of NMR relaxation times. Five locations with contrasting soil properties and composition within the two asparagus‐cultivation regions Rhineland and Lower Franconia were selected for this project. For the first time, entire asparagus plants in their authentic soil environment excavated directly from the original harvest site were imaged by the NMR technique. However, they could not be employed for determination of relaxation times of spears in situ, because of artifacts arising from soil properties. Instead, market‐ready asparagus spears and freshly prepared spear saps from the five locations were used to acquire MRI data sets with different (slow and fast) imaging methods and to compute spatially resolved distributions (maps) of T1, T2, and T2* relaxation times. Comparison of the data for pith, vascular tissue, and peel of the spears yielded only marginal, if any, differences in T1, T2, and T2* between the specimens from the five locations, which were not sufficient for an unambiguous region‐related distinction. More pronounced differences in T1, T2, and T2* were visible for the spear saps, allowing a clear distinction between individual specimens for each of the two cultivation regions. The results are discussed in terms of an application potential for correlated NMR relaxation times of tissue saps for future geographic authentication of agricultural produces.  相似文献   

5.
Avocado (Persea americana Mill.) is a major tropical fruit, with origin in Mesoamerica area. Avocado is a very variable species and taxonomically poorly understood. It has been grown in the Neotropics since ancient times and it seems that the domestication of this tree in Mesoamerica started before other annual crops. In addition, it seems that much of avocado diversity as ecological differences, were originated as a result of cultural diversity. In view of this, avocado represents an interesting model to study domestication of tropical trees and develop forest management and germplasm conservation strategies. At present time, P. americana is worldwide distributed with Mexico as the main producer. However, there are some aspects on the origin, dispersion, and domestication of the species that remain to be answered. In this paper, we present a survey of these issues from the earliest to present time in Mesoamerica.
Resumen El aguacate (Persea americana Mill.) es una importante fruta tropical, originaria del área de Mesoamérica. El aguacate es una especie altamente variable y su taxonomía aún no ha sido totalmente definida. El aguacate se ha desarrollado en el Neotrópico desde tiempos antiguos y es posible que su domesticación en Mesoamérica se iniciara antes que otras plantas anuales. También es probable que en gran medida su diversidad se originara además de las diferencias ecológicas, también como resultado de la diversidad cultural. Debido a esto, el aguacate representa un modelo interesante para estudiar procesos de domesticación en árboles tropicales y desarrollar estrategias de manejo en bosques y conservación del germoplasma. Actualmente, P. americana está distribuida en todo el mundo y México es el principal productor. Sin embargo, algunos aspectos del origen, dispersión y domesticación de la especie no han sido clarificados. En este artículo presentamos una investigación sobre estos aspectos, desde tiempos antiguos hasta el presente en el área de Mesoamérica.
  相似文献   

6.
Two commonly consumed plant foods, onion bulbs and asparagus spears, were subjected to typical domestic processing, including chopping, maceration, and boiling. The impact of these processes on flavonol content was assessed. Further, the consequences of these processes on the antioxidant capacity of the tissues were evaluated with the beta-carotene bleaching method. Chopping significantly affected rutin content in asparagus, yielding an 18.5% decrease in 60 min; but in onions, quercetin 3,4'-diglucoside (Q(DG)) and quercetin 4'-glucoside (Q(MG)) were virtually unaffected by chopping. Boiling for 60 min had more severe effects, as it caused overall flavonol losses of 20.6 and 43.9% in onions and asparagus, respectively. Chopping of tissues did not considerably influence the antioxidant capacity, but boiling did provoke notable changes.  相似文献   

7.
Effect of storage on wall-bound phenolics in green asparagus   总被引：2，自引：0，他引：2  
The cell walls of green asparagus spears have been analyzed for their phenolic and carbohydrate composition as modified by postharvest storage. Esterified phenolic components were released by sequential alkaline hydrolysis and identified and quantified by diode array HPLC. Significant quantities of ferulic acid (FA) and its derivatives were found to increase at least 3-fold during storage, particularly in walls from the lower parts of the stem, where accompanying changes in sugar composition were also observed. In fresh asparagus, >60% of the total FA was in the form of diferulic acid, and this increased to approximately 70% after 3 days of storage. The main FA dehydrodimers were 8-8-, 8-O-4-, and 8-5-diferulates. These have been detected in other monocotyledonous and dicotyledonous plants, but as a smaller proportion of the total FA. The possible roles phenolic esters might have in relation to the mechanical, textural, and wound-response properties of asparagus spears are discussed.  相似文献   

8.
A pectolytic enzyme preparation from Aspergillus niger (pectinase AN) decreased most rutin content and antioxidant activity of asparagus juice. To investigate the mechanism of such loss, we analyzed several possible related enzyme activities in pectinase AN. We found that the activity of pectinase AN to oxidize guaiacol had no significant difference with or without the presence of H2O2; thus it was laccase activity, not peroxidase (PO) activity, that pectinase AN contained. We did not find any polyphenol oxidase (PPO) activity in pectinase AN. Laccase in pectinase AN could be the major cause of loss of rutin and antioxidant activity of asparagus juice. When most laccase activity of pectinase AN was inactivated after heating at 70 degrees C for 1.5 min and incubated with asparagus juice, the loss rate of rutin was only 9% of that treated with unheated pectinase AN, and the antioxidant activity was even increased. Rhamnosidase activity was detected in pectinase AN and can change rutin in asparagus juice to quercetin-3-glucoside, which has higher antioxidant activity than rutin. This may explain the increase of antioxidant activity of asparagus juice treated with heated pectinase AN that still contained some rhamnosidase activity. The discovery of our research is helpful to produce juice with high antioxidant activity and high health benefits in the juice industry.  相似文献   

9.
Traditional use of noncultivated vegetables has decreased with the development of agriculture and global supply chains. However, some species are still consumed as part of our traditional Mediterranean diet. Plants are among the most important sources of natural antioxidants for retarding lipid oxidative rancidity in foods or for pharmaceutical applications against chronic diseases related to free radicals production. The present study reports tocopherols composition and antioxidant activity of eight wild greens traditionally used in Spain. According to the edible part consumed, two groups were differentiated. Leafy vegetables whose young stems with leaves are consumed (Apium nodiflorum (L.) Lag., Foeniculum vulgare Mill., Montia fontana L. and Silene vulgaris (Moench) Garcke), and wild asparagus whose young shoots with leaf buds scarcely developed are eaten (Asparagus acutifolius L., Bryonia dioica Jacq., Humulus lupulus L. and Tamus communis L.). Among the leafy vegetables, Silene vulgaris and Apium nodiflorum presented the highest antioxidant capacity and antioxidants contents. Among the wild asparagus, the highest antioxidant capacity was obtained in Humulus lupulus.  相似文献   

10.
The present research work describes the major changes in the antioxidant properties during development of acerola from five different clones. Ripening improved fruit physicochemical quality parameters; however, total vitamin C and total soluble phenols (TSP) contents declined during development, which resulted in a lower total antioxidant activity (TAA). Despite the decline in TSP, at ripening, the anthocyanin and yellow flavonoid content increased and was mainly constituted of cyanidin 3-rhamnoside and quercetin 3-rhamnoside, respectively. The activities of oxygen-scavenging enzymes also decreased with ripening; furthermore, the reduction in vitamin C was inversely correlated to membrane lipid peroxidation, indicating that acerola ripening is characterized by a progressive oxidative stress. Among the studied clones, II47/1, BRS 237, and BRS 236 presented outstanding results for vitamin C, phenols, and antioxidant enzyme activity. If antioxidants were to be used in the food supplement industry, immature green would be the most suitable harvest stage; for the consumer's market, fruit should be eaten ripe.  相似文献   

11.
芦笋是一种高档而名贵的蔬菜，定植后第3年才进入盛产期；种植前期产量低收益少。利用芦笋定植前期根系较小、行距较宽和娃娃菜株型小、根系浅的特性，在芦笋定植当年进行“芦笋+娃娃菜”间作生产，可提高土地利用率和早期收益。我们基于临泽县当地种植专业合作社的生产实践，从茬口安排、品种选择、育苗、整地覆膜、灌溉系统配备、定植(移栽)及田间管理等方面总结了河西走廊灌区芦笋+娃娃菜间作栽培技术，为河西灌区芦笋-娃娃菜间作栽培提供技术支持。  相似文献   

12.
Grape byproducts were subjected to an extraction process under various different experimental conditions (namely, solvent type, temperature, solvent-to-solid ratio, time contact, and raw material) in order to study the effect of these conditions on the yield of phenolic compounds and the corresponding antiradical activity of extracts. Although the order of decreasing capacity to extract soluble materials was ethanol > methanol > water, methanol was the most selective for extracting phenolic compounds. Temperature and solvent-to-solid ratio were found to have a critical role in extraction efficiency; values of 50 degrees C (between 25 and 50 degrees C) and 1:1 (between 1:1 and 5:1) maximized the antiradical activity of phenolic extracts. In addition, extracts from grape samples previously subjected to distillation reached higher antiradical values in comparison to those coming directly from pressing; in both cases, seed extracts showed better results than those of stem when ethanol or water was employed, whereas the opposite occurred in the case of methanol. These differences were attributed to the different phenolic compositions of the considered fractions.  相似文献   

13.
The Maillard reaction has a dramatic impact on the overall acceptance and nutritional quality of most of the foods consumed daily in European countries. Melanoidins are polymeric structures formed in the last stage of the Maillard reaction with nearly unknown effect on the human health. The antiradical activity of several melanoidins isolated from model systems and coffee has been studied. A novel antiradical efficiency concept has been applied to describe the antiradical activity in an aqueous medium by bleaching the radical cation N,N-dimethyl-p-phenylenediamine (DMPD(*)(+)). Melanoidins exerted a significantly lower antiradical activity than classical antioxidant compounds (tannic acid, ferrulic acid, caffeic acid, gallic acid, and Trolox) in an aqueous medium. Significant differences have been observed according to the type of amino acid used as reactant during the formation of the melanoidin structure and the antiradical efficiency exerted.  相似文献   

14.
The application of a novel process based on the hydrothermal treatment of olive oil waste (alperujo) led to a final liquid phase that contained a high concentration of simple phenolic compounds. This study evaluated the effects of time (15-90 min) on the composition of the phenolic compounds isolated at a fixed temperature of 160 °C. Phenolic compounds were extracted with ethyl acetate. Both qualitative and quantitative HPLC analyses of the extracts showed variation of the concentrations of phenolic compounds with time. In addition, new phenols that were not present in the untreated control have been characterized. The antioxidant activities of different phenolic extracts was measured by various assays conducted in vitro: antiradical capacity (using DPPH and ABTS radicals), ferric reducing power (P(R)), inhibition of primary and secondary oxidation in lipid systems, and other tests, such as inhibition of tyrosinase activity. The results show that the phenolic extracts inhibited oxidation in aqueous and lipid systems to a significantly greater extent than the untreated control, and they performed as well as or better than vitamin E in this capacity.  相似文献   

15.
Summary The possible relationship between asparagus decline and the root necrosis potential (RNP) of soil was investigated for 11 asparagus and 4 nonasparagus soils. Asparagus seedlings were grown in each soil in climate chambers. A root necrosis index was used to determine RNP. RNP was correlated with the decline observed in the field for seven white asparagus crops, but not for three white and one green asparagus crops. Low RNP values were obtained from the soils not planted to asparagus.Fusarium oxysporum andF. oxysporum var. redolens accounted for 7070 of the fungi isolated from necrotic roots in RNP tests. BothFusarium were obtained from all soils. AllF. oxysporum andF. oxysporum var. redolens isolates tested were highly virulent on asparagus seedlings in inoculation experiments.F. solani, Penicillium verrucosum var.corymbiferum, andRhizoctonia violacea were isolated less frequently but were also highly virulent. It is concluded that soil RNP indicated a risk of decline caused by fusaria, but other soil factors were likely to be involved in the aetiology of decline. The study of these factors is necessary to develop a method for the prognosis of decline associated with fusaria.  相似文献   

16.
The effects of pearling on the content of phenolics and antioxidant capacity of two Canadian wheat classes, namely, Canada Western Amber Durum; Triticum turgidum L. var. durum; CWAD) and Canada Western Red Spring; Triticum aestivum L.; CWRS) were examined. The antioxidant activity of wheat phenolics was evaluated using oxygen radical absorbance capacity (ORAC), inhibition of photochemiluminescence (PCL), Rancimat method, inhibition of oxidation of low-density lipoprotein, and DNA. The phenolic composition of wheat extracts was determined using high-performance liquid chromatography. The antioxidant capacity of both pearled grains and byproducts significantly decreased as the degree of pearling increased. Among grains, the unprocessed whole grains demonstrated the highest antioxidant capacity. The byproducts always demonstrated higher antioxidant capacity compared to the pearled grains, regardless of the wheat class. The resultant byproducts from 10-20% pearling possessed the highest antioxidant capacity. Processing of cereals may thus exert a significant effect on their antioxidant activity. The concentration of grain antioxidants is drastically reduced during the refining process. As phenolic compounds are concentrated in the outermost layers, the bran fractions resulting from pearling may be used as a natural source of antioxidants and as value-added products in the preparation of functional food ingredients or for enrichment of certain products.  相似文献   

17.
The effect of Al on the growth and chemical composition of onions (Allium cepa L. cv Pukekohe longkeeper), asparagus (Asparagus officinalis L. cv Lucullus) and squash (Cucurbita maxima L. cv Delica) was investigated using a low ionic strength solution‐culture technique. Onions and asparagus were sensitive to Al while squash was relatively tolerant. The dry matter yields of onion, asparagus and squash tops were reduced 50% by 5, 3, and 26 μM Al in the solution, respectively. Similarly, root dry matter yields were reduced 50% by 1, 5, and 26 μM Al, respectivley. Aluminium reduced the concentration of macro nutrients in both asparagus and onion tops but had no consistent effect on squash tops. Plant analysis and visible symptoms indicated that Al affected magnesium nutrition more than that of any other nutrient.

The roots of squash showed an ability to recover from Al stress by modifying their morphology. However, this effect was insufficient to totally alleviate Al toxicity. Squash also became more sensitive to Al as the growing period progressed. These observations suggest that care is needed in using short term experiments to assess Al tolerance for some species.  相似文献   

18.
Almond hulls and grape pomace are residues abundantly generated by agricultural industries, which could be processed to obtain bioactive products. To this purpose, crude ethanol extracts from both agricultural byproducts were attained and subsequently fractionated in order to obtain an organic/water fraction (FOW). Extracts and fractions were analyzed for antioxidant power and their phenolic components tentatively identified by HPLC-MS. Chromatographic peaks of almond hull extracts showed the occurrence of hydroxybenzoic and cinnamic acid derivatives, with minor presence of flavan-3-ols (ECG, EGCG), whereas the FOW fraction offered the additional presence of epicatechin (EC) and glycosylated flavonols. In the composition for extracts of white and red grape pomace several of these compounds were also detected but basically consisted of glycosylated flavonols (quercetin, kaempferol). As a difference between both grape pomaces, myricetin glycosyde was found in that from the red variety, whereas flavan-3-ols (EC, afzelechin) were only identified in white pomace. When their FOW fractions were analyzed, gallic acid and some hydroxybenzoic acids were additionally detected. Antioxidant activity was assessed by DPPH and TBARS assays. Almond hulls showed inhibition percentages lower than 50% in both assays, while the inhibition percentage ranged from 80% to 90% in pomace extracts. Red grape pomace extract was the most efficient antioxidant, with an EC50 value of 0.91 g/L for TBARS and 0.20 g/L for DPPH. Even appearing as two quite different vegetal matrixes, the composition of phenolics in grape pomace and almond hulls is quite similar, the main difference being the major occurrence of flavonols in grape pomace. This fact could presumably explain the lower antiradical activity of hull extracts.  相似文献   

19.
The concentrations of mercury, lead, cadmium, and arsenic were evaluated in 96 samples, 12 by each one of the following eight fish species: snook (Centropomus undecimalis), crevalle jack (Caranx hippos), Serra Spanish mackerel (Scomberomorus brasiliensis), southern red snapper (Lutjanus purpureus), blue runner (Caranx crysos), Atlantic tarpon (Megalops atlanticus), ladyfish (Elops saurus), and Atlantic goliath grouper (Epinephelus itajara), which were collected during 1 year in the Atrato River Delta in the Gulf of Urabá, Colombian Caribbean. Three fish were caught from each of the following sites the community usually uses to catch them (known as fishing grounds): Bahía Candelaria, Bahía Marirrío, Bocas del Roto, and Bocas del Atrato. The quantification of metals was performed by microwave-induced plasma-optical emission spectrometry. The Pb concentration fluctuated from 0.672 to 3.110 mg kg?1, surpassing the maximum permissible limit (MPL?=?0.3 mg kg?1) for human consumption for all species. The Hg concentration ranged between < Limit of detection and 6.303 mg kg?1, and in the crevalle jack and Atlantic tarpon, concentrations exceeded the MPL (0.5 mg kg?1). The levels of Cd and As were not significant in the studied species and did not exceed the MPL (0.05 mg kg?1).  相似文献   

20.
Antioxidant compounds and antioxidant activity in "early potatoes"   总被引：1，自引：0，他引：1  
The antioxidant content and the antioxidant capacity of both hydrophilic and lipophilic antioxidant extracts from four "early potato" cultivars, grown in two different locations (Racale and Monteroni), were examined. There was a considerable variation in carotenoid content and weak differences in the ascorbic acid concentration of the examined cultivars of "early potato" and between the harvested locations. An increase in both methanol/water (8:2 v/v) and phosphate buffer soluble (PBS) free phenols (70%) and bound phenols (28%) in the extracts from the cultivars grown at Racale site was found and discussed. Examination of individual phenols revealed that chlorogenic acid and catechin were the major phenols present in potato tuber extracts; a moderate amount of caffeic acid and ferulic acid was also detected. The total equivalent antioxidant capacity (TEAC) was higher in the Racale extracts and a highly positive linear relationship ( R (2) = 0.8193) between TEAC values and total phenolic content was observed. The oxyradical scavenging capacity (TOSC) of methanol/water and PBS extracts of peel and whole potatoes against the reactive oxygen species (ROS) peroxyl radicals, peroxynitrite, and hydroxyl radicals was also analyzed. A highly significant linear correlation ( R (2) = 0.9613) between total antioxidant capacity (as a sum of peroxyl radicals + peroxynitrite) and total phenol content of methanol/water extracts was established. Moreover, proliferation of human mammalian cancer (MCF-7) cells was significantly inhibited in a dose-dependent manner after exposure to potato extracts. These data can be useful for "early potato" tuber characterization and suggest that the "early potato" has a potential as a dietary source of antioxidants.  相似文献   

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