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 31 毫秒
1.
The contents of total phenolic compounds, flavonoids, and phenolic acids were determined in selected garlic cultivars grown at four locations. The total phenolic content varied from 3.4 mg gallic acid equivalents (GAE)/g of dry matter (dm) to 10.8 mg GAE/g of dm with a mean value of 6.5 mg GAE/g of dm. The myricetin, quercetin, kaempferol, and apigenin flavonoids were not detected in any of the samples. Caffeic acid and ferulic acid were the major phenolic acids found with mean values of 2.9 mg/kg of dm and 2.6 mg/kg of dm, respectively. The mean contents of vanillic, p-hydroxybenzoic, and p-coumaric acids were comparable (0.4–0.8 mg/kg of dm), and the level of sinapic acid was negligible (< 0.1 mg/kg of dm). There was a significant effect of location but an insignificant effect of genotype on contents of caffeic, vanillic, p-hydroxybenzoic, and p-coumaric acids. However, genotype but not location affected the contents of total phenolics and ferulic acid. On average, the white garlic cultivars and Chinese garlic cultivars contained higher contents of total phenolics and ferulic acid than the purple garlic cultivars. However, the differences in the total phenolic content between the purple and white garlic cultivars were not significant.  相似文献   

2.
The antioxidative activities of water extract (WE) and crude hot-water soluble polysaccharide (PS) from Ficus carica L. fruit were investigated using various assays in vitro, including scavenging abilities on DPPH, superoxide and hydroxyl radicals and reducing power. The immunity activities of PS were evaluated using the carbon clearance test and serum hemolysin analysis in mice. In addition, total phenolics and flavonoids contents were also determined. Both WE and PS have notable scavenging activities on DPPH with the EC50 values of 0.72 and 0.61 mg/ml, respectively. The PS showed higher scavenging activity than WE on superoxide radical (EC50, 0.95 mg/ml) and hydroxyl anion radical (scavenging rate 43.4% at concentration of 4 mg/ml). The PS (500 mg/kg) also has a significant increase in the clearance rate of carbon particles and serum hemolysin level of normal mice. The results indicate that both WE and PS might be applicable in healthy medicine and food industry.  相似文献   

3.
Aerial parts (leaves and stem) of Raphanus sativus, which are usually discarded were found to possess potent antioxidant and radical scavenging activity, as measured by standard antioxidant assays. Methanolic and acetone extracts of R. sativus leaves had total polyphenolic content of 86.16 and 78.77 mg/g dry extract, which were comparable to the traditional rich sources such as green tea and black tea. HPLC identification of polyphenolics indicated the presence of catechin, protocatechuic acid, syringic acid, vanillic acid, ferulic acid, sinapic acid, o-coumaric acid, myricetin, and quercetin in leaves and stem. Among the different extraction solvents, methanolic extract of leaves and stem showed potent reductive capacity, significantly inhibited linoleic acid peroxidation and displayed metal chelating activity. Further, they scavenged free radicals effectively with IC50 (half maximal inhibitory concentration) of 31 and 42 μg/ml for DPPH radical, 23 and 52 μg/ml for superoxide radical, 67 and 197 μg/ml for hydrogen peroxide, and 56 and 62 μg/ml for nitric oxide, respectively. Leaves showed most potent antioxidant and radical scavenging activity as compared to stem, which may be accounted for the high polyphenolic content. Leaves and stem of R. sativus, often under-utilized part of this vegetable, thus possessed considerable amount of polyphenolics. Hence, it should be regarded as a potential source of natural antioxidants and could be effectively employed as an ingredient in health or in functional food.  相似文献   

4.
The aim of the study was to confirm the presence of rutin, one of the most common quercetin glycosides, and other quercetin derivatives in plants of genus Amaranthus, to investigate the influence of the species and variety on rutin distribution in the plant and content changes during growing season. The rutin content was determined by micellar electrokinetic capillary chromatography in individual plant parts at the beginning of the growth, at the flowering stage and at the maturity stage of five Amaranthus species. The total quercetin content was determined by micellar electrokinetic capillary chromatography too. The rutin content in amaranth ranged from 0.08 (in seeds) to 24.5 g/kg dry matter (in leaves). Comparison of the determined total quercetin content and the calculated content of quercetin released from rutin did not prove important presence of quercetin or other quercetin derivatives than rutin. Only amaranth leaves sampled at the maturity stage probably contained quercetin or quercetin derivatives. Significant differences in the rutin content were established among species and as well varieties. Amaranthus hybrid and A. cruentus were the best sources of rutin.  相似文献   

5.
The variation in the content and composition of Origanum majorana L. essential oil has been studied. Plant material has been harvested at four phenological stages (early vegetative, late vegetative, budding and full-flowering). Essential oil yield varied from 0.04 to 0.09% reached during the full-flowering stage. Analysis of the essential oils by GC and GC/MS revealed the presence of 38 components represented mainly by oxygenated monoterpenes (64.01–71.4%), monoterpene hydrocarbons (21.73–29.92%) and sesquiterpene hydrocarbons (1.47–4.05%). The main components were terpinen-4-ol (29.13–32.57%), cis-sabinene hydrate (19.9–29.27%), trans-sabinene hydrate (3.5–11.61%), γ-terpinene (2.11–8.20%), bornyl acetate (1.52–2.94%) and linalool (1.05–1.39%). On the other hand, phenolic contents varied from 2.706 to 6.834 mg/g of dry weight obtained during the later vegetative stage. RP-HPLC analysis of the methanolic extract of O. majorana L. dried aerial parts showed the predominance of phenolic acids during the early vegetative stage whereas flavonoids predominate during the other stages of growth. The main phenolic acids identified were trans-2-hydroxycinnamic, rosmarinic, vanillic, chlorogenic, gallic and cinnamic whereas the main flavonoids were amentoflavone, apigenin, quercetin, luteolin, coumarin and rutin. Results obtained showed that later vegetative stage is characterized by the highest contents of bioactive compounds and therefore it could be considered as the best stage for harvesting marjoram plants.  相似文献   

6.
Eriobotrya plants are known to have significant amounts of phenolics and flavonoids, and exhibit a strong antioxidant activity. Experiments were conducted to examine variation in the contents of total phenolics and flavonoids, and antioxidant activities in the leaves of 11 Eriobotrya species (Tibet loquat, Daduhe loquat, Hengchun loquat, Taiwan loquat, Oak leaf loquat, Bengal loquat, Fragrant loquat, Guangxi loquat, Obovate loquat, Big flower loquat, and common loquat, the last species include two materials, one is a cultivar ‘Zaozhong 6’, another is a wild tree). In these species, ‘Zaozhong 6′ loquat is a cultivar. The leaf extracts of ‘Tibet’, ‘Obovate’, ‘Taiwan’, ‘Bengal’ and ‘Hengchun’ loquats exhibited significantly higher contents of total flavonoids and total phenolics, compared with those of other species. Of these 11 species, the highest contents of total phenolics and total flavonoids were observed in ‘Tibet’ and ‘Obovatae’ loquats, respectively. The significantly stronger antioxidant abilities assessed by the DPPH radical scavenging activity and reducing power were obtained in the leaf extracts of ‘Taiwan’, ‘Tibet’, ‘Bengal’, ‘Oak leaf’, ‘Hengchun’ and ‘Obovate’ loquats, compared with the other species. In addition, significant correlations were found between the contents of total phenolics or flavonoids and DPPH radical scavenging activity/reducing power. This work indicates that the leaf extracts of the wild Eriobotrya species, ‘Tibet’, ‘Obovatae’, ‘Taiwan’, ‘Bengal’, ‘Oak leaf’ and ‘Hengchun’ loquats, exhibited significantly higher levels of total phenolics and flavonoids, and significantly stronger antioxidant activities, compared with the cultivated species, ‘Zaozhong 6′ loquat, which suggests that these wild species have a better utilization value.  相似文献   

7.
Carotenoids are pigments responsible for the yellow-reddish color of many foods and are related to important functions and physiological actions, preventing several chronic-degenerative diseases. The objective of this study was to confirm the carotenoid composition of jackfruit by high-performance liquid chromatography connected to photodiode array and mass spectrometry detectors (HPLC-PDA-MS/MS). The main carotenoids were all-trans-lutein (24–44%), all-trans-β-carotene (24–30%), all-trans-neoxanthin (4–19%), 9-cis-neoxanthin (4–9%) and 9-cis-violaxanthin (4–10%). Either qualitative or quantitative differences, mainly related to the lutein proportion, were found among three batches of jackfruit. Since the fruits from batch A showed significantly lower contents for almost all carotenoids, it also had the lowest total carotenoid content (34.1 μg/100 g) and provitamin A value, whereas the total carotenoid ranged from 129.0 to 150.3 μg/100 g in the other batches. The provitamin A values from batches B and C were 3.3 and 4.3 μg RAE/100 g, respectively. The carotenoid composition of jackfruit was successfully determined, where 14 of the 18 identified carotenoids were reported for first time. Differences among batches may be due to genetic and/or agricultural factors.  相似文献   

8.
Eight lupin (Lupinus angustifolius L.) genotypes grown at four locations in south central Alberta in 2004 were evaluated for variability in phenolic constituents and antioxidant activity measured by a photochemiluminescence assay. Genotype was the main source of variation for content of phenolic compounds and antioxidant activities. Phenolic compounds in genotypes varied minimally from 11.9 to 14.7 mg catechin equivalent and 4.15 to 4.95 mg rutin equivalent g−1 lupin for total phenolic and flavonoid contents, respectively. Lupin genotypes exhibited weak antioxidant activity based on water–soluble substances (ACW) of 0.54 to 1.07 μmole Trolox equivalent antioxidant capacities (TEAC)/g with lag time ranging from 70 to 153 s and an antioxidant index of 6.7 to 14.5 and 1.9 to 3.3 μmole TEAC/g based on measurements of lipid-soluble substances (ACL). Antioxidant activity of lupin genotypes was not related to phenolic contents of seeds.  相似文献   

9.
Bromelia pinguin L. is a plant native to Sinaloa, Mexico, where its fruit is used as food or as a phytotherapeutic agent. The fruits of B. pinguin were characterized and they could be considered as a functional food. These fruits show an average weight of 13.7 g and a yellow color of high luminosity (b* = 43.2, L* = 74.5). The values for acidity (4.6%, as citric acid) and pH (3.7) of B. pinguin fruit are similar to those of citrics. The edible portion is characterized by a high content of vitamin C (126 mg/100 g), ash (10.6 g/100 g d.w.), crude fiber (3.4 g/100 g d.w.), calcium (1290 mg/100 g d.w.), magnesium (500 mg/100 g d.w.), manganese (2.95 mg/100 g d.w.) and it is a good source of zinc (2.8 mg/100 g d.w.). Polar fractions extracted from the pulp fruit showed activity against several genera of human pathogenic-bacteria (Staphylococcus, Streptococcus, Enterococcus, Salmonella, Shigella, Escherichia and Pseudomonas).  相似文献   

10.
To contribute to the development of new methods to reduce the contamination of coffee beans with Aspergillus ochraceus and ochratoxin A, a toxin produced by this fungus, the present work initially aimed to select plant extracts active against A. ochraceus. Among the extracts from 43 plant species, the most active was the one obtained from leaves of Heteropterys byrsonimifolia. This extract was subjected to a fractionation process that resulted in the purification of four flavonoids, among which the most active against the fungus was rutin, which presented a minimal inhibitory concentration (MIC, 32.5 μg/mL) close to the value obtained for the commercial fungicide benzalkonium chloride (7.84 μg/mL). In vitro studies with the isolated flavonoids and other four from commercial sources showed that the MIC for the flavonoid chrysin is equal to that observed for rutin, and results from an in silico study suggested that these flavonoids act against A. ochraceus by binding to a protein kinase produced by this fungus. Consequently, this enzyme and the studied flavonoids are potentially useful for the development of new products to control A. ochraceus in coffee beans.  相似文献   

11.
Porophyllum tagetoides is an annual warm-weather herb that has an intense typical smell. Its leaves are commonly used in soup preparation and traditional medicine for treatment of inflammatory diseases. Its volatile compounds and antioxidant properties were evaluated in crude, aqueous and ethanol leaf extract and an oil emulsion using different antioxidant assays in vitro, such as: DPPH radical scavenging activity, redox potential, polyphenol content, reducing power and optical density. A high antioxidative activity was found when comparing leaves with stems. The crude extract from leaves showed a very high reducing power (2.88 ± 0.20 O.D.) and DPPH radical-scavenging activity (54.63 ± 4.80%), in concordance with a major concentration of vitamin C (23.97 ± 0.36 mg/100 g). Instead, the highest polyphenol content (264.54 ± 2.17 mg GAE/g of sample) and redox potential (561.23 ± 0.15 mV) were found by the ethanol and aqueous extract, respectively. Aldehydes and terpenes such as nonanal, decanal, trans-pineno, β-myrcene and D-limonene were the major volatiles found. This study suggests that Porophyllum tagetoides extracts could be used as antioxidants.  相似文献   

12.
Two wild (Dioscorea polygonoides and Rajana cordata) and seven cultivated varieties of Jamaican yams (Dioscorea spp.) were analyzed for their proximate composition and the levels of antinutritional factors. The protein level range was 47.8 ± 2.6 to 88.0 ± 2.5 g/kg dry weight. The lowest level was seen in D. cayenensis. The range for the dietary fiber content in the tubers was 16.3 ± 0.7 to 63.5 ± 0.4 g/kg dry weight. The wild yam varieties recorded higher levels. Saponins level was < 600 mg/kg dry weight in all the tubers analyzed except for bitter yam (2962.5 ± 60.5 mg/kg dry weight). Total phenol content ranged from 1.3 ± 0.1 to 79.3 ± 6.1 g/kg while total condensed tannin content ranged from 0.1 ± 0.0 to 26.7 ± 3.8 g/kg dry weight. Samples that showed high levels of phenols also had high levels of condensed tannins. All the samples analyzed contained low levels of lectins and no alkaloids were detected. The levels of antinutritional factors did not clearly delineate the wild varieties from the edible varieties.  相似文献   

13.
This work was carried out to investigate the pulp composition of four mango cultivars (Haden, Tommy Atkins and Ubá) at the ripening stage in relation to three components with antioxidant potential (total phenolics, carotenoids and ascorbic acid). Total phenolic compound content was estimated by the Folin-Ciocalteu reagent and total carotenoid content by spectrophotometry at 450 nm. The contents of β-carotene and total vitamin C (ascorbic acid and dehydroascorbic acid) were quantified by high performance liquid chromatography. Differences were found among the four mango cultivars in all the components analyzed. The content of phenolic compounds ranged from 48.40 (Haden) to 208.70 mg/100 g (Ubá); total carotenoid from 1.91 (Haden) to 2.63 mg/100 g (Palmer); β-carotene from 661.27 (Palmer) to 2,220 μg/100 g (Ubá) and total ascorbic acid ranged from 9.79 (Tommy Atkins) to 77.71 mg/100 g (Ubá). These results corroborated previous information that mangoes are a good source of antioxidants in human diet.  相似文献   

14.
This study was conducted in order to compare the nutrient and chemical contents of two Korean teas: traditional Chungtaejeon tea (CTJ) with that of green tea (GT). Main bioactive compounds and the antioxidant activities using four radical scavenging assays (ABTS, CUPRAC, FRAP and DPPH) in methanol and acetone extracts of both teas were determined. It was found that the contents of vitamin C, amino acids and total nitrogen in CTJ were lower than that of GT (p < 0.05). Caffeine, reducing sugar and chlorophyll contents in CTJ were similar to GT. Catechin (C), epicatechin (EC), and epigallocatechin (EGC) contents were lower in CTJ than in green tea (p < 0.05), but gallocatechin (GC), epicatechin gallate (ECG), epigallocatechin gallate (EGCG) and catechin gallate (CG) showed no significant differences between CTJ and GT (p ≥ 0.05). The contents of polyphenols, flavonoids, flavanols and tannins in CTJ methanol were 229.30 ± 11.3 mg GAE/g dry weight (DW), 15.24 ± 0.8 mg CE/g DW, 109.10 ± 5.1 mg CE/g DW and 25.68 ± 1.2 mg CE/g DW, respectively, and significantly higher than in acetone extracts (p < 0.05). Flavonoids (quercetin and kaempferol) were higher in GT than in CTJ and myricetin was higher in CTJ (p < 0.05). Threonine and aspartic acid was lower, and glutamic acid was higher in CTJ compared with GT (p < 0.05). Free amino acid content in CTJ and GT showed no significant difference. Potassium and magnesium in CTJ were lower compared to GT, but no significant difference was found for iron, manganese and calcium. Also, the level of the antioxidant activity by all four used assays was significantly higher in CTJ and in methanol was higher than in acetone extracts (p < 0.05). In conclusion, traditional fermented Korean tea Chungtaejeon contains high quantities of bioactive compounds and possesses high antioxidant activity. The contents of the bioactive compounds and the levels of antioxidant activities are significantly higher in methanol than in acetone extracts. 3-D fluorescence and FTIR- spectroscopy showed slight differences between the two investigated tea samples and can be used as additional tools for identification of polyphenols. Both studied teas can be recommended as a source of bioactive compounds.  相似文献   

15.
黄酮类与儿茶素类物质对茶叶感官品质和生物活性起重要作用,因此建立一种茶叶中总黄酮(包括黄酮类和儿茶素类)含量的测定方法很有必要.采用70％甲醇提取茶样,以芦丁为对照品,利用亚硝酸钠-硝酸铝-氢氧化钠溶液显色,在510 nm下测定吸光度,建立测定茶叶中总黄酮含量的分光光度法,并对其进行方法学考察.应用该法测定了绿茶、白茶、乌龙茶和红茶4个茶类15个茶样中总黄酮含量,采用福林酚法测定其茶多酚含量,并比较二者相关性.结果表明,芦丁质量浓度在0.2～1.0 mg·mL-1范围内与吸光度线性关系良好,回归方程为Y=1.2465X+0.0074(R2=0.9997).方法学考察结果表明,该方法精密度、重复性和稳定性的吸光度RSD为1.17％、2.92％和6.01％,平均加标回收率为84.35％(RSD=4.15％).15个茶样中总黄酮含量范围为5％～10％,总黄酮含量规律为:绿茶、白茶>乌龙茶>红茶.福林酚比色法测得茶多酚含量范围为7％～15％.双变量相关性分析显示,总黄酮含量与茶多酚含量呈极显著正相关,Pearson相关系数达0.874.由此表明,该方法操作简便,精密度、重复性与稳定性好,可用于茶叶总黄酮含量测定.  相似文献   

16.
The proximate composition of three varieties ofPiper guineense (Odusa — Ibibio/Efik) viz. Uyat Odusa (cultivated and peppery), Eting-keni Ikot (wild forest variety) and Eting-keni mben inyang (wild, riverine variety), were determined using available standard methods. Also determined were mineral, antinutrient and ascorbate levels. The cultivated pepperic variety had the highest content of crude protein and moisture (18.9% and 97% respectively) while the wild, riverine variety had the highest content of ether extract, carbohydrate and calories (7.79%, 63.38% and 398 cals respectively). The cultivated variety had appreciable amounts of phosphorus (1.12 mg/100 g), potassium (1.2 mg/100 g), sodium (0.24 mg/100 g), zinc (0.18 mg/100 g), and copper (0.18 mg/100 g) while the forest variety contained more of calcium (12.38 mg/100 g), magnesium (1.21 mg/100 g) and iron (0.85 mg/100 g). The wild riverine variety appeared to have the least mineral content but had the highest ascorbate level of 173.4 mg/100 g. Of four antinutrients assayed, the cultivated pepperic one had the least quantities while the forest variety was highest in hydrocyanic acid (85.8 mg/100 g) and glucosinolates (0.20 mg/100 g). The wild riverine variety had the highest level of total oxalate (165.0 mg/100 g). These quantities are however far below documented toxic levels.  相似文献   

17.
The phenolic compounds and flavonoids were determined from the extracts of Withania somnifera root (WSREt) and leaf (WSLEt). The WSREt has 28.26 mg/g total phenolic compounds and 17.32 mg/g flavonoids, whereas WSLEt has 5.4 mg/g total phenolic compounds and 5.1 mg/g flavonoids. The WSREt, WSLEt and glibenclamide were orally administered daily to diabetic rats for 8 weeks. After the treatment, the levels of urine sugar, blood glucose, liver glycogen, and antioxidants like vitamin C and E in plasma and superoxide dismutase (SOD), catalase (CAT), thiobarbituric acid reactive substances (TBARS), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and reduced glutathione (GSH) in liver, kidney and heart were determined. Diabetic rats showed a significant (p < 0.05) elevation in glucose and TBARS and a significant (p < 0.05) reduction in glycogen, vitamin C and E, SOD, CAT, GPx, GST, and GSH levels when compared to normal control rats. Administration of WSREt, WSLEt and glibenclamide to diabetic rats restored the levels to normal. In the light of aforesaid facts, it is suggested that the presence of phenolic compounds including flavonoids in W. somnifera root and leaf extracts and their antioxidant activity may play a vital role in reduction of blood glucose level in alloxan-induced diabetic rats.  相似文献   

18.
Natural oleoresins rich in lycopene were obtained from two varieties of tomato (Zedona and Gironda) and their nutraceutical potential (antioxidant and antimutagenic capacity) was evaluated. Both oleoresins had a high content of lycopene, 58.33 ± 1.67 mg/g (Zedona) and 63.97 ± 0.80 mg/g (Gironda). The antioxidant activity (AA) of the oleoresins by β-carotene method were 56.4–74.5% (Zedona) and 51–72.8% (Gironda), while when using the free radical stable 2,2-diphenyl-picryl-hydrazyl (DPPH) method, the antiradical activity (ARA) was determined to be 18.2–32.7% (Zedona) and 16.6–26.7% (Gironda) for the concentrations tested that of 200–400 μM equivalents of lycopene. The antimutagenic activity of the oleoresins was tested against aflatoxin B1 (AFB1) using the microsuspension assay, both varieties had a very high antimutagenic potential against AFB1 (60–66%).These results suggest the NCRT can be taken advantage to obtaining rich oleoresin in lycopene with a nutraceutical value.  相似文献   

19.
Studies on Indian Green Leafy Vegetables for Their Antioxidant Activity   总被引：1，自引：0，他引：1  
To identify the potential of green leafy vegetables (GLV) as antioxidants, methanolic extracts of Amaranthus sp., Centella asiatica, Murraya koenigii and Trigonella foenum graecum were studied for their antioxidant activity in different systems at multiple concentrations. Total antioxidant activity assessed by phosphomolybdenum method, free radical scavenging activity by 1,1-diphenly-2-picryl hydrazyl (DPPH), reducing power and ferrous ion chelating activity were determined. The GLV were analyzed for ascorbic acid, total and β-carotene and total polyphenol contents. The ascorbic acid, total carotene, β-carotene and total phenolic content (tannic acid equivalents) of the GLV ranged between 15.18–101.36, 34.78–64.51, 4.23–8.84 and 150.0–387.50 mg/100 g GLV, respectively. The extracts were found to have significantly different levels of antioxidant activities in the systems tested. The total antioxidant activity was highest in Murraya koenigii (2,691.78 μmol of ascorbic acid/g sample) and least in Centella asiatica (623.78 μmol of ascorbic acid/g sample). The extract concentration causing 50% inhibition of DPPH (IC50) was determined (M. koenigii < C.asiatica < Amaranthus sp. < T. graecum). The maximum DPPH scavenging activity and reducing power was exhibited by Murraya koenigii. Multiple regression analysis showed that the relationship of total antioxidant activity, free radical scavenging activity, and reducing power with polyphenol and total and β-carotene was highly significant. Paper awarded the Young Scientist Award in Experimental Nutrition at the Young Scientist Award Session of the 39th Annual Meet of the Nutrition Society of India, Hyderabad, India on 15–16th Dec 2007.  相似文献   

20.
Proximate composition, energy, mineral and vitamin contentsand the effect of blanching methods and times on the trypsinand chymotrypsin inhibitor activities were studied usingcabbage, collard, turnip, peanut, and sweet potato leaves.Results of this study indicated that, crude protein, crudefat, carbohydrate and ash contents were in the range of 15.5–25.6%, 1.4–6.5%, 60.4–73.1% and 6.8–7.5%,respectively. Total dietary fiber was lowest in cabbage (28.2 g/100 g) and highest in the collard leaves (43.1%)while energy content per 100 g of vegetables was highestin sweet potato leaves (402 kcal) and lowest in cabbage(379 kcal). The mineral content per 100 g of vegetableswere in the range of 33.4–249.8 mg, 241.2–471.2 mg,12.1–75.1 mg, 14.9–98.9 mg, 0.5–3.5 mg and 0.9–3.1 mgfor Ca, K, Na, Mg, Fe and Zn, respectively. For ascorbicacid, riboflavin, thiamin and total carotenoids, concentrations in 100 g of vegetables were in the range of45.1–112.7 mg, 0.2–0.3 mg, 0.3–0.8 mg and 2.0–7.3 mg,respectively. The trypsin inhibitory activity per gram ofthe vegetables was highest in collard (60.1 TIU/g) andlowest in peanut leaves (41.0 TIU/g). Chymotrypsin inhibitoractivity was highest in the peanut (69.6 CIU/g) but lowestin the collard leaves (48.0 CIU/g). Both trypsin and chymotrypsin inhibitor activities were significantly (p<0.05) reduced by most of the treatments in eitherthe conventional or microwave blanching methods. In the conventional blanching method, trypsin inhibitor activitywas reduced by 0.5, 6.8, 11.9, 9.0 and 19.3 percent in cabbage, collard, turnip, sweet potato and peanut leaves,respectively, when the vegetables were blanched for 2.5 minutes but after blanching for 10 minutes, the trypsininhibitor activity was reduced by 29.7, 34.9, 54.3, 52.3and 65.6 percent in cabbage, collard, turnip, sweet potatoand peanut greens, respectively. For the microwave ovenblanching, trypsin inhibitor activity was reduced by 3.8,3.3, 32.7, 5.0 and 9.5 percent in cabbage, collard, turnip,sweet potato and peanut leaves, respectively when thevegetables were blanched for 30 seconds. When blanched for60 seconds, trypsin inhibitor activity was reduced by 16.2,45.8, 46.2, 51.0 and 42.4 percent in cabbage, collard, turnip, sweet potato and peanut greens, respectively.Similar trends in the reduction of chymotrypsin inhibitoractivity were observed when the vegetables were conventionally blanched for 2.5, 5 and 10 minutes andwhen blanched by microwave oven for 30, 45 and 60 seconds.Based on the results of this study, the vegetables weregood dietary sources of minerals, vitamins, carbohydrateand proteins. Also, blanching was an effective method forreducing the trypsin and chymotripsin inhibitor activitiesin the leafy vegetables, however, further investigation onthe heating times for both conventional and microwaveblanching methods is suggested.  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