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1.
The nutrient and antinutrient components of tubers from seven cultivars ofDioscorea alata were determined. The average crude protein content ofD. alata tubers was 7.4%. Starch (75.6–84.3%) was the predominant fraction of the tuber dry matter. Significant differences in crude protein and starch contents were observed among cultivars. Vitamin C content of the yam tubers ranged from 13.0 to 24.7 mg/100 g fresh weight. The results showed yams to be reasonably good sources of minerals. Phytic acid contents of the yams were low, with values ranging from 58.6 to 198.0 mg/100 g dry matter. Total oxalate levels in yam tubers were found to be in the range of 486–781 mg/100 g dry matter, but may not constitute a nutritional concern since 50–75% of the oxalates were in the water-soluble form. The overall results are suggestive of the nutritional superiority of yams compared to other tropical root crops.  相似文献   

2.
The fruits of some wild plants were examined for their contents of mineral elements and ascorbic acid.High levels of ascorbic acid were found in fruits ofSclerocarya birrea (403.3 mg/100 g) andAdansonia digitata (337 mg/100 g). In nine of the fruits examined, the mineral contents (Ca, P) were comparable with average values found in common fruits. The iron contents were however 2–5 times higher than the values for common fruits.  相似文献   

3.
The nutrient composition, ofColocasia esculenta flowers (CF) and leaves (CL), and the green fruits ofSolanum melongena (SM) were carried out as a means to determine their nutritional potential. Results showed that these food materials had high moisture and fiber levels which ranged between 888 and 906 g·kg–1; and 204 and 303 g·kg–1 dry weight (dw) for moisture and fiber respectively. The calorific values were between 3889 and 4001 kcals·kg–1 dw, while the total lipids ranged from 53 in CF to 71 g·kg–1 dw in SM. The leaves ofColocasia esculenta had the highest crude protein value of 307 g·kg–1 dw. The flowers had 149 g·kg–1 dw while SM had 138 g·kg–1 dw. The amino acid profile in the flowers and leaves ofColocasia esculenta in contrast to SM were balanced comparable to the reference FAO pattern. Ash values were high (ranging from 76 in SM to 98 g·kg–1 in CL) with potassium being the principal element. Iron and Zinc levels were also high especially in CF (with 303 and 82 mg·kg–1 dw respectively). These foods also contained moderate quantities of calcium, phosphorus and magnesium but were poor in manganese and copper.  相似文献   

4.
The lipid content and fatty acid profiles of four lesser known tropical seeds,Piper guineense, Chrysophyllum albidum, Garcinia kola andDennettia tripetala, were determined. The total lipid content (g/kg dry weight) ranged between 31.8 and 68.9. The ranges of values for neutral lipids, triacylglycerol of neutral lipids, glycolipids and phospholipids were 17.3–58.0, 15.0–49.6, 3.0–7.2 and 3.7–11.2, respectively. The fatty acid profiles showed variation among different seeds. All the seeds contained substantial amounts of unsaturated fatty acids. Oleic and linoleic acids were the most abundant fatty acids.Dennettia tripetala andPiper guineense also contained moderate amounts of linolenic acid.  相似文献   

5.
The effects of the water extract ofSphenostylis stenocarpa were observed on the guinea pig ileum and rabbit jejunum. The extract produced dose dependent — contractions of the guinea pig ileum with an ED50 of 3.664×10–5 g/ml and a calculated dose ratio of 1.25. The extract specifically stimulated muscarine receptors. Atropine (8×10–7 g/ml) caused a parallel shift to the right of the log dose — response curve in the guinea pig ileum suggesting a competitive antagonism. Boiling for about 12 h did not affect the contractile action of the extract on tissue preparations. However, boiling for 12–14 h completely abolished its contractile effect. Incubation of the extract with cholinestrerase at 37°C for 1 h did not abolish its contractile action on the intestine.  相似文献   

6.
Flax shives are the woody residue left over from processing flax straw into fiber, and are an abundant renewable lignocellulosic material with a potential for the conversion into bioethanol and other value added products. In this study, prior to enzymatic hydrolysis for the liberation of fermentable sugars, such as glucose and xylose, flax shives were treated with concentrated phosphoric acid. In order to optimize the phosphoric acid pretreatment and enzymatic hydrolysis steps, the effects of three process variables on the fractionation of flax shives, and enzymatic digestibility of pretreated flax shives were evaluated. The optimization process employed a central composite design (CCD), where the variables selected were concentration of phosphoric acid (40.8–86.2%), pretreatment time (9.5–110.5 min), and cellulase loading (13.1–71.9 FPU/g cellulose). Using three-variable and five-level CCD, all tested independent variables were identified to have significant effects (P < 0.05) on the digestibility of pretreated flax shives. It was found that the level of phosphoric acid (P < 0.0001) affects the digestibility most significantly when compared with other variables. When the optimization was conducted under a constrain of minimum cellulase loading, the maximum digestibility of 94.8% was predicted when the phosphoric acid concentration, pretreatment time, and cellulase loading were 86.2%, 110.5 min, and 13.1 FPU/g cellulose at 50 °C and 120 h, respectively. Under these conditions, digestibility of pretreated flax shives in the validation study reached a maximum of 93% at 120 h of incubation, showing good agreement with the values from the validation experiment of 93.4%, indicating high accuracy of the CCD procedure. When triticale straw, pine wood, and poplar wood were pretreated and hydrolyzed under optimum conditions obtained from the flax shives experiment, the digestibility reached 98.2, 74.8, and 95.7%, respectively, suggesting that the modest pretreatment process using phosphoric acid is an effective method for perennial plants as well as hard wood.  相似文献   

7.
Seven accessions of the underutilized legume, Cassia hirsuta L., seeds collected from seven different agroclimatic regions of Tamil Nadu, India, were analyzed for proximate composition, total proteins, protein fractions, mineral profiles and selected antinutritional factors. Crude protein ranged from 15.52 to 20.74%, crude lipid 3.77–7.04%, crude fiber4.68–6.92%, ash 3.98–6.42% and carbohydrates 62.45–70.16%. Energyvalues of the seeds were 1549–1634 kJ/100 g (DM), which are comparable to those of other legumes. Data on seed protein fractions revealed thatglobulins constituted the bulk of the seed protein as in most legumes. Mineralcontents of the seeds showed greater variation. Potassium was the mostabundant mineral (1029–1786 mg/100 g), whereas manganese was low (2.1–2.2 mg/100 g). Antinutritional factors such as total free phenolics,tannins, L-DOPA and lectins were analyzed. The results of the studydemonstrated that the accessions of C. hirsuta seeds collectedfrom Tamil Nadu, India, could be good sources of some important nutrientsfor humans.  相似文献   

8.
A rapid and convenient method to separate and quantify ursolic acid (UA) and oleanolic acid (OA) of cornus (Macrocarpium officinale (Sieb. et Zucc.) Nakai), a traditional Chinese medicine and food materials, was established by reversed-phase high performance liquid chromatographic (RP-HPLC). The Linear ranges were 1.01–6.06 μg/μl for UA and 0.51–2.55 μg/μl for OA with good correlation. The average recovery rates were 103.0% of UA and 97.9% of OA, respectively. The precision and the repeatability of the analytical method were satisfied. Samples of cornus at different developmental stages were detected, and the UA contents varied from a high of over 0.520% to less than 0.107%, while OA contents varied from 0.221% to 0.050% during the fruit growth. This study showed that the contents of UA and OA varied considerably with fruit development, especially with the development of exocarp, and the results indicated that the appropriate picking time was in later September. The distinct contents of UA and OA in different parts of cornus (exocarp, sarcocarp, and core) suggested the two compounds mainly located in exocarp of the fruit.  相似文献   

9.
The seed oils ofParkia biglobosa andParkia bicolor (Mimosaceae) have been analysed for their possible edible utility and to provide some physical data on both oils. The fatty acid composition of the oils was identified. Six major fatty acids were identified in the oil ofP. bicolor while five were identified in that ofP. biglobosa by Gas Chromatography (GC) and Gas Chromatography — Mass Spectroscopy (GC — MS). The two oils contained five similar fatty acids in almost the same ratios. Arachidic acid was the most abundant fatty acids (greater than forty per cent) in both oils. Other fatty acids in the oils were behenic, stearic, palmitic and linoleic acids. The sixth fatty acid inP. bicolor was an odd number of carbon atom and un unsaturated fatty acid (C20H37COOH) named bicolargic acid. The oils were also found to be non toxic.  相似文献   

10.
Samples of sundried, matured red pepper,Capsicum annum with a moisture content (MC) of 12.7–26.8 percent had on dry weight basis, vitamin C, 5.0–6.4 mg/100 g; crude protein, 0.8–1.2 percent; total soluble solids, 3.3–4.1 percent, and fungal counts of log 4.4–4.5/g. Ordinary matured redC. annum had MC, 75.7–78.2 percent vitamin C, 36.1–38.5 mg/100 g; crude protein, 2.4–2.8 percent; total soluble solids, 9.3–9.9 percent and fungal count of log 3.32–3.39/g. Sundried matured redC. frutescens had corresponding values of 9.4–18.7 percent; 5.8–6.3 mg/100 g; 0.8–1.1 percent; 0.9–2.6 percent and log 3.2–3.4/g. No aflatoxins were detected in sundried, matured redC. frutescens, but aflatoxin B1 values obtained fromC. annum varied from non-detectable to 2.2 µg/kg. Dominant fungi isolated fromC. annum andC. frutescens wereRhizopus oryzaze,Aspergillus niger,A. flavus,Geotrichum candidum andSaccharomyces spp.  相似文献   

11.
The activities of endogenous (R-type) and exogenous acting (D-type) protein inhibitors ofalpha-amylase and the activities ofalpha- and total amylase were determined in milling fractions of rye. High D-type amylase inhibitor activities were detected in the embryo (255 IU/g) and in the endosperm fraction (64·9 IU/g), low inhibitor activities were found in the aleurone layer fraction (25·9 IU/g). The highest R-typealpha-amylase inhibitor activity was found in the aleurone layer fraction (32·6 IU/g), and the lowest value in the epidermis containing fraction (5·0 IU/g). The D- and R-typealpha-amylase inhibitor activities varied with growing conditions. D-type amylase inhibitor activities were found to be high in those samples which grew under drought conditions and low in samples cultivated under wet and cool weather. Higher R-typealpha-amylase inhibitor activities were found in rye genotypes cultivated under wet conditions and lower values under dry weather. There were small variations inalpha-amylase inhibitor activities between sprout-stable and sprout-sensitive rye genotypes. The D- and R-typealpha-amylase inhibitor activities of all varieties were stable during 72 h of germination. Similar soil conditions will therefore lead to differentialalpha-amylase inhibitor activities depending on weather conditions during growth.  相似文献   

12.
Effects of soaking, cooking and autoclaving on changes in polyphenols, phytohaemagglutinating activity, phytic acid, hydrogen cyanide (HCN), oligosaccharides and in vitro protein digestibility were investigated in seeds ofDolichos lablab var.vulgaris. Both distilled water and NaHCO3 solution soaking and autoclaving significantly reduced the contents of total free phenolics (85–88%) compared to raw seeds. Autoclaving (45 min) reduced the content of tannins by upto 72%. Soaking seemed to have limited effect in eliminating phytohaemagglutinating activity, whereas autoclaving (45 min) seemed to eliminate the haemagglutinating activity completely. The reduction in content of phytic acid was found to be some what greater in distilled water soaking (28%) compared to NaHCO3 solution soaking (22%). Only a limited loss in content of phytic acid was observed under cooking as well as autoclaving. Loss of HCN was greater under autoclaving (87%) compared to the other processes studied. Of the three sugars analysed, soaking reduced the level of verbascose more than that of stachyose and raffinose. Autoclaving reduced the content of oligosaccharides more efficiently (67–86%) than ordinary cooking (53–76%). Autoclaving improved the in vitro protein digestibility (IVPD) significantly (13%). Of all the different water and hydrothermal treatments studied autoclaving seemed to be the most efficient method in improving IVPD and eliminating the antinutrients investigated except phytic acid.  相似文献   

13.
Four ferulic acid dehydrodimers were isolated from rye bran and purified by preparative HPLC after alkaline hydrolysis. The identity of the compounds were confirmed by UV,1H and13C-NMR and mass spectroscopy. The content of the four identified dimers corresponded to a total dimer concentration of 307 μg/g (dry matter) of the whole grain. The concentrations in the bran fraction were 10–20 times higher than in the starchy endosperm. The four dimers were in decreasing amounts: ((Z)- β -{4-[(E)-2-carboxyvinyl]-2-methoxyphenoxy}-4-hydroxy-3-methoxy-cinnamic acid (8-O-4′-DiFA);trans -5-[(E)-2-carboxyvinyl]-2-(4-hydroxy-3-methoxy-phenyl)-7-methoxy-2,3-dihydrobenzofuran-3-carboxylic acid (8-5′-DiFA benzofuran form), (E,E)-4,4′-dihydroxy-5,5′-dimethoxy-3,3′-bicinnamic acid (5-5′-DiFA) and (E,E)-4,4′-dihydroxy-3,5′-dimethoxy-β,3′-bicinnamic acid (8-5′-DiFA). The ferulic acid dehydrodimers were also synthesised by a simple procedure from ethyl ferulate using peroxidase and hydrogen peroxide.  相似文献   

14.
The protein, trypsin inhibitor (TI), tannin, phytate, phytic acid phosphorus and in vitro protein digestibility (IVPD) of cultivars of the African yambean (Sphenostylis stenocarpa) — AYB, pigeon pea (Cajanus cajan) — PP and cowpea (Vigna unguiculata) — CP were determined. The protein content of CP (24–28.0%) was higher than those of PP (21–22.5%) and AYB (21–22.5%). The cream and speckled AYB contained more TI (30.9 and 25.3 mg/g) than PP (7.5–14.1 mg/g) and CP (9.8–20.5 mg/g). Apart from the white CP cultivar, they contained more tannin (1.24–1.42 mg/g) than PP (0.14–0.97 mg/g) and AYB (0.71–1.17 mg/g). Phytate was lowest in the AYB (6.30–7.49 mg/g) than PP (8.31–11.31 mg/g) and CP (8.40–9.92 mg/g). Phytic acid contributed 67–74% of the phosphorous in the AYB, 66–75% in PP and 54–59% in CP. The IVPD of the AYB (73.3±0.7%) was significantly lower (p<0.05) than those of PP (76.34±0.2%) and CP (77.8±0.4%). There was a significant negative correlation between TI and IVPD (r=–0.63,p<0.05). There was no significant correlation between IVPD and phytate and tannin contents. There was a positive correlation between protein content and IVPD (r=0.69**) for the legumes under study. These legumes may pose no serious problems to populations consuming them especially when heat treatment is applied before consumption.  相似文献   

15.
Summary The phenolic acids benzoic, caffeic, chlorogenic, ferulic, p-coumaric, protocatechuic, salicylic, sinapic, syringic and vanillic together with vanillin, were tested for their ability to inhibit polygalacturonic acid lyase (PL) and polygalacturonase (PG) in culture filtrates ofErwinia carotovora subsp.carotovora. None of the compounds inhibited PL at 200 μg/ml, although syringic and sinapic acids caused a 54% and 43% reduction respectively at 400 μg/ml. PG was strongly inhibited by caffeic acid (57% inhibition at 100 μg/ml) and chlorogenic acid caused slight inhibition. Little if any inhibition of PG was caused by benzoic, ferulic, p-coumaric, protocatechuic, salicylic, sinapic, syringic, and vanillic acids or vanillin. The percentage inhibition of PG by chlorogenic acid was not affected by pH values over the range 4–7.  相似文献   

16.
The influence of irradiation on biosynthesis of ascorbic acid and riboflavin in germinating soybean seeds in tap and distilled water at ambient (25–35°C) conditions was investigated. Ascorbic acid was not detectable in the original seeds and the initial level of riboflavin was 3.3 g/g. The rate of synthesis of these vitamins increased with increasing germination time up to 72–96hr followed by a decreasing pattern depending upon the treatment. The effect of irradiation and germination on the synthesis of these vitamins was statistically significant (P<0.01). Maximum amounts of ascrobic acid 16.2 and 15.0 mg/ 100 g (fresh weight basis) were found in the 0.10 kGy sample after 72 hr of germination in tap and distilled water, respectively. However, a radiation dose of 0.20 kGy resulted in the development of maximum values of riboflavin, 30.0 and 27.0 g/g (dry weight basis) on germination in tap and distilled water respectively.  相似文献   

17.
The fermented food, trahanas (a milk-wheat flour combination prepared in Greece), was studied to determine the microbiological and chemical changes that occur during fermentation. It is a lactic acid bacterial fermentation in whichStreptococcus lactis, Streptococcus diacetylactis, Leuconostoc cremoris, Lactobacillus lactis, Lactobacillus casei, Lactobacillus bulgaricus andLactobacillus acidophilus play the major acid- and aroma-producing role. The whole fermentation lasts about 50 hours. The pH of the final dried trahanas was 4.07–4.75, the acidity 0.60–1.00%, the moisture content 8.6–11.5% and the protein content 10.4–13.6%. The product offers possibilities as an increased nutritive value or high-protein food.  相似文献   

18.
Protein efficiency ratio (PER), relative PER (RPER), net protein ratio (NPR) and relative NPR (RNPR) values, and amino acid scores were calculated for 20 food products (casein, casein + Met, beef salami, skim milk, tuna, chicken frankfurters, sausage, heated skim milk, peanut butter, rolled oats, soy isolate, chick peas, pea concentrate, kidney beans, wheat cereal, pinto bean, lentils, rice-wheat gluten cereal, macaroni-cheese, and beef stew). In most cases, PER, RPER, NPR or RNPR ranked the products in the same order and positive correlations among the protein quality methods were highly significant (r=0.98–0.99). Amino acid scores (based on the first limiting amino acid, Lys-Met-Cys, Lys-Met-Cys-Trp or lys-Met-Cys-Trp-Thr) were positively correlated to the PER, RPER, NPR or RNPR data (r=0.61–0.75). Inclusion of the correction for true digestibility of protein improved the correlations between amino acid scores and the indices based on rat growth. The correlations were especially high between Lys-Met-Cys scores (corrected for true digestibility of protein) and PER, RPER, NPR or RNPR (r=0.86–0.91). Inclusion of the correction for true digestibility of individual amino acids did not result in further improvements of the correlations in most cases. It is concluded that adjusting amino acid scores for true digestibility of protein would be sufficient and further correction for digestibility of amino acids would be unnecessary in mixed diets.This paper was presented in part at the 71st annual FASAB meeting, Washington, DC, March 29–April 2, 1987.  相似文献   

19.
Four accessions of the lesser-known legume, Cassia obtusifolia L. (Sickle pod), collected from four different agroclimatic regions of Western Ghats, were evaluated for agrobotanical traits and chemical composition. Amongthe four accessions, the Keriparai accession had the highest values for plant height (cm), number of flowers per cluster, number of pods per cluster, pod length (cm), seeds per pod, seed weight (g) per pod and seed recovery percentage. Crude protein ranged from 18.56–22.93%, crude lipid was between 5.35–7.40%, crude fiber ranged from 6.83–9.45%, ash content ranged from 5.14–5.83% and carbohydrate varied from 57.00–60.69%. Globulins constituted the bulk of the seed protein as in most legumes. Mineral profiles, viz., sodium, potassium, calcium, magnesium, phosphorus, iron, copper, zinc and manganese ranged from 42.92–84.83, 758.05–1555.79, 559.92–791.72, 456.36–709.47, 629.13–947.79, 8.42–12.35, 0.93–2.06, 10.60–30.04 and 2.12–4.12 Mg/100 g seeds flour, respectively. Seed proteins of all accessions exhibited relatively high levels of non-essential and essential amino acids, with the exception of threonine. The in vitro protein digestibility of the legume ranged from 74.66 to 81.44%. Antinutritional substances such as total free phenolics ranged from 0.34–0.66%; tannins were between 0.47–0.60%, L-DOPA content ranged from 0.98–1.34%; trypsin inhibitor activity varied from 11.4–13.5 TIU/mg protein and chymotrypsin inhibitor activity ranged from 10.8–12.3 CIU/mg protein. Phytohemagglutinating activity also was assayed. Inconclusion, the accessions of C. obtusifolia, collected from Western Ghats, South India, could serve as a low-cost source of some important nutrients for humans. The antinutritional factors might have little nutritional significance, if the seeds are processed properly.  相似文献   

20.
The acid extract viscosities and β-glucan contents of ten two- and six-rowed barley cultivars grown at seven locations in three consecutive years in Spain were studied in the present work. The viscosities varied from 2·4 to 24·8 centistokes (cSt) and the mean value was 6·4 cSt. The average β-glucan content of barleys determined by HPLC was 3·5% with a range of 1·9–5·5%. Significant differences were found in both β-glucan content and acid extract viscosity between different cultivars, locations and years. The β-glucan contents and viscosities of winter cultivars were higher than those of spring. Cvs. Barbarrosa and Hatif de Grignon were the genotypes with the highest values for both parameters, while cv. Beka had the lowest viscosity and β-glucan content. Environmental factors influenced both parameters. The acid extract viscosities of barleys were correlated negatively with the amount of precipitation (r=−0·754;P<0·05). Barleys grown in wet and rainy areas (Girona and La Coruña) had lower viscosity values.  相似文献   

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