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.
《Food chemistry》1998,62(2):207-215
Four varieties of Jatropha curcas which originated from Nicaragua (Cape Verde and Nicaragua toxic varieties cultivated in Managua), Nigeria (a wild variety from Ife; toxicity unknown) and Mexico (a wild non-toxic variety collected from Papantla) were studied. The average seed weight was 0.69, 0.86, 0.53 and 0.65 g for Cape Verde, Nicaragua, Ife-Nigeria and non-toxic Mexico varieties, respectively. The kernel to shell ratio in seeds was relatively similar (62.7:37.3 for both Cape Verde and Nicaraguan, 60:40 for Ife-Nigerian and 63.5:36.5 for non-toxic Mexican). The shell of the seeds composed mainly of fiber (>83% neutral detergent fiber) and very little crude protein (CP < 6%). The kernels were rich in CP (22.2–27.7%) and lipid (53.9–58.5%). The meal (defatted kernels) had a CP content of 57.3, 61.9, 56.1 and 64.4% for Cape Verde, Nicaragua, Ife-Nigeria and non-toxic Mexico varieties, respectively, and about 90% of this CP was true protein. The pepsin insoluble nitrogen was from 5.5 to 7%. The amino acid composition of meals from Cape Verde, Nicaragua and non-toxic Mexico varieties was similar. The levels of essential amino acids except lysine were higher than that for the FAO reference protein. The meal from the toxic variety (Cape Verde) did not have any anti-fermentative activity on rumen microbes. The estimated digestible organic matter (DOM) and metabolizable energy (ME) for the shells were low (26.2–27.1% and 2.4–2.8 MJ kg−1), whereas these values for Jatropha meals were 77.3–78.4% and 10.7–10.9MJ kg−1. For commercially available (heat-treated) soyabean meal, DOM and ME were 87.9% and 13.3MJ kg−1, respectively. The in-vitro rumen degradable nitrogen (% of total nitrogen) for meals from Cape Verde, Nicaragua, Ife-Nigeria and non-toxic Mexico varieties was 43.3, 37.7, 38.7 and 28.9, respectively, and for the soyabean meal it was 80.9%. Tannins, cyanogens, glucosinolates and amylase inhibitors were not detected in meals of any of the four varieties. A small amount of tannins were present in shells (2.0–2.9% as tannic acid equivalent). High levels of trypsin inhibitor activity (18.4–26.5 mg trypsin inhibited g−1), lectin (51–102; inverse of the minimum amount in mg ml−1 of the assay which produced haemagglutination in presence of 10 mM Mn2+) and phytate (7.2–10.1%) were observed in the meals. The concentrations of phorbol esters in kernels of Cape Verde, Nicaragua and Ife-Nigeria varieties were 2.70, 2.17 and 2.30mg g−1, whereas kernels of non-toxic Mexican had a very low level (O.11 mg g−1) of phorbol esters.  相似文献   

2.
《Food chemistry》2001,74(4):507-511
Nine accessions of the wild jack bean (Canavalia ensiformis L. DC) seeds collected from nine different locations of south India were analysed for proximate composition and mineral profiles. The major findings of the study were as follows: crude protein ranged from 28.9 to 35.0%, crude lipid 3.4–4.7%, crude fibre 7.0–10.7%, ash 3.0–5.8%, carbohydrates 46.1–54.5% and energy levels 1469–1574 kJ 100 g−1 DM. Significant (P<0.05) diversity was observed in crude protein and carbohydrate contents among the accessions collected from different locations based on analysis of variance (ANOVA) analysis. Potassium was the most abundant mineral, which ranged from 634 mg 100 g−1 in Dasukuppam accession to 1017 mg 100g−1 in Valacode accession. Sodium and magnesium levels are generally low with mean values of 63 and 250 mg 100 g−1, respectively. In the present study, in all minerals, significant diversity was observed among the accessions collected from different locations.  相似文献   

3.
Thirty‐eight rice varieties, grown in Low Country Wet Zone, during Yala (2006) and Maha (2006/2007) seasons were screened for stable high iron rice varieties and were statistically analysed. Iron contents ranged 1.89–3.73 mg 100 g?1 and varied significantly (P < 0.05) with variety and season. Selected fifteen high iron rice varieties, at degree of polishing 8–10% were analysed for iron, zinc and phytate. High iron contents in endosperm were observed in Suduru Samba (0.47 mg 100 g?1), Basmati 370 (0.37 mg 100 g?1), Kalu Heenati (0.42 mg 100 g?1), Rathu Heenati (0.44 mg 100 g?1) and Sudu Heenati (0.37 mg 100 g?1). Phytate contents of polished rice varieties ranged from 200–300 mg 100 g?1. Large reduction in iron content (84.5–93.6%) was observed in polished rice while the reduction in phytate content (18.9–40.8%) was low. Percentage dialyzability of iron in selected endosperm high iron rice varieties ranged from 1.73 to 8.71. Dialysability of iron in cooked polished rice did not show a relation to the phytate content in raw rice.  相似文献   

4.
In the present study, the influence of Beta vulgaris root powder (BVP) incorporated at 0%, 5%, 7.5%, 10% and 12.5% levels on the empirical and fundamental rheological characteristics; dough texture properties; nutritional and bioactive components in the doughnut were carried out. The addition of BVP, decreased the WAC (58.4%–51.2%), DDT (6.19–1.31 min), extensibility (148–95 mm), and springiness (4.56–3.24 N) and viscosity parameters to varying extent. The frequency sweep test indicated that both the dynamic moduli increased and G' was higher than G" at all levels indicating the solid elastic structure of the dough. The dimensional characteristics of the doughnuts indicated a decrease in volume (103.3–85 mL) and an increase in weight (35.8–46.7 g) and compression force (11.6–14.5 N). The sensory studies indicated that 10% BVP incorporated doughnut was highly acceptable with higher dietary fibre content. The higher retention of betacyanin (17.88 mg 100 g−1), betaxanthin (12.9 mg 100 g−1), betanin (6.61 mg 100 g−1), TPC (25.74 mg GAE 100 g−1), TFC (77.08 mg QE 100 g−1) and TAC (28.76 mMTE 100 g−1) was observed.  相似文献   

5.
The hemicellulosic fraction of brewer's spent grain (BSG) was hydrolysed with diluted acid under different conditions of liquid/solid ratio (8–12 g g−1), sulfuric acid concentration (100–140 mg g−1 dry matter) and reaction time (17–37 min) in order to produce a liquor with a large amount of xylose and good fermentability to produce xylitol. Results showed that all the evaluated reaction conditions were able to hydrolyse xylan and arabinan with efficiencies higher than 85.8 and 95.7% respectively, and even under the mildest reaction condition a considerable amount (92.7%) of the hemicellulosic fraction could be extracted. The hydrolysates presented different fermentabilities when used as fermentation media for xylitol production by Candida guilliermondii yeast, owing to the differences in their composition. Based on statistical analysis, the best condition for BSG acid hydrolysis was the use of a liquid/solid ratio of 8 g g−1, 100 mg H2SO4 g−1 dry matter and a reaction time of 17 min. Under this condition a high extraction efficiency of hemicellulosic sugars (92.7%) and good fermentation results (YP/S = 0.70 g g−1 and QP = 0.45 g dm−3 h−1) were attained. Copyright © 2005 Society of Chemical Industry  相似文献   

6.
trans-Resveratrol, antioxidant activity, phenolic compounds, proximate composition, and fatty-acid composition were quantified in different parts (peel, pulp, and seeds) of four grape varieties: Brazil (Vitis vinifera), Benitaka (V. vinifera), Isabel (Vitis labrusca) and Niagara (V. labrusca). Large concentrations of polyunsaturated fatty acid (18.84 and 9204.27 mg 100 g− 1), linoleic acid (LA, 18:2n-6), from 5890.87 to 9148.93 mg 100 g− 1, and alpha-linolenic (LNA, 18:3n-3), from 5.25 to 56.85 mg 100 g− 1, were found in different parts of the four grape varieties. The lowest concentrations necessary for 50% inhibition of DPPH were (9.26 to 126.91 ??g mL− 1) in seeds; the pulp did not have antioxidant activity. The total phenolic content varied between 0.04 and 122.35 mg EAG g− 1; seeds had the highest concentrations (89.83 to 122.35 mg EAG g− 1), especially in Niagara and Isabel varieties. trans-Resveratrol was detected in peels (1.17 to 12.96 ??g g− 1) and seeds (2.03 to 2.44 ??g g− 1) of the four varieties; however, it was absent in the pulp.  相似文献   

7.
In this study, the chemical composition, total phenolic content and antioxidant activity (DPPH, ORAC and FRAP assays) of A. subrufescens and P. ostreatus, cultivated with handmade and commercials supplements, were compared. Additionally, the compounds ergosterol, saccharopine, and hexitol were identified in A. subrufescens by HPLC-MS/MS. The antioxidant compound p-coumaric acid and dihexoses was found in both mushroom species. A. subrufescens presented higher total phenolic content (73.8 ± 0.6 mg GAE 100 g−1) and antioxidant activity than P. ostreatus (16.6 ± 0.5 mg GAE 100 g−1). The handmade supplement based on the waste of noble grains presented statistically similar phenolic content to the mushrooms cultivated with commercial ones Spawn Mate II SE (86.1 ± 1.4 and 92.9 ± 0.3 mg GAE 100 g−1, respectively). Therefore, the results support the use of handmade supplements based on agro-wastes as a viable alternative to the use of high-cost commercial ones.  相似文献   

8.
In the volcanic islands of the Azores archipelago, pasture is available the entire year and affects the composition of bovine milk fat. The composition of cows' milk butter manufactured in this region was evaluated. All brands showed excellent microbiological and oxidative quality. The fatty acid profile range presented a low n-6/n-3 ratio (1.81–3.38), low atherogenic (2.86–3.11) and thrombogenicity (3.27–3.60) indices and reduced cholesterol content (136–143 mg 100 g−1). In addition, Azorean butters have a high content of conjugated linoleic acid (0.44–0.64 mg 100 g−1), β-carotene (0.12–0.17 mg 100 g−1) and α-tocopherol (1.40–2.20 mg 100 g−1). Sensory analysis revealed high scores for appearance, consistency and flavour of all brands. These results indicate that Azorean butters produced from cows’ milk based on grass-feeding have a potentially healthier fat content and a desirable flavour that, associated with its “natural image”, may be promoted for product differentiation.  相似文献   

9.
《Food chemistry》2001,72(3):389-394
A high-performance liquid chromatographic (HPLC) assay for the extraction and quantitative determination of L-Dopa, L-3-carboxy-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline and 1-methyl-3-carboxy-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline in Mucuna pruriens var. utilis seeds has been developed. All the three compounds, L-Dopa, CDTHIQ and MCDTHIQ in the white variety of whole (4.96 g 100 g−1, 130.3 and 116.8 mg 100 g−1) and dehulled (5.21 g 100 g−1, 138.3 and 125.9 mg 100 g−1) seeds have been found to be significantly (P<0.05) higher than the black variety, respectively. The method makes use of a reversed-phase system with a C18-bonded column and yields quantitative recovery of all the three compounds, L-Dopa (101.8%), CDTHIQ (98.2%) and MCDTHIQ (94.5%). This procedure is superior to other analytical techniques currently available because of its simplicity with regard to sample preparation, the sensitivity and rapidity of the method.  相似文献   

10.
A protocol using HCl-acidified 4-dimethylaminocinnamaldehyde (DMACA) was developed for screening proanthocyanidins (PA) in plants. Individual PA-containing cells could be observed following staining of decolourised leaves with DMACA. The quantitative assay using DMACA-HCl to detect soluble PA and butanol–HCl to detect insoluble PA could detect PA content lower than 0·4 mg g−1 dry matter (DM). The DMACA–HCl protocol is recommended for PA detection in low-PA plants because of its higher sensitivity than vanillin–acid protocols. Twenty-two forage legume species, most of which had been reported free of leaf PA but bloat-safe, were re-examined using the DMACA–HCl protocol. PA-positive cells were observed in leaves of 15 species. Measurable amounts of PA were detected in leaves of seven species, with the PA content ranging from 0·6 to 11 mg g−1 DM. White clover ( Trifolium repens L), red clover ( T pratense L) and lucerne ( Medicago sativa L) were also found to have PA-positive leaf trichomes. By analysis of these data and the literature, the threshold PA content for bloat safety in forage legumes was estimated to be 1–5 mg PA g−1 DM.  相似文献   

11.
Barbarea vulgaris, Barbarea verna and Lepidium campestre were selected as potential new oilseed crops. To evaluate the nutritional and technological quality of the seeds, the chemical composition was studied. The major constituents found were dietary fibre, crude fat and crude protein. Barbarea contained about 350 g kg−1 dietary fibre, 295 g kg −1 crude fat and 170 g kg−1 crude protein, while Lepidium contained about 400 g kg−1 dietary fibre, 200 g kg−1 crude fat and 190 g kg−1 protein. The amino acid composition was found to be suitable for human consumption when comparison with the amino acid pattern for high quality protein was made. Fatty acid composition was dominated by erucic acid in B vulgaris (28%) and B verna (50%) and by linolenic acid in L campestre (34%). Insoluble dietary fibres were dominated by Klason lignin in both Barbarea and Lepidium. Uronic acid and glucose residues were also found in large amounts. Soluble dietary fibres were dominated by uronic acid, arabinose and galactose residues. The major glucosinolates found were glucobarbarin in B vulgaris (108 μmol g−1), gluconasturtiin in B verna (106 μmol g−1) and sinalbin in L campestre (110 μmol g−1). No cyanogens were found in any of the seeds. © 1999 Society of Chemical Industry  相似文献   

12.
The protein, amino acid, ash, and mineral composition of different Brassica spp. grown in several areas of Galicia (Northwest Spain) were studied. The highest protein values were observed in Galega kales (crude protein: 29.66 g per 100 g) and turnip greens and turnip tops (27.74–31.46 g per 100 g), whereas the leaves showed higher protein contents than the stems. Glutamic acid was the most abundant amino acid present (14.53% in turnip greens to 18.45% in white cabbage). Other amino acids such as arginine, aspartic acid, lysine, alanine and glycine were also observed in higher quantities. The stems contained the same amino acid as the leaves but at a lower level. Furthermore, differences in amino acid contents were observed among varieties. The proportion of essential amino acids was high (41% in leaves of turnip top to 47% in external leaves of oxheart cabbage). The studied varieties are also a good source of some minerals, which include as main element potassium (27.24–37.57 mg g?1 in whole plants), followed by calcium (4.27–17.48 mg g?1 in whole plants) and magnesium (1.62–2.92 mg g?1 in whole plants). Significant differences among varieties and edible portions were found concerning ash and mineral contents.  相似文献   

13.
Phytosterol and tocopherol contents and oxidative stability were evaluated from seeds oils of four safflower (Carthamus tinctorius L) varieties originating from Spain (Rancho), India (Sharda) and Morocco (Cartamar and Cartafri), which were cultivated at the experimental station in Oujda (a semi‐arid region of eastern Morocco). Total phytosterols ranged from 3640 to 4140 mg kg?1. GC analysis allowed the identification of nine compounds, of which β‐sitosterol was the major component. Total tocopherols ranged from 461.56 to 499.68 mg kg?1. HPLC analysis allowed the identification of three compounds, α‐tocopherol (99.45%–98.84%), β‐tocopherol (0.94%–0.5%) and γ‐tocopherol (0.21%–0.01%). Oxidative stability study showed that Sharda had the lowest induction period of 2.3 h compared with 7.18, 7 and 6.67 h for Cartafri, Rancho and Cartamar, respectively. Likewise, we established a positive correlation between the oxidative stability and γ‐tocopherol; however, this difference was not significant.  相似文献   

14.
The content of total polyphenolics, antioxidative capacity and antiproliferative activity were tested in wild and cultivated blackberry pomace. Wild blackberry pomace extract Tw2 showed the highest following contents: total polyphenolics (50.16 mg GAE g−1 dw), flavonoids (7.73 mg Qc g−1 dw), flavonols (6.63 mg Qc g−1 dw) and total monomeric anthocyanins (13.40 mg Cy g−1). Tw2 extract significantly inhibited free radicals: IC50DPPH = 127.76 μg mL−1, IC50ABTS = 26.53 μg mL−1 and IC50 ˙ OH = 168.62 μg mL−1, and the growth of breast adenocarcinoma IC50MCF7 = 306.68 μg mL−1 and cervix epitheloid carcinoma cell lines IC50HeLa = 315.49 μg mL−1. Wild blackberry varieties had higher extraction yields, higher total polyphenolic contents and possessed stronger biological effects compared to cultivated blackberries (P < 0.05). All blackberry extracts showed high biological potential that could be attributed to high total polyphenols and flavonoids content and could be utilised as value-added functional food.  相似文献   

15.
Twelve sunflower (Helianthus annuus L) cultivars grown in Spain were analysed and tested in experiments with rats. The dehulled seeds contained an average of 32.2 MJ kg−1 dry matter (DM) gross energy, 653 g kg−1 DM fat, 60 g kg−1 DM total non-starch polysaccharides (NSP) and 6 g kg−1 DM Klason lignin. The sunflower seed hulls contained 20.2 MJ kg−1 DM gross energy, 53 g kg−1 DM fat, 562 g kg−1 DM total NSPs and 239 g kg−1 DM Klason lignin. The sunflower samples were dehulled and partially defatted (to ∼17% fat) and included in diets for rats. The dehulled, partially defatted samples contained on average 74.6 g nitrogen kg−1 DM and 1.409 mg g−1 phenolic compounds (chlorogenic acid + caffeic acid + derivative 1 + derivative 2) varying from 0.677 to 2.847 mg g−1. Groups of five growing rats were fed diets (9.38% crude protein) containing one of the sunflower cultivars as the only source of protein. Apparent ileal and faecal digestibilities were determined by using an indigestible marker (Cr2O3) and faecal digestibility based on total faecal collections. Apparent ileal, caecal and faecal digestibilities of organic matter were 81.2–91.5% (P = 0.05), 95.8–97.1% (P = 0.005) and 94.7–95.3% (P = 0.94) respectively. The apparent faecal digestibilities of DM, energy and protein (N × 6.25) were 93.2–93.8%, 93.5–94.3% and 81.6–84.3% respectively with no differences among cultivars. Biological value (BV) ranged between 63.8 and 73.2% (P = 0.0001) and net protein utilisation (NPU) between 59.9 and 69.5% (P = 0.0001). BV and NPU were positively correlated with lysine and threonine contents, but no correlation with the analysed phenolic compounds was detected. © 1999 Society of Chemical Industry  相似文献   

16.
Proximate composition, fatty acids profiles and other nutritional values were evaluated for fillets of Limanda aspera (yellowfin sole), Lepidopsetta bilineata (southern rock sole) and Lepidopsetta polyxystra (northern rock sole) and compared to North Sea plaice (Pleuronectes platessa). Additional information is given on the composition of fillets from arrowtooth flounder (Atheresthes stomias). Plaice (0.8% lipid) and Alaska soles (1.0–1.2% lipid) can be classified as lean species, resulting in low 0.3–0.5 g ∑EPA+DHA/100 g muscle, although the fatty acid profiles of the extracted lipids were characterised by high amount of n‐3 fatty acids (33.2–47.3%). Arrowtooth flounder belong to the medium‐fat species (4.3%). Taurine was the most prevalent free amino acid; mean values ranging between 221 mg100 g?1 and 247 mg100 g?1 wet weight. The selenium content varied between 130 and 310 μg kg?1 ww. Sensory attributes of Southern and Northern rock sole were comparable to plaice.  相似文献   

17.
Asparagus (Asparagus officinalis L.) hard-stem, woody bottom of the asparagus stalk, is a rich source of bioactive compounds and is discarded as an eco-friendly agricultural waste. Therefore, we intended to explore the antioxidant, amino acid composition, and antihypertensive potentials of enzymatically hydrolysed asparagus hard-stem. The treated samples exhibited higher total free amino acids (11437 mg 100 g−1), total phenolics (1749 mg 100 g−1), and ability to inhibit (78.38%) angiotensin-converting enzyme (ACE) compared to control (ACE inhibition of 46.88%). Hydrophobic amino acids (39%) and gallic acid (48%) were the highly eluted bioactive compounds. The ability to inhibit ACE had been positively correlated with hydrophobic amino acids (r = 0.959–0.987) and gallic acid (r = 0.966), indicating the role of amino acids and phenolics in controlling ACE reactions. Thus, asparagus hard-stem can be a potential source to develop natural health supplements for the management of hypertension and related health risks.  相似文献   

18.
《Food microbiology》1996,13(2):123-132
The keeping times of sardines were 21–27 h (average 23 h) at ambient temperature (Tamb) and 8–11 days (average 9.5 days) in ice. The muscle pH increased from 6.15 to 6.85 atTamband from 6.24 to 6.55 in ice. Trimethylamine–nitrogen (TMA-N) and total volatile basic nitrogen (TVB-N) accumulated rapidly atTambto reach 11.2 mg 100 g−1of fish and 57.3 mg 100 g−1of fish, respectively at spoilage. In ice, the rate was rapid for two trials (2.72 mg TMA-N 100 g−1of fish per day and 5.20 mg TVB-N 100 g−1of fish per day) and slow for three trials (0.21 mg TMA-N 100 g−1of fish per day and 3.7 mg TVB-N 100 g−1of fish per day). Likewise, the histamine development rate was rapid during one trial (5.4 per day atTamband 0.313 per day in ice), slow (average rate 3.503 per day during four trials atTamb, 0.305 per day during one trial in ice) and zero during the other three ice-trials. Bacteria multiplied rapidly atTamb; psychrotrophs multiplied slowly, and represented 10–68% of mesophiles at rejection point.In ice, bacteria multiplied slowly after lag phases of up to 120 h, but reached levels of rejection similar to those observed forTambstorage, H2S-producing bacteria represented 0.5–7% of the initial fish flora and 3–10.1% at rejection point. They grew with a shorter lag phase as was the situation with the total flora.  相似文献   

19.
The quality of the oil of four safflower varieties, originating from Spain (Rancho), India (Sharda) and Morocco (Cartamar and Cartafri), which were cultivated at the experimental station in Oujda (a semi‐arid region of eastern Morocco) was evaluated through analysis of their phenolic and carotenoid contents. The composition of the phenolic compounds of safflower oil has not yet been documented. Therefore, in this preliminary study, Thirty different phenolic compounds were identified, and significant differences between the oil varieties were observed (P < 0.05). In the seed oil from the Rancho and Sharda safflower varieties, the main phenolic compound was trans‐chalcone, representing 13.45% and 11.8%, respectively, of the total phenolics, whereas in Cartamar and Cartafri oils, naringin accounted for 26.82% and 16.5%, respectively, of the total phenolics. The total carotenoid contents ranged from 1.13 mg kg?1 (Rancho) to 1.34 mg kg?1 (Cartamar and Cartafri). We observed that β‐cryptoxanthin (0.31–0.37 mg kg?1) and β‐carotene (0.3–0.35 mg kg?1) were the predominant carotenoids in all of the safflower oils that were studied.  相似文献   

20.
Nitrogen content and composition of amino acids in juice and rind of navel oranges were studied. The compared varieties were ‘Navelina’ ‘Washington Navel’ and ‘Navelate’, early, mid-season and late types, respectively. Total N content in juice increased during the season with values from about 60 to near 100 mg 100 ml?1 in Navelina and ‘Washington Navel’ and from 60 to about 80 mg 100 ml?l in ‘Navelate’; amino N increased from 30 to 60 mg 100 ml?lapproximately in the three varieties. The total N content in rind was quite similar in all cases, with values that decreased with time from 1 to around 0·6 g 100 g?l dry weight (DW), 50–60% corresponding to the protein N. The main free amino acids in juice and rind at different maturity stages are tabulated. Proline represents at maturity around 50% of the total free amino acids in rind, with values near to 1·5 mmol 100 ml?l in juice and over 5·0 mmol 100 g?1 DW in rind. Total protein amino acids in rind decreased during maturation, reaching final values of about 20 mmol 100 g?1 DW. Differences in composition among the three studied varieties are discussed.  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