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1.
Cell walls were isolated from flesh and skin of five plum varieties corresponding to three species (Prunus domestica L., Prunus salicina Lindl. and Prunus insititia Lindl.) using the alcohol-insoluble solids (AIS) procedure. Yields varied from 83 to 114 g kg−1 dry weight in the flesh and from 192 to 361 g kg−1 dry weight in the skins. Their main sugars were uronic acid (224–322 mg g−1 AIS), cellulosic glucose (139–170 mg g−1 AIS), galactose and arabinose. Galactose and arabinose ratio were variable between the varieties. The degrees of methylation were high (62–84).  相似文献   

2.
Berries and red fruits are rich dietary sources of polyphenols with reported health benefits. More than 50 different flavonols (glycosides of quercetin, myricetin, kaempferol, isorhamnetin, syringetin and laricitrin) have been detected and quantified with HPLC–MSn in fruits of blueberry, bilberry, cranberry, lingonberry, eastern shadbush, Japanese wineberry, black mulberry, chokeberry, red, black and white currants, jostaberry, red and white gooseberry, hardy kiwifruit, goji berry, rowan, dog rose, Chinese and midland hawthorn, wild and cultivated species of blackberry, raspberry, strawberry and elderberry. The phenolic constituents and contents varied considerably among the analyzed berry species. Elderberry contained the highest amount of total flavonols (450–568 mg kg−1 FW), followed by berry species, containing more than 200 mg kg−1 FW of total: chokeberry (267 mg kg−1), eastern shadbush (261 mg kg−1), wild grown blackberry (260 mg kg−1), rowanberry (232 mg kg−1), american cranberry (213 mg kg−1) and blackcurrants (204 mg kg−1). Strawberry (10.5 mg kg−1) and white currants (4.5 mg kg−1) contained the lowest amount of total flavonols. Quercetins represent the highest percentage (46–100%) among flavonols in most analyzed berries. In wild strawberry and gooseberry the prevailing flavonols belong to the group of isorhamnetins (50–62%) and kaempferols, which represent the major part of flavonols in currants (49–66%). Myricetin glycosides could only be detected in chokeberry, rowanberry and species from the Grossulariaceae, and Adoxaceae family and Vaccinium genus. Wild strawberry and blackberry contained from 3- to 5-fold higher total flavonols than the cultivated one.  相似文献   

3.
The contents of As, Cd, Cr, Cu, Fe, Hg, Mg, Mn, Ni, Pb, and Zn in eleven fruiting bodies of Boletus tomentipes were determined. The results showed the values of the studied elements decreased in the order: Mg (208–279 mg kg−1) > Fe (106–137 mg kg−1) > Mn (29.5–46.8. mg kg−1) > Zn (18.7–23.1 mg kg−1), > Cu (11.4–15.8 mg kg−1) > Cr (3.36–4.78 mg kg−1) > Pb (1.38–3.88 mg kg−1) > Ni (1.68–3.01 mg kg−1) > Cd (0.16–0.32 mg kg−1) > As (0.10–0.24 mg kg−1) > Hg (<0.06 mg kg−1).  相似文献   

4.
Fructose, glucose and sucrose, as the major soluble sugars and citric and malic acids, as the major organic acids, were identified and determined in kale (Brassica oleraceae L. var. acephala DC., black cabbage) leaves. Fructose was the predominant sugar (2011 mg 100 g−1 dry wt) identified, followed by glucose (1056 mg 100 g−1 dry wt) and sucrose (894 mg 100 g−1 dry wt). The contents of citric and malic acids were at 2213 and 151 mg 100 g−1 dry wt in the leaves. The 16:0, 18:2n − 6 and 18:3n − 3 fatty acids were the most abundant fatty acids in the leaves. Considering the level of these fatty acids, 18:3n − 3 was found to be the highest (85.3 μg g−1 dry wt), contributing 54.0% of the total fatty acid content. Linoleic acid (18:2n − 6), being the second most abundant fatty acid was present at 18.6 μg g−1 dry wt, contributing 11.8% of the total fatty acid content. In the seed oil of kale, 22:1n − 9 was the most abundant fatty acid (4198 μg g−1 dry wt, 45.7%), with 18:2n − 6 (1199 μg g−1 dry wt, 12.3%) and 18:1n − 9 (1408 μg g−1 dry wt, 14.8%) being the second next most abundant fatty acids. The most abundant amino acid was glutamic acid (Glu) which was present at 33.2 mg g−1 dry wt. Aspartic acid, which was the second most abundant amino acid, was present at 27.6 mg g−1 dry wt and accounted for 10.2% of the total amino acid content of kale leaf. The amino acid content was assessed by comparing the percentages of the essential amino acids in kale leaf versus those of a World Health Organization (WHO) standard protein. The protein of kale leaf compares well with that of the WHO standard. Only one amino acid, lysine, had a score that fell below 100%; the lysine score of kale leaf was 95%. This study attempts to contribute to knowledge of the nutritional properties of the plant. These results may be useful for the evaluation of dietary information.  相似文献   

5.
Concentrations of As, Cd, Cu, Hg and Pb were measured by atomic absorption spectrometry (AAS) in muscle tissues of four fish species: anchovy (Engraulis encrasicholus), mackerel (Scomber japonicus), red mullet (Mullus surmuletus) and picarel (Spicara smaris) from the Croatian waters of the Adriatic Sea during 2008 and 2009. Metal levels measured in anchovy were in the following ranges (mg kg−1): As 0.01–54.8, Cd 0.001–0.02, Cu 0.001–6.29, Hg 0.001–0.52 and Pb 0.001–0.34 mg kg−1. Metal ranges in red mullet were (mg kg−1): As 0.01–70.9, Cd 0.002–0.85, Cu 0.001–57.3, Hg 0.001–2.07 and Pb 0.001–0.27 mg kg−1. Metal level ranges measured in mackerel were (mg kg−1): As 0.01–36.4, Cd 0.001–0.1, Cu 0.001–15.9, Hg 0.001–0.78 and Pb 0.002–0.24 mg kg−1. In picarel, metal level ranges were (mg kg−1): As 0.01–54.6, Cd 0.001–0.1, Cu 0.08–32.9, Hg 0.001–0.207 and Pb 0.001–0.46 mg kg−1. Significant differences in metal concentrations were found among fish species. The results presented on metal contents in the examined species give an indication of the environmental conditions. Concentrations of Cd, Cu, Hg and Pb obtained were far below the established values by the European Community regulations. However, arsenic levels found in red mullet were higher than the recommended legal limits for human consumption and as such may present a human health issue.  相似文献   

6.
Ten popular species of both edible and medicinal Korean mushrooms were analysed for their free amino acids and disaccharides. The average total free amino acid concentration was 120.79 mg g−1 in edible mushrooms and 61.47 mg g−1 in medicinal mushrooms, respectively. The average total of free amino acids for all mushrooms, edible mushrooms and medicinal mushrooms was 91.13 mg g−1. Agaricus blazei (227.00 mg g−1) showed the highest concentration of total free amino acids; on the other hand, Inonotus obliquus (2.00 mg g−1) showed the lowest concentration among the 10 species of mushrooms. The average total carbohydrates concentration was 46.67 mg g−1 in the 10 species of mushrooms, where the edible mushrooms contained 66.68 mg g−1 and the medicinal mushrooms contained 26.65 mg g−1. The carbohydrates constituents of the 10 mushroom species were mainly mannose (36.23%), glucose (34.70%), and xylose (16.83%).  相似文献   

7.
The first chemical characterization of abbamele, a traditional honey decoction from Sardinia (Italy) is hereby reported. Water content (from 17.7% to 27.7%), electrical conductivity (from 0.19 to 0.81 mS cm−1), pH (from 3.21 to 3.92), free acidity (from 26.1 to 87.6 meq kg−1), invertase activity (from 0 to 1.02 U kg−1), 5-(hydroxymethyl)-2-furaldehyde, HMF (from 881 to 4776 mg kg−1), total polyphenols (from 188 to 984 mg kg−1) and free amino acid contents of thirteen abbamele samples, from industrial and traditional producers, were obtained in an attempt to compare this traditional product with honey and to study the relationship between its main features and the production procedures. The long thermal treatment involved in the production of abbamele has been identified as the main cause of very low (or absent) invertase activity and free amino acid content as well as the very high content of HMF.  相似文献   

8.
The formaldehyde (FA) content in different fish products was evaluated using a solid phase microextraction (SPME)-GC–MS method based on fiber derivatisation with pentafluorobenzyl-hydroxyl-amine hydrochloride. LOD and LOQ values of 17 and 28 μg kg−1, respectively were calculated. Fish quality was assessed by the analysis of 12 species (sea-fish, freshwater-fish and crustaceans), revealing variable FA levels. Fresh, deep frozen, canned, boiled and roasted fish were analysed; cooking always produced a decrease in the analyte content. Fish belonging to the Gadidae family were the samples with the highest FA concentration (from 6.4 ± 1.2 mg kg−1 to 293 ± 26 mg kg−1), in four cases out of 14 exceeding the value of 60 mg kg−1 proposed by the Italian Ministry of Health. Storage on ice was also investigated, showing moderate FA production also at temperature around 0 °C. FA contents lower than 22 mg kg−1 were finally found in all the other samples.  相似文献   

9.
The influence of the drying method on volatile compounds of Rosmarinus officinalis was evaluated. The drying methods tested were convective (CD) and vacuum-microwave (VMD), as well as a combination of convective pre-drying and VM finish-drying (CPD–VMFD). Rosemary drying kinetics was described by a simple exponential model for CD and VMD, while VMFD kinetics consisted of two periods: linear until a critical point and exponential beyond that point. Volatile compounds of rosemary samples were extracted by steam-hydrodistillation and analyzed by GC–MS. Thirty-four compounds were tentatively identified, with α-pinene, bornyl acetate, camphene and 1,8-cineole being the major components. The total volatiles concentration of fresh rosemary (135 g kg−1) decreased considerably during both CD (87.2 g kg−1) and VMD (61.9 g kg−1). CPD–VMFD was the best option for drying rosemary because the time required was relatively short (30 min), and the aroma quality was good according to both instrumental (100 g kg−1) and sensory analyses.  相似文献   

10.
The influence of the drying method on volatile compounds of Origanum vulgare was evaluated. The drying methods tested were convective (CD) at 60 °C and vacuum-microwave (VMD), as well as a combination of convective pre-drying and VM finish-drying (CPD–VMFD). The volatile compounds of fresh and dried oregano were extracted by steam-hydrodistillation and analyzed by GC–MS. Oregano drying kinetics was described by a simple exponential model for CD and CPD–VMFD, while VMD kinetics consisted of two periods: linear until a critical point and exponential beyond that point. Thirty-four compounds were tentatively identified, with carvacrol, thymol, and γ-terpinene, being the major components. The total volatiles concentration of fresh oregano (33.0 g kg−1) decreased significantly during drying, independently of the method used (CD: 10.2 g kg−1, CPD–VMFD: 13.1 g kg−1, and VMD: 27.9 g kg−1). The final conclusion was that VM dehydrated Polish oregano was of better aromatic quality than that dried using hot air.  相似文献   

11.
Minor carbohydrates present in carrot (Daucus carota L.) have been studied by GC–MS analysis of their trimethylsilyl derivatives because of their remarkable role in a variety of biological functions. Scyllo-inositol and sedoheptulose (d-altro-2-heptulose), identified for the first time in this paper were present in all the carrots analysed in concentrations ranging 1.5–5.8 and 1.4–24.6 mg g−1 dried weight, respectively. Other minor carbohydrates detected in carrot were myo- inositol (2.2–9.8 mg g−1) and mannitol (traces-1.3 mg g−1). Whereas small amounts (close to 2 mg g−1) of scyllo-inositol were experimentally determined in other vegetables from the Apiaceae family (parsley, coriander and fennel), sedoheptulose was only detected at trace levels.  相似文献   

12.
A simple and fast method for the simultaneous analysis of thiobencarb, deltamethrin and 19 organochlorine pesticide residues in fish by gas chromatography–mass spectrometry was investigated in this study. Samples are extracted with acetonitrile. Most of lipids in the extract are eliminated by low-temperature cleanup, prior to solid-phase extraction cleanup. The lipids extracted from the fish samples were easily removed without any significant losses of the pesticides. Aminopropyl (NH2) cartridge was effective to eliminate the remaining interference. Spiked experiments were carried out to determine the recovery, precision and limits of detection (LODs) of the method. The method detection limits ranged from 0.5 μg kg−1 to 20 μg kg−1, whilst recoveries of the pesticides were in the range of 81.3–113.7% with relative standard deviations ?13.5% at a spiked concentration of 0.05 mg kg−1, 0.02 mg kg−1 and 0.1 mg kg−1. The newly developed method is demonstrated to give efficient recoveries and LODs for detecting pesticide multiresidues in fish.  相似文献   

13.
Essential and contaminant elements concentrations were determined in the muscle tissue of octopus (Octopus vulgaris), squid (Loligo vulgaris) and cuttlefish (Sepia officinalis), caught off the Portuguese coast in 2004–2005. As expected, the largest concentrations found correspond to Cl, S, K, Na, P and Mg (average values between 629 mg (100 g)−1, for Cl, and 435 mg kg−1, for Mg, in octopus and squid, respectively). Above average concentrations of Zn, Cu, Fe and Sr were also found. The highest total Hg concentration was found in cuttlefish (0.36 mg kg−1); however, this value did not exceed the recommended limit proposed by EU (0.5 mg kg−1). Lead levels observed in all samples were always significantly lower than the EU limit (1.0 mg kg−1). Regarding Cd, the 1.0 mg kg−1 limit was only exceeded in two octopus samples. It may be concluded that the cephalopods studied do not constitute cause for concern, in terms of toxic elements, and could be safely used for daily intake of essential elements. Nevertheless, the squid contribution for elemental DI is minor in comparison to the other two species.  相似文献   

14.
The concentrations of flavonols (kaempeferol, quercetin, myricetin) were determined in 22 plant materials (9 vegetables, 5 fruits, and 8 medicinal plant organs). The materials were extracted with acidified methanol (methanol/HCl, 100:1, v/v) and analyzed by reverse phase high-performance liquid chromatographic (RP-HPLC) with UV detection. The total flavonols contents varied significantly (P < 0.05) among vegetables, fruits and medicinal plant organs ranged from 0 to 1720.5, 459.9 to 3575.4, and 2.42 to 6125.6 mg kg−1 of dry matter, respectively. Among vegetables, spinach and cauliflower exhibited the highest amounts of flavonols (1720.5 and 1603.9 mg kg−1, respectively), however, no flavonols were detected in garlic. Within fruits, highest level of flavonols was observed in strawberry (3575.4 mg kg−1), whereas, the lowest in apple fruit (459.9 mg kg−1). Of the medicinal plant organs, moringa and aloe vera leaves contained the highest contents of flavonols (6125.6 and 1636.04 mg kg−1), respectively, whereas, lowest was present in barks (2.42–274.07 mg kg−1). Overall, leafy green vegetables, soft fruits and medicinal plant leaves exhibited higher levels of flavonols.  相似文献   

15.
L. Gašperlin  B. Lukan  B. ?lender  T. Polak 《LWT》2009,42(8):1313-1319
Mutagenic heterocyclic amines (HAs) originate in processed proteinaceous foods. The effects of the presence of skin (with vs. without) and of grilling method (two plate vs. infrared) on the content of HAs in grilled chicken pectoralis superficialis muscle (temperature, 220 °C) were investigated. HA precursors (creatine, creatinine, free amino acids and carbohydrates) and HAs of these raw and grilled breast muscles were determined. The muscles originated from 24 birds of either sex (provenance Ross; aged 40-45 days). The HA content was determined in homogenates of the upper and lower surface slices of the grilled muscles (Ti = 82 °C). A higher content of total free amino acids was seen for the muscle (27.1 mmol kg−1 raw meat) than for the skin (21.7 mmol kg−1 raw meat). The creatine, creatinine and carbohydrate levels in the skin were below the limits of detection. The contents of creatine (31.8-38.7 mmol kg−1) and creatinine (0.24-0.33 mmol kg−1) in the breast muscle were determined. Relatively high levels were seen for glucose (23 mmol kg−1 raw meat) and fructose (10 mmol kg−1 raw meat) in the muscle, with other sugars present at low levels (<2 mmol kg−1 raw meat). For the chicken muscle grilled on a two-plate grill, the contents of total HAs (PhIP, MeIQx, DiMeIQx, Harman and Norharman) were lower with the skin in place than in the muscle grilled without the skin (3.5 μg kg−1vs. 4.8 μg kg−1). Also, during infrared grilling with the skin, lower amounts of HAs were formed than with grilling on the two-plate grill (2.4 μg kg−1vs. 3.5 μg kg−1). On average, the infrared-grilled samples with skin contained 3-fold more total HAs than similar samples without the skin (2.4 μg kg−1vs. 0.8 μg kg−1), with the highest levels seen for PhIP and MeIQx.  相似文献   

16.
Studies were conducted in the early season of 2002 and 2003 at the Teaching and Research Farm, Obafemi Awolowo University, Ile-Ife, Nigeria to evaluate the effect of phosphorus (P) on fruit yield and chemical composition of two landraces of Trichosanthes cucumerina L. For the purpose of the study, two landraces of T. cucumerina named Landrace I and Landrace II were used. The five levels of phosphorus evaluated were 0, 30, 60, 90 and 120 kg P2O5 ha−1 using single super phosphate fertilizer (8% P). Statistical analysis showed that 90 kg P2O5 ha−1 gave statistically significant higher fruit yield (16.4 tons ha−1) compared to other P levels. The fruit yield of the two Landraces did not differ significantly. Except for crude protein content, the 90 kg P2O5 ha−1 produced significantly higher ether extract (1.22 g 100 g−1), crude fibre (1.93 g 100 g−1), moisture content (90.5 g 100 g−1), ash (0.90 g 100 g−1), total sugars (0.81 g 100 g−1) and ascorbic acid (28.7 mg 100 g−1) than other P levels. The essential amino acids compositions were also significantly higher at 90 g 100 g−1 compared to other lower P levels. Landrace I had significantly higher ether extract (0.90 g 100 g−1) content than Landrace II (0.62 g 100 g−1) while Landrace II in turn had significantly higher total sugar (0.76 g 100 g−1) compared to Landrace I (0.61 g 100 g−1). The essential amino acids composition is high and the oxalate composition is low. The high ascorbic acid and amino acid content together with a low oxalate composition suggested a strong basis for encouraging the cultivation of this indigenous fruit vegetable to augment nutrient requirement, improve diet and consequently alleviate poverty, preserve the biodiversity and increase the gene bank of neglected wild species of high quality nutrient sources.  相似文献   

17.
Sezai Ercisli 《Food chemistry》2007,104(4):1379-1384
Fruits of Rosa canina, Rosa dumalis subsp. boissieri, Rosa dumalis subsp. antalyensis, Rosa villosa, Rosa pulverulenta and Rosa pisiformis were assayed for total phenolics, ascorbic acid, total soluble solids, total dry weight, total fat, fatty acids, pH, acidity, moisture, fruit colour and macro- and micro-elements. The highest total phenolic content was observed in Rosa canina (96 mg GAE/g DW). Rosa dumalis subsp. boissieri had the highest total fat content (1.85%), followed by Rosa pulverulenta (1.81%) and Rosa canina (1.78%), respectively. Nine major fatty acids were determined in rose species and α-linolenic acid was found to be dominant for all species. Total soluble solids, total dry weight, moisture and ascorbic acid contents of rose species varied from 29.42% (Rosa villosa)–37.33% (Rosa dumalis subsp. boissieri), 33.85% (Rosa villosa)–40.35% (Rosa dumalis subsp. boissieri), 59.65% (Rosa dumalis subsp. boissieri)–66.15% (Rosa villosa) and 727 mg/100 g FW (Rosa villosa) and 943 mg/100 g FW (Rosa dumalis subsp. boissieri), respectively. Nitrogen and mineral compositions of the rose species, e.g., N, P, K, Ca and Mg, were (averagely): 1.26%, 513 mg/100 g DW, 639 mg/100 g DW, 196 mg/100 g DW and 114 mg/100 g DW, respectively. The present study shows that the native rose genotypes are extremely rich sources of phenolics, carbohydrates and ascorbic acid, demonstrating their potential use as a food or food additive.  相似文献   

18.
A new analytical method was developed to simultaneously determine residues of 109 pesticides (including isomers) in the foods of animal origin. Acetonitrile was selected for accelerated solvent extraction (ASE) for effectively extracting the pesticides from the fatty samples. The cleanup was performed with an automated gel permeation chromatography (GPC) cleanup system. The prepared samples were analysed with GC–MS in the selected ion monitoring mode (SIM) using one target and two qualitative ions for each analyte. Chlorpyrifos-d10 was used as an internal standard. The lowest limit of detection was 0.3 μg kg−1 for some pesticides. The recoveries and relative standard deviations (RSDs) were checked by spiking untreated samples with pesticides at 0.05, 0.1 and 0.2 mg kg−1. The average recoveries of most pesticides were from 62.6% to 107.8%. The precision values expressed as RSD were all ?20.5% (n = 6). Good linearity (r ? 0.99) was observed between 0.05 and 1.5 μg mL−1.  相似文献   

19.
Trace element levels in honeys from different regions of Turkey   总被引:1,自引:0,他引:1  
A survey of 25 honey samples from different botanical origin, collected all over the Turkey was conducted to assess their trace element contents. The aim of this study was to determine the levels of cadmium (Cd), lead (Pb), iron (Fe), manganese (Mn), copper (Cu), nickel (Ni), chromium (Cr), zinc (Zn), aluminium (Al) and selenium (Se) in honey samples from different regions of Turkey. Trace element contents were determined by a flame and graphite furnace atomic absorption spectrometry technique after dry-ashing, microwave digestion and wet-digestion. The accuracy of the method was corrected by the standard reference material, NIST-SRM 1515 Apple leaves. The contents of trace elements in honey samples were in the range of 0.23–2.41 μg g−1, 0.32–4.56 μg g−1, 1.1–12.7 μg g−1, 1.8–10.2 μg g−1, 8.4–105.8 μg kg−1, 2.6–29.9 μg kg−1, 2.4–37.9 μg kg−1, 0.9–17.9 μg kg−1, 83–325 μg kg−1 and 38–113 μg kg−1 for Cu, Mn, Zn, Fe, Pb, Ni, Cr, Cd, Al and Se, respectively. Iron was the most abundant element while cadmium was the lowest element in the Turkish honeys surveyed. The results showed that trace element concentrations in the honeys from different regions were generally correlated with the degree of trace element contamination of the environment.  相似文献   

20.
The physical characteristics (diameters, height and mass), chemical composition (tritratable acidity, soluble solids, pH, moisture, ash, protein, lipids and total dietary fiber), occurrence and content of vitamin C (ascorbic acid and dehydroascorbic acid), carotenoids (??-carotene, ??-carotene, ??-cryptoxanthin and lycopene), vitamin E (??-, ??-, ??- and ??-tocopherol and tocotrienol) and folates (tetrahydrofolate, 5-methyltetrahydrofolate and 5-formyltetrahydrofolate) were evaluated in the cagaita obtained from the Cerrado of Minas Gerais, Brazil. The analyses of vitamin C and carotenoids were performed by HPLC-DAD and vitamin E and folates by HPLC with fluorescence detection. The cagaita pulp presented high content of moisture (91.56 g 100 g− 1), vitamin C (34.11 mg 100 g− 1) and folates (25.74 ??g 100 g− 1). The presence of protein (0.63 g 100 g− 1), ash (0.18 g 100 g− 1), lipids (0.57 g 100 g− 1), carbohydrates (5.54 g 100 g− 1), dietary fiber (1.54 g 100 g− 1) and carotenoids (0.77 mg 100 g− 1) was observed in its composition. Vitamin E isomers were not detected. Consumption of cagaita (100 g) contributed significantly to supply the daily requirements of vitamin C (on average 71.0%), vitamin A (on average 7.5%) and folates (on average 7.9%). The cagaita showed high pulp yield, reduced total energy value and was considered a source of vitamin C, which play important role in human health.  相似文献   

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