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1.
Structure and health effects of inulin-type fructans have been extensively studied, while less is known about the properties of the graminan-type fructans in wheat. Arabinoxylan (AX) is another important indigestible component in cereal grains, which may have beneficial health effects. In this study, the fructan content in milling fractions of two wheat cultivars was determined and related to ash, dietary fibre and AX contents. The molecular weight distribution of the fructans was analysed with HPAEC-PAD and MALDI-TOF MS using 1H NMR and enzymatic hydrolysis for identification of fructans. The fructan content (g/100 g) ranged from 1.5 ± 0.2 in flour to 3.6 ± 0.5 in shorts and 3.7 ± 0.3 in bran. A correlation was found between fructan content and dietary fibre content (r = 0.93, P < 0.001), but with a smaller variation in fructan content between inner and outer parts of the grain. About 50% of the dietary fibre consisted of AX in all fractions. The fructans were found to have a DP of up to 19 with a similar molecular weight distribution in the different fractions.  相似文献   

2.
Avocado seed contains elevated levels of phenolic compounds and exhibits antioxidant properties. We investigated the effect of Avocado Seed Flour (ASF) on the lipid levels in mice on a hyperlipidemic diet. The concentration of phenols was determined by high-performance liquid chromatography, antioxidant activity was evaluated using the Trolox equivalent antioxidant capacity method, and dietary fiber was measured using the Association of Official Analytical Chemists (AOAC) method. The LD50 of ASF was determined using Lorke’s method and hypolipidemic activity was evaluated in a hypercholesterolemic model in mice. Protocatechuic acid was the main phenolic compound found in ASF, followed by kaempferide and vanillic acid. The total phenolic content in the methanolic extract of ASF was 292.00 ± 9.81 mg gallic acid equivalents/g seed dry weight and the antioxidant activity resulted in 173.3 μmol Trolox equivalents/g DW. In addition, a high content of dietary fiber was found (34.8%). The oral LD50 for ASF was 1767 mg/kg body weight, and treatment with ASF significantly reduced the levels of total cholesterol, LDL-C, and prediction of the atherogenic index. Therefore, the antioxidant activity of phenolic compounds and dietary fiber in ASF may be responsible for the hypocholesterolemic activity of ASF in a hyperlipidemic model of mice.  相似文献   

3.
Sugar profiles of different almond and chestnut cultivars were obtained by high-performance liquid chromatography (HPLC), by means of a refractive index (RI) detector. A solid-liquid extraction procedure was used in defatted and dried samples. The chromatographic separation was achieved using a Eurospher 100-5 NH2 column using an isocratic elution with acetonitrile/water (70:30, v/v) at a flow rate of 1.0 ml/min. All the compounds were separated in 16 min. The method was optimized and proved to be reproducible and accurate. Generally, more than 95% of sugars were identified for both matrixes. Sugars profiles were quite homogeneous for almond cultivars; sucrose was the main sugar (11.46 ± 0.14 in Marcona to 22.23 ± 0.59 in Ferragnes g/100 g of dried weight), followed by raffinose (0.71 ± 0.05 in Ferraduel to 2.11 ± 0.29 in Duro Italiano), glucose (0.42 ± 0.12 in Pegarinhos two seeded to 1.47 ± 0.19 in Ferragnes) and fructose (0.11 ± 0.02 in Pegarinhos two seeded to 0.59 ± 0.05 in Gloriette). Commercial cultivars proved to have higher sucrose contents, except in the case of Marcona. Nevertheless, chestnut cultivars revealed a high heterogeneity. Sucrose was the main sugar in Aveleira (22.05 ± 1.48), Judia (23.30 ± 0.83) and Longal (9.56 ± 0.91), while glucose was slightly prevalent in Boa Ventura (6.63 ± 0.49). The observed variance could serve for inter-cultivar discrimination.  相似文献   

4.
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   

5.
Recently, polyphenols have been found to affect blood lipids in animals in a similar manner as soluble dietary fibre. The aim was to assess whether an insoluble dietary fiber very rich in polyphenols has a beneficial effect on serum lipids in humans. In a double-blind randomized placebo-controlled clinical study with parallel arms, 88 volunteers with hypercholesterolemia were randomly assigned to consume daily either, fiber with insoluble 84% polyphenols 4 g twice a day (n = 43) or placebo (n = 45). Serum total, LDL and HDL cholesterol and triglycerides were assessed at baseline and after 4 weeks. The insoluble polyphenols consumption reduced the total cholesterol by 17.8 ± 6.1% (p < 0.05), LDL cholesterol by 22.5 ± 8.9% (p < 0.001), LDL: HDL cholesterol ratio by 26.2 ± 14.3% (p < 0.001) and triglycerides by 16.3 ± 23.4% (p < 0.05) at the end of the study compared with baseline. No significant differences were found during the study time in the placebo group for the lipid profile. The consumption of fiber very rich in insoluble polyphenols shows beneficial effects on human blood lipid profile and may be effective in prevention and treatment of hyperlipemia.  相似文献   

6.
Although about 225 000 t dry matter (DM) pea straw is produced annually in the UK, no recent data exist with respect to its nutritive value when offered to ruminants. This study, to examine field pea crop waste (straw) from 12 commercial cultivars of combining peas, was therefore undertaken when material grown as part of a European field pea network trial at Reading in 1998 was made available. The straw was subjected to chemical analysis and examined in vitro using the Reading Pressure Technique to generate gas production profiles and to determine both rate and extent of DM and organic matter degradation. Ash and crude protein (CP) concentrations (69 and 65 g kg–1 DM) were generally lower than published values for legume straws but higher, especially CP, than cereal straws. Neutral‐detergent fibre concentrations were slightly lower, and metabolizable energy (ME) values, derived from degradable organic matter assessed in vitro (iOMD), higher than cereal straws, ranging from 6·0 to 8·1 MJ ME kg–1 DM. Both cumulative gas production and rate of gas release varied significantly between cultivars, as did degradation with 96‐h iOMD values ranging from 468 to 602 g kg–1. By combining these with the quantity of material harvested, ME yields for the different cultivars were found to range from 15 to 27 GJ ME ha–1. Considerable, and general highly significant, variation was found between the cultivars examined, which may be used to rank straws with respect to their nutritive value. The cultivars Baccara and Solara followed by Athos and Vital were readily ranked higher than the other cultivars in terms of in vitro fermentation parameters and ME yields. These data suggest that pea straw, although often incorporated into the soil in post‐harvest operations, shows excellent potential as a ruminant forage feedstuff.  相似文献   

7.
Summary Calcium levels in the periderm of tubers (cv. Sebago) growing in irrigated sands were influenced by the stem position at which the tuber grew, but the effect was not consistent over two seasons. Calcium levels were increased at all tuber positions by addition of calcium to soil; combined treatments of gypsum (1400 kg Ca2+/ha) pre-plant and calcium nitrate (37 kg Ca2+/ha) side dressings gave the greatest response. Percentage incidence of soft rot lesions caused byErwinia chrysanthemi pv.zeae was not influenced by periderm calcium content. The severity of infection (weight of tissue macerated within 48 h at 30°C) was significantly reduced only by the pre-plant gypsum treatment, but there was no correlation with calcium content of the periderm. Calcium levels in periderm tissue (60–208 mg Ca2+/100g) are within the range of published data for other cultivars and results support previous reports that the correlation between tuber susceptibility toErwinia spp. and periderm calcium content is inconsistent.  相似文献   

8.
Structure and health effects of inulin-type fructans have been extensively studied, while less is known about the properties of the graminan-type fructans in wheat. Arabinoxylan (AX) is another important indigestible component in cereal grains, which may have beneficial health effects. In this study, the fructan content in milling fractions of two wheat cultivars was determined and related to ash, dietary fibre and AX contents. The molecular weight distribution of the fructans was analysed with HPAEC-PAD and MALDI-TOF MS using 1H NMR and enzymatic hydrolysis for identification of fructans. The fructan content (g/100 g) ranged from 1.5 ± 0.2 in flour to 3.6 ± 0.5 in shorts and 3.7 ± 0.3 in bran. A correlation was found between fructan content and dietary fibre content (r = 0.93, P < 0.001), but with a smaller variation in fructan content between inner and outer parts of the grain. About 50% of the dietary fibre consisted of AX in all fractions. The fructans were found to have a DP of up to 19 with a similar molecular weight distribution in the different fractions.  相似文献   

9.
Prolipid a known mixture of herbs is used as a plasma lipid lowering medicine. No side effects were registered. However, the bioactive substances of Prolipid were not investigated. Therefore in this investigation Prolipids bioactive compounds and antioxidant activity were studied. The contents of polyphenols and flavonoids were 19.87 ± 2.09 and 3.09 ± 0.31 mg gallic acid equivalent GAE/g DW and 2.09 ± 0.24 and 0.57 ± 0.05 mg catechin equivalent CE/g DW in water and methanol fractions, respectively. Anthocyanins (0.02 ± 0.001 mg/g DW) and flavanols (7.58 ± 0.81 μg CE/g DW) were found only in water fraction. The antioxidant activity of Prolipid, as determined by four different antioxidant assays [ferric-reducing/antioxidant power (FRAP); cupric reducing antioxidant capacity (CUPRAC); trolox equivalent antioxidant capacity (TEAC); 1, 1-diphenyl-2-picrylhydrazyl radical (DPPH)], was higher in water than in methanol fraction. The correlation coefficients between polyphenols, flavonoids and antioxidant activities of Prolipid water extracts with TEAC were 0.97 and 0.90, respectively. It can be concluded that the content of polyphenol compounds in Prolipid is very high and they are the main contributors to Prolipids overall antioxidant activity. Prolipid is widely used in human treatment without known side effects on patients and is comparable to other medicinal plants, and as a strong antioxidant mixture could be used as a supplement to known atherosclerosis preventing diets.  相似文献   

10.
The effects of vegetable type, vegetable dimensions, and solar drier load on dehydration rate; and texture, color, water activity, and carotene content of solar-dried carrots, sweet potatoes, and collard greens were studied. Mean dehydration rates (moisture loss,%/hr) for solar dried loads of 430 g/m2 and 715 g/m2 were 3.3 ± 0.30% and 3.8 ± 0.20% for carrots and sweet potatoes, respectively. Loads of 360 g/m2 and 465 g/m2 of collard greens had dehydration rates of 6.3 ± 0.10% moisture loss per hr. The results showed that vegetable type accounted for significant differences (p < 0.01) in dehydration rate, and beta-carotene content. Vegetable dimensions affected (p < 0.05) water activity. Solar drier load affected water activity (p < 0.01), and hue angle (p < 0.05). Beta-carotene contents (dry basis) of dehydrated carrot, sweet potato, and collard treatments were 10.9–17.4%, 7.6–9.8%, and 11.9–21.5%, respectively. Among the carrot treatments, the 5-mm thick slices packed at a load of 715 g/m2 contained the highest beta-carotene (17.4%, dry basis) and vitamin A activity (362 IU/g, dry basis), and good physical properties. For collard greens, the 2-cm and 3-cm wide strips packed at 360 g/m2 loads had the best combinations of high beta-carotene (21.5% and 17.2%, dry basis, respectively), vitamin A activity (357.2 and 293.1 IU/g, dry basis, respectively), and optimal color, texture, and water activity. Beta-carotene losses due to solar dehydration were 48.9–67.5%, 4.0–5.8%, and 1.9–19.8% (dry basis) in carrots, sweet potato and collard greens, respectively.  相似文献   

11.
Nutrient and antinutritional/toxic factors present in some edible flowers consumed in Mexico were determined. The edible flowers were: Agave salmiana, Aloe vera, Arbutus xalapensis, Cucurbita pepo (cultivated), Erythrina americana, Erythrina caribaea, Euphorbia radians benth and Yucca filifera. The nutrient content in the flowers studied is similar to that of the edible leaves and flowers studied mainly in Africa. The moisture content of the flowers varied from 860 to 932 g kg−1. Crude protein (CP) was between 113 to 275 g kg−1 DM, crude fiber, 104 to 177 g kg−1 DM and the nitrogen free extract, between 425 to 667 g kg−1 DM. The highest chemical score (CS) was found in E. americana and A. salmiana; in five samples the limiting amino acid was lysine, and in three of them it was tryptophan. Trypsin inhibitors and hemaglutinnins had a very low concentration. Alkaloids were present in both the Erythrina species and the saponins in A. salmiana and Y. filifera. Cyanogenic glucosides were not found in the studied flowers. The traditional process of preparing these specific flowers before consumption is by cooking them and discarding the broth; in this way the toxic substances are diminished or eliminated. These edible flowers from wild plants consumed in local areas of the country play an important role in the diet of the people at least during the short time of the season where they are blooming.  相似文献   

12.
The purpose of this study was to evaluate the hypolipidemic effect of a methanolic extract from Opuntia joconostle seeds fed to mice in a hypercholesterolemic diet. Acute toxicity of the methanolic extract was investigated by an established method. Phenolic composition and antioxidant activity were determined by high-performance liquid chromatography and DPPH, respectively. The total phenolic content of Opuntia joconostle seeds was 47.85?±?1.29 mg gallic acid equivalents/g dry weight. The main phenolic compounds were identified as quercetin, rutin, and cafeic acid. Percent inhibition of DPPH+ was 49.76?±?0.49 %. The oral LD50 for the methanolic extract from the Opuntia joconostle seeds was >5,000 mg/kg BW. Mice fed a hypercholesterolemic diet for six days exhibited significantly (P?≤?0.001) higher plasma lipid levels than mice fed a normal diet. Remarkably, supplementation with methanolic extract from Opuntia joconostle at doses of 1, 2, and 5 g/kg body weight significantly (P?≤?0.001) prevented the increase in total cholesterol, low-density lipoprotein cholesterol, triglycerides level, and atherogenic index. Similar concentrations of the HDL cholesterol were observed in both treated and control groups. A significant dose-dependent reduction in lipid levels was noted for treated groups compared to the hypercholesterolemic group. We attribute this result to the seeds’ phenolic composition. This methanolic extract has potential to be included in short-term hypercholesterolemia treatment regimens as it exhibits hypolipidemic activity with no apparent toxic manifestations.  相似文献   

13.
In Thailand, beverages containing mulberry leaf (Morus alba L.) are believed to promote good health, especially in people with diabetes. We examined the effects of long-term administration of an ethanolic extract of mulberry leaf (MA) on blood glucose, oxidative damage, and glycation in streptozotocin-induced diabetic rats. Daily administration of 1 g/kg MA for six weeks decreased blood glucose by 22%, which was comparable to the effect of 4 U/kg insulin. Lipid peroxidation, measured as malondialdehyde and lipid hydroperoxide concentrations (3.50 ± 0.33 and 3.76 ± 0.18 μM, respectively) decreased significantly (P < 0.05) compared to nontreated control diabetic rats (8.19 ± 0.45 and 7.50 ± 0.46 μM, respectively). Hemoglobin A1C, a biomarker for chronic exposure to high concentration of glucose, was also significantly decreased in the MA-treated group (6.78 ± 0.30%) in comparison to untreated group (9.02 ± 0.30%). The IC50 of in vitro antiglycation and free radical scavenging activities of MA were 16.4 ± 5.6 μg/ml and 61.7 ± 2.1 μg/ml, respectively. These findings support that long-term administration of MA has antihyperglycemic, antioxidant and antiglycation effects in chronic diabetic rats, which may be beneficial as food supplement for diabetics.  相似文献   

14.
Three New Zealand grown tomato (Lycopersicon esculentum L.) cultivars, Aranka, Encore, and Flavourine, were analysed for colour (CIELAB L∗ a∗ b∗ values), ascorbic acid, total phenolics, lycopene, and total antioxidant activity (ABTS assay). Colour analyses of the air-dried tomatoes showed that the colour degradation as measured by the L∗ a∗ b∗ values was minimal, and the colour was not significantly different (p < 0.05) between each of the dried cultivars. In general, there was no significant difference (p < 0.01) between the fresh cultivars in terms of antioxidant components or total antioxidant activity. The average values obtained for antioxidant components in the three fresh cultivars were: ascorbic acid, 276 mg/100 g DM, total phenolics, 613 mg gallic acid equivalents (GAE)/100 g dry matter (DM) and lycopene 38 mg/100 g DM. Total antioxidant activity of the fresh cultivars was 2917 μmole Trolox equivalent antioxidant capacity (TEAC)/100 g DM. Following forced air-drying treatment at 42 ∘C for 48 hr, all cultivars showed significant decreases in ascorbic acid, total phenolics and total antioxidant activity, and increases in extractable lycopene contents. This study was undertaken to identify cultivars that would provide the best colour and nutrient contents after commercial air drying.  相似文献   

15.
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   

16.
J. Vos 《Potato Research》1997,40(2):237-248
Summary The response of potato to different rates of nitrogen supply ranging from 0–40 g m−2 N was studied in five field experiments near Wageningen. NL (520 North). In total two late potato cultivars and two sites were used during successive seasons. The results are summarized in a set of regression equations separately for total crop and tubers. The relation between nitrogen taken up (g m−2) in the total crop and total dry matter production (g m−2) could be described with the exponential equation: 1942–1900 * 0.93X (r2=0.953, n=62). Nitrogen concentrations in the dry matter increased linearly with nitrogen uptake. Harvest indices for dry matter and nitrogen tended to decline with increase in N uptake. Cultivars differed only in the effect on N on tuber dry matter concentration. The relation between nitrogen uptake and nitrogen supply could be fitted with quadratic regression models. but coefficients were influenced by site and season.  相似文献   

17.
Zusammenfassung Fünf Speisekartoffelsorten wurden w?hrend einer sechsmonatigen Lagerung fünfmal auf α-Solanin und α-Chaconin untersucht. Es wurden vier Gewebebereiche der Knolle getrennt überprüft. Der Gesamtglykoalkaloidgehalt betrug im Augenbereich 164, in der restlichen Schale 101 und in der Gef?ssbündelzone mit ?usserem Speichergewebe 8mg/100g. Trockensubstanz. Im restlichen Innenk?rper waren nur noch Spuren (0.164mg/100g TS) nachzuweisen. Zwischen den Sorten und diesen Gewebepartien traten statistisch gesicherte Wechselwirkungen auf, die im wesentlichen von einer Sorte verursacht wurden. W?hrend der Lagerung sind die Alkaloidgehalte leicht, aber statistisch nicht gesichert gesunken. α-Solanin und α-Chaconin kamen generell im Verh?ltnis von etwa 1∶1.5vor; die Korrelation zwischen beiden Formen ist sehr eng (r=0.865). Bezogen auf die gesamte Knolle lagen die Gesamtglykoalkaloide je nach Sorte zwischen 2.4 und 8mg/100g Frischsubstanz und damit im gesundheitlich unbedenklichen Bereich.
Summary Five table potato cultivars (Erna, Granola, Gusto, Ulse, Margit) from the same source were examined for their content of α-solanine and α-chaconine during a sixmonths storage period. For the testing and subsequent analysis the tubers were dissected into four kinds of tissues: eye-zone, peel, vascular bundle region, medulla. The total glycoalkaloid content (TGA) in the total tuber mass varied between 2.4 and 8mg per 100g fresh matter depending on cultivar (Fig. 1). Despite significant differences between cultivars (Table 1), all potato cultivars remained within the safe range during the entire storage period. Remarkable differences in TGA per 100g dry matter could be noted in the tuber parts. For the eye-zones a TGA of 164mg was found; the peel region showed 101mg and the vascular bundle zone 8mg. The medulla of the tubers contained only traces of TGA (0.164mg/100g dry matter, Fig. 2). The statistical analysis only revealed significant interactions between cultivars and tuber parts (Table 1), mainly caused by the cultivar Gusto which showed higher contents of α-solanine and α-chaconine in its vascular bundle regions (Figs 3–5). The ratio between amounts of α-solanine and α-chaconine was approximately 1∶1.5, and after eliminating effects of cultivar, storage and tuber parts, the correlation coefficient between amounts was 0.865. This close correlation can be used for breeding. The non-significant, slightly negative effect of the six-months storage period on alkaloid content was noteworthy. It is assumed that only after long storage periods or through inappropriate storage (sprouting of tubers) a significantly higher glycoalkaloid content may be expected.
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18.
Silicon (Si) not only plays an important role in plant growth but also contributes significantly to the long‐term terrestrial carbon sink in the form of phytoliths. This study investigated Si content of 184 plant species in meadow steppe and typical steppe of northern China to examine the influential factors of Si distribution and evaluate the potential phytolith carbon sequestration of these grasslands. Our results indicated that the average Si content generally decreased in the following order of Equisetopsida > Monocotyledoneae > Dicotyledoneae. Within angiosperms, although most Si accumulator plants were commelinid monocots, many eudicots also accumulated abundant Si in their above‐ground tissues. The Si content of plant above‐ground parts in typical steppe (6.53 ± 2.88 g/kg) was significantly higher than that in meadow steppe (2.15 ± 0.92 g/kg). The estimated phytolith‐occluded carbon (PhytOC) production flux in typical steppe (0.81 ± 0.36 kg CO2 ha?1 year?1) was higher than that in meadow steppe (0.54 ± 0.23 kg CO2 ha?1 year?1). This study demonstrates that plant phylogeny influences the Si content of individual species, whereas grassland type with different mean annual precipitation and mean annual temperature may significantly affect the abundance of high Si species. We conclude that increasing the abundance of grass species with high Si content in meadow steppe and appropriate grazing and fertilizer application in typical steppe will enhance the phytolith carbon sequestration in grasslands of northern China.  相似文献   

19.
Summary Tubers of twelve cultivars ofSolanum tuberosum L., with a varying content of reducing sugars (0.49–2.30 g/100 g fresh weight), were sliced and fermented for up to 48 h by lactic acid bacteria in a brine of 1.5% NaCl, prior to frying. The content of reducing sugars decreased by 80 to 100%, depending on the initial sugar level. Colour of chips was measured using the CIE (1976) L*a*b* colour system, where L* is lightness, a* is redness and b* is yellowness of the material and by IBVL colour cards, photographs used for grading the colour of potato chips. L*-values were the best measurement of chip colour. The scale of the IBVL colour cards was too narrow (scale 1–9) for this study, as chips from eight of the cultivars were scored lighter than IBVL 9 after 48 h of fermentation. Lighter coloured chips significantly correlated with lower contents of reducing sugars. The sugar content decreased as fermentation time increased. Fermentation time can thus be used to control potato chip colour, and all the cultivars tested can be used for production of chips with regard to colour.  相似文献   

20.
The absorption, distribution and elimination of carnosic acid, the main antioxidant found in rosemary was studied, in vivo, in rats. Therefore, carnosic acid was administrated in a single dose, intravenously (20.5 ± 4.2 mg/kg) and orally (64.3 ± 5.8 mg/kg), to four and nine rats, respectively. Blood samples were collected at different time points, and plasma concentrations of carnosic acid were determined using LC-MS. Furthermore, total collection of urine and feces was done during 4 h and 24 h for the intravenous and oral administrations, respectively. After euthanizing the rats, intestinal content, liver and muscle tissue were sampled to determine carnosic acid concentrations. The bioavailability of carnosic acid, after 360 min, was 40.1%. Traces of carnosic acid were found in the rats intestinal content, liver and muscle tissue of abdomen and legs. The recovery of carnosic acid in the feces, 24 h after oral administration, was 15.6 ± 8.2%. Carnosic acid is absorbed into the bloodstream after oral administration in rats and is therefore bioavailable. It was found that carnosic acid in vivo is present in its free form and that its main elimination route is the fecal route.  相似文献   

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