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1.
Carotenoids are important antioxidants and valuable bioactive compounds contributing to the health benefits of different foods, and rose hips are known for high bioactive content. This study investigated the content of carotenoids and chlorophylls in hips from four rose species during the ripening period. Carotenoid content varied greatly between harvesting times, although species and year, and interactions between factors, also played an important role. Some carotenoids were identified only in hips of specific rose species. Some of the investigated compounds decreased (chlorophyll a) or increased (lycopene) consistently over the ripening period and could therefore be useful as maturity markers. An optimal content of total or specific carotenoids, e.g. for food products containing rose hips, might be obtained by proper choice of harvesting time and rose species.  相似文献   

2.
This work was conducted to investigate changes in the bioactive nutrient content of hot (pungent) paprika as a function of ripening in four of the most important varieties cultivated in Hungary. For the quantitative determination, recent liquid chromatographic (HPLC) methods were applied. Forty carotenoids were separated, with β‐carotene and lutein of interest from the biological point of view. The major component of vitamin E was α‐tocopherol. Capsaicin, dihydrocapsaicin and nordihydrocapsaicin were the dominant pungency principles. As for vitamin C components, only ascorbic acid could be detected and determined. The results indicated that all the examined compounds were at low level in the mature green fruits, and the onset of climacteric ripening caused their content to grow. In accord with the advance in ripening, carotenoids were being formed even at the overripening stage, while tocopherols, capsaicinoids and ascorbic acid reached their maximum level at the colour break or red stage and then declined. The highest values with regard to carotenoids were estimated in SZ‐178 and F0‐3 cultivars. The best retention of ascorbic acid was found in SZ‐178, which contained 4.86 mg g?1 dry matter in the dry pods. On the other hand, retention of α‐tocopherol during ripening and natural drying was found to depend on variety. The highest value for vitamin E was recorded in SZ‐178 followed by K‐V2, which contained the highest level of α‐tocopherol at the red stage of ripening. © 2001 Society of Chemical Industry  相似文献   

3.
ABSTRACT

It is important to explore new sources of natural additives because the demand for these compounds by consumers is increasing. These products also provide health benefits and help in food preservation. An unexplored source of nutrients and antioxidant compounds is rosehip, the fleshy fruit of roses. This work compares the antioxidant compound (vitamin C, neutral phenols and acidic phenols) content of four Rosa species rosehips: R. pouzinii, R. corymbifera, R. glauca and R. canina from different geographical zones. Results show quantitative variability in ascorbic acids and neutral phenols content, and quantitative and qualitative differences in acidic phenol content, depending on species. Vitamin C concentration was highly variable depending on species, R. canina being the one with the highest concentration and R. pouzinii the one with the lowest content. Variability was found in total neutral polyphenols concentration and a correlation between freshness of the rosehips and concentration of neutral polyphenols was also found. Significant differences were found in the acidic phenols content among the studied species. Generally antioxidant activity was higher in the vitamin C fraction.  相似文献   

4.
BACKGROUND: Carnosic acid and carnosol, the two major phenolic diterpenes present in rosemary and sage extracts, have received attention in food science and biomedicine because of their potent antioxidant properties. In plants, these compounds have been identified as being present in some species of the family Lamiaceae, but there is still little information about their distribution within the plant kingdom. The aim of the present study was to gain a better understanding of the occurrence of these compounds within leaf extracts of the genus Salvia and also to examine to what extent leaf senescence may influence their accumulation in relation to that of α‐tocopherol (vitamin E). RESULTS: Methanolic leaf extracts of 60 species of the genus Salvia were tested for the presence of carnosic acid and carnosol. These two diterpenes were detected in 48 and 27 species respectively. In contrast, α‐tocopherol was present in all species examined. Leaf senescence in Salvia officinalis resulted in α‐tocopherol increases by up to 5.5‐fold, while carnosic acid and carnosol increased by up to 18 and 290% respectively. Isorosmanol, an oxidation product of carnosic acid, increased by up to 2.1‐fold in senescing leaves. CONCLUSION: It was found that, while α‐tocopherol is ubiquitous in the genus Salvia, phenolic diterpenes are present in several but not all species. It was also shown that leaf senescence may increase the yield of both phenolic diterpenes and α‐tocopherol in sage extracts. Copyright © 2008 Society of Chemical Industry  相似文献   

5.
考察辅酶Q10和天然维生素E在不同配方组成下的稳定性,并进行安全毒理学评价实验研究,说明辅酶Q10与维生素E配伍作为保健食品原料的食用安全性。采用高效液相色谱法,对经过加速破坏试验的五个不同配方的辅酶Q10天然维生素E软胶囊进行含量分析和安全性毒理学评价。在各个不同的配方中,未见辅酶Q10和α-生育酚的量发生明显变化,含量测定结果均在测定的误差范围内,并且在保留时间的3倍延长时间内未发现有新的色谱峰产生,且辅料的存在亦未对其稳定性产生任何的影响。辅酶Q10与天然维生素E在24个月的有效期内长期混合不会发生化学反应。安全性毒理学评价实验结果表明辅酶Q10与天然维生素E配伍使用具有食用安全性。  相似文献   

6.
The seed oils of different varieties of 4 Passiflora species cultivated in Brazil were analyzed and compared regarding their physicochemical parameters, fatty acid composition and the presence of minor components, such as phytosterols, tocopherols, total carotenoids, and phenolic compounds. The antioxidant capacities of the oil extracts were determined using the 2,2'azinobis [3‐ethylbenzothiazoline‐6‐sulfonic acid] and oxygen radical absorbance capacity methods. The results revealed that all studied Passiflora seed oils possessed similar physicochemical characteristics, except for color, and predominantly contained polyunsaturated fatty acids with a high percentage of linolenic acid (68.75% to 71.54%). Other than the total phytosterol content, the extracted oil from Passiflora setacea BRS Pérola do Cerrado seeds had higher quantities (% times higher than the average of all samples), of carotenoids (44%), phenolic compounds (282%) and vitamin E (215%, 56%, 398%, and 100% for the α‐tocopherol, β‐tocopherol, γ‐tocopherol, and δ‐tocopherol isomers, respectively). The methanolic extracts from Passiflora setacea BRS Pérola do Cerrado seed oil also showed higher antioxidant activity, which was positively correlated with the total phenolic, δ‐tocopherol, and vitamin E contents. For the first time, these results indicate that Passiflora species have strong potential regarding the use of their seeds for oil extraction. Due to their interesting composition, the seed oils may be used as a raw material in manufacturing industries in addition to other widely used vegetable oils.  相似文献   

7.
生育酚抑制油脂氧化机制研究进展   总被引:1,自引:0,他引:1       下载免费PDF全文
生育酚是天然脂溶性抗氧化剂维生素E的重要组成部分,广泛存在于各种食用油中。但在加热条件下,油脂中生育酚在参与延缓油脂氧化反应过程中自身会发生损耗、转化和迁移,其转化产物是否还具备抗氧化活性成为研究热点。针对中餐食用油以高温煎炸为主的使用习惯,研究生育酚在高温煎炸条件下的转化及抗氧化活性维持十分重要。结合油脂氧化机理,主要总结了油脂中生育酚的抗氧化机制,重点对加热条件下生育酚抑制油脂氧化机制相关研究进展进行综合分析,旨在为合理及正确使用脂溶性抗氧化剂维生素E、发挥其营养保健功效、维持油脂品质提供一定参考。  相似文献   

8.
The impact of different irrigation regimes based on two ripeness index, on the quantity and quality of virgin olive oil from the introduced olive cultivar Olea europaea L. Koroneiki grown at a high‐density olive orchard in northern Tunisia, was assessed. Olive trees were subjected to three treatments (T1, T2 and T3) that received a seasonal water amount equivalent to 50%, 75% and 100% of the estimated local evaporative demand by a drip irrigation system and olives were collected in two different ripeness index. The olive oil content decreased when the water applied was increased but rose during ripening. The quality indexes and fatty acid composition were less affected by the irrigation schedule but most significantly by the maturity of olives. Moreover, phenol contents increased according to fruit ripening whereas no clear cut differences or consistent effects were observed by irrigation. α‐tocopherol decreased slightly in the oils as ripening progressed while insignificant differences between the irrigation treatments studied were obtained. Consequently, a restitution of 75% of crop evapotranspiration (ETc.) was sufficient to achieve good minor compounds; however, higher water volumes (100% ETc.) gave little additional α‐tocopherol and phenols increases.  相似文献   

9.
Arbutus unedo is a widespread shrub with economic importance, derived from the use of its berries in the production of alcoholic beverages and in folk medicine. This work intends to evaluate for the first time the effect of fruit ripening stage on antioxidant activity, total phenolic content, fatty acid profile and tocopherol composition. Ripe fruits shown higher extraction yield (45.04 ± 2.23%) when compared to other fruit ripening stages. By contrast, total phenol contents were higher in the unripe and intermediate stage of ripeness (108 and 111 mg GAES/g dry fruit, respectively, against 60 mg/g dry fruit when ripe). Ripe and intermediate fruits shown the lower EC50 values on the DPPH radicals (0.25 ± 0.02 mg/mL) and reducing power assay (1.09 ± 0.05 mg/mL), respectively. A significant correlation was established between antioxidant activity and fruits ripening stage. Fatty acid profiles were very similar between the ripening stages, being alfa-linolenic, linoleic and oleic, the three major ones. Polyunsaturated fatty acids (PUFA) represent as much as 60% of the total fatty acids, with a highly favorable omega 3/omega 6 ratio. From the analysis of the vitamin E vitamers, the most important was ??-tocotrienol, with a clear reduction in the total free vitamin E content with ripening.These results highlight that the fruits of intermediate ripeness can be regarded important sources of biologically active compounds with a fatty acid profile rich in omega-3 PUFA, properly supplemented with high vitamin E amounts.  相似文献   

10.
Forty organically grown spring and winter wheat genotypes were investigated for content and compositions of tocopherol and tocotrienol. The selected genotypes belonged to five different genotypic groups, i.e. landraces, old cultivars, modern cultivars, spelt wheat, and primitive wheat. The total tocochromanols content (21.9–37.3 mg/kg) wheat were in similar ranges as previously reported for conventionally grown wheat. The vitamin E activity varied among the genotypic groups and corresponded to 12–25% of the recommended daily intake. Primitive wheat was found to contain the highest percentage of tocotrienols (74%). Content of tocochromanols and vitamin E activity are known to decrease by heating. Organic wheat is more commonly consumed as whole and sprouted grain when compared to conventional wheat and might therefore be a good source of tocochromanols in health food. The large variation in tocopherols and tocotrienols in the investigated wheat genotypes indicated a great potential for the development of specific wheat genotypes with health promoting properties in future breeding programmes.  相似文献   

11.
Abstract: Marine algae are a promising source of beneficial compounds for human use. Among these, pro‐vitamin A carotenoids and vitamins B, C, and E stand out. The objective of this study was to investigate seasonal variation of α‐tocopherol levels in 5 species of green marine algae of the Caulerpa genus. This research was carried out with both fresh and dry specimens; and, in addition, differences arising as a result of the drying process were examined. Analyses were carried out by high‐performance liquid chromatography (HPLC) using an isocratic system and a reversed‐phase C‐18 column. The distribution of α‐tocopherol throughout the year in Caulerpa genus was variable. All samples of both fresh and dried algae contained α‐tocopherol, except for the dried C. racemosa from March 2006. The drying process was responsible for losses of α‐tocopherol ranging from 21% to 93%.  相似文献   

12.
13.
BACKGROUND: Tocopherol (vitamin E) is an antioxidant essential in human nutrition. Several approaches have aimed to enhance tocopherol content in crops by the genetic modification of plants, a practice that generates some social concern. As tocopherol accumulates with leaf age in some wild plants and the antioxidant mechanisms respond with flexibility to stress conditions, it is hypothesised that tocopherol content can be increased in edible plants by the manipulation of harvesting time and growth conditions, in particular irradiance. RESULTS: Ontogenic changes in tocopherol concentration have been studied in photosynthetic tissues of edible leaves (lettuce, spinach, corn salad and dandelion) and green fruits (cucumber and pepper). In all species, tocopherol content increased with tissue age. Spinach showed the fastest rate of tocopherol accumulation, and growth at higher irradiance had a synergistic effect on the rate of accumulation. The same irradiance dependence of this accumulation was observed in fruits, but a final decrease with senescence occurred in cucumber. CONCLUSION: This study demonstrates that the content of tocopherol in vegetables can be notably enhanced (or reduced) by simply selecting the appropriate harvesting time and/or by manipulating the environmental conditions during the growth period. Copyright © 2010 Society of Chemical Industry  相似文献   

14.
15.
Morphological parameters (size, weight, color), the content of sugars, organic acids, lycopene, β‐carotene, and phenolics were determined in hips of Rosa canina (RCA), Rosa sweginzowii (RSW), Rosa rugosa (RUG), and selected ornamental Rosa cultivars Fru Dagmar Hastrup (FDH), Repandia (REP), Veilchenblau (RVB), Aloha (RAL), Bonica (BON), and Golden Gate (RGG). Although traditionally used RCA hips contained the highest amount of cyanidin‐3‐glucoside (83 μg/g DW) and were the reddest (h° = 17.5), they did not stand out in other analyzed parameters. RGG climber had the biggest hips (8.86 g), which also contained highest sugar levels (50.9 g/100 g DW). RAL stood out as the cultivar rich in organic acids (33.9 g/100 g DW), mainly because of high quinic acid content (17.6 g/100g DW). FDH and RSW hips were characterized by particularly high ascorbic acid levels (4325 mg/100 g DW and 4711 mg/100 g DW). Other ornamental cultivars contained low amounts of ascorbic acid compared to the analyzed species. The phenolic profile was species/cultivars‐specific. The greatest diversity of phenolic compounds was detected in RUG and FDH hips (55 and 54 different tentatively identified compounds with HPLC/MS). Flavanols represented the main phenolic class in most of the investigated species/cultivars and RGG hips contained the highest amount of catechin and proanthocyandin derivatives (15855 μg/g DW). Altogether RAL hips contained the highest quantity of phenolics (44746 μg/g DW) mainly due to high levels of hydrolysable tannins compared to other species/cultivars. Although small, hips of BON and REP were most abundant regarding β‐carotene and lycopene content, respectively.  相似文献   

16.
The vitamin E group includes tocopherols and tocotrienols and their isomers, esters, and derivatives. They differ not only in biopotencies as antisterility agents but also in activities in other physiological and chemical relationships. Unlike vitamins A and D, foods (vegetable oils) are among the richest sources of vitamin E, and assay methods for vitamin E include food applications more often than for the former vitamins. Phys‐icochemical methods are replacing bioassays for vitamin E and tocopherol wherever possible because of greater specificity and less variability, time, and, sometimes, expense. Unless careful purifications and isolations are carried out and some of the relative vitamin E activities of components are calculated, bioassays are still required for total vitamin E activity. The vitamin E group is separated by column, paper, thin‐layer, gas‐liquid, and high‐pressure liquid chromatography (HPLC): Gas‐liquid chromatography has been more successfully used for vitamin E than for other fat‐soluble vitamins. Recently developed HPLC methods for vitamin E are sensitive and apparently require less cleanup of extracts and less time than former methods; HPLC may prove to be the most useful technique for vitamin E in foods, especially if other fat‐soluble vitamins can be determined simultaneously on the same sample extract.  相似文献   

17.
The content and the retention of the antioxidant nutrients, selenium and tocopherol (vitamin E), in boneless Chef's PrimeTM pork loin roasts cooked by different methods to 71 and 82C internal temperatures were determined. Roasts were cooked at 163C by roasting, braising, and in an oven cooking bag. Yield, moisture, and crude fat measurements were similar for all treatments. The only form of vitamin E in the sample was α-tocopherol. Selenium and vitamin E content as well as true retention values were similar in pork cooked to the two internal temperatures by the three household methods with one exception; the selenium content was significantly higher in pork cooked in the bag and roasted than in those prepared by braising. Overall, the selenium and vitamin E content of the cooked pork was 101.8 ± 0.5 μg/100g (X?± SEM) and 0.144 ± 0.006 mg α-TE/100g, respectively. Over half of the vitamin E but little to none of the selenium in the pork was lost during these household cooking procedures.  相似文献   

18.
《Food chemistry》2005,89(2):207-215
The effect of fruit ripeness on the antioxidant content of `Hojiblanca' virgin olive oils was studied. Seasonal changes were monitored at bi-weekly intervals for three consecutive crop years. Phenolic content, tocopherol composition, bitterness index, carotenoid and chlorophyllic pigments and oxidative stability were analysed. In general, the antioxidants and the related parameters decreased as olive fruit ripened. The phenolics and bitterness, closely related parameters, did not present significant differences among years. Although in general, the tocopherols decreased during olive ripening γ-tocopherol increased. Differences between crop years were found only for total tocopherols and α-tocopherol, which showed higher content in low rainfall year oils. The pigment content decreased during ripening, chlorophyll changing faster. For low rainfall years, the level of pigments was higher, reaching significant differences between yields. Significant differences among years were found for oil oxidative stability; higher values were obtained for drought years. A highly significant prediction model for oxidative stability has been obtained.  相似文献   

19.
Edible flowers are referred to the non-toxic flowers that can be consumed by human beings for their additional nutritional or medical properties. These flowers are rich source of natural antioxidants, thus exert specific positive health effects on chronic diseases and act as a potential function food. This research paper is focused on the determination of total phenolic content (TPC), total flavonoids content (TFC), and antioxidant capacities of different kinds of edible flowers in China and compared systematically. Sixty-five flower samples were collected from parks in Guangzhou and also purchased from Qingping Market. TPC, TFC, and three anti-oxidative assays (DPPH free radical scavenging activity, ABTS radical scavenging activity, and Ferric reducing antioxidant capacity (FRAP) assay) were conducted. Different flowers presented diverse range of antioxidant capacities, phenolic contents, and flavonoid contents. A high correlation between TPC and antioxidant activity (as accessed using three different methods) was reported. However, a low relationship was observed between TFC value and antioxidant capacities. This study revealed that five Rosa species exhibited strong antioxidant capacities among other samples, and these can be used as potential functional foods to counterbalance the effect of reactive oxygen species (ROS) and oxidative stress.  相似文献   

20.
Bio‐availability of different α‐tocopherol forms in livestock animals is measured by the increase in plasma or tissue concentrations of α‐tocopherol after oral administration. It is generally accepted that RRR‐α‐tocopheryl acetate (natural source vitamin E derived from vegetable oil) has a higher bio‐availability compared to allrac‐α‐tocopheryl acetate (synthetic vitamin E, i.e. α‐tocopherol produced by chemical synthesis). However, different bio‐availability ratios have been reported in the literature. The major reason for conflicting results in literature studies was the inability to separate the proportion of α‐tocopherol originating from test materials, from the proportion of α‐tocopherol originating from basal dietary ingredients and pre‐feeding. This causes significant variability. For bio‐availability determination, a baseline or control treatment is essential. The estimation of bio‐availability without correction for basal vitamin E status will lead to incorrect interpretation of the results. When using proper methodologies, it is possible to correct for the impact of α‐tocopherol intake from basal ingredients and α‐tocopherol originating from pre‐feeding, therefore yielding results reflecting the true relative bio‐availability of different α‐tocopherol substances. When reviewing literature data a critical evaluation of the method used in determination of relative bio‐availability is recommended. Copyright © 2010 Society of Chemical Industry  相似文献   

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