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1.
The objectives of the present study were to develop a simple high performance thin layer chromatography (HPTLC)-based protocol: (i) to allow high-throughput profiling of phenolic compounds of microwaved roots from 295 sweet potato varieties and breeding lines, (ii) to quantify the content of anthocyanins and caffeoylquinic acid (CQA) derivatives, and (iii) to determine their respective contributions to the antioxidant activity of sweet potato methanolic extracts using the DPPH test. Analysed accessions were separated into three groups: white-fleshed (n = 100), orange-fleshed (n = 64) and purple-fleshed (n = 131). Purple-fleshed accessions presented the highest mean CQA content. After DPPH treatment and transmittance scanning of the plate at 517 nm, the most active free radical scavengers were found to be the four CQAs (CGA, 3,4-, 4,5- and 3,5-diCQA) while the anthocyanins were found to be less active. The total antioxidant capacity of the sweet potato methanolic extracts was mostly linked to total CQAs content. This method can now be used for fast routine analysis and selection of sweet potato breeding clones.  相似文献   

2.
The effect of fertilisation rates of nitrogen: 0 (control treatment—no soil fertilisation), 40, 80 and 120 kg/ha and potassium: 0 (control treatment), 120, 150 and 180 kg/ha on the content of anthocyanins, phenolic acids and antioxidant capacity in purple–blue potato cv. ‘Blue Congo’ was examined. Anthocyanins and phenolic acids were identified and quantified by LC–MS and UPLC–PDA. Nitrogen was more effective in increasing the anthocyanin content—their quantity in tubers after nitrogen application was twice as much as that found after potassium application. Among phenolic acids, the dominant one was chlorogenic acid, the content of which significantly increased after nitrogen fertilisation at 120 kg/ha, in line with the increase in total concentration of phenolic acids and antioxidant capacity. The adjustment of nitrogen and potassium fertilisation levels during the growth of purple–blue potatoes seems to be an effective way to increase the expression of polyphenolic compounds in these cultivars. Therefore, fertilisation with N at 120 kg/ha and K at 120 and 150 kg/ha is recommended as a way to improve the content of biologically active compounds and antioxidant properties, and consequently, to enhance the nutritional value and the functionality of purple–blue potatoes.  相似文献   

3.
The sweet potato is an important industrial crop and a source of food that contains useful dietary fiber and vitamins. Recently, orange- and purple-fleshed varieties have come under the spotlight due to their healthful components, carotenoids and anthocyanins, respectively. In this study, an HPLC-DAD method was applied to determine the carotenoid composition and content in nine Korean cultural varieties of sweet potato. Changes in carotenoid contents and composition were also observed during home-processing of an orange-fleshed cultivar with high carotenoid content (530 ± 60 μg/g of dry weight, DW as all-trans-β-carotene). A loss of the carotenoids was observed for all of the home-processing methods examined; the baked or boiled or steamed sweet potatoes had higher amounts of all-trans-β-carotene (246 ± 34, 253 ± 29 and 240 ± 21 μg/g DW, respectively) than pressure-cooked, sautéed and fried ones (194 ± 21, 201 ± 28 and 111 ± 19 μg/g DW, respectively). Interestingly, cis-isomer of the all-trans-β-carotene, 13Z-β-carotene was found in elevated amounts in all of the processed samples, particularly in baked, pressure-cooked and steamed sweet potatoes compared to control. Variations in anthocyanin content in the nine cultural varieties and home-processed sweet potatoes were also determined by an HPLC-DAD method.  相似文献   

4.
Several ancient apple varieties and a wild apple variety grown in Croatia were analysed for the polyphenol content and compared to two varieties grown in USA. In the flesh, flavanols, dihydrochalcones and phenolic acids (24 to 137, 23 to 109, 3 to 238 mg kg−1 of fresh weight (FW), respectively) were found. Peel contained flavanols, dihydrochalcones, phenolic acids, flavonols and anthocyanins (65 to 690, 21 to 141, 0 to 107, 205 to 1223, 0 to 213 mg kg−1 FW, respectively). The wild apple was characterized by much higher flavanol and phenolic acid content in the flesh (301 and 734 mg kg−1 FW, respectively) while the peel was similar to other apples. The polyphenol profile was similar to apples from USA. The varieties Zimnjara, Lještarka and Adamova zvijezda could be highlighted as sources of polyphenols. Varieties are categorized by the content of dihydrochalcones and flavanols in the flesh (whether that content is high or low), and by the relative portion of phenolic acids and flavanols in the flesh (high phenolic acid proportion, lower flavanol proportion and vice versa). There was not observed to be as strong a pattern for categorizing differences in the peel.  相似文献   

5.
The present work deals with the study of the anthocyanin profile of two different black carrots (Daucus carota L. ssp. sativus var. atrorubens Alef.) cultivars, associated with Antonina and Purple Haze varieties, from Cuevas Bajas (Málaga, Spain) and some of their antioxidant features. The main anthocyanins detected by LC–MS were found to correspond to five cyanidin-based anthocyanins: cyanidin 3-xylosylglucosylgalactoside, cyanidin 3-xylosylgalactoside and the sinapic, ferulic and coumaric acids derivative of cyanidin 3-xylosylglucosylgalactoside. The anthocyanins present in the black carrots were essentially acylated and their levels were found to correspond to 25% and 50% of the total phenolic content for the Purple Haze and Antonina varieties, respectively. Moreover, the reducing capacity of the two black carrots extracts (86.4 ± 8.0 and 182.0 ± 27 μM TE/100 g fw) and the radical scavenging ability (17.6 ± 9.0 and 240.0 ± 54.0 μM TE/100 g fw) expressed in Trolox equivalents units were determined. The antioxidant features of the black carrot extracts were shown to be significantly higher than those of orange carrots used herein for comparison. Overall, this work highlights the Cuevas Bajas black carrots as rich sources of anthocyanins with significant antioxidant capacities and good nutritional value.  相似文献   

6.
The anthocyanins from acerola and açai, two tropical fruits known for their bioactive compounds, were studied. Two varieties of acerola in natura and one brand of frozen pulp of açai were analyzed by high-performance liquid chromatography connected to photodiode array and mass spectrometry detectors (HPLC–PDA–MS/MS). The açai pulp presented 282–303 mg/100 g of total anthocyanin, with predominance of cyanidin 3-glucoside and cyanidin 3-rutinoside, in average proportions of 13% and 87%, respectively. The composition of the two acerola varieties (Waldy Cati 30 and Olivier) were similar, being cyanidin 3-rhamnoside (76–78%) the major anthocyanin, followed by pelargonidin 3-rhamnoside (12–15%). The acerola Waldy variety showed total anthocyanin content of 6.5–7.6 mg/100 g, while 7.9–8.4 mg/100 g were found in the Olivier variety, for fruits harvested in 2003 and 2004. No statistical differences were found between varieties and harvests for the total anthocyanin content in acerola fruits.  相似文献   

7.
Acrylamide, a probable carcinogen, is formed via the Maillard reaction between reducing sugars and the amino acid asparagine during heating of carbohydrate-rich foods. Potatoes contain high levels of these precursors, and thus potato crisps can contain high levels of acrylamide. In this study, the effect of blanching on the concentration of precursors and acrylamide content was studied in three potato clones stored at 4 °C or 8 °C. After 6, 12 and 18 weeks of storage, potatoes were sliced and blanched for 3 min in water at 80 °C and deep-fat fried for 3 min at an initial frying temperature of 180 °C and a final frying temperature of 160 °C. Blanching reduced the acrylamide content by 51–73%. Interestingly, blanching affected the levels of the precursor sugars and asparagine, but not the acrylamide content to the same extent. The reduction of precursors was 17–66%. This may be due to restriction of the transport of precursors to the surface, as the availability of precursors for reactions is crucial for acrylamide formation. In conclusion, blanching was an efficient way to reduce acrylamide content in potato crisps, in addition to using potatoes low in asparagine and reducing sugars.  相似文献   

8.
The effect of strawberry (Fragaria x ananassa Duchesne) cultivars (cvs) and storage temperature on the stability of polyphenols in cloudy juices was determined. Identification of phenolic compounds by ultra performance liquid chromatography-electrospray ionization/mass spectrometry (UPLC–ESI/MS), as well as quantitative analysis by ultra-performance liquid chromatography–photodiode array–fluorescence (UPLC–PDA–FL), were carried out on fresh and stored products (6 months, 4 °C and 20 °C) from 7 different strawberry cvs. A total of 32 polyphenolic compounds were identified: flavan-3-ols (6), anthocyanins (8), flavonols (4) and flavones (3), hydroxycinnamic acids (4), and ellagic acid derivatives (7). Total polyphenol content ranged from 642.08 mg/L in fresh ‘Florence’ cv. juice to 296.72 mg/L in ‘Honeoye’ cv. juice after 6 months of storage at 20 °C. Anthocyanins (max. 161.40 mg/L in ‘Honeoye’ juice) demonstrated the greatest degree of degradation (31–100%, depending on the molecular structure and temperature). Cyanidin-3-malonylglucoside was less labile than 3-glucoside. In the case of pelargonidin glycosides, 3-glucoside was more stable. The degradation process was the least advanced in ‘Kimberly’ cv. juice (58.53% at 4 °C). Storage conditions also influenced the decrease in p-coumaroyl-hexose, and quercetin-glucuronide content. However, low temperatures limited this process. This was especially noticeable in ‘Florence’ and ‘Honeoye’ cvs. In turn, proanthocyanidins showed the most stability and were the main polyphenols identified in juices (212–434 mg/L). Generally, it was observed that the total content of polyphenols and their stability in juices was dependent on the cultivar, and the duration of storage conditions.  相似文献   

9.
The information about nutritional composition of potatoes at both the ingredient and recipe levels in the Food Composition Data Base (FCDB) of Latvia is insufficient. Therefore, the aim of this research was to determine the nutritional composition and energy content of potatoes prepared by traditional cooking methods before and after storage. Five Latvian potato varieties were selected: Lenora, Brasla, Imanta, Zile and Madara. A two-year research was conducted during two periods: just after harvesting (2007, 2008) and after six months of storage (2008, 2009). The following cooking methods were used: shallow frying (150 ± 5 °C); deep-fat frying (180 ± 5 °C) and roasting (210 ± 5 °C). The weight of the potatoes was recorded before and after frying along with the time and temperature during frying. Chemical analyses were performed to determine the content of reducing sugars, starch, fructose, glucose, sucrose, fibre, fat, protein, moisture, vitamin C and amino acids. The content of the analyzed nutrients differed significantly between both potato varieties and applied cooking methods: differences between potato varieties and cooking methods were found for vitamin C, moisture, reducing sugars, fructose, glucose, sucrose, amino acids, essential amino acids, and energy content, whereas significant differences in starch, fibre, fat and protein content were found between cooking methods.  相似文献   

10.
Different kinds of chocolates produced in Serbia were analyzed regarding total polyphenol, flavonoid and proanthocyanidin content using spectrophotometric methods. Flavan-3ols and methylxanthines in all samples were determined with RP-HPLC. DPPH, FRAP, ABTS and ORAC assays were applied for measuring antioxidant capacity. The average of all four antioxidant tests for each cocoa product was used for calculating antioxidant potency composite index (ACI). Obtained results for all four assays have shown that antioxidant capacity of analyzed chocolate/cocoa extracts followed cocoa, polyphenol, flavonoid, and proanthocyanidin contents. Although the addition of raspberries to dark chocolates had no significant influence on their total polyphenol, flavonoid and proanthocyanidin contents, statistical analysis showed that there was significant increase in the antioxidant capacity of dark chocolates with raspberry compared to plain dark chocolates (p = 0.007). Overall range for theobromine content varied from 5.5 to 22.3 mg/g depending on the product type, while the content of caffeine was 13–30 times lower in all analyzed cocoa products. In addition, correlation between antioxidant potency composite index and declared percentage of cocoa was high (R2 = 0.798, p < 0.05) and indicated that declared cocoa content was a reliable indication for antioxidant capacity of chocolates produced in Serbia.  相似文献   

11.
Thinning consists of reducing fruit load at immature stage and thus allowing remaining fruits to develop to their maximum size and quality. The waste material produced during this farming practice was characterised in 9 pomegranate cultivars, by evaluating: weight, size, maturity index, pH, organic acids and sugars profiles, contents of minerals, punicalagin, and ellagic acid, total polyphenols and antioxidant activity. Citric and quinic were the main organic acids. Potassium was the predominant mineral, reaching up to 11 g kg−1 dry weight (dw). Total polyphenol content ranged from 777 to 1660 g GAE kg−1 dw, α-punicalagin from 101 to 195 and β-punicalagin from 80.1 to 111 g kg−1 dw. The antioxidant activity was assessed by three methods and its values varied from 2923 to 4486 for ABTS, from 3153 to 4685 for FRAP, and from 2075 to 2934 mmol Trolox kg−1 dw for DPPH. Pomegranate thinning fruits, especially sour-sweet cultivars, are rich in bioactive compounds, with a potential use in the food, chemical and pharmaceutical industries.  相似文献   

12.
The qualitative and quantitative characteristics of iridoids and anthocyanins of cornelian cherry (Cornus mas L.) ripe fruits were investigated. The characteristics of these compounds were determined using HPLC-DAD, LC–ESI-MS, and NMR methods. Two iridoids (loganic acid and cornuside) and five anthocyanins (delphinidin, cyanidin, and pelargonidin glycosides) were identified in cornelian cherry fruits. The MS fragmentation pathways of the two iridoids were studied. A total of 26 different cultivars and 2 ecotypes, harvested from five locations in the years 2007–2011 were analyzed. The content of total iridoids in cornelian cherry fruits covered a wide range, i.e. from 86.91 to 493.69 mg/100 g fw. Loganic acid was the most dominant iridoid compound identified in cornelian cherry fruits and amounted to 88–96% of total iridoids. The total content of anthocyanins in red cultivars of cornelian cherry fruits was in a wide range from 5.59 to 134.57 and 341.18 mg/100 g fw. In most cornelian cherry fruits, pelargonidin 3-galactopyranoside was dominant.  相似文献   

13.
The anthocyanin composition was analysed in fig fruit (Ficus carica L.) from five different varieties (Colar, Cuello de Dama (green), Cuello de Dama (dark purple), Granilla and Bursa Siyahi). Fifteen anthocyanin pigments were detected, most of them containing cyanidin (Cy) as aglycone; some pelargonidin (Pg) derivatives were also found. Rutinose and glucose were present as substituting sugars, as well as acylation with malonic acid. Minor levels of peonidin 3-rutinose (Pn 3-rutinoside) in the pulp were also detected. Other noticeable aspects in the pigment composition of the fig were the detection of anthocyanidin-derived pigments, namely 5-carboxypyranocyanidin-3-rutinoside, a cyanidin 3-rutinose dimer and five condensed pigments containing C–C linked anthocyanins (Cy and Pg) and flavanol (catechin and epicatechin) residues. Total anthocyanin content in the skin ranged between 32 and 97 μg g−1 and between 1.5 and 15 μg g−1 in the pulp. The main anthocyanin in both parts of the fruit was Cy 3-rutinoside (48–81% in skin and 68–79% in pulp) usually followed by Cy 3-glucoside (5–18% in skin and 10–15% in pulp). Malonyl derivatives were more abundant in the skin (1.2–6.5%) than in the pulp (1.0–2.6%).  相似文献   

14.
Blueberries (Vaccinium spp.) may be considered one of the best potential sources of antioxidants in the diet. This characteristic results from the presence of flavonoids (especially anthocyanins), tannins and phenolic acids in the fruits. The objective of this work was to analyze the anthocyanin stability and antioxidant activity of refrigerated whole blueberry juice stored at 4 °C for 10 d, and of fruits stored frozen (−18 °C) for 6 months, in order to determine the changes occurring during storage. The frozen fruits showed a significant increase (p < 0.05) in antioxidant activity during the 3rd month of frozen storage, followed by a decrease up to the end of the 6-month period. The juice was analyzed every other day, and the antioxidant activity changed on the 8th d of refrigerated storage, remaining stable up to the 10th d. There were significant losses of anthocyanins both in the frozen fruits (59%) and refrigerated juice (83%). The antioxidant capacity was shown to be stable during cold storage both in the case of the fruits and whole juice, whereas the anthocyanins were degraded, possibly due to oxidations and/or condensation reactions with other phenolic compounds. More studies are required to optimize the storage time and temperature of these products with respect to nutrient stability.  相似文献   

15.
Fruit extracts of two raspberry (Rubus idaeus L.) cultivars (Autumn Bliss and Polka) were analysed for total phenolic (TPC) and anthocyanin (TACY) content. Correlation of TPC with total antioxidant capacity (TAC) showed higher free-radical scavenging properties of Autumn Bliss (r2 = 0.9999) compared to Polka (r2 = 0.8972). Correlation coefficient between TACY and TAC were higher in Autumn Bliss (r2 = 0.9939) compared to Polka fruits (r2 = 0.8419). Although total protein concentrations were similar in both cultivars (∼0.35 mg mL−1), activities of peroxidases and polyphenol oxidases were much higher in Polka, which were confirmed with isoelectric focusing in cationic (pI 9.3) and anionic (pI 3.6) range. HPLC detection showed that among detected flavonoids (catechin, epicatechin, epicatechin gallate, rutin, myricetin, resveratrol, quercetin and kaempferol) epicatechin appears to be the most abundant compound. Chlorogenic, caffeic and p-coumaric acid were also detected. The results indicate that the changes in enzymes activities related to content of substrates play an important role in nutrient quality definition of raspberry fruits.  相似文献   

16.
Solanum sisymbriifolium Lam. (Litchi tomato) is grown ornamentally, and in Europe it is used as a trap crop for management of the potato cyst nematode (PCN). Its berries are edible, but little is known about their nutritional content. If more was known about their nutritional value this could provide incentive to grow it as a food crop. Phytonutrient content was characterized in berries from four varieties and four synthetic breeding lines developed to have reduced spininess. Litchi tomatoes contained 6.8–10.4 mg of total phenolics per g dry weight. Antioxidants measured by FRAP ranged from 148 to 242 μmol TE/g DW. HPLC analysis showed chlorogenic acid (1856–4385 μg/g DW) was the most abundant phenylpropanoid. Ascorbic acid ranged from 2042 to 4511 μg/g DW. The yellow/orange flesh color was due to carotenoids, with β-carotene the most abundant (204–633 μg/g DW). Soluble protein in Litchi tomato ranged from 86.9 to 120.9 mg/g. Of the cultivated Litchi tomato varieties analyzed, SS91 had the highest amount of antioxidant activity, ascorbic acid, chlorogenic acid and β-carotene. These results suggest that Litchi tomato fruits can be a good source of phytonutrients, expanding the plant's functionality beyond its use as a PCN trap crop.  相似文献   

17.
After the EU banned the use of the neonicotinoids in flowering crops that honeybees might visit, there has been an increased interest in determining the neonicotinoid residues in honeybee products such as honey. The aim of this study was to develop and optimize an HPLC-DAD analytical method with dispersive liquid–liquid microextraction (DLLME) and QuEChERS sample preparation procedures for the simultaneous analysis of seven neonicotinoids (dinotefuran, nitenpyram, thiametoxam, clothianidin, imidacloprid, acetamiprid and thiacloprid) in honey samples. The liquid chromatographic conditions were optimized by Response surface methodology with Box–Behnken design and Derringer's desirability. The optimized method was validated to fulfill the requirements of SANCO/12571/2013 standard for both sample pretreatment procedures providing results for accuracy (73.1–118.3%), repeatability (3.28–10.40%) and within-laboratory reproducibility (6.45–17.70%), limits of detection (1.5–2.5 μg kg−1) and quantification (5.0–10.0 μg kg−1) with the use of matrix-matched calibration to compensate the matrix effects. For the first time 104 honey samples from Vojvodina were analyzed. The presence of thiacloprid, imidacloprid and thiametoxam was found in a small number of samples implicating the usefulness of ongoing control of honey. Residues were confirmed by LC–MS/MS.  相似文献   

18.
In Australia, thiamin is mandatorily added to bread-making flour with the main purpose of fortification and reducing the prevalence of Wernicke–Korsakoff syndrome. This study aims to measure the retention of added thiamin through laboratory-scale bread processing and provide an update on thiamin contents in commercially fortified bread and flatbread varieties since the introduction of the program in 1991. Even though baking caused degradation loss of thiamin (approximately 16%), the laboratory fortified white bread had a 25% higher thiamin content than its corresponding flour, and laboratory fortified wholemeal bread showed a 16% increase (p < 0.05). Thiamin levels in commercially fortified bread and flat bread varieties ranged between 0.24 and 1.9 mg/100 g (dry weight basis). It can be suggested that most of the bread varieties were made from flour fortified at the minimum mandated level (0.64 mg/100 g flour). Samples of flat bread varieties (white without yeast, wholemeal with yeast and wholemeal without yeast) showed low thiamin levels (0.24–0.49 mg/100 g, dry weight basis). The results suggest that the flat bread varieties were likely made from either commercially under-fortified flour or unfortified general-purpose flour, as only bread-making flour is fortified with thiamin.  相似文献   

19.
Non-destructive applications for the detection of food quality, especially internal properties, are highly relevant for process control in the food industry. In this respect, colour measurement and near-infrared spectroscopy (NIRS) were evaluated and compared for their ability to predict β-carotene content in mango cv. ‘Nam Dokmai’. Colorimetric analysis of peel and flesh colour as well as NIR measurements in the short- (700–1100 nm) and long-wave regions (1000–2500 nm) were analysed for prediction ability. It was found that β-carotene content could be estimated by multiple linear regression (MLR) models developed from b* and hue angle (h°) values of the flesh with good results for coefficient of determination (R2) and standard errors of cross validation (SECV) of 0.941 and 10.2 retinol equivalents (RE) 100 g−1 edible part (EP), respectively, while peel colour showed poor results. However, flesh colour measurement is a destructive method. NIRS calibration showed good results with R2 > 0.800 and standard error of prediction (SEP) 11.642–20.2 RE 100 g−1 EP. Long-wave NIR provided better prediction ability than short-wave. From these results, NIRS can be recommended for non-destructive and reliable determination of β-carotene content in mango. The results have implications for quality control in the industrial handling and processing of fruits.  相似文献   

20.
A survey was conducted on the presence of hydroxymethylfurfural (HMF) and furfural in bread and bakery products; for this purpose a reliable extraction procedure followed by high performance liquid chromatography (HPLC) was applied. The performance of the method was evaluated in terms of linearity (r always > 0.99); detection limits (0.001 mg L−1 for furfural and 0.006 mg L−1 for HMF); recovery percentages (98.5–100.5% for HMF and 94.9–98.9% for furfural); intraday precision (<4.65%) and interday precision (<7.51%). Two batches of a wide variety of products commercially available were analysed (a total of 88 samples). HMF and furfural levels presented high variability between products and batches of the same product. Cake/pastry samples showed the lowest HMF content (3.0 mg kg−1 fw) while biscuits showed the highest content (7.8 mg kg−1 fw) (p < 0.05). Regarding furfural, bread samples presented the highest furfural content (5.3 mg kg−1 fw) (p < 0.05), cake/pastry and biscuits showed the lowest content (1.9 and 3.0 mg kg−1 fw, respectively). Chocolate containing samples presented higher amounts of furfural (>20 mg kg−1). These results indicate that special attention should be given to furfural content of bread (due to its daily high consumption) and re-evaluation of dietary exposure.  相似文献   

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