•Tocol contents in color-grained wheat, tritordeum and barley were assessed.•Higher tocol content in spring wheat compared to winter wheat was determined.•Higher tocol content was characteristic for ...blue- and purple-grained spring wheat.•Growing year conditions affected tocol levels in some cereal genotypes.•In barley 6–8 tocols were quantified, in tritordeum and wheat four tocols.
Colored-grain spring and winter wheat, spring tritordeum and barley (blue aleurone, purple pericarp, and yellow endosperm) from the harvests 2014 and 2015 were evaluated for tocol contents by HPLC-FD. Higher content of total tocols was found in spring wheat varieties compared with winter varieties. Four tocols (β-tocotrienol, α-tocotrienol, β-tocopherol, and α-tocopherol) were identified in wheat and tritordeum varieties. Dominant tocols in purple- and blue-grained wheat and yellow-grained tritordeum were α-tocopherol and β-tocotrienol, whereas spring barley varieties differed from wheat and tritordeum by high α-tocotrienol content. Tocol content was significantly affected by genotype and in a lesser extent in some varieties and lines also by rainfall and temperatures during crop year. Higher rainfall and lower temperatures caused in most varieties higher tocol contents. Purple- and blue-grained wheat lines with higher tocol, anthocyanin and phenolic acids with health benefits may be useful for breeding new varieties.
Cereal grains contain many phytochemicals, some of which significantly influence the grain colour. Anthocyanins are accumulated in the aleurone or pericarp layer and give blue, purple or combination ...of these colours. Flavonoids, such as yellow C-glycosides of flavones, flavonols, flavanonols, proanthocyanidins and reddish-coloured phlobaphenes are mainly present in the outer layer of grains while carotenoids that are responsible for yellow grain are in the endosperm. Therefore, accumulation of these pigments in the grain can represent an important target in breeding programmes aimed at increasing the concentrations of bioactive components in grain and products. This review therefore summarises our current knowledge of anthocyanin and carotenoid pigments, their genetic control and variation in levels in different wheat lines.
•Critical overview of new knowledge about pigments in wheat grain.•Genetic determination of yellow endosperm, purple pericarp and blue aleurone.•Chemical characteristics of red, purple, blue and yellow pigments in wheat grain.•Utilization and value of colour-grained wheat.
Major antioxidants and antioxidant activity in eight varieties of tomatoes were determined. Hydrophilic and lipophilic antioxidant activity (HAA and LAA) was determined by the ABTS assay and ascorbic ...acid and carotenoid contents were determined by HPLC-DAD. The HAA has far more significant impact on total antioxidant activity (83%) as compared with LAA. HAA was increasing during all ripening stages and was strongly correlated with ascorbic acid content (r = 0.83). During the ripening the LAA was increasing till the III. stage of maturity and then decreased. The main carotenoids determined in the red-fruit tomatoes were lycopene, β-carotene and lutein. The content of lycopene has been increasing equally during the ripening. β-Carotene and lutein were intensively synthesized between the I. and II. stage of maturity. Among ascorbic acid, α-tocopherol, lycopene, β-carotene and lutein standards ascorbic acid was determined as the most efficient antioxidant followed by α-tocopherol and β-carotene. Antioxidant activity of ascorbic acid, α-tocopherol, β-carotene and lutein grew equally with increasing concentration, however lycopene was the most effective in its lowest concentration. The analysis of two-component mixtures showed significant synergism between lycopene-lutein, lycopene-β-carotene and α-tocopherol-β-carotene.
•Purple wheat varieties and breeding lines contained higher levels of carotenoids than blue ones.•Purple wheat varieties and breeding lines were high in esterified forms of xanthophylls.•Lutein was ...predominant in wheat and tritordeum while zeaxanthin in barley.•Antheraxanthin was quantified at very low levels in mature cereal grain.•High temperature and drought during the growing season promoted carotenoid biosynthesis.
Carotenoids are important phytonutrients responsible for the yellow endosperm color in cereal grains. Five carotenoids, namely lutein, zeaxanthin, antheraxanthin, α- and β-carotene, were quantified by HPLC-DAD-MS in fourteen genotypes of wheat, barley and tritordeum harvested in Czechia in 2014 and 2015. The highest carotenoid contents were found in yellow-grained tritordeum HT 439 (12.16μg/gDW), followed by blue-grained wheat V1-131-15 (7.46μg/gDW), and yellow-grained wheat TA 4024 (7.04μg/gDW). Comparing carotenoid contents, blue varieties had lower whereas purple ones had the same or higher levels than conventional bread wheat. Lutein was the main carotenoid found in wheat and tritordeum while zeaxanthin dominated in barley. The majority of cereals contained considerable levels of esterified forms (up to 61%) of which lutein esters prevailed. It was assessed that cereal genotype determines the proportion of free and esterified forms. High temperatures and drought during the growing season promoted carotenoid biosynthesis.
•Total of nine carotenoids were identified and quantified in potatoes.•Only (Z)-isomers of violaxanthin and neoxanthin were found.•Coloured cultivars contained only a fifth of the carotenoid levels ...present in yellow cultivars.•Boiling was more destructive towards carotenoids compared to baking.•Lutein, followed by β-carotene, were the most stable carotenoids.
This research aimed to investigate the effect of thermal processing on carotenoid profile, quantity and stability in 22 colour-fleshed potato cultivars grown in the Czech Republic. The total of nine carotenoids was analysed by HPLC using a C30 column and PDA detection. The total carotenoid content for all cultivars ranged from 1.44 to 40.13μg/g DM. Yellow cultivars showed a much higher average total carotenoid content (26.22μg/g DM) when compared to red/purple-fleshed potatoes (5.69μg/g DM). Yellow cultivars were dominated by antheraxanthin, whereas neoxanthin was the main carotenoid in red/purple cultivars. Thermal processing significantly impacted all potato cultivars. Boiling decreased the total carotenoids by 92% compared to baking (88%). Lutein was the most stable carotenoid against thermal processing (decreased by 24–43%) followed by β-carotene (decreased by 78–83%); other carotenoids were degraded nearly completely. Increased formation of (Z)-isomers by thermal processing has not been confirmed.
Potatoes are a significant source of essential macronutrients and many other health-promoting phytochemicals. However, under thermal processing, undesirable harmful acrylamide might be formed. In the ...present study, the content of acrylamide (LC–ESI-MS/MS) after baking and frying in thirteen colored potato varieties was investigated. Asparagine (LC–ESI-MS/MS), glucose, fructose, sucrose (HPLC–RI) and chlorogenic acid isomers (HPLC–DAD) were determined in raw tubers. Yellow-fleshed potato varieties produced lower acrylamide content (190 μg/kg FW after frying and 25.2 μg/kg FW after baking) than red- (1120 μg/kg FW and 112 μg/kg FW) and purple-fleshed (2005 μg/kg FW and 59.1 μg/kg FW). Acrylamide content positively correlated with fructose (R = 0.265 frying and R = 0.225 baking at p < 0.05), glucose (R = 0.262 frying), and sucrose contents (R = 0.316 frying) that were more limiting in acrylamide formation than higher asparagine levels. Chlorogenic acid isomers also showed a positive effect on the formation of acrylamide content, which was higher in baking (R = 0.356 at p < 0.05). However, under the same temperature, frying caused significantly higher acrylamide production compared to baking (16.5× on average). Climatic conditions at two growing localities had a significant effect on the amount of acrylamide formed in the heat-treated tubers, as higher temperature and lower precipitation caused lower acrylamide content.
Display omitted
•Deep-frying caused higher acrylamide formation in tubers than baking.•Red- or purple-fleshed varieties showed higher acrylamide content than yellow ones.•Acrylamide content was positively correlated with sugars and chlorogenic acid.•No clear relationship between the asparagine and acrylamide formation was found.•Heat-treated tubers from a cool and humid locality had a higher acrylamide content.
Apple trees (Malus domestica Borgh) are a rich source of dihydrochalcones, phenolic acids and flavonoids. Considering the increasing demand for these phytochemicals with health-benefitting ...properties, the objective of this study was to evaluate the profile of the main bioactive compounds—phloridzin, phloretin, chlorogenic acid and rutin—in apple tree bark, leaves, flower buds and twigs. The variety in the phenolic profiles of four apple tree cultivars was monitored during the vegetation period from March to September using chromatography analysis. Phloridzin, the major glycoside of interest, reached the highest values in the bark of all the tested cultivars in May (up to 91.7 ± 4.4 mg g−1 of the dried weight (DW), cv. ‘Opal’). In the leaves, the highest levels of phloridzin were found in cv. ‘Opal’ in May (82.5 ± 22.0 mg g−1 of DW); in twigs, the highest levels were found in cv. ‘Rozela’ in September (52.4 ± 12.1 mg g−1 of DW). In the flower buds, the content of phloridzin was similar to that in the twigs. Aglycone phloretin was found only in the leaves in relatively low concentrations (max. value 2.8 ± 1.4 mg g−1 of DW). The highest values of rutin were found in the leaves of all the tested cultivars (10.5 ± 2.9 mg g−1 of DW, cv. ‘Opal’ in September); the concentrations in the bark and twigs were much lower. The highest content of chlorogenic acid was found in flower buds (3.3 ± 1.0 mg g−1 of DW, cv. ‘Rozela’). Whole apple fruits harvested in September were rich in chlorogenic acid and phloridzin. The statistical evaluation by Scheffe’s test confirmed the significant difference of cv. ‘Rozela’ from the other tested cultivars. In conclusion, apple tree bark, twigs, and leaves were found to be important renewable resources of bioactive phenolics, especially phloridzin and rutin. The simple availability of waste plant material can therefore be used as a rich source of phenolic compounds for cosmetics, nutraceuticals, and food supplement preparation.
•Potato starch cultivars were evaluated for starch, amylose and phosphorus contents.•In starch samples granule size and amylose/amylopectin have been determined.•Impact of cultivars, locations and ...years on analysed parameters has been assessed.•Enzymatic and iodine reagent methods for amylose determination have been compared.•Selected potato cultivars for food/industrial starch processing may be recommended.
In recent time the interest of industry increases particularly in processing and use of potato high amylopectin (AMP) starches. Therefore the plant breeders effort to obtain “waxy” potato cultivars with low amylose (AMS) content. In this four-year study sixteen potato cultivars grown on five experimental locations were evaluated on the percentage of AMS/AMP by enzymatic method, starch content by the underwater weight method, phosphorus (P) content in starch digests spectrophotometrically, and starch granule size determined by laser diffraction method. Between enzymatic and iodine–potassium iodide method good correlation has been revealed (r=0.71). The correlation analysis between AMS and P levels showed a clear negative correlation. For all measured parameters (starch, AMS, P, starch granule size) significant impact of cultivar has been determined. Location and year have lower, but significant impact. No statistically significant effect of year on AMS has been found. The cultivar Amado distinguished with the highest AMP and P contents and the cultivar Westamyl showed all positive values interesting for growers and processors.
PDF
