Identification and Quantification of Anthocyanin and Catechin Compounds in Purple Tea Leaves and Flakes.

Tea is the first most popular beverage worldwide and is available in several selections such as black (fully oxidized), Oolong (partially oxidized) and green (non-oxidized), in addition to purple tea, an emerging variety derived from the same tea plant (Camellia sinensis). This study investigated purple tea leaves (non-oxidized) and flakes (water extractable) to thoroughly identify their composition of anthocyanins and catechins and to study the effect of a water extraction process on their compositional properties in comparison with green tea. Anthocyanin and catechin compounds were separated and quantified using UPLC, and their identity was confirmed using LC-MS/MS in positive and negative ionization modes. Delphinidin was the principal anthocyaninidin in purple tea, while cyanidin came in second. The major anthocyanin pigments in purple tea were delphinidin-coumaroyl-hexoside followed by delphinidin-3-galactoside and cyanidin-coumaroyl-hexoside. The water extraction process resulted in substantial reductions in anthocyanins in purple tea flakes. There were no anthocyanin compounds detected in green tea samples. Both purple and green tea types were rich in catechins, with green tea containing higher concentrations than purple tea. The main catechin in purple or green tea was epigallocatechin gallate (EGCG) followed by either epicatechin gallate (ECG) or epigallocatechin (EGC), subject to tea type. The extraction process increased the concentration of catechins in both purple and green tea flakes. The results suggest that purple tea holds promise in making healthy brews, natural colorants and antioxidants and/or functional ingredients for beverages, cosmetics and healthcare industries due to its high content of anthocyanins and catechins.

Identification of Carotenoids in Hairless Canary Seed and the Effect of Baking on Their Composition in Bread and Muffin Products.

Carotenoids are essential components in the human diet due to their positive functions in ocular and cognitive health. This study investigated composition of carotenoids in hairless canary seed (HCS) as a novel food and the effect of baking on carotenoids in bread and muffin made from HCS, wheat and corn. Three bread formulations made from wheat and HCS blends were evaluated and compared with control wheat bread. In addition, three low-fat muffin recipes prepared from HCS alone or in blends with corn were assessed. The fate of carotenoid compounds in breads and muffins was monitored after dry mixing, dough/batter formation and oven baking. Carotenoids in products were quantified using UPLC and their identification was confirmed based on LC-MS/MS. Hairless canary seed and corn were fairly rich in carotenoids with a total content of 7.6 and 12.9 µg/g, respectively, compared with wheat (1.3 µg/g). Nineteen carotenoid compounds were identified, with all-trans lutein being the principal carotenoid in HCS followed by lutein 3-O-linoleate, lutein 3-O-oleate and lutein di-linoleate. There were significant reductions in carotenoids in muffin and bread products. It appears that batter or dough preparation causes more reductions in carotenoids than oven baking, probably due to enzymatic oxidation and degradation. Muffin-making resulted in lower lutein reductions compared with the bread-making process. The results suggest that muffins made from hairless canary seed alone or in blends with corn could boost the daily intake of lutein and/or zeaxanthin.

Consumption of whole purple and regular wheat modestly improves metabolic markers in adults with elevated high-sensitivity C-reactive protein: a randomised, single-blind parallel-arm study.

Whole-grain wheat, in particular coloured varieties, may have health benefits in adults with chronic metabolic disease risk factors. Twenty-nine overweight and obese adults with chronic inflammation (high-sensitivity C-reactive protein) > 1·0 mg/l) replaced four daily servings of refined grain food products with bran-enriched purple or regular whole-wheat convenience bars (approximately 41-45 g fibre, daily) for 8 weeks in a randomised, single-blind parallel-arm study where body weight was maintained. Anthropometrics, blood markers of inflammation, oxidative stress, and lipaemia and metabolites of anthocyanins and phenolic acids were compared at days 1, 29 and 57 using repeated-measures ANOVA within groups and ANCOVA between groups at day 57, with day 1 as a covariate. A significant reduction in IL-6 and increase in adiponectin were observed within the purple wheat (PW) group. TNF-α was lowered in both groups and ferulic acid concentration increased in the regular wheat (RW) group. Comparing between wheats, only plasma TNF-α and glucose differed significantly (P < 0·05), that is, TNF-α and glucose decreased with RW and PW, respectively. Consumption of PW or RW products showed potential to improve plasma markers of inflammation and oxidative stress in participants with evidence of chronic inflammation, with modest differences observed based on type of wheat.

Bioaccessibility and Cellular Uptake of Lutein, Zeaxanthin and Ferulic Acid from Muffins and Breads Made from Hairless Canary Seed, Wheat and Corn Blends.

Using a simulated gastrointestinal digestion model combined with a Caco-2 cell model, this study aims to assess the bioaccessibility and cellular uptake of dietary lutein, zeaxanthin, and ferulic acid from muffins and bread prepared from blends of hairless canary seed (HCS), wheat, and corn. Residual digestive enzymes damaged the Caco-2 monolayer and necessitated the requirements for the additional clean-up of the digesta. Several digesta cleanup treatments were examined, and the C18 column, along with AEBSF inhibitor, was selected as the most effective treatment. However, the cleanup treatment reduced lutein, zeaxanthin, and ferulic acid concentrations. The bioaccessibility of lutein from muffins was high at 92-94% (without clean-up) and 81-86% (with cleanup); however, the cellular uptake was low (7-9%). The bioaccessibility and cellular uptake (4-11%) of zeaxanthin were lower than lutein. Ferulic acid from muffins exhibited a wide range of bioaccessibility for non-cleanup (105-229%) and clean-up (53-133%) digesta samples; however, cellular uptake was very low (0.5-1.8%). Bread made from wheat/HCS had higher lutein bioaccessibility (47-80%) than the control bread (42%), with an apical cellular uptake ranging from 4.3 to 9.2%. Similar to muffins, the bioaccessibility of zeaxanthin from bread was lower than lutein, while ferulic acid had a fairly high bioaccessibility at 98-103% (without clean-up) and 81-102% (with cleanup); however, zeaxanthin cellular uptake was low (0.2%). These results suggest that muffins and bread could boost the daily consumption of lutein, zeaxanthin, and ferulic acid, allowing for a small portion to be absorbed in the small intestine.

Changes in Phenolic Acids and Antioxidant Properties during Baking of Bread and Muffin Made from Blends of Hairless Canary Seed, Wheat, and Corn.

Phenolic acids are the major polyphenols in cereal grains and they undergo changes in their composition and structure during processing. This study investigated changes in phenolic acids and antioxidant properties during baking of bread and muffin made from hairless canary seed (HCS), Phalaris canariensis L., alone or in blends with corn and wheat. The changes were monitored after dry mixing, dough/batter formation, and oven baking. Phenolic acids were quantified in products using HPLC and antioxidant activity was based on DPPH, ABTS, and ORAC assays. Eight phenolic acids were primarily present in the bound fraction extracts, while only a few phenolic acids were detected in the free or unbound fraction extracts. Ferulic was the dominant phenolic acid in wheat, corn, and HCS followed by p-coumaric acid but the latter was extremely high in HCS compared to wheat and corn. After baking, bound phenolic acids decreased in breads and muffins, while the unbound phenolic acids increased. Dough preparation resulted in about 5-13% reductions in bound ferulic acid in addition to 2-9% after oven baking with a total reduction of about 10-20% subject to bread formulation. On the contrary unbound ferulic acid increased by 48-307% after dough preparation and 138-225% after oven baking with a total increase 273-495%. Similarly, muffin-making process resulted in 26-30% reductions in bound ferulic acid after batter preparation and 4-7% after oven baking with reductions of 34-37% in muffins, while the unbound ferulic acid increased by about 35-105% and 9-29%, respectively, with a total increase 47-116%. The baking process resulted in improved DPPH, ABTS, and ORAC antioxidant activities in breads and muffins despite the initial reductions after dough preparation. In general, baking process resulted in tangible increases in unbound phenolic acids which eventually could improve their bioavailability and bioactivity.

Compositional and antioxidant properties of anthocyanin-rich products prepared from purple wheat.

Demands for anthocyanin-rich ingredients are steadily growing due to their positive functions in human health and food coloration. Commercially available purple wheat was evaluated as a source of functional ingredients based on anthocyanin composition and antioxidant properties. Anthocyanins were concentrated in the bran fraction by about 2-fold and then the bran was further processed into anthocyanin-rich powder using ethanol extraction and column purification. Batch studies showed that anthocyanin concentration factor increased by about 81- to 135-fold in the powder depending on batch size. Characterization of anthocyanins with a triple quad mass spectrometry showed a complex anthocyanin profile with 5 pigments making up 93-96% of the total anthocyanin content. These pigments were cyanidin-3-glucoside, cyanidin-3-(6-malonyl glucoside), cyanidin-3-rutinoside, peonidin-3-glucoside and peonidin-3-(6-malonylglucoside) but their concentrations varied between bran and powder. The purple wheat bran and powder exhibited exceptional antioxidant capacity based on scavenging of DPPH, ABTS and peroxyl radicals holding a promise as functional ingredients.

Identification of synthetic regioisomeric lutein esters and their quantification in a commercial lutein supplement.

Synthetic mixtures of 24 mono- and diesters of the asymmetric hydroxylated carotenoid lutein with lauric, myristic, palmitic, and stearic acids were analyzed by liquid chromatography-ultraviolet/visible spectroscopy (LC-UV-vis) and characterized by LC-mass spectrometry (MS) and nuclear magnetic resonance spectroscopy (NMR). These compounds were then used for identifying the composition of a commercial lutein supplement. This is the first report of chromatographic separation of mixed fatty acid lutein diesters. Preferential MS loss of fatty acids or water occurred initially at the 3'-hydroxy position in the epsilon-ionone ring and subsequently at the 3-hydroxy position in the beta-ionone ring. This selective fragmentation leads to facile assignment of the specific fatty acids to the appropriate regioisomeric ionone ring. A commercial lutein supplement contained low levels of two pairs of regioisomeric monoesters and nearly equal levels of three homogeneous diesters and five pairs of mixed diesters. Palmitic acid was the predominant fatty acid, with lower amounts of myristic, stearic, and lauric acids.

Identification and quantification of seed carotenoids in selected wheat species.

Selected primitive and modern wheat species were evaluated on the basis of their carotenoid composition and effects of the genotype and environment on lutein using spectrometry and liquid chromatography. Carotenoids in the wheat extracts were identified and confirmed on the basis of their UV/vis and mass spectra compared with those of authentic standards. The protonated molecule (M + 1)+ at m/z 569 was the predominant ion for zeaxanthin compared to the fragment ion at m/z 551 for lutein. A similar carotenoid profile was obtained for the wheat species investigated, but significant differences were observed in the concentration of carotenoids. Einkorn (Triticum monococcum) exhibited the highest level of all-trans-lutein, averaging 7.41 microg/g with small amounts of all-trans-zeaxanthin, cis-lutein isomers, and beta-carotene. Durum, Kamut, and Khorasan (Triticum turgidum) had intermediate levels of lutein (5.41-5.77 microg/g), while common bread or pastry wheat (Triticum aestivum) had the lowest content (2.01-2.11 microg/g). Lutein in einkorn appeared to be influenced significantly by environmental growing conditions.

Comparison of four C18 columns for the liquid chromatographic determination of deoxynivalenol in naturally contaminated wheat.

Three long and 1 short reversed-phase C18 columns were compared for separation of deoxynivalenol (DON) in extracts of naturally contaminated wheat samples using liquid chromatography with ultraviolet detection and liquid chromatography/mass spectrometry (LC/MS). Among the 3 long columns used, a Symmetry C18 column with an isocratic solvent mixture of water-acetonitrile-methanol (90 + 5 + 5, v/v/v) gave the best separation for DON without interferences from other compounds in the wheat extracts. The Symmetry short (75 mm) column was comparable with the long column (250 mm) in resolving DON but significantly reduced retention time (i.e., 5.8 versus 16.3 min). Increasing the column temperature from 25 to 45 degrees C resulted in a further reduction in retention time. Identity of DON in the wheat extracts and standard solutions was confirmed by LC/MS in the positive ion mode, whereby DON appeared with an (M+1)+ ion at a mass-to-charge ratio of 297 plus fragment ions associated with loss of water and/or a 30 atomic mass unit (amu) CH2O fragment. The Symmetry short column was also capable of separating a mixture of the mycotoxins DON, 15-acetyl-DON, nivalenol, and zearalenone by use of a combination of an isocratic and gradient solvent system. The overall method showed high precision, exhibiting a relative standard deviation of 4.8%, limit of detection of 50 ng/g, and limit of quantitation of 165 ng/g. It was significantly correlated with enzyme-linked immunosorbent assay analysis, indicating its appropriateness for safety and quality assurance of wheat and related grains.

Effect of processing on phenolic acids composition and radical scavenging capacity of barley pasta.

Phenolic acids, total phenolics content and DPPH radical scavenging capacity in raw ingredients, fresh and dried spaghetti, and in uncooked and cooked spaghetti were evaluated and compared with semolina spaghetti as a reference. Ferulic acid was the major phenolic acid found in the free and bound phenolic extracts in all the investigated pasta samples. The addition of barley flour into pasta at incorporation levels of 30, 50 and 100% increased phenolic acids and total phenolics content. Pasta processing did not significantly affect the total phenolics content and free radical scavenging capacity, but a significant reduction in total phenolic acids measured by HPLC was found. Drying process differently affected individual phenolic compounds in the free and bound fractions, and thus, the total phenolic acids content. Free vanillic, caffeic and p-coumaric acids did not significantly change, while p-hydroxybenzoic and ferulic acids of the free extracts showed higher values compared to the corresponding fresh pasta. Cooking did not greatly affect total phenolic acids, more leading to conserving free and bound phenolic compounds.

Anthocyanin composition in black, blue, pink, purple, and red cereal grains.

Anthocyanin pigments from a wide variety of edible and ornamental black, blue, pink, purple, red, and white wheat, barley, corn, rice, and wild rice were identified and quantified to evaluate their potential as natural colorants or functional food ingredients. The total anthocyanin contents varied significantly and exhibited a range of 7-3276 microg/g. Some grains, such as red rice and black rice, contained a limited number of pigments, whereas others, such as blue, pink, purple, and red corns, had complex anthocyanin profiles. Of the 42 anthocyanin compounds observed, 9 were characterized by comparison of the spectroscopic and chromatographic properties with those of authentic standards. The remaining compounds were tentatively identified on the basis of spectroscopic properties and electrospray ionization mass spectra. The most abundant anthocyanins were cyanidin 3-glucoside in black and red rices and in blue, purple, and red corns, pelargonidin 3-glucoside in pink corn, and delphinidin 3-glucoside in blue wheat.

Composition of Lutein Ester Regioisomers in Marigold Flower, Dietary Supplement, and Herbal Tea.

Characterization of lutein and its esters in a health product is necessary for its efficacy. In the current study lutein ester regioisomers were quantified and identified in several dietary supplements and herbal teas in comparison with marigold flower, the commercial source of lutein. The products were extracted with three solvents and separated on a C30 column. The separated esters were identified/confirmed with LC-MS in APCI+ve mode with the use of synthetic lutein esters. The total content of lutein esters substantially varied among marigold flowers (167-5752 µg/g), supplements (88,000-110,700 µg/g), and herbal teas (12.4-91.3 µg/g). Lutein supplement had a lutein profile similar to that of marigold flower, whereas herbal tea showed an extremely different profile. Lutein dipalmitate was the dominant compound in supplements and marigold flowers followed by lutein 3'-O-myristate-3-O-palmitate and lutein 3'-O-palmitate-3-O-myristate. Lutein was the major compound in marigold herbal tea with small amounts of lutein mono- and diesters. Differences in the concentration and composition of lutein compounds among marigold products could indicate distinct product quality and lutein bioavailability.

Accelerated, microwave-assisted, and conventional solvent extraction methods affect anthocyanin composition from colored grains.

Anthocyanins are important dietary components with diverse positive functions in human health. This study investigates effects of accelerated solvent extraction (ASE) and microwave-assisted extraction (MAE) on anthocyanin composition and extraction efficiency from blue wheat, purple corn, and black rice in comparison with the commonly used solvent extraction (CSE). Factorial experimental design was employed to study effects of ASE and MAE variables, and anthocyanin extracts were analyzed by spectrophotometry, high-performance liquid chromatography-diode array detector (DAD), and liquid chromatography-mass spectrometry chromatography. The extraction efficiency of ASE and MAE was comparable with CSE at the optimal conditions. The greatest extraction by ASE was achieved at 50 °C, 2500 psi, 10 min using 5 cycles, and 100% flush. For MAE, a combination of 70 °C, 300 W, and 10 min in MAE was the most effective in extracting anthocyanins from blue wheat and purple corn compared with 50 °C, 1200 W, and 20 min for black rice. The anthocyanin composition of grain extracts was influenced by the extraction method. The ASE extraction method seems to be more appropriate in extracting anthocyanins from the colored grains as being comparable with the CSE method based on changes in anthocyanin composition. The method caused lower structural changes in anthocaynins compared with the MAE method. Changes in blue wheat anthocyanins were lower in comparison with purple corn or black rice perhaps due to the absence of acylated anthocyanin compounds in blue wheat. The results show significant differences in anthocyanins among the 3 extraction methods, which indicate a need to standardize a method for valid comparisons among studies and for quality assurance purposes.

Stability of lutein in wholegrain bakery products naturally high in lutein or fortified with free lutein.

Lutein is a yellow pigment found in common foods that promotes the health of eyes and skin and is associated with reduced risk of age-related macular degeneration and cataracts. In the present study, selected high-lutein wheat and corn were milled into wholegrain flours by two mills to improve flour uniformity. The high-lutein and lutein-fortified wholegrain flours were processed into breads, cookies, and muffins to study lutein stability during baking and subsequent storage. Lutein and its isomers were separated, identified, and quantified by LC-UV/vis and LC-MS following extraction with water-saturated 1-butanol. Baking resulted in a significant reduction in all-trans-lutein and the formation of cis-lutein and cis-zeaxanthin isomers. Subsequent storage at ambient temperature had a slight impact on the content of all-trans-lutein. Effects of processing were more pronounced in lutein-fortified products, and the degradation rate of lutein was influenced by concentration and baking recipe. Fortified cookies and muffins showed greater lutein reduction compared with bread. Despite the significant reduction in lutein, the fortified bakery products still possessed reasonable amounts per serving that would enhance daily intake and consumption of wholegrain foods.

Fractionation of blue wheat anthocyanin compounds and their contribution to antioxidant properties.

Demands for anthocyanin-rich foods and supplements are steadily increasing due to their significant roles in human health and food coloration. In the development of blue wheat as a functional food ingredient, dry milling was employed to separate the bran fraction where anthocyanins are concentrated 2.3-fold as compared to whole grain (13.9 mg/100 g). Anthocyanins were then extracted with aqueous ethanol and partially purified into a highly concentrated powder. The total anthocyanin content in the isolated powder as analyzed by high-performance liquid chromatography (HPLC) averaged 3378 mg/100 g and afforded a 243-fold increase in concentration relative to the whole grain product. Four main anthocyanins, delphinidin-3-glucoside (45%), cyanidin-3-glucoside (28%), delphinidin-3-rutinoside (22%), and cyanidin-3-rutinoside (2%), were isolated from the powder using preparative HPLC. Anthocyanin products and compounds were assessed against scavenging of 2,2-diphenyl-1-picryl-hydrazyl and 2,2'-azino-di-(3-ethylbenzthiazoline sulfonate) radicals and inhibition of human low-density lipoprotein cholesterol oxidation. Significant differences in antioxidant capacity were observed with anthocyanin powder and compounds exceeding that of butylated hydroxytoluene, indicating a potential for the development of blue wheat-based natural antioxidants and colorants.