Phytochemicals and heavy metals content of hairless canary seed: A variety developed for food use

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.

Health Promoting Bioactive Properties of Novel Hairless Canary Seed Flour after In Vitro Gastrointestinal Digestion

The bioactive properties and health-promoting effects of two novel yellow (C09052, C05041) and two brown (Calvi, Bastia) hairless canary seed (Phalaris canariensis L.) cultivars were investigated in comparison to two common cereal grains (wheat and oat). The cereal flours were digested using the standardized INFOGEST in vitro human gastrointestinal digestion model. The three-kilo dalton molecular weight cutoff (3 kDa MWCO) permeate of the generated digestates was assessed in vitro for their antioxidant, chelating, antihypertensive and antidiabetic activities. The results showed no significant differences in studied bioactivities between yellow and brown canary seed cultivars, except for antioxidant activity by the DPPH and chelating Fe2+ assays, where brown cultivars had higher activities. Canary seeds had superior or equivalent antioxidant activity than those from oat and wheat. The anti-hypertensive activity (Angiotensin-converting enzyme (ACE) inhibition) in yellow canary seed cultivars was significantly higher than that of oat and wheat, particularly for C09052 and Calvi varieties. Peptides exhibiting the highest antihypertensive activity from the permeate of the C09052 canary seed variety were further fractionated and identified by mass spectrometry. Forty-six peptides were identified belonging to 18 proteins from the Pooideae subfamily. Fourteen of the parent proteins were homologous to barley proteins. Peptides were analyzed in silico to determine potential bioactivity based on their amino acid composition. All 46 peptides had potential anti-hypertensive and anti-diabetic activities and 20 had potential antioxidant activity, thereby validating the in vitro assay data. Canary seed peptides also exhibited potential antiamnestic, antithrombotic, immunostimulating, opioid and neuro-activity, demonstrating important potential for health promoting effects, particularly against cardiovascular disease.

Hairless Canaryseed: A Novel Cereal with Health Promoting Potential

Glabrous canaryseeds were recently approved for human consumption as a novel cereal grain in Canada and the United States. Previously, canaryseeds were exclusively used as birdseed due to the presence of carcinogenic silica fibers; therefore the nutritional value of the seeds has been seriously overlooked. Two cultivars of glabrous canaryseeds (yellow and brown) were created from the hairy varieties. They are high in protein compared to other cereal grains, and contain high amounts of tryptophan, an amino acid normally lacking in cereals, and are gluten-free. Bioactive peptides of canaryseeds produced by in vitro gastrointestinal digestion have shown antioxidant, antidiabetic, and antihypertensive activity. The seeds contain other constituents with health promoting effects, including unsaturated fatty acids, minerals, and phytochemicals. Anti-nutritional components in the seeds are comparable to other cereal grains. Because of their beneficial health effects, canaryseeds should be regarded as a healthy food and have immense potential as a functional food and ingredient. Further research is required to determine additional bioactive peptide activity and capacity, as well as differences between the yellow and brown cultivars.

Antioxidant and Antihypertensive Potential of Protein Fractions from Flour and Milk Substitutes from Canary Seeds (Phalaris canariensis L.)

Canary seed (Phalaris canariensis) is used to feed birds but it has been recently considered a promising cereal with nutraceutical potential for humans. The aim of this work was to analyze the protein fractions from canary seed flour and from milk substitutes (prepared by soaking the seeds in water 12 and 24 h), and to evaluate antioxidant and antihypertensive capacity of peptides obtained after in vitro digestion. Prolamins were the major protein fraction, followed by glutelins. After digestion, albumins and prolamins fractions from milks presented higher levels of peptides than flour, globulins showed more peptides in flour and glutelins were found in similar concentrations in all samples; 24 h milk prolamins had the highest concentration of peptides. Purification by high performance liquid chromatography (HPLC), sequencing of peptides, in vitro antioxidant ABTS (2,2'-azino-bis, 3-ethylbenzothiazoline-6-sulphonic acid) and DPPH (2,2-diphenyl-1-picrylhydrazyl) assays, and antihypertensive capacity (angiotensin converting enzyme (ACE) assay), indicated that peptides from canary seed prolamins were the most efficient compounds with antioxidant and antihypertensive activity. Canary seeds may be considered an accessible and cheap source to prepare milk substitutes with high contents of bioactive peptides with remarkable functional properties to promote better human health and healthy ageing.

Performance, health and tissue weights of broiler chickens fed graded levels of hairless hulled yellow and brown canary seed (Phalaris canariensis L.)

Classen, H., Cho, M., Hucl, P., Gomis, S. and Patterson, C. A. 2014. Performance, health and tissue weights of broiler chickens fed graded levels of hairless hulled yellow and brown canary seed (Phalaris canariensis L.). Can. J. Anim. Sci. 94: 669–678. Research examined the effects of dietary levels (0, 15, 30 and 45%) of hulled yellow (C05041) and brown (CDC Maria) canary seed on the performance and health of broiler chickens. Eight (six birds each) and five (four birds each) replications per treatment were used from 0 to 21 and from 22 to 35 d of age, respectively. Growth rate and feed intake were affected in a quadratic manner by canary seed level from 0 to 21 d with the highest growth achieved by 15 and 30% treatments, but were not affected from 22 to 35 d. Feed to gain ratio decreased linearly with increasing canary seed for both 0- to 21-d and 22- to 35-d time periods. Mortality was not affected by level of canary seed, but more birds fed the C05041 cultivar died as a result of yolk sac infection and infectious causes than did birds fed CDC Maria. Level of canary seed affected jejunum, kidney and bursa of Fabricius proportional weights in a quadratic manner with no differences between the 0 and 45% treatments. No interactions were found between dietary level and cultivar of canary seed. Treatment did not affect gross necropsy at trial end or histopathology of key organs. Yellow and brown hairless canary seed has merit and is safe for poultry feeding.

Safety assessment of consumption of glabrous canary seed (Phalaris canariensis L.) in rats

Canary seed is a nutrient-rich cereal grain; however, it has not been used in human food in part due to concerns regarding safety of consumption. Glabrous or hairless canary seed has potential human food use as trichomes are absent. The objective of the oral feeding studies reported here was to assess the safety of yellow and brown glabrous canary seed cultivars as human cereal foods. The first study was a 90-day rat oral toxicity study, which compared the effects of diets containing 50% of either brown dehulled glabrous, brown hulled glabrous, or brown hulled pubescent (hairy) hulled canary seed to a diet containing 50% wheat. No significant adverse effects were observed. In a 28-day and a 90-day study rats were fed yellow or brown glabrous canary seed groats in the AIN-76 diet at concentrations levels of 2.5%, 5% and 10%. The NOAELs in 90-day study were 5.15 g/kg/d and 5.23 g/kg/d for yellow and brown canary seed groats. Consumption of canary seed was associated with reduced incidence and severity of liver lipidosis as compared to controls. The combined results of these studies clearly demonstrate the safety of consumption of glabrous canary seed, and support its use as a human cereal grain.

In vitro gastrointestinal digestion of glabrous canaryseed proteins as affected by variety and thermal treatment

Glabrous or hairless canaryseed is a nutritional grain that could be a good addition to the diet if approved as a novel food. To assess the impact of thermal treatment on its digestibility; raw, roasted or boiled flours prepared from three different varieties of glabrous canaryseed were subjected to in vitro gastrointestinal digestion conditions and the effect on protein electrophoretic profiles was examined using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Roasting was done by dry-heat in an oven at 176 °C for 12 min whereas boiling was done in water at 98 °C for 12 min. SDS-PAGE showed approximately twenty-five protein bands in the undigested raw flour with molecular masses (MM) ranging from <14 kDa to >97 kDa. The dominant proteins had low MM, between the ranges of ~57 to 12 kDa. Roasting markedly altered the protein electrophoretic profile with the appearance of large molecular weight aggregates. Canaryseed proteins were more easily digested after thermal treatment and under sequential gastric-duodenal conditions than under gastric or duodenal conditions alone. Furthermore, roasting appeared to have a greater impact on in vitro protein digestibility than boiling.

Analysis of glabrous canary seeds by ELISA, mass spectrometry, and Western blotting for the absence of cross-reactivity with major plant food allergens

Glabrous (hairless) canary seed belongs to the Poaceae (Gramineae) family and could serve as an alternative source of gluten-free cereal grain. In this study, allergenic cross-reactivities between hairless, dehulled canary seeds (Phalaris canariensis) and major allergenic proteins from gluten, soy, peanuts, tree nuts, sesame, and mustard were studied using commercial enzyme-linked immune sorbent assay (ELISA) kits specific for these target allergens. Mass spectrometry (MS) and immunoblotting were further used to assess for the presence of gluten-specific protein fragments. MS results revealed the likely presence of proteins homologous with rice, oat, corn, carrot, tomato, radish, beet, and chickpea. However, no presence of celiac-related gluten fragments from wheat, rye, barley, or their derivatives was found. Immunoblotting studies yielded negative results, further confirming the absence of gluten in the canary seed samples tested. No cross-reactivities were detected between canary seeds and almond, hazelnut, mustard, peanut, sesame, soy, walnut, and gluten using ELISA.