Evaluation of physical and antioxidant properties of pigmented barley tortillas

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dc.contributor.authorHatzir, Tomer
dc.contributor.examiningcommitteeBadea, Ana (Food and Human Nutritional Sciences)
dc.contributor.examiningcommitteeSorenson, John (Chemistry)
dc.contributor.supervisorBeta, Trust
dc.date.accessioned2025-06-12T19:05:11Z
dc.date.available2025-06-12T19:05:11Z
dc.date.issued2025-04-24
dc.date.submitted2025-06-11T22:06:48Zen_US
dc.degree.disciplineFood and Human Nutritional Sciences
dc.degree.levelMaster of Science (M.Sc.)
dc.description.abstractBarley contains bioactive compounds like β-glucan and polyphenols that promote health. Food processing, while necessary, can change barley's physical properties and adversely affect polyphenols' antioxidant activity through heat and the food matrix. Thus, identifying compounds post-production, including new chemical structures, is essential. Five barley genotypes (CDC Rattan, CDC McGwire, Roseland, HB21147, and HB21148) produced tortillas at varying pH levels (1, 3, 5, 7). Their texture and physical properties were assessed. Identification and quantification were achieved through high-performance liquid chromatography (HPLC) with standards. Assays on the acidified ethanol extract measured the total phenolic and anthocyanin content, along with antioxidant properties, which were evaluated via in vitro and ex vivo methods. CDC Rattan tortillas decreased in thickness significantly between pH 1 and 7. At pH 5, extensibility was lower, with the hardest texture across genotypes. HB21148 recorded the highest total phenolic (14.0±1.2 mg gallic acid equivalent/g) and total anthocyanin content (313.9±33.4 cyanidin-3-glucoside equivalent/kg) among raw forms. Catechin was most concentrated in HB21148, followed by HB21147. Roseland exhibited the highest trans-cinnamic acid (13.5±0.5 mg/kg). Gentisic acid appeared only at pH 5 in genotypes with high β-glucan, HB21147 and CDC Rattan. Antioxidant activities were similar at pH 3 and 7 per the FRAP assay. HB21147 and Roseland showed parallel activity across pH levels with the ABTS method. Caco-2 cell tests found CDC Rattan enriched with anthocyanins resulted in significantly higher CAA (cellular antioxidant activity) than HB21148 at 200 μg/ml. The study suggests pH 3 optimizes antioxidant properties with minimal texture impact, potentially through new compounds involving β-glucan and polyphenols. These insights may aid in developing food products that integrate natural bioactive compounds for health benefits.
dc.description.noteOctober 2025
dc.identifier.urihttp://hdl.handle.net/1993/39110
dc.language.isoeng
dc.subjectBarley
dc.subjectTortillas
dc.subjectpH treatment
dc.subjectTexture
dc.subjectSize
dc.subjectAntioxidant activity
dc.subjectCell culture
dc.subjectAnthocyanin stability
dc.titleEvaluation of physical and antioxidant properties of pigmented barley tortillas
local.subject.manitobayes
project.funder.nameNatural Sciences and Engineering Research Council of Canada
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