Cold-climate grown sorghum: their physicochemical and functional properties related to starch and phenolic contents
| dc.contributor.author | Adjetey, Francis Ala | |
| dc.contributor.examiningcommittee | Rosell, Cristina (Food and Human Nutritional Sciences) | |
| dc.contributor.examiningcommittee | Yang, Chengbo (Animal Science) | |
| dc.contributor.supervisor | Beta, Trust | |
| dc.date.accessioned | 2024-08-29T13:47:49Z | |
| dc.date.available | 2024-08-29T13:47:49Z | |
| dc.date.issued | 2024-08-21 | |
| dc.date.submitted | 2024-08-22T17:37:04Z | en_US |
| dc.date.submitted | 2024-08-28T21:06:01Z | en_US |
| dc.degree.discipline | Food and Human Nutritional Sciences | |
| dc.degree.level | Master of Science (M.Sc.) | |
| dc.description.abstract | Sorghum, a C4 plant, has the potential to support circular and agriculturally smart economies. However, its potential for use in colder regions remains largely untapped due to cultivation challenges. Recent breeding strategies have yielded sorghum varieties that adapt to these cold climates, yet their properties and applications have not been explored. This research analyzed the physicochemical attributes of isolated starches and phenolic and anthocyanin contents and their thermal stability in selected sorghum genotypes. The study focused on sorghum genotypes from the Netherlands (Dusormil varieties: HD) and Canada (CGSH varieties), each bred to adapt to cold climates. Wet milling was used for starch isolation, and acidified methanol with ultrasonic-assisted extraction for phytochemical isolation. The isolated starch granules displayed polymorphism with surface indentation and granule sizes ranging from 1µm to 20µm. Colorimetric analysis showed distinct hues of pink, with CGSH-9 being the lightest (L* value of 92.49%) and HD101 the darkest (L* value of 82.29%). All the samples exhibited type-A starch with relative crystallinity ranging from 25.24-28.74%. HD7 had the highest peak viscosity (3842 cP), while CGSH-9 had the lowest (2672 cP). Gelatinization temperature ranged from 61.86±1.66°C to 77.44±1.86°C, with an average temperature range of 15.59°C. Phytochemical analysis revealed that black sorghum varieties (HD100 and HD101) had higher total phenolic content (TPC) and total anthocyanin content (TAC). than the brown (HD7) and white (HD19) varieties. The TPC and TAC positively correlated to their activities against ABTS and DPPH. Cooking negatively affected the TAC except for the decorticated HD7 and HD19 samples that showed improved concentration post-cooking, and the TPC appeared more stable. HPLC analysis revealed three dominant anthocyanins in the samples: luteolinidin, apigeninidin and peonidin. The bran of HD7 exhibited the highest cellular antioxidant activity. These findings underscore the potential of these newly bred sorghum accessions, specifically tailored for cold climates, as viable substitutes for gluten-containing starches in industrial applications and consumption. The phytochemical analysis also revealed their potency in combating the menace associated with reactive oxygen species for improved health. | |
| dc.description.note | October 2024 | |
| dc.description.sponsorship | Canada Research Chairs (File Number: 950-232080) | |
| dc.identifier.uri | http://hdl.handle.net/1993/38448 | |
| dc.language.iso | eng | |
| dc.rights | open access | en_US |
| dc.subject | Cold-climate sorghum | |
| dc.subject | Starch | |
| dc.subject | Phytochemical composition | |
| dc.subject | Cellular antioxidant activity | |
| dc.subject | Functional properties | |
| dc.subject | Anthocyanin | |
| dc.title | Cold-climate grown sorghum: their physicochemical and functional properties related to starch and phenolic contents | |
| dc.type | master thesis | en_US |
| local.subject.manitoba | no | |
| oaire.awardNumber | RGPIN-261516-2010 | |
| oaire.awardTitle | NSERC Discovery Grant | |
| project.funder.identifier | NSERC | |
| project.funder.name | Natural Sciences and Engineering Research Council (NSERC) |