Phytochemicals, antioxidant activity and grain quality in pigmented and non-pigmented rice
| dc.contributor.advisor | Sharma, Neerja | |
| dc.contributor.author | Gosangi Avinash | |
| dc.date.accessioned | 2023-12-11T11:15:57Z | |
| dc.date.available | 2023-12-11T11:15:57Z | |
| dc.date.issued | 2023 | |
| dc.description.abstract | Pigmented rice are rich source of bioactive compounds especially polyphenolic components, tocopherols, (TOC), tocotrienols (T3) and γ- oryzanol, which impart positive effects on human health. The present study, was therefore, planned to study the variation in phytochemical composition, antioxidant activity and grain quality of a set of rice genotypes, comprising 9 pigmented (PR, 3 black and 6 red ) and 7 non-pigmented (NP) rices. The results revealed that PR rices (black followed by red) had higher ash, crude protein, crude fat and crude fibre content compared to NP rices in the bran, whole grain and milled rice fractions. Total dietary fibre content was highest in black rice genotypes. Insoluble dietary fibres were ~10 - folds higher than soluble dietary fibres in all the three colour groups. NP rices were observed to have the best milling, cooking and physicochemical quality parameters. Black rice genotypes displayed the highest total phenolic content (TPC) and the contribution of bound phenolics to TPC in all 16 genotypes under study was higher than free phenolics. The in vitro antioxidant activity of black rice group was highest followed by red and NP group. The total flavonoid and anthocyanin content was highest in black rice group while proanthocyanidins were highest in red rice group in both bran and whole grain fraction. In all the three colour groups, bound phenolic acid content was higher than free phenolic acids. The main bound phenolic acids were t-ferulic acid, p-coumaric acid, and 2,5 - hydroxybenzoic acid (2,5-DHA), while in the free form, p- hydroxybenzoic acid and syringic acid were the major phenolic acids in both the grain fractions of all three colour groups. 2, 5 - DHA was quantified for the first time in bran and whole grain fractions of NP rices. The total γ- oryzanol content in bran was highest in black rice followed by red and NP group. 24 methylene cycloartenyl ferulate and cycloartenyl ferulate were the major contributors to total γ- oryzanol content in all 16 genotypes. Total vitamin E content was highest in black rices followed by red and NP rices. In bran, α -T3 and δ-TOC were found to be major contributors to total vitamin E content while in whole grain these were γ-T3 and δ- TOC, irrespective of colour of genotypes. The free phenolics were more susceptible to degradation on parboiling compared to bound phenolics. These findings contributed towards further understanding of the distribution of nutritional and phytochemical components in rice grain fractions of PR and NP rices, and may assist rice breeders and rice growers with new opportunities to promote production of rice with enhanced level of phytochemicals to augment human health. | |
| dc.identifier.citation | Gosangi Avinash (2023). Phytochemicals, antioxidant activity and grain quality in pigmented and non-pigmented rice (Unpublished Ph.D. Dissertation). Punjab Agricultural University, Ludhiana, Punjab, India. | |
| dc.identifier.uri | https://krishikosh.egranth.ac.in/handle/1/5810202503 | |
| dc.keywords | Pigmented rice | |
| dc.keywords | non-pigmented rice | |
| dc.keywords | phenolic acids | |
| dc.keywords | tocotrienols | |
| dc.keywords | tocopherols | |
| dc.keywords | γ- oryzanol parboiling and phenolic constituents. | |
| dc.language.iso | English | |
| dc.pages | 133 | |
| dc.publisher | Punjab Agricultural University | |
| dc.research.problem | Phytochemicals, antioxidant activity and grain quality in pigmented and non-pigmented rice | |
| dc.sub | Biochemistry | |
| dc.theme | Phytochemicals, antioxidant activity and grain quality in pigmented and non-pigmented rice | |
| dc.these.type | Ph.D | |
| dc.title | Phytochemicals, antioxidant activity and grain quality in pigmented and non-pigmented rice | |
| dc.type | Thesis |