Effect of foam-mat drying conditions on drying rate and anthocyanin content in purple sweet potato powder
| dc.contributor.author | Nguyen, Chi Dung | |
| dc.contributor.author | Hong, Van Hao | |
| dc.contributor.author | Tran, Ngoc Giau | |
| dc.contributor.author | Nguyen, Minh Thuy | |
| dc.contributor.author | Ngo, Van Tai | |
| dc.date.accessioned | 2026-08-06T10:48:31Z | |
| dc.date.available | 2026-08-06T10:48:31Z | |
| dc.date.issued | 2025-01-01 | |
| dc.description.abstract | The study aimed to optimise foam-mat drying parameters for producing purple-fleshed sweet potato (PFSP) powder. Egg albumin (EA) (5–15%), xanthan gum (XG) (0.1–0.5%), and drying temperature (50–70 °C) were used as independent variables for optimisation via Response Surface Methodology with a Box-Behnken design. The response variables (drying rate and anthocyanin content) were assessed by 18 treatments, which included 6 central points. The analysis of variance showed a high coefficient of determination (> 88%) between predicted and experimental values across all models. Optimal foam-mat drying conditions were 11.02% EA, 0.34% XG, and 65.1 °C to achieve the highest drying rate (2.49 g water.g dry matter<sup>–1</sup>.min<sup>–1</sup>) and anthocyanin content (1.01 mg.g<sup>–1</sup>). After 3.5 h of drying at 65.1 °C, the foam-mat dried PFSP showed a low moisture content (4.35%) and water activity (0.29). Its water solubility index, water absorption index, rehydration ratio, total polyphenols, and antioxidant activity were determined to be 56.49%, 3.55%, 3.82, 3.66 ± 0.06 mg GAE.g<sup>–1</sup>, and 58.49 ± 0.88%, respectively. Under these conditions, the powder maintained its natural beautiful and characteristic purple colour. The microstructure of the foam-mat dried PFSP powder (via SEM images) was also observed. | |
| dc.identifier.citation | Research in Agricultural Engineering, 71(4), 224-234, 2025 | |
| dc.identifier.doi | 10.17221/116/2025-RAE | |
| dc.identifier.issn | 12129151 | |
| dc.identifier.other | 2-s2.0-105034433925 | |
| dc.identifier.uri | https://dspace.kmitl.ac.th/handle/123456789/16267 | |
| dc.source | Research in Agricultural Engineering | |
| dc.subject | foam-mat drying | |
| dc.subject | microstructure | |
| dc.subject | nutritional quality | |
| dc.subject | optimisation | |
| dc.subject | purple sweet potato | |
| dc.title | Effect of foam-mat drying conditions on drying rate and anthocyanin content in purple sweet potato powder | |
| dc.type | Article |