Effect of extraction processes on the quality of Roselle (Hibiscus sabdariffa L.) antioxidants | |
| Author | Niranut Khua-oua |
| Call Number | AIT Thesis no.FB-10-27 |
| Subject(s) | Roselle Hibiscus Antioxidants |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Food Engineering and Bioprocess Technology, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. no.FB-10-27 |
| Abstract | The present study aimed to study the effect of drying of roselle calyxes by hot air oven and infrared treatment . Optimum conditions for extraction of roselle was investigated by comparing different extraction methods. Finally , evaluated the qualities of ice cream after fortification with anthocyanin from roselle. Rosel le calyxes are a natural source of antioxidant such as anthocyanin. Roselle calyxes were dried with hot air drying (HA) and infrared drying (IR) at 45, 55, 65 and 75 o C. Drying temperature had effect on equilibrium moisture content and drying rate. There ar e several mathematic models of drying such as Lewis, Page’s, and Henderson and Pabis were applied to develop drying equations. All the models were compared according to coefficient of determination (R 2 ), root mean square error (RMSE), and reduced chi - squar e (ᵡ 2 ). The Page model was found to be the most suitable for describing drying curves of roselle calyxes. Drying temperature and drying method had effect on total anthocyanin content (TAC). Infrared drying at 55 o C gave the highest TAC and mentained the red color of roselle better than other drying condition. In order to study the optimum conditions for extraction of roselle and investigate the anthocyanin degradation in roselle. Roselle calyxes were dried by IR at 55 o C and extracted with water bath shaker e xtraction (WSE), ultrasound - assisted extraction (UAE) and microwave - assisted extraction (MAE), at 3 different temperatures (40, 50, 60 o C) and 3 different times (30, 60, 90 min). MAE at 50 o C, 60 min had the highest TAC ( 2330.7 mg TAC/ liter ). Application of roselle extract which was supplemented in milk ice cream at a level 2.5% had the highest overall preference. However, addition of too much of roselle concentrated leads to bad texture. Overall extraction of natural roselle as nutrient source for a produ ce like ice cream is highly recommended. |
| Year | 2010 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. no.FB-10-27 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Food Engineering and Bioprocess Technology (FB) |
| Chairperson(s) | Rakshit, Sudip Kumar; |
| Examination Committee(s) | Athapol Noomhorm;Anal, Anil Kumar; |
| Scholarship Donor(s) | RTG Fellowship; |
| Degree | Thesis (M. Sc.) - Asian Institute of Technology, 2010 |