Hussin, Napisah (2018) Physicochemical Properties Of Starch And Prebiotic Potential Of Oligosaccharides From Dioscorea Hispida. PhD thesis, Perpustakan Hamzah Sendut.
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Abstract
The underutilised Dioscorea hispida Dennst. tuber was processed for its starch and was evaluated for its physicochemical properties. The tuber contained 97.95% total starch comprising of amylose (25.27%) and amylopectin (72.68%). Dioscorea hispida starch contained crude protein (0.42%), crude fat (0.23%), ash (0.47%) and crude fiber (0.93%). The starch granules were coarse-surfaced polyhedral shape with an average diameter of 2-4 μm. The starch exhibits B-type in X-ray diffraction pattern and had gelatinisation peak temperature of 87 °C and pasting temperature of 78 °C. The swelling power, solubility, water-holding and oilholding capacities were 14.22 g/g, 5.48 g/g, 2.78 g/g and 1.14 g/g, respectively. Different concentrations of D. hispida starch (5%, 10%, 15%, and 20%) were hydrolysed by individual enzymes α-amylase, amyloglucosidase or pullulanase or combination of the enzymes to yield D. hispida oligosaccharides (DHOS). The maximum yield of DHOS (19.67 mg/g) was obtained from the hydrolysis of 10% (w/v) of D. hispida starch with combination of α-amylase (pH 5.5; 90°C) and pullulanase (pH 5.5; 45°C) for 6 h. The DHOS when analysed for prebiotic characteristics was found to be resistant to hydrolysis by gastric juice at pH 3-4 (88.78-99.76% DHOS residue) for 3 h but less resistant to hydrolysis at pH 1-2. DHOS was also found to be less resistant towards hydrolysis by gastrointestinal tract enzymes and intestinal absorption as the remaining DHOS after hydrolysis was ranging from 40.62-52.04%. In term of bacterial growth study, DHOS positively
| Item Type: | Thesis (PhD) |
|---|---|
| Subjects: | T Technology > T Technology (General) > T1-995 Technology(General) |
| Divisions: | Pusat Pengajian Teknologi Industri (School of Industrial Technology) > Thesis |
| Depositing User: | Mr Hasmizar Mansor |
| Date Deposited: | 26 Oct 2026 02:04 |
| Last Modified: | 26 Oct 2026 08:39 |
| URI: | http://eprints.usm.my/id/eprint/65169 |
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