Physicochemical properties of starch and prebiotic potential of oligosaccharides from dioscorea hispida

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...

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Main Author: Napisah Hussin (Author)
Format: Thesis Book
Language:English
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LEADER 03364cam a2200313 7i4500
001 0000095462
005 20191212090000.0
008 190303s2018 my eng
040 |a UniSZA 
050 0 0 |a QK643.D6 
090 0 0 |a QK643.D6   |b N37 2018 
100 0 |a Napisah Hussin   |e author  
245 1 0 |a Physicochemical properties of starch and prebiotic potential of oligosaccharides from dioscorea hispida   |c Napisah Binti Hussin. 
264 0 |c 2018. 
300 |a xxiii, 252 leaves:   |b illustrations (some colour);   |c 31 cm. 
336 |a text  |2 rdacontent 
337 |a unmediated  |2 rdamedia 
338 |a volume  |2 rdacarrier 
502 |a Thesis (Degree of Doctor of Philosophy) - Universiti Sains Islam Malaysia, 2018 
504 |a Includes bibliographical references (leaves 210-238) 
505 0 |a 1. Introduction -- 2. Literature review -- 3. Materials and methods -- 4. Results and discussion -- 5. Conclusion and recommendations 
520 |a 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 (0.4 7%) and crude fiber (0.93%). The starch granules were coarse-surfaced polyhedral shape with an average diameter of 2-4 urn. 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 oil¬holding capacities were 14.22 gig. 5.48 gig, 2.78 gig and 1.14 gig, respectively. Different concentrations of D. hispida starch (5%. 10%, 15%, and 20%) were hydrolysed by individual enzymes a-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 a-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 influenced the growth of beneficial rat faecal rnicroflora (lactobacilli and bifidobacteria) and negatively influenced the growth of detrimental bacteria (bacteroides. clostridia and enterobacteria). The prebioiic index (PI) was calculated to compare the positive effect of DHOS with other prebiotics. The PI of DHOS, fructooligosaccharides (FOS) and inulin after 72 h fermentation were +7.72, +8.69 and +9.27 respectively. Lactic acid and short chain fatty acids (SCFA) were significantly produced in the media containing DHOS. The activity of  
610 0 0 |a Universiti Sains Islam Malaysia --   |x Dissertations  
650 0 |a Dissertations, Academic  
650 0 |a Starch  
650 0 |a Yams  
650 0 |a Dioscoreaceae  
710 2 |a Universiti Sains Islam Malaysia  
999 |a 1000175816  |b Thesis  |c Reference  |e Badak Thesis Collection