Clostridium butyricum Short chain fatty acid (SCFA) profile produced by Clostridium butyricum grown on medium containing type 3 resistant starch (RS3) of sweet potato
5 Some benefits of resistant starch are the slow hydrolysis of RS makes it useful for the slow
release of glucose, which can be especially useful in controlling glycaemic plasma responses, increase faecal bulk, lower faecal pH, and increase excretion of butyrate and acetate Philip et al. 1995.
Besides physiological benefits in human, RS has been reported to have potential as a unique ingredient that can yield high-quality foods. For example, application tests of RS showed
improvement of crispiness and expansion in certain products and better mouthfeel, colour and flavour as compared with products produced with traditional, insoluble fibres.
The process of making resistant starch is consisted of gelatinizing a slurry of the starch, treating the gelatinized starch with a debranching enzyme, deactivating the enzyme, cooling and
isolating the starch product Schmiedel et al., 2003. Gelatinization process is purposed to make debranching enzyme easier to hydrolize
α-1,6 glicosidic bond. Cooling process will stimulate retrogradation which form crystalline structures. The crystalline structure of granules may cause
starch to be resistant to enzyme hydrolysis. Starch product can be isolated by hot air dyring, freeze drying, and spray drying.
Pullulanase pullulan 6-glucanohydrolase, EC 3.2.1.41, an important debranching enzyme in starch processing, can cleave
α-1,6 linkages in pullulan, amylopectin and other related polysaccharides Lin et al. 2006. Debranching of amylopectin will provide an increased opportunity
to molecule alignment or aggregation, to form crystalline structures, and is, hence, helpful in RS formation. The pullulanase enzyme preferably reacts with a pH from 4.5 to 5.5 at temperature of 40°C
to 60°C. Berry 1986 reported a substantially increased RS3 content during monitoring the debranching effect of pullulanase on potato amylopectin, and attributed this effect to an increase in
linear starch chains resulting from debranching.