| Summary: | Breadfruit (Artocarpus altilisi or sukun is a Malaysian traditional food crop that is
commonly harvested for their pulp as a food. However, due to poor storability of the
fresh fruits, thus limited its research and industrial applications. This study aims to
determine the physicochemical properties of breadfruit flour and starch, to identify the
suitable processing conditions for the production of breadfruit resistant starch type III
(BFRS3) and to assess the fermentability of HCI-breadfruit resistant starch type III
(HCI-BFRS3) by lactic acid bacteria (LAB); Lactobacillus plantarum (ATCC® 13649)
and Lactobacillus brevis (ATCC® 8287) against the detrimental bacterium,
Escherichia coli (ATCC® 11775). Mature breadfruits were harvested and processed
into flour, starch and resistant starch type III (RS3). The physicochemical properties
were determined for breadfruit flour and starch, respectively. Eight (8) processing
conditions of the breadfruit starch which involved starch gelatinization, enzymatic
debranching of starch polymer, retrogradation and drying were conducted during the
production of BFRS3. The purification of BFRS3 was done using acid hydrolysis to
produce HCI-BFRS3. The fermentability of HCI-BFRS3 was assessed using selected
LAB. Breadfruit flour and starch exhibited highest in ash and crude fibre; 2.25%, 4.85%
and 0.86%, 2.89%, respectively. Breadfruit flour contained 63.71% of total starch
content with a 33:67 ratio of amylose and amylopectin. The swelling power and
solubility increased with temperatures as well as water and oil holding capacities also
higher were recorded for breadfruit flour and starch. Breadfruit flour granules were
spherical, indented with umbilical point appeared at the center and average sizes of 5 to
10 urn. Breadfruit starch has larger granules (8 to 10 urn) than its flour, indented with
smooth and retained granular structure. Breadfruit flour displayed a B-type crystal with
gelatinization temperature (Te) and enthalpy gelatinization (~H) of 77.01 °C and 4.83
Jig. BFRS3 with highest resistant starch (RS) content, 54.59% was produced when the
breadfruit starch suspended in distilled water and gelatinized by boiling at 90°C for 30
minutes, debranched with pullulanase enzyme at 60°C for 24 hours, autoclaved at
1210C for 1 hour and stored cold at 4°C for 24 hours. Purification ofBFRS3 with 0.5
M HCI acid at 60°C for 24 hours (denoted as HCI-BFRS3) has increased the RS content
up to 57.86%. HCI-BFRS3 granules had a rougher outer surface than breadfruit starch
and BFRS3. HCI-BFRS3 has higher T, (79.73°C), ~H (14.64 Jig) and smaller transition
temperature range, Tc- To (4.28°C) as compared to breadfruit starch. HCI-BFRS3 was
further assessed for in- vitro fermentation. HCI-BFRS3 has supported the growth of L.
plantarum and L. brevis, also reduced the pH of fermentation medium with 0.34 and
0.26 respectively. The highest prebiotic activity score (PAS) was obtained by L.
plantarum at 24 hours fermentation compared to the positive control (inulin and
fibersol-2). From this study, breadfruit flour and starch possessed different
physicochemical properties which made it distinguished from each other and the HCI
BFRS3 exhibited ability to be fermented by selected LAB. Thus, HCI-BFRS3 has
potential as a prebiotic material that worth to be explored as a functional food ingredient
in the food industry.
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