Abstract:
Nowadays, consumption of dietary fiber (DF) has increased in popularity due to the
beneficial health effects, thus many attempts have been made to produce DF-enriched
foods. However, high incorporation of DF ingredients from conventional sources such as
soybean hull, rice bran, and wheat bran causes several defects in product characteristics
such as texture, mouthfeel, odor/flavor, as well as poor structure, particularly in bakery
products. At present, commercial resistant starch (RS) captures the attention of the food
industries for both functional properties and potential health benefits that are similar to
dietary fiber. This study aimed to formulate three types of resistant starch wheat flour mix
(RSFM), namely soft flour mix (SFM), hard flour mix (HFM), and all-purpose flour mix
(AFM) by partially substituting three types of commonly utilized wheat flour with
commercial resistant starch (Hi-maize). SFM was applied into butter cake and sponge
cake. HFM was applied into bread and breadsticks. AFM was applied into butter cookies
and waffles. Substitution of wheat flour with Hi-maize affected rheological properties
and baking quality was indicated by decreased peak and final viscosities, breakdown, and
setback. Moreover, batter and dough were weaker and less elastic than those made from
wheat flour alone. After baking, reduction in volume of bread and cake, loss of bread
elasticity, firmer product’s texture, reduction in cookie spread and floury odor were
observed in Hi-maize-enriched products. Nevertheless, results from product application
testing and sensory evaluation indicated that Hi-maize could partially substitute wheat
flour up to 20%, 40% and 50% for hard wheat flour, soft wheat flour and all-purpose wheat
flour, respectively. Furthermore, sensory evaluation revealed that products baked from
formulated flour mixes were accepted by the panelists and tended to be superior to those
reported to be made with traditional fiber sources with overall acceptability scores above 6
(like slightly) in all products and were relatively high for 50% AFM waffle (7.18) and 40%
SFM sponge cake (7.44).
The formulated HFM, SFM and AFM had total dietary fiber (TDF) values of 13, 22,
and 27 g/100 g, respectively. This is markedly higher than control wheat flours, about 5
times, 8 times and 10 times for HFM, SFM and AFM, respectively. Moreover, the bakery
products made from these flour mixes provided TDF in the range of 13-30 % of Thai RDI
per serving.
The cost estimation of formulated flour mixes was relatively higher than the
commercial wheat flour. However, when taking its high TDF content into consideration,
these flour mixes could be recommended as an alternative choice for health-conscious
consumers. This, in turn, will enhance their dietary fiber intake toward the recommended
level.