Incorporating chitosan and lauric acid into starch based filmshowed
more effective antimicrobial ability against B. subtilis and E. coli [167],
and the film had synergistic antimicrobial effect when chitosan and
lauric acid were combined. The starch-based film incorporated with
lauric acid and chitosan showed better flexibility than when purely
starch-based film was formulated. The solution of starch and chitosan
with different mixing ratios (w/w) 8:2 and 9:1 were the most effective
ratio with greater inhibition on both B. subtilis and E. coli than other
solution in agar plate and liquid culture test. The control (pure wheat
starch) and antimicrobial (AM) film (incorporated with chitosan and
lauric acid) were produced by casting method. The antimicrobial effectiveness
of control (pure wheat starch) and AM film incorporated with
chitosan and lauric acid are shown in Fig. 25A and B. A wide clear zone
on solid media was observed for B. subtilis growth inhibition whereas
inhibition for E. coliwas not as effective as B. subtilis. Fromthe liquid culture
test, the AM films clearly demonstrated a better inhibition against
B. subtilis than E. coli.