Effects of Chemical and Enzymatic Modifications on Starch–Oleic Acid Complex Formation

Abstract

The solubility of starch-inclusion complexes affects the digestibility and bioavailability of the included molecules. Acetylation with two degrees of substitution, 0.041 (low) and 0.091 (high), combined without or with a β-amylase treatment was employed to improve the yield and solubility of the inclusion complex between debranched potato starch and oleic acid. Both soluble and insoluble complexes were recovered and analyzed for their degree of acetylation, complexation yields, molecular size distributions, X-ray diffraction patterns, and thermal properties. Acetylation significantly increased the amount of recovered soluble complexes as well as the complexed oleic acid in both soluble and insoluble complexes. High-acetylated debranched-only starch complexed the highest amount of oleic acid (38.0 mg/g) in the soluble complexes; low-acetylated starch with or without the β-amylase treatment resulted in the highest complexed oleic acid in the insoluble complexes (37.6-42.9 mg/g). All acetylated starches displayed the V-type X-ray pattern, and the melting temperature generally decreased with acetylation. The results indicate that starch acetylation with or without the β-amylase treatment can improve the formation and solubility of the starch-oleic acid complex.

Effect of Acetylation and Beta‐Amylase Treatment on Complexation of Debranched Starch with Naringenin

“…The soluble complex had a similar DS as the insoluble complex within the same treatment for both starches (Table ). The β‐amylase treatment resulted in starch with a significantly greater DS for both complexes because of the inability of β‐amylase to hydrolyze anhydroglucose units that were acetylated, agreeing with the findings of Arijaje et al and Arijaje and Wang …”

“…Although their amylose contents were distinctly different, the similar distribution of acetyl groups was attributed to the rapid reaction of acetylation and the location of the acetyl groups nearby the amylopectin branching points . Under the conditions studied, soluble complexes were formed at a DS of 0.034 and 0.032 for potato starch and Hylon VII, respectively, which were lower than the DS reported for the formation of soluble complexes between acetylated potato starch and stearic (DS 0.063), oleic and linoleic acids (DS 0.048) . More planar molecules tend to be included in a greater proportion into the amylose helix, causing the complex to precipitate, hence a greater DS was required to maintain the soluble complex as demonstrated by Wulff and Kubik and Wulff et al which showed that hydroxypropylated amylose of DS 0.06–0.075 was needed to maintain soluble complexes with sodium dodecyl sulfate.…”

“…A noticeable decrease in the amount of complexed fenchone was observed for acetylated amylose with a DS 0.43 and greater, presumably because of the destabilization of the helical conformation by the acetylation and an increased steric hindrance. Recently Arijaje et al and Arijaje and Wang demonstrated that acetylation and enzymatic modification of starch increased complex formation of starch with stearic, oleic, and linoleic acids. The formation of soluble complexes between debranched starch with stearic acid increased by 8.3% when starch was acetylated, and increased by 154–245% when the DP was reduced by β‐amylase.…”

“…In general, the recovery of insoluble complexes for these fatty acids decreased 23–52% as acetylation was combined with DP reduction. The amount of complexed fatty acids increased as the starch was acetylated and debranched …”

“…Although β‐cyclodextrin has been employed to improve naringenin solubility, little work has been done on complexation of starch with naringenin. Potato and Hylon VII starches were selected to study naringenin complexation because both display a B‐type X‐ray diffraction pattern with a greater proportion of chains with longer degree of polymerization (DP), which were suggested to have a greater complexing capability . Therefore, the objective of this study was to investigate the effect of acetylation and DP reduction on Hylon VII and potato starch for their complexing capability with naringenin.…”