Effect of Hydroxypropylation and Beta‐Amylase Treatment on Complexation of Debranched Starch With Naringenin

Abstract

Naringenin exhibits many health benefits but it has limited water solubility and consequently low bioavailability. The objective of this study is to investigate the effect of hydroxypropylation and enzymatic treatments on starch complexation with naringenin. Potato starch and Hylon VII are hydroxypropylated to two substitution degrees and then debranched or debranched/β‐amylase treated prior to complexing with naringenin. Both soluble and insoluble complexes are recovered and characterized. An increase in hydroxypropylation level improves recovery of soluble complexes, while total recovery remains unchanged; the β‐amylase treatment further increases soluble complex recovery. For the same treatment, the naringenin content is greater in Hylon VII complexes (6.72–15.15 mg g−1) than in potato starch complexes (2.45–11.18 mg g−1). Insoluble complexes have greater naringenin contents (3.91–15.15 mg g−1) compared to their soluble counterparts (2.45–9.43 mg g−1). All complexes exhibit a mixture of B + V X‐ray diffraction pattern. This work is the first one to demonstrate that hydroxypropylated starch forms complexes with naringenin, and an appropriate level of beta‐amylase hydrolysis further improves their complexation.

Expression, biochemical and structural characterization of high-specific-activity β-amylase from Bacillus aryabhattai GEL-09 for application in starch hydrolysis

“…Additionally, recombinant AmyBa maintained a high level of stability under weak acidic to weak alkaline conditions (4.5–7.0) (Fig. 4 B), which is consistent with most microbial β-amylases, including those from B. cereus [ 25 ], B. flexus [ 39 ], B. circulans [ 18 ], and B. megaterium [ 40 ]. However, bacterial and plant β-amylases demonstrate different optimal pH ranges, with a previous reporting maximal activities under neutral and weak acidic conditions, respectively [ 7 ].…”

“…Table 3 shows that recombinant AmyBa exhibited the highest specific activity among reported mesothermal microbial β-amylases, with results showing 2.53-, 1.74-, and 1.23-fold higher activity relative to those from P. polymyxa [ 35 ], B. cereus [ 25 ], and B. flexus [ 36 ], respectively. A major impediment to wide industrial application of enzymes is the cost.…”

“…Notably, the fermentation activity (U/mL) of recombinant β-amylase is mainly affected by two factors: protein yield (mg/mL) and enzyme specific activity (U/mg). However, previous studies report that microbial β-amylase exhibits low specific activity [ 18 , 25 ], which dramatically influences fermentation activity (U/mL). Therefore, identifying a β-amylase that can be efficiently produced in a heterologous expression system and exhibiting high specific activity is critical.…”