Molecular characterization and in vitro digestibility of normal maize starch hydrolyzed by maltotriohydrolase
Introduction
Amylases have been widely used in the production of sugars and enzyme-modified starches [1]. In the presence of amylase, starch undergoes significant hydrolysis. Therefore, amylase addition may result in tailored starch molecules with discrepant molecular characterization. It is important to understand the molecular characteristics of starch to develop specific functional foods [2]. Based on the scientific literature, starch molecules of different weight average molar mass (Mw), number average molar mass (Mn), molar mass distribution, molecular dimension, and structural conformation [2] are of commercial interest. Molecular characterization of enzyme-modified starch has been partially performed [3], [4], [5], [6]. However, the molecular degradation mechanisms of starch under some specific amylases remain unclear. Among such amylases, glucan 1,4-alpha-maltotriohydrolase (AMTS, EC 3.2.1.116) is a potential enzyme for the production of maltotriose from starch [7], [8]. It has been reported that AMTS uniquely transfers maltotriosyl units during maltooligosaccharide hydrolysis [7]. Based on these, the molecular characteristics of AMTS-hydrolyzed starches were evaluated in this study.
Enzyme-modified starches of different digestibility have gained considerable interest in the past years [4], [6], [9], [10], [11]. Based on its rate and extent of digestibility, starch can be classified into rapidly digestible starch (RDS), slowly digestible starch (SDS), and resistant starch (RS) [12]. The molecular structure of starch hydrolyzed by amylase has been shown to affect cooked starch digestibility [3], [4], [10]. However, to the best of our knowledge, no studies have focused on the relationships between the molecular characteristics and digestibility of AMTS-hydrolyzed starch.
The objective of this work is to understand the influence of AMTS hydrolysis on the soluble oligosaccharides released, starch molecular characteristics and digestibility. To achieve this aim, normal maize starch was hydrolyzed by AMTS to different extents. Data on the molecular characteristics of AMTS-hydrolyzed starches were derived from high performance size exclusion chromatography equipped with a multi-angle laser light scattering detector and a refractive index detector (HPSEC-MALLS-RI; Wyatt Technology, Santa Barbara, CA, USA). Additionally, the correlations between molecular characteristics and starch digestibility were studied. By doing this, it is hoped that useful information is shed about the molecular structure-property relationships of starch after AMTS hydrolyzed.
Section snippets
Materials
Normal maize starch was kindly donated by Puluoxing Starch Co., Ltd. (Hangzhou, China). AMT 1.2 L was purchased from Amano Enzyme Inc. (Nagoya, Japan); α-amylase from porcine pancreas and glucose oxidase–peroxidase assay kit were purchased from Sigma–Aldrich Chemical Co. (St. Louis, USA). Amyloglucosidase and isoamylase were acquired from Megazyme International Ireland Co. (Wicklow, Ireland).
AMTS preparation
AMTS was purified from the commercial enzyme AMT 1.2 L according to a previously described laboratory
AMTS hydrolysis and soluble oligosaccharides released
In this study, normal maize starch was hydrolyzed by AMTS. As shown in Table 1, the DH increased in time scales during the experiment. At 120 min and 360 min, DH was 23.5% and 44.0%, respectively. After 480 min, DH slightly increased to 45.2%. The slowing trend in DH can be partially attributed to structural hindrance of starch residues toward further hydrolysis [17], [18].
The soluble oligosaccharides present in the supernatants are shown in Fig. 1; maltotriose concentration and percentage in the
Conclusions
In this study, normal maize starch was hydrolyzed by AMTS, resulting in the production of maltotriose. HPAEC results revealed that the transglycosylation might take place in the extensive hydrolysis of starch and the purity of maltotriose could be easily altered by controlled hydrolysis. In the initial AMTS hydrolysis (≤240 min), Rz and ρ of starch displayed linear relation to the progressively degraded Mw, and starch molecule retained the spherical structure. However, extensive hydrolysis gave
Acknowledgements
This study was financially supported by the Natural Science Foundation of China (project nos. 31230057, 31301505, and 31201381).
References (29)
- et al.
Food hydrocolloid.
(2012) - et al.
Food Chem.
(2014) - et al.
Carbohydr. Polym.
(2014) - et al.
Carbohydr. Polym.
(2011) - et al.
Food Chem.
(2014) - et al.
Carbohydr. Res.
(2014) - et al.
Int. J. Biol. Macromol.
(2014) - et al.
Food Chem.
(2014) J. Biol. Chem.
(1945)Anal. Chim. Acta
(1993)
Carbohydr. Polym.
Food hydrocolloid.
Food Chem.
J. Chromatogr. A
Cited by (8)
Properties of a neutral, thermally stable and surfactant-tolerant pullulanase from worker termite gut-dwelling Bacillus safensis as potential for industrial applications
2022, HeliyonCitation Excerpt :However, this complex structure could only be broken down by specific glucanase amylolytic enzyme called pullulanase, a debranching enzyme (Da Cruz, 2013; Zhang et al., 2020). Debranching enzymes are capable of catalyzing α-1,6 glycosidic linkages thereby leading to their hydrolysis (Wu, 2015; Dakhmouche et al., 2021). Debranching enzymes are classified into indirect and direct branching enzymes.
Progress in tailoring starch intrinsic structures to improve its nutritional value
2021, Food HydrocolloidsHydrolytic mechanism of α-maltotriohydrolase on waxy maize starch and retrogradation properties of the hydrolysates
2017, Food HydrocolloidsCitation Excerpt :Glucan 1,4-α-maltotriohydrolase (AMTS; EC 3.2.1.116) is a member of the glycoside hydrolase family 13 (http://www.cazy.org/). AMTS successively removes maltotriose units from the non-reducing ends of starch (C. Wu, Zhou, Wei, et al., 2014). The production of high-quality maltotriose from starch by AMTS is promising due to its low cost (Takasaki et al., 1991; C.; Wu, Zhou, Wei, et al., 2014).
Purification and biochemical characterization of pullulanase produced from Bacillus sp. modified by ethyl-methyl sulfonate for improved applications
2024, Preparative Biochemistry and BiotechnologyThe scientific basis for healthful carbohydrate profile
2019, Critical Reviews in Food Science and Nutrition