Effects of heat‐moisture and alkali treatment on the enzymatic hydrolysis of porous sago ( Metroxylon sagu ) starch

Abstract

Pretreatment(s) of heat-moisture treatment (HMT) and alkali treatment was tested for the enzymatic hydrolysis of sago (Metroxylon sagu) starch. HMT was undergone by autoclaving the sago starch at 120°C for 60 min. While sodium hydroxide pellets (0.60% [w/w starch dry basis (d.b.)] to 50 g of sago starch) were applied as the alkali treatment. Dual pretreatments were also evaluated. The dextrose equivalent values of porous starch with alkali pretreatment (31%), HMT (37%), and dual pretreatments (42%) were significantly higher than those of non-pretreated porous sago starch (21%). Greater porosity of pretreated starch granules (0.91-5.19 µm) was also obtained. The thermal properties (gelatinization temperature) of porous starch with pretreatments were improved compared to the non-pretreated porous sago starch.In addition, the pretreatment(s) also improved the oil adsorption capacity of the porous starch. Dual pretreatments were an efficient way to facilitate enzymatic hydrolysis in preparing porous sago starch. Practical applicationsPorous starch is in high demand as a natural carrier for food applications such as flavor retention, food structure improvement, and extension of food shelf life. The porosity of the starch provides higher surface area and better immobilization to food ingredients, especially as a functional food. The abundance and lower cost of sago starch added the preference. Hence, the main purpose of the study is to produce highly porous sago starch granules with enhanced surface area to fulfill the processing requirement of food industries. Thus, the effect of pretreatment(s) on sago starch using heat-moisture and alkali treatments prior to enzymatic hydrolysis was evaluated. Both heat-moisture and alkali pretreatment(s) enhanced the enzymatic hydrolysis of sago starch and formed the intended porous structure. Porous sago starch has better absorption capacity and efficient oil adsorption. Besides, the thermal properties of pretreated sago starch were improved compared to the non-pretreated porous sago starch. Hence, the pretreated sago starch is the potential to be an excellent adsorbent. Overall, the outcome shows that the objective is positively achieved via the dual of the pretreatment(s). S U PP O RTI N G I N FO R M ATI O N Additional supporting information may be found online in the Supporting Information section. How to cite this article: Zhy Ying B, Kamilah H, Karim AA, Utra U. Effects of heat-moisture and alkali treatment on the enzymatic hydrolysis of porous sago (Metroxylon sagu) starch. J Food Process Preserv. 2020;44:e14419. https://doi.

The Digestibility and Bacterial Growth Rates of Microwave Treated Sago (Metroxylon sagu) Starch

“…Meanwhile, the resistant starch contents were drastically lower for the cooked samples compared to the uncooked counterparts. No significant difference was observed between the As the sago starch has a gelatinisation temperature of around 79 °C, this process was possible during the preparation of cooked starch samples (Ying et al, 2020).…”

“…(a) Lactobacillus casei, (b) Bifidobacterium lactis and (c) Escherichia coli growth rates for uncooked and cooked resistant starch samples of microwave-treated sago starch cooked sample content of resistant starch. Cooking the starch destroyed the granule's structure by undergoing gelatinisation.As the sago starch has a gelatinisation temperature of around 79 °C, this process was possible during the preparation of cooked starch samples(Ying et al, 2020). The gelatinisation process caused the leaching of amylose and low molecular weight amylopectin chains(Li et al, 2020;Fan et al, 2019).…”

Physicochemical properties of microwave heated sago (Metroxylon sagu) starch

“…Like other starches such as corn starch, modification of sago starch is essential to improve its properties and increase its usability. Various modification techniques, such as hydrolyzed-hydroxypropylation, octenyl succinic anhydride (OSA), alkaline, heat moisture, and gamma-irradiation treatments have been applied to sago starch (Abiddin et al, 2018;Oladzadabbasabadi et al, 2017;Othman et al, 2015;Ying et al, 2020). There are three main types of modification techniques, namely, physical, chemical, and enzymatic treatments.…”