Optimization of microwave‐assisted alkali pretreatment of cassava rhizome for enhanced enzymatic hydrolysis glucose yield

Abstract

This research establishes the optimal microwave‐assisted alkali pretreatment (MAP) condition of cassava rhizome (CR) using response surface methodology with Box–Behnken design for enhanced enzymatic hydrolysis glucose yield. The pretreatment parameters included microwave power (300–900 W), irradiation time (5–15 min), and NaOH concentration (3%–7% w/v); and the enzymatic hydrolysis was 24 and 48 hr. Quadratic models were generated and statistical analysis performed to validate the adequacy of the models. The results indicated that the optimal MAP condition was 840 W microwave power, 9 min irradiation time, and 3% w/v NaOH concentration. Under the optimal condition, the predicted and experimental glucose yields were 15.39 and 15.82 g/100 g native cassava rhizome (NCR) for 24 hr hydrolysis, and 16.40 and 16.95 g/100 g NCR for 48 hr hydrolysis, indicating good agreement. In addition, this study examined the effect of MAP on the physical characteristics and morphology of NCR and pretreated CR. The results showed significant structural changes in pretreated CR, indicating that MAP enhanced enzymatic accessibility and glucose yield.

Optimization and Characterization of Microwave-Assisted Hydro-Distillation Extraction of Essential Oils from Cinnamomum camphora Leaf and Recovery of Polyphenols from Extract Fluid

“…Moreover, the high p-values of the "lack of fit" of the models were 0.2473 and 0.1399, suggesting that the "lack of fit" had no statistical significance, which verified the reliability of the models [34]. The variation coefficients (C.V.) of 5.75 and 3.54%, which were both lower than 10%, also indicated the high accuracy and predictability of the equations [35].…”

Microwave Irradiation Optimization for Efficient Lignin Removal From Cocoa Shell Waste Using Alkali

“…BBD was used to optimize microwave parameters as the factor in assisting the caustic removal of lignin from CSW via 15 experiments in random order with three replications at the centre point. The design of experiment was of three-factor and two-level factorial Box-Behnken design (BBD) [17]. The three factors were microwave power (X1), temperature (X2), and treatment time (X3) with low, moderate, and high levels factor as represented by −1, 0, and 1 as shown in Table 1.…”

“…Sodium hydroxide (NaOH) is an effective alkaline in breaking down lignin structure [15,16] that leads to an increase in surface area and pore volume in the substrate. Meanwhile, microwave radiation results in rapid heating due to interaction between an irradiated object and electromagnetic field [17,18]. Thus, this high efficiency of treatment eases the implementation [19,20] of breaking down lignocellulosic material bonding.…”

“…Several studies reported on the optimization of treatment process parameters for other agricultural wastes. For instance, Sombatpraiwan et al [17] conducted microwave -assisted on cassava rhizome by varying microwave power (300-900 W), irradiation time (5-15 min), and NaOH concentration (3%-7% w/v). It was found that optimal conditions for lignin removal were 840 W microwave, 9 min, and 3% w/v NaOH.…”

Corrigendum

“…In the article by Sombatpraiwan S et al, entitled “Optimization of microwave‐assisted alkali pretreatment of cassava rhizome for enhanced enzymatic hydrolysis glucose yield,” (Sombatpraiwan et al 2019) Dr. Tawarat’s family name has been corrected and his full name should read “Tawarat Treeamnuk.”…”