Microwave technology: a novel approach to the transformation of natural metabolites

Hu, Qi; He, Yanan; Fang, Wang; Wu, Jing; Ci, Zhimin; Chen, Lumeng; Xu, Rui‐hua; Ming, Yang; Lin, Junzhi; Han, Li; Zhang, Dingkun

doi:10.1186/s13020-021-00500-8

Cited by 52 publications

(18 citation statements)

References 147 publications

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“…Microwave heating has many advantages, for example, low energy use, very high heating rate, improved treatment time, better physical and chemical properties (due to shorter exposure to higher temperatures), simplicity, and lower risk for the environment. These attributes assigned to microwave heating have not been observed during heating with conventional methods [ 62 , 63 , 64 ].…”

Section: Influence Of the Reaction Parameters On The Lignocellulose S...mentioning

confidence: 99%

Lignocellulose Biomass Liquefaction: Process and Applications Development as Polyurethane Foams

et al. 2023

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One of the main strategies for sustainable human society progress is the development of efficient strategies to limit waste production and maximize renewable resource utilization. In this context, this review highlights the opportunity to transform vegetable biomass residues into valuable commercial products. Biomass conversion entails the depolymerization of lignocellulosic biomass towards biopolyols and the synthesis and characterization of the valuable products obtained by using them. The influence of the reaction parameters in both acid and basic catalysis is highlighted, respectively the influence of microwaves on the liquefaction reaction versus conventional heating. Following the depolymerization reaction, polyols are employed to produce polyurethane foams. As a special characteristic, the addition of flame-retardant properties was emphasized. Another interesting topic is the biodegradability of these products, considering the negative consequences that waste accumulation has on the environment.

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Section: Influence Of the Reaction Parameters On The Lignocellulose S...mentioning

confidence: 99%

Lignocellulose Biomass Liquefaction: Process and Applications Development as Polyurethane Foams

et al. 2023

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“…The MWT at high power and long operation times can lead to the elevated temperature of the sample. The generated heat acts particularly on polar bonds of the compounds, contributing to chemical reactions such as oxidation, dehydration, structural changes, and esterification that can react or transform secondary plant metabolites into other structures 22 . Furthermore, excessive microwave exposure can degrade phytochemicals of natural products due to the electromagnetic force of microwave, thermal-accelerated oxidative deterioration, especially in heat-sensitive substances (e.g., polyphenols) 23 .…”

Section: Resultsmentioning

confidence: 99%

Microwave treatment of rice bran and its effect on phytochemical content and antioxidant activity

Pokkanta

Yuenyong

Mahatheeranont

et al. 2022

Sci Rep

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An alternative approach for rice bran stabilization is microwave treatment. However, the effects of the microwave treatment on the contents of bioactive compounds and antioxidant activities of the rice bran have rarely been reported in detail. In this study, microwave pretreatment (130–880 W for 0.5–5.0 min) of rice bran was proposed where the antioxidant activity, total flavonoids, and total phenolic contents were determined using UV–Vis spectrometry. Tocols, γ-oryzanols, squalene, phytosterols and phenolic compounds were quantified using high-performance liquid chromatography. The results showed an increase in the antioxidant activity (0.5 folds), total phenolic contents (1.3 folds), total flavonoid contents (0.9 folds), total tocols (2.6 folds), total γ-oryzanols (1.6 folds), and total phytosterols (1.4 folds). Phytochemicals were enhanced, especially trans-p-coumaric acid (10.3 folds) and kaempferol (8.6 folds). The microwave treatment at 440 W for 2.5 min provided the best contents of the bioactive compounds and antioxidant activity. This work revealed the microwave treatment as a potential tool for stabilizing rice bran and increasing the usability of its phytochemicals, which applies to several industries concerning the use of rice bran as an ingredient.

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“…With the advantages of mildness, no pollution and good product quality, Shuai et al ( 13 ) used papain method to extract polysaccharides from Artemisia annua with a yield of nearly 11%. The principle of microwave extraction is to use electromagnetic waves with a frequency between 300 MHz and 300 GHz in plants, causing the internal temperature of the plant to rise, increasing collision and friction to promote cell breakage and exudation of polysaccharides ( 39 ). This method is energy-saving, fast, and controllable, but Wei et al ( 18 ) used microwaves to extract polysaccharides from Artemisia annua , and the yield was only 9.72%.…”

Section: Discussionmentioning

confidence: 99%

Optimization of the Artemisia Polysaccharide Fermentation Process by Aspergillus niger

et al. 2022

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In order to investigate the fermentation process of Artemisia polysaccharides, this paper showcases an investigation into the effects of fermentation time, fermentation temperature, strain inoculum, Artemisia annua addition, and shaker speed on the polysaccharides production of Artemisia annua. The yield of Artemisia polysaccharides content was determined based on the optimization of single-factor test, and then a response surface test was conducted with temperature, inoculum, and time as response variables and the yield of Artemisia polysaccharides as response values. The fermentation process was then optimized and the antioxidant activity of Artemisia polysaccharides was monitored using DPPH, ABTS+, OH, and total reducing power. The optimum fermentation process was determined by the test to be 5% inoculum of Aspergillus niger, temperature 36°C, time 2 d, shaker speed 180 r/min, and 4% addition of Artemisia annua, and the extraction of Artemisia polysaccharides was up to 17.04% by this condition of fermentation. The polysaccharides from Artemisia annua fermented by Aspergillus Niger had scavenging effects on DPPH, ABTS, and OH free radicals.

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Microwave technology: a novel approach to the transformation of natural metabolites

Cited by 52 publications

References 147 publications

Lignocellulose Biomass Liquefaction: Process and Applications Development as Polyurethane Foams

Lignocellulose Biomass Liquefaction: Process and Applications Development as Polyurethane Foams

Microwave treatment of rice bran and its effect on phytochemical content and antioxidant activity

Optimization of the Artemisia Polysaccharide Fermentation Process by Aspergillus niger

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