Ultrasound-assisted Acid Hydrolysis Research Articles

Rapid and efficient high-performance liquid chromatography-ultraviolet determination of total amino acids in protein isolates by ultrasound-assisted acid hydrolysis

This study presents the optimization and validation of an ultrasound-assisted acid method for the HPLC-UV determination of amino acids in plant-based proteins. The research focuses on enhancing hydrolysis efficiency and reducing environmental impact. Ultrasound treatment significantly accelerated hydrolysis by creating cavitation, which increases local pressure and temperature, leading to faster reaction rates. The optimal condition was a 30-minute treatment at 90 °C with 6 M hydrochloric acid. The 9-fluorenylmethyloxycarbonyl chloride derivatization was best performed at pH 9.0 using borate buffer, ethanol as the organic solvent, and a 5-minute derivatization time with a 5 mM concentration. The method’s analytical performance, validated according to FDA guidelines, showed excellent selectivity, specificity, linearity (r2 > 0.999), accuracy (recovery between 80–118 %), and precision (RSD<10.9). The analysis of 15 plant-based proteins revealed distinct amino acid profiles. Compared to traditional acid hydrolysis methods, the ultrasound-assisted approach demonstrated no significant difference in results (p-value > 0.05), confirming its reliability. The optimized ultrasound-assisted method is a reliable and efficient alternative for amino acid analysis, offering significant cost and time savings while maintaining high analytical performance. These findings are crucial for nutritional planning and developing functional foods to improve health outcomes.

Combinatorial preparation and structural characterization of anthocyanins and aglycones from Purple-heart Radish for evaluation of physicochemical stability and pancreatic lipase inhibitory activity

In this study, an efficient approach to preparation of different anthocyanins from Purple-heart Radish was developed by combining microwave-assisted extraction (MAE), macroporous resin purification (MRP) and ultrasound-assisted acid hydrolysis (UAAH) for evaluation of physicochemical stability and pancreatic lipase (PL) inhibitory activity. By optimization of MAE, MRP and UAAH processes, the anthocyanins reached the yield of 6.081 ± 0.106 mg/g, the purity of 78.54 ± 0.62 % (w/w) and the content of 76.29 ± 1.31 % (w/w), respectively. With high-resolution UHPLC-Q-Orbitrap/MS, 15 anthocyanins were identified as pelargonins with diverse glucosides and confirmed by pelargonidin standard. By glycosylation, pelargonins exhibited higher stability in different pH, temperature, light, metal ions environments than that of pelargonidin. However, PL inhibitory assay, kinetic analysis and molecular docking demonstrated that pelargonidin had higher PL inhibitory activity than pelargonins even though with similar binding sites and a dose–effect relationship. The above results revealed that the effect of glycosylation and deglycosylation on PL inhibitory activity and physicochemical stability.

Influence of acetic acid on physical and rheological properties of cassava starch nanoparticles

In this study, the influence of different acetic acid concentrations (1.7 M, 2.9 M, 4.0 M) via ultrasound-assisted acid hydrolysis was used for the first time to isolate the cassava starch nanoparticles (CSNP). The results showed that the recovery yield decreases as the acid concentration increases. All CSNPs and native starch exhibited a shear-thickening effect. The particle size of all CSNPs was found to decrease as the concentration of acid increased. 2.9 M of acetic acid was found to be the most optimal concentration to achieve the highest viscosity of CSNP solution with relatively smaller particle size. These properties show that CSNP has the potential to be utilized in numerous well-established applications, including drug delivery, fillers, foods, and enhanced oil recovery (EOR).

Intensification of delignification and subsequent hydrolysis of sustainable waste as banana peels for the HMF production using ultrasonic irradiation

The present work deals with the intensification of delignification of banana peels and subsequent acid hydrolysis and HMF production using ultrasound assisted approach. The delignification by conventional method was only 45.78% which increased to 92% for ultrasound clearly demonstrating intensification. The study into effect of operating parameters in the ultrasound-assisted acid hydrolysis on the yields of reducing sugars established optimum conditions as 4% acid concentration (v/v%), solid to solvent ratio of 0.0143, temperature of 80°C, power of 110 W, duty cycle of 70% and time as 3 h. Comparison of sugar yields using conventional approach, ultrasonic horn, and ultrasonic bath indicated that the yield of reducing sugars were 4 times more in ultrasonic horn and 2 times more in ultrasonic bath than conventional method. The studies for conversion of sugars to 5-hydroxymethylfurfural using acid catalyzed hydrothermal treatment revealed the best yield as 50 g/L after 1 h of treatment with 5% sulphuric acid for the approach of ultrasound assisted delignification and acid hydrolysis followed by hydrothermal treatment whereas the conventional approach resulted in much lesser yield of 6.1 g/L. The obtained results demonstrated that there was significant intensification in HMF yield based on using ultrasound for both alkaline pretreatment and acid hydrolysis.

Whey protein isolate/jujube polysaccharide-based edible nanocomposite films reinforced with starch nanocrystals for the shelf-life extension of banana: Optimization and characterization

The formulation of new bionanocomposite (BNC) films using whey protein isolates (WPI, 3.3–11.7 %)-jujube polysaccharide (JPS, 1.59–18.41 %)/starch nanocrystals (SNCs, 0.32–3.68 %) blends was optimized. The ultrasound-assisted acid hydrolysis produced ~63.1 nm SNCs from native starch with −24.3 mV ζ-potential. The extracted JPS purification led to a single symmetrical peak for galactoarabinan-rich fraction (1.35 × 105 Da). The optimal levels of barrier (oxygen (11.85 cm3 m−2 d−1 atm−1) and water vapor (3.22 × 10−10 g m−1 s−1 Pa−1) permeability rate), optical (opacity index (2.7 AU μm−1), total color difference (18.69), and whiteness index (77.40)), and thermal (glass transition temperature (−8.29 °C) and melting point (110.38 °C)) properties were obtained at 5.0 % WPI, 15.0 % JPS, and 3.0 % SNCs. The film-forming solution of optimal BNCs had a significant antibacterial effect against Staphylococcus aureus and Escherichia coli. The improved crystallinity of BNCs at an optimal SNC level was confirmed by the X-ray diffraction (XRD). The field emission-scanning electron (FE-SEM) and atomic force (AFM) microscopy images confirmed a continuous and uniform network for the optimal BNCs without any pores or cracks accompanied by low surface roughness. The FTIR spectroscopy proved covalent interaction and hydrogen bonding among chemical functional groups of WPI and JPS reinforced with SNCs. The optimal BNC could preserve banana fruits with favorable physicochemical and microbial quality during storage.

The physical, mechanical, thermal and barrier properties of starch nanoparticle (SNP)/polyurethane (PU) nanocomposite films synthesised by an ultrasound-assisted process

This article reports on the ultrasound-assisted acid hydrolysis for the synthesis and evaluation of starch nanoparticles (SNP) as nanofillers to improve the physical, mechanical, thermal, and barrier properties of polyurethane (PU) films. During the ultrasonic irradiation, dropwise addition of 0.25 mol L-1 H2SO4 was carried out to the starch dispersion for the preparation of SNPs. The synthesized SNPs were blended uniformly within the PU matrix using ultrasonic irradiation (20 kHz, 220 W pulse mode). The temperature was kept constant during the synthesis (4 °C). The nanocomposite coating films were made with a regulated thickness using the casting method. The effect of SNP content (wt%) in nanocomposite coating films on various properties such as morphology, water vapour permeability (WVP), glass transition temperature (Tg), microbial barrier, and mechanical properties was studied. The addition of SNP to the PU matrix increased the roughness of the surface, and Tg by 7 °C, lowering WVP by 60% compared to the PU film without the addition of SNP. As the SNP concentration was increased, the opacity of the film increased. The reinforcement of the SNP in the PU matrix enhanced the microbial barrier of the film by 99.9%, with the optimal content of SNP being 5%. Improvement in the toughness and barrier properties was observed with an increase in the SNP content of the film.

Synthesis of cellulose nanocrystals (CNCs) from cotton using ultrasound-assisted acid hydrolysis

This present work reports the synthesis of Cellulose nanocrystals (CNCs) from cotton using an ultrasound-assisted acid hydrolysis. Further, the synthesized CNCs was comprehensively characterized using Fourier Transform Infrared Spectroscopy (FTIR) to analyze surface functional groups and X-ray diffraction (XRD) in studying structural characteristics. Differential Thermal Analysis (DTA) and Thermogravimetric Analysis (TGA) have been used to study the thermal properties of CNCs. Morphology of CNCs was studied using a Transmission Electron Microscope (TEM) and Scanning Electron Microscope (SEM). The crystallite size was found to be 10–50 nm using XRD data and the average particle size to be 221 nm using PSD analysis.

Study of Ultrasound-assisted Acid Hydrolysis to Obtain Quercetin and their Antioxidant Activities from some Plants

In this study, acidic hydrolysis to release the aglycone quercetin from plant extracts under ultrasound-assisted conditions was investigated. Based on the stability of quercetin, the suitable conditions were as follows: methanol/H2O (50:20, v/v) was added to the powder plants (ratio 50:1, ml/g), these mixtures were placed in ultrasonic bath of 37 kHz/550W; kept at 70°C within 30 min and then filtered. The filtrate was acidified with HCl (70:8, ml/ml). Lastly, the ultrasonication was carried out for hydrolysis for 1 hour (the second ultrasound) to obtain quercetin. We have obtained quercetin containing hydrolyzed extract from 10 plants to determine quercetin concentrations (using the HPLC optimized conditions) and evaluate the antioxidant activity (the capability to scavenge the DPPH radical). In 10 samples of plants that were obtained, both quercetin concentrations and antioxidant activity in the plant extract of the flower buds of Sophora japonica L have the highest value, then to the plant extract of Nelumbo nucifera Gaertn. In the Sophora flower-bud and the lotus leaf, quercetin content is calculated on dry material (mg/100g), 15423.04 and 5190.82 respectively; the average percentage inhibition of DPPH 100 µM (%) 55.26% and 32.23%., respectively.&#x0D; Keywords: Quercetin, HPLC, acid hydrolysis, ultrasound-assisted, antioxidant activity.&#x0D; References&#x0D; [1] S.G. Dmitrienko, V.A. Kudrinskaya, V.V. Apyari, Methods of extraction, preconcentration, and determination of quercetin, Journal of Analytical Chemistry 67 (4) (2012) 299-311. https://doi.org/ 101134/S106193481204003X.[2] H. Nishimuro, H. Ohnishi, M. Sato, M. Ohnishi-Kameyama, I. Matsunaga, S. Naito, K. Ippoushi, H. Oike, T. Nagata, H. Akasaka, S. Saitoh, K. Shimamoto, M. Konori, Estimated daily intake and seasonal food sources of quercetin in Japan, Nutrients 7 (4) (2015) 2345-2355. https://doi.org/ 10.3390/nu7042345.[3] C. Zhao, X. Ren, C. Li, H. Jiang, J. Guan, W. Su, Y. Li, Y. Tian, T. Wang, S. Li, Coupling ultrasound with heat-reflux to improve the extraction of quercetin, kaempferol, ginkgetin and sciadopitysin from Mairei Yew leaves, Applied Sciences 9 (4) (2019) 795-810. https://doi.org/10.3390/app9040795.[4] J. Azmir, M.S.I. Zaidul, M.M. Rahman, K.M. Sharif, A. Mohamed., F. Sahena, A.H.M. Jahurul, K. Ghafoor, N.A.N. Norulain, K.A.M. Omar, Techniques for extraction of bioactive compounds from plant materials : A review, Journal of Food Engineering 117 (4) (2013) 426-434. https://doi. org/10.1016/j.jfoodeng.2013.01.014.[5] L.H. Hoang, D.T.H. Anh, D.T. Hue, T.T.K. Oanh, N.Q. Huy, Determination of Quercetin Aglycone in Flos Sophorae japonicae Extract by High Performance Liquid Chromatography, VNU Journal of Science: Natural Sciences and Technology 33 (1S) (2017) 214-223 (in Vietnamese). https://doi.org/10.25073/2588-1140/ vnunst.4534. [6] A.M. Nuutila, K. Kammiovirta, M. Oksman-Caldentay, Comparison of methods for the hydrolysis of flavonoids and phenolic acids from onion and spinach for HPLC analysis, Food Chemistry 76 (4) (2002) 519-525. https://doi.org/ 10.1016/S0308-8146(01)00305-3.[7] L. Qiao, Y. Sun, R. Chen, Y. Fu, W. Zhang, X. Li, J. Chen, Y. Shen, X. Ye, Sonochemical effects on 14 flavonoids common in citrus : Relation to stability, Plos One 9 (2) (2014) e87766. https://doi. org/10.1371/journal.pone.0087766.[8] W. Brand-Williams, M.E. Cuvelier, C. Berset, Use of a free radical method to evaluate antioxidant activity, LWT - Food Science and Technology 28 (1995) 25-30. https://doi.org/10.1016/S0023-6438 (95)80008-5.&#x0D; [9] M. Biesaga, Influence of extraction methods on stability of flavonoids, Journal of Chromatography A 1218 (2011) 2505-2512. https://doi.org/10.1016/ j.chroma.2011.02.059.[10] L. Paniwnyk, E. Beaufoy, J.P. Lorimer, T.J. Manson, The extraction of rutin from flower buds of Sophora japonica, Ultrasonics Sonochemistry 8 (3) (2001) 299-301. https://doi.org/10.1016/S1350 -4177(00)00075-4.[11] X. He, Y. Bai, Z. Zhao, X. Wang, J. Fang, L. Huang, M. Zeng, Q. Zhang, Y. Zhang, Z. Zheng, Local and traditional uses, phytochemistry, and pharmacology of Sophora japonica L.: A review, Journal of Ethnopharmacology 187 (2016) 160-182. https://doi.org/10.1016/j.jep.2016.04.014.[12] I.Y. Bae, B.Y. Kwak, H.G. Lee, Synergistic antiradical action of natural antioxidants and herbal mixture for preventing dioxin toxicity, Food Science and Biotechnology 21 (2) (2012) 491-496. https://doi.org/10.1007/s10068-012-0062-9.

Furfural production from lignocellulosic biomass by ultrasound-assisted acid hydrolysis

Furanic platforms (e.g. furfural, furfuryl alcohol and hydroxymethylfurfural) can be obtained from biomass, being considered as a green alternative to petrochemical products such as fuels, and solvents. In this work, the use of ultrasound energy was investigated for the conversion of several lignocellulosic materials into furfural. The following parameters were evaluated: reaction time (30 to 120 min), ultrasound amplitude (20 to 70%) and feedstock amount (100 to 500 mg). The ultrasound-assisted acid hydrolysis (UAAH) process was applied to several lignocellulosic materials (sugar cane straw, rice husk, yerba-mate waste, grass and wood waste) aiming an investigation about the effects when working with real and complex feedstock. Better furfural yields (72.4 ± 4.3 mg g−1) were obtained from 0.1 g of grass, employing an ultrasound cup horn system operating at 20 kHz, 20 mL of 4 mol L−1 HNO3, at 30 °C, 50% amplitude, and 60 min of sonication. Under the same reaction conditions, the results were compared with those obtained at silent condition (mechanical stirring, 100 to 500 rpm), which demonstrate the ultrasound effects for furfural synthesis. Therefore, the proposed UAAH process can be considered as a suitable alternative for biomass conversion to furfural, because it does not need previous step of lignin removal and might be performed in a single step.

Ultrasound-Assisted Ultra-Mild-Acid Hydrolisis of -Carrageenan

The low molecular weight fraction of κ-carrageenan is useful in biomedical applications. An ultrasound-assisted acid hydrolysis of κ-carrageenan has been studied. κ-carrageenan with an initial number-average molecular weight of 629 kDa was dispersed in distilled water to form a 5 g/l solution. The pH (3 and 6) of the solution was adjusted by adding HCl solution. The depolymerization reaction was carried out in an ultrasonic device at various temperatures (30, 40, 50, and 60°C) and times (8, 16, 24, and 32 min). The experimental results showed that ultrasound positively contributed to acid hydrolysis process. The number-average molecular weight of the treated k-carrageenan was lower or the percentage of reduction was higher at lower pH, longer reaction time, and higher temperature. The lowest number-average molecular weight (14 kDa) or the highest percent of molecular weight reduction reduction (97.7%) was achieved after ultrasonic irradiation at 60°C and pH 3 for 32 min. Keywords: depolymerization; midpoint scission; ultrasonication

Optimization of Ultrasonic Assisted Saccharification of Sweet Lime Peel for Bioethanol Production Using Box–Behnken Method

In this study, ultrasonication was investigated for hydrolysis of sweet lime peel instead of utilizing it as a pretreatment process. Ultrasonication is one of the upcoming hydrolysis techniques that can offer high reducing sugar yield in shorter times and temperature with reduced acid consumption. Optimization studies of the hydrolysis process parameters were carried out to maximize the reducing sugar yield using the Box–Behnken method. From Box–Behnken design, 46 experiments were conducted and the effect of sulfuric acid concentration, peel concentration, sonication time, temperature and amplitude of ultrasound on reducing sugar yield were investigated. Fermentation of the hydrolysate was performed using baker’s yeast and the effect of time and pH on ethanol production was studied. Maximum ethanol yield by fermentation was observed as 64%. Scanning electron micrographs revealed that the regular and compact surface of raw biomass was altered into an irregular and scattered surface as a result of pretreatment and hydrolysis, which showed the prospective feasibility of sulfuric acid assisted steam explosion pretreatment and ultrasound assisted acid hydrolysis. From the experimental study, it was observed that ultrasonication can be explored for hydrolysis of pretreated lignocellulosic biomass to obtain high reducing sugar yield for bioethanol production.

Ultrasound-assisted acid hydrolysis of cellulose to chemical building blocks: Application to furfural synthesis

In this work, the use of ultrasound energy for the production of furanic platforms from cellulose was investigated and the synthesis of furfural was demonstrated. Several systems were evaluated, as ultrasound bath, cup horn and probe, in order to investigate microcrystalline cellulose conversion using simply a diluted acid solution and ultrasound. Several acid mixtures were evaluated for hydrolysis, as diluted solutions of HNO3, H2SO4, HCl and H2C2O4. The influence of the following parameters in the ultrasound-assisted acid hydrolysis (UAAH) were studied: sonication temperature (30 to 70°C) and ultrasound amplitude (30 to 70% for a cup horn system) for 4 to 8molL−1 HNO3 solutions. For each evaluated condition, the products were identified by ultra-performance liquid chromatography with high-resolution time-of-flight mass spectrometry (UPLC-ToF-MS), which provide accurate information regarding the products obtained from biomass conversion. The furfural structure was confirmed by nuclear magnetic resonance (1H and 13C NMR) spectroscopy. In addition, cellulosic residues from hydrolysis reaction were characterized using scanning electron microscopy (SEM), which contributed for a better understanding of physical-chemical effects caused by ultrasound. After process optimization, a 4molL−1 HNO3 solution, sonicated for 60min at 30°C in a cup horn system at 50% of amplitude, lead to 78% of conversion to furfural. This mild temperature condition combined to the use of a diluted acid solution represents an important contribution for the selective production of chemical building blocks using ultrasound energy.

Modification of NanoCrystalline Cellulose (NCC) by Hyperbranched Polymer

Objectives: The surface modification of NanoCrystalline Cellulose (NCC) recently has been paid attention due to the increasing opportunities in the application. The objective of this paper is to modify the surface of NCC by the HyperBranched Polymer (HBP) with hydroxyl terminal groups ends. Methods/Statistical Analysis: The NCC surfaces were modified with HBP using solvent evaporation methods. First, the NCC was synthesized via ultrasound assisted acid hydrolysis process and the obtained NCC was surface coated by using HBP with different concentration through solvent evaporation technique. Finally, the obtained NCC and Modified NCC were characterized by using FTIR, XRD and TGA. Findings: Results revealed that there are significant differences of FTIR pattern analysis indicated that the NCC has been modified, however the modification NCC with HBP under various conditions did not change the X-ray patterns of NCC which indicates that the HBP only coated on the surface of NCC. Application/Improvements: This modification of NCC showed promising results which can be used for various applications.

Spherical nanocrystalline cellulose (NCC) from oil palm empty fruit bunch pulp via ultrasound assisted hydrolysis

Nanocrystalline cellulose (NCC) was isolated from oil palm empty fruit bunch pulp (EFBP) using ultrasound assisted acid hydrolysis. The obtained NCC was analysed using FESEM, XRD, FTIR, and TGA, and compared with raw empty fruit bunch fibre (REFB), empty fruit bunch pulp (EFBP), and treated empty fruit bunch pulp (TEFBP). Based on FESEM analysis, it was found that NCC has a spherical shaped after acid hydrolysis with the assistance of ultrasound. This situation was different compared to previous studies that obtained rod-like shaped of NCC. Furthermore, the crystallinity of NCC is higher compared to REFB and EFBP. According to thermal stability, the NCC obtained shows remarkable sign of high thermal stability compared to REFB and EFBP.

Hydrolysis of agricultural waste to obtain reducing sugars using conventional and ultrasound-assisted technologies

&lt;div&gt; &lt;p&gt;The main objective of this study was to evaluate the hydrolysis of rice hulls to obtain reducing sugars by conventional and ultrasound-assisted acid hydrolysis. For this purpose, the methodology of experimental design was used to evaluating the influence of temperature, moisture content and concentration of phosphoric acid on the yield of reducing sugars. The yields at optimized conditions were of 141.1 and 162.0 g.kg&lt;sup&gt;-1&lt;/sup&gt;, for conventional and ultrasound-assisted hydrolysis, respectively. It was possible to obtain high yield using less acid and low temperature, in a manner that ultrasound can be used as a technology for process intensification.&amp;nbsp;&lt;/p&gt; &lt;/div&gt; &lt;p&gt;&amp;nbsp;&lt;/p&gt;

Optimization of Ultrasound-Assisted Acid Hydrolysis of Total Isoflavones in Radix puerariae Using Response Surface Methodology

The present study reports on ultrasound-assisted hydrolysis of total isoflavones in Radix puerariae using hydrochloric acid as catalyst and the influence of different hydrolysis parameters on the yield of puerarin. Based on the single factor test, response surface methodology (RSM, Box–Behnken Design) was used to develop predictive models for simulation and optimization of the hydrolysis conditions in order to increase the yield of puerarin. The optimum hydrolysis conditions were as follows: hydrolysis time of 48 min, hydrolysis temperature of 78°C, ultrasonic power of 180 W and the concentration of hydrochloric acid of 4.6% (v/v). Under these optimal conditions, the concentration of puerarin was increased to 15.92%, which is 19.5% higher than that in the original crude extract. At the same time, compared with the traditional acid hydrolysis, the time needed in ultrasound-assisted hydrolysis is only 45 min, which is 120 min shorter than traditional hydrolysis.

Ultrasound-assisted acid hydrolysis of palm leaves (Roystonea oleracea) for production of fermentable sugars

This work is focused on the ultrasound-assisted hydrolysis of palm leaves to obtain fermentable sugars using phosphoric acid as catalyst. The effects of phosphoric acid concentration (5.0–20wt%) and temperature (30–65°C) on the hydrolysis and kinetic parameters were evaluated. The maximum amounts of fermentable sugar obtained were 0.55 and 0.59g sugarg−1 dry material, leading to maximum efficiencies of hydrolysis of 68.8 and 74.0% in the absence and presence of ultrasound, respectively. The kinetic parameters obtained from the overall reaction curves showed that the ultrasound intensified the releasing of fermentable sugars in the period of constant reaction rate, since 51% of total fermentable sugar was released in this period in comparison with 45% in the absence.

Ultrasound assisted extraction of pectin from Trachystemon orientalis L.

Pectin, a natural bio polymer, has wide range of applications in different fields because of its gelling, stabilizing and emulsifying ability as food additive/preservative and drug carrier etc. Main objective of this study was to describe the extraction of pectin for the first time from Trachystemon orientalis L., a medicinal plant grown in black sea region of Turkey. Pectin was extracted from the plant by ultrasound assisted acid hydrolysis method. Obtained pectin was characterized by using ATR-FT-IR and TGA methods. It was observed that the plant contained 2.5% pectin (0.25 g pectin/ per 10 g dried sample). Obtained pectin was labeled as High Methyl esterified Pectin (HMP) as its methoxyl- content was found to be 80% by using titrimetric method. ATR-FT-IR and TGA images were obtained as well. It can be concluded that Trachystemon orientalis L. could be a new source for pectin production for food and pharmaceutical industries.