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Volatile fatty acids (VFA) and reducing sugars (RS) are widely used as platform molecules in biorefineries, facilitating the production of valuable biofuels and chemicals. From an environmental, economic and social perspective, third generation biomass, including macroalgae beach-cast, represents an innovative and optimal solution for the production of these commodities. This study explores the impact of ultrasound pretreatment on the invasive macroalga Rugulopteryx okamurae, aiming to produce RS and VFA through enzymatic hydrolysis and dark fermentation. Several ultrasound conditions were tested: amplitudes (0, 70-100 %), suspension volumes (300, 600 mL), and algal concentrations (4-8 %). Optimal results emerged with 100 % amplitude, 300 mL volume, and 4 % (w/v) algal concentration, leading to the maximum COD solubilization of 61.5 mg COD g-biomass-1. For enzymatic hydrolysis, the pretreated sample achieved maximum RS concentrations (0.124 g-RS g-biomass-1) with half the enzyme dosage required by the non-pretreated alga (25 vs 50 FPU g-biomass-1), implying significant economic benefits for large-scale processes. The kinetic model proposed by Romero-Vargas et al. aligned perfectly with the experimental data, obtaining higher values of all the kinetic parameters for the pretreated sample. Dark fermentation showed substantial increases in organic matter solubilization and VFA production (10.36 mg-HAc g-biomass-1) post ultrasound pretreatment: 21.1 % higher solubilization and 9.4 % increased VFA compared to non-pretreated biomass. The resulting VFA composition comprised 73 % acetic acid, 13 % propionic acid, and 8 % butyric acid. Utilization of chemical agents during sonication may further enhance overall processing yields. [ABSTRACT FROM AUTHOR]

One of the most significant dried foods is raisin, used directly as ingredients in confectionary and in the form of raisin paste used in sauces, fillings, baked goods, microwaveable coatings, and other culinary products to color them naturally. The purpose of this study is to investigate the effects of ultrasound pretreatment (53 kHz, 300 W, 30 °C, 300 s, in a mixture of 5% K2CO3+ 1% OO solution) and drying air temperatures (40–60 °C) on the drying behavior, color values, physicochemical properties (moisture content, VCC, TPC, RSC, and antioxidant capacity (DDPH)) and rehydration capacity of Sultani Çekirdeksiz grapes. Both the drying kinetic (drying time, drying rate, and effective moisture diffusivity) and the quality characteristics of grapes were significantly improved by ultrasound pretreatment (p < 0.05). In addition, the vitamin C (0.75–3.86 mg/g) and total phenolic content (1.31–1.80 mg GA/kg) of raisins were highly protected with the high drying temperature and ultrasound pretreatment. The antioxidant capacity (1.15–5.50 mM Trolox) of samples increased with drying temperature whereas the antioxidant capacity decreased with ultrasound application. The rehydration time of all samples was found around 800 min. As a result of this study, it can be said that the ultrasound application may be used successfully for drying grapes and that a greater degree of the nutritional value of the grapes can be maintained. [ABSTRACT FROM AUTHOR]

Bioethanol from cornstarch is the largest renewable liquid biofuel currently in use. However, corn is the basis of the population's diet in many countries so other feedstock must be considered. This article proposes non-conventional starch from Ramon tree (Brosimum alicastrum), a specie native to the Mesoamerican region and widely distributed in the Yucatan Peninsula, Mexico. Ultrasound has appeared as a promising green technique used to make physical, chemical, and biological processes, including enzymatic reactions, more efficient. Ultrasonic pretreatments (UL) alone and combined with commercial enzymes and enzymatic extracts of native fungi (Trametes hirsuta Bm-2) with a power of 70 W at 42 kHz, for 30 min at 45 °C, 60 °C, and 70 °C, were used. The results indicate that the pretreatment conditions do not inhibit the enzymatic activity; on the contrary, they decrease the operational temperature, giving the best results at 45 °C. All the treatments presented significantly higher dextrose equivalent values than the control without sonication. In the fermentation process, 91% efficiency was reached using the native strain Candida tropicalis PL-1, which infers yields of 314 and 235 L/ton of Ramon seed flour (RF) for samples pretreated by UL combined with α-amylase and raw enzymatic extract respectively. Based on the above, the ultrasonic treatment combined with enzymes applied to RF is outlined as an option of non-conventional starch pretreatment for the bioethanol production to avoid the use of basic food in the quest of clean energy. [ABSTRACT FROM AUTHOR]

Introduction: The present research describes the utilization of natural deep eutectic solvent in combination with ultrasound for the extraction of milk thistle polyphenols. The extracts obtained under different conditions were evaluated for their in vitro antioxidant activities and hepatoprotective activities in Albino mice (in vivo). Methods: The extraction parameters involving liquid-to-solid ratio (S/L), ethanol-to-natural deep eutectic solvent ratio (EtOH/DES), extraction time (t), and ultrasound treatment time were investigated and optimized to enhance the recovery of bioactives, their phenolic content, Trolox equivalent antioxidant capacity (TEAC), and radical scavenging capacity (RSC). Results and discussions: The extraction of milk thistle polyphenols using glucose/citric acid (1:1)-based natural deep eutectic liquid coupled with ultrasound for 1.0min under an S/L of 6.2, EtOH/DES 9, and extraction time of 120.8min offered 35.89 ± 2.29 g/100 g of crude extracts, which were three-fold higher than that by conventional solvent extraction (CSE). Each gram of milk thistle extracts thus obtained comprised 377.93 ± 6.17mg GAE of TPC and exhibited 298.70 ± 3.06 μmol TEAC and 93.16 ± 0.58 percent inhibition of DPPH free radicals. In addition, the administration of milk thistle extracts obtained as given above at 25 mg/Kg body weight in Albino mice significantly (p ≤ 0.05) improved the liver function parameters at the end of treatment (7 days). Conclusion: Overall, it was observed that NaDES in combination with medium-level ultrasound energy (700 watt) might work as a sustainable choice to enhance the recovery of bioactive phenolics from milk thistle powder without compromising their antioxidant and hepatoprotective potential. [ABSTRACT FROM AUTHOR]

In this study, we used experimental analysis and numerical simulation to describe and compare the convective drying (CD) of banana slices, without and with pretreatment with ultrasound (US) at 25 kHz. Banana slices, with an average initial thickness of about 6.60 × 10−3 m and an average diameter of about 3.01 × 10−2 m, were subjected to CD at temperatures of 60, 70, and 80°C, with air speed of 1.5 m s−1. Considering such dimensions, the one‐dimensional diffusion equation in Cartesian coordinates was numerically solved by the finite volume method, using a fully implicit formulation (direct problem). A solver with a numerical solution was developed for the direct problem. This solver was coupled to an optimizer to determine the parameters a and b of functions that relate the effective moisture diffusivity (D) with the local moisture ratio, and also to determine the convective mass transfer coefficient (h) (inverse problem), considering the shrinkage. The proposed model was used to describe the data obtained. The results revealed that the drying rate increased in samples that were subjected to pretreatment with US, for each drying temperature. The best‐simulated results were those that related D to the local moisture ratio by means of a bcosh (aMR2) function. It could be observed that pretreatment with US allowed saving of time (and consequently energy) of 28.3%, 16.0%, and 12.4% at drying temperatures of 60, 70, and 80°C, respectively. Practical applications: The main contribution of this paper is to present a solver and an optimizer to determine the mass transfer properties considering the shrinkage during convective drying of banana pieces pretreated with ultrasound by the inverse problem. With the information obtained for the mass transfer properties and the proposed numerical model with a hyperbolic cosine type function for the effective moisture diffusivity, it is possible to more accurately determine the time and, therefore, the energy savings of processing banana chips pre‐treated with ultrasound. [ABSTRACT FROM AUTHOR]

Osmotic dehydration (OD) of carrots was studied by varying the OD conditions (ultrasound as pretreatment [USP], ultrasound‐assisted OD [USOD], and OD without ultrasound [no treatment]), solute concentration (50, 60, and 70°Brix) and solid‐to‐solution ratio (1:3, 1:4, and 1:5). The osmotically dehydrated carrots obtained from the different combinations were then analyzed for solid‐gain (SG) and water loss. Color and texture measurements along with carotenoid content were also studied. Among the different solid‐to‐solution ratios (1:3, 1:4, and 1:5), samples dehydrated with 1:4 yielded the best result for different tests. USOD samples (1:4) gave significantly (p < 0.05) better results for water‐loss (68.74%) and SG (16.57%) as compared to SG of USP (12.46%) and SG of non‐treated samples (11.6%). USOD samples underwent the least amount of color change but had significantly higher values of hardness (240.38 N) than other treatments. The yield of total carotenoids was also significantly (p < 0.05) higher in the USOD samples (22.30 mg/100 g) when compared with USP (18.27 mg/100 g) and non‐treated samples (13.94 mg/100 g). The better quality of products from USOD treatment in terms of color, texture, and nutrition can make it a popular choice in the food industry for various applications. Practical applications: Osmotic dehydration (OD) is a useful technique to preserve the nutritional and sensory qualities of carrots and extend its shelf life. OD is a time‐consuming process and the rate of mass transfer from foods can be increased when OD is combined with other processes. Ultrasound (US) processing is a non‐thermal process that can be used to increase the mass transfer rate during the OD process. In the present work, US was applied as a pretreatment before carrying out the OD process and during the OD process, that is, US was applied in the osmotic solution after putting the carrot slices to see which method was better in increasing the mass transfer rate and preserving the quality of the dehydrated carrots. The findings will help in deciding the proper way for US to be applied for the OD process for carrots and can be extended to other fruits and vegetables. [ABSTRACT FROM AUTHOR]

Pea pod (PP) is an agricultural by‐product with 10%–13% protein content which has a potential to be converted to value‐added ingredients. In this study, different protein extraction strategies including three different solvents (water, salt, and alkaline) and two different pretreatments (ultrasound [US] and enzyme such as pectinase and Viscozyme®) before conventional alkaline extraction were employed to maximize the extraction yield. The US‐pretreated alkaline extraction achieved the highest yield (21.1%) in protein extracts under optimum conditions (30% amplitude for 5 min). PP protein concentrates showed significant differences in solubility, sodium dodecyl sulfate–polyacrylamide gel electrophoresis protein patterns, scanning electron microscopy images, and color depending on the applied extraction method. All PP residues after extraction still remained protein (5.2–8.0 g/100 g) regardless of the extraction techniques, representing the challenges in protein extraction from agricultural by‐products with a lignocellulosic matrix. The combined use of US and enzyme treatments should be further investigated for higher extraction yields. Practical Applications: Agricultural wastes and by‐products could be potential protein sources; however, their lignocellulosic structure could be challenging for protein extraction. In the current study, different extraction strategies including ultrasound (US) and enzyme pretreatments were performed for the extraction of proteins from pea pods which is an agro‐industrial by‐product. Results suggest that US pretreatment may have promising applications for the extraction of valuable compounds from agricultural and industrial by‐products, contributing to sustainable food processing strategies. [ABSTRACT FROM AUTHOR]

Ultrasound has been widely used as a green and efficient non-thermal processing technique to assist with enzymatic hydrolysis. Compared with traditional enzymatic hydrolysis, ultrasonic-pretreatment-assisted enzymatic hydrolysis can significantly improve the efficiency of enzymatic hydrolysis and enhance the biological activity of substrates. At present, this technology is mainly used for the extraction of bioactive substances and the degradation of biological macromolecules. This review is focused on the mechanism of enzymatic hydrolysis assisted by ultrasonic pretreatment, including the effects of ultrasonic pretreatment on the enzyme structure, substrate structure, enzymatic hydrolysis kinetics, and thermodynamics and the effects of the ultrasonic conditions on the enzymatic hydrolysis results. The development status of ultrasonic devices and the application of ultrasonic-assisted enzymatic hydrolysis in the food industry are briefly described in this study. In the future, more attention should be paid to research on ultrasound-assisted enzymatic hydrolysis devices to promote the expansion of production and improve production efficiency. [ABSTRACT FROM AUTHOR]

IntroductionThe present research describes the utilization of natural deep eutectic solvent in combination with ultrasound for the extraction of milk thistle polyphenols. The extracts obtained under different conditions were evaluated for their in vitro antioxidant activities and hepatoprotective activities in Albino mice (in vivo).MethodsThe extraction parameters involving liquid-to-solid ratio (S/L), ethanol-to-natural deep eutectic solvent ratio (EtOH/DES), extraction time (t), and ultrasound treatment time were investigated and optimized to enhance the recovery of bioactives, their phenolic content, Trolox equivalent antioxidant capacity (TEAC), and radical scavenging capacity (RSC).Results and discussionsThe extraction of milk thistle polyphenols using glucose/citric acid (1:1)-based natural deep eutectic liquid coupled with ultrasound for 1.0 min under an S/L of 6.2, EtOH/DES 9, and extraction time of 120.8 min offered 35.89 ± 2.29 g/100 g of crude extracts, which were three-fold higher than that by conventional solvent extraction (CSE). Each gram of milk thistle extracts thus obtained comprised 377.93 ± 6.17 mg GAE of TPC and exhibited 298.70 ± 3.06 μmol TEAC and 93.16 ± 0.58 percent inhibition of DPPH free radicals. In addition, the administration of milk thistle extracts obtained as given above at 25 mg/Kg body weight in Albino mice significantly (p ≤ 0.05) improved the liver function parameters at the end of treatment (7 days).ConclusionOverall, it was observed that NaDES in combination with medium-level ultrasound energy (700 watt) might work as a sustainable choice to enhance the recovery of bioactive phenolics from milk thistle powder without compromising their antioxidant and hepatoprotective potential.

The present study aimed to analyze and establish an effective combination of ultrasound and immersion pretreatment processes for drying Taikor (Garcinia pendunculata Roxb.) fruits. Taikor slices were first immersed in 10 % sucrose, fructose, and glucose solution. Then, the immersed slices were treated in an ultrasonic bath at 30 °C for 10, 20, and 30 min. Drying operations were carried out at 50, 60, and 70 °C, with a fixed relative humidity of 30 %. The Page, Newton, Henderson and Pabis, and Weibull distribution models were fitted to the obtained drying data to determine the best kinetic model that effectively describes the drying properties of Taikor. After drying operations, changes in quality parameters, e.g., β-carotene, vitamin C, B vitamins, color, antioxidant activities, and microbial loads, were measured to obtain the best drying temperature and the most effective pretreatment combination with minimum loss of nutrients of the sample. Among different kinetic models, both Page and Weibull distribution models showed the best R2 values of 0.9867 and 0.9366, respectively. The chemical properties were preserved to the greatest extent possible by drying at 50 °C with glucose pretreatment. The color parameters were better preserved by fructose pretreatment. Sonication time also had profound effect on the quality parameters of dried Taikor slices. However, higher temperature drying required a shorter time for drying and exhibited better performance in microbial load reduction. This study's findings will help to establish an effective drying condition for Garcinia pedunculata fruits.

Due to the length of the time required for protein hydrolysis, ultrasound, as a cheap technology, can be used as a pre-treatment in protein hydrolysis to shorten the time. The aim of this study was to investigate the effect of hydrolysis time and ultrasonic pretreatment on enzymatic hydrolysis of edible mushroom proteins by pancreatin enzyme to produce short chain peptides with high antioxidant capacity. In this research first edible mushrooms were turned into powder then hydrolysed during 30-210 min with enzyme to substrate ratio of 1% and at temperature of 40 °C without pretreatment, and with pretreatment by 80 and 40% ultrasound power. Increasing the power of ultrasonic treatment increased the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity and total antioxidant capacity at shorter hydrolysis time. The highest DPPH free radical scavenging activity in untreated and treated samples with 40 and 80% ultrasound power were 39.96, 42.91 and 47.76, respectively. The highest total antioxidant capacity for untreated and treated samples with 40 and 80% ultrasound power was 1.64, 1.73 and 1.98 (absorption at 695 nm), respectively. The results showed that the highest reducing power of Fe3+ in untreated and treated samples with 40 and 80% ultrasound power were 2.61, 2.84 and 2.90 (absorption at 700 nm), respectively. These results showed that pre-treated samples with 80% ultrasound compared to samples without pretreatment and pre-treated with 40% ultrasound had the highest antioxidant properties. Therefore, the use of high power ultrasonic pretreatment shortens the hydrolysis time to achieve peptides with higher antioxidant capacity.

In the quest for sustainable waste management solutions, this study explores the integration of ultrasonic pretreatment as a preparatory step for the anaerobic digestion of landfill leachate. Employing response surface methodology (RSM) coupled with central composite design (CCD), we systematically optimize the process parameters, including pH, inoculum volume, and ultrasonic pretreatment duration, to maximize the yield of bio-methane potential (ml CH4/g VS). The results demonstrate the effective application of RSM-CCD for predicting and modelling methane generation, with a highly significant model (R2 = 0.899). The optimized conditions reveal a remarkable biomethane potential of 177 ml CH4/g VS. Additionally, this study contributes to the understanding of the positive effect of ultrasound pretreatment on the anaerobic digestion of landfill leachate, and the quality of the digestate obtained after anaerobic digestion was studied and different valorisations were proposed.

Copyright of Journal of Research & Innovation in Food Science & Technology is the property of Research Institute of Food Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The effects of different periods (0, 5, 15, 25 and 35 min) of ultrasound pretreatment at a power of 200 W on the structural characteristics of sea cucumber gonad protein hydrolysates prepared with neutral protease were investigated by ultraviolet-visible (UV-Vis) spectroscopy, Fourier transform infrared (FTIR) spectroscopy and fluorescence spectroscopy as well as determination of surface hydrophobicity and particle size distribution and microstructure observation. The results showed that the UV absorbance, β-sheet relative content, fluorescence intensity (FI), surface hydrophobicity and particle size of sea cucumber gonad protein hydrolysates initially increased and then decreased with ultrasound pretreatment time, while the opposite trend was observed for α-helix relative content. Ultrasound pretreatment for 15 min increased the UV absorbance, β-sheet relative content, FI and surface hydrophobicity of hydrolysates by 7.30%, 50.72%, 4.50% and 13.42%, respectively, and decreased the α-helix relative content by 9.98% (P < 0.05). Moreover, this treatment resulted in the smallest particle size and distribution range of hydrolysates as observed under scanning electron microscopy (SEM). Therefore, appropriate ultrasound pretreatment could promote the unfolding of sea cucumber gonad protein structure and reduce protein aggregation, and the effect of ultrasound pretreatment for 15 min was most pronounced.

Spine gourd (SG) is a nutritionally and medicinally rich seasonal vegetable grown in tropical areas. Therefore, the present study accessed the effect of drying temperature (40, 50, 60, and 70 °C) on chlorophyll, ascorbic acid, proximate, antioxidant, and minerals contents of ultrasound (US) pretreated SG. The increase in drying temperature (40−70 °C) after pretreatment increased the total flavonoids, fiber, protein and ash content compared to freeze-dried (control) sample. In contrast, elevated drying temperature significantly degraded the chlorophyll, ascorbic acid, carbohydrates, fat, total phenolic, and DPPH activity. In addition, the effect of drying temperature on the mineral contents was comparable and a significant variation was observed between control and US pretreated samples. The FTIR spectra revealed that functional group integrity was preserved even at higher drying temperatures. Conclusively, the US pretreated sample dried at 40 °C showed a better nutritional content (comparable to freeze-dried samples) than those dried at higher temperatures. However, samples dried at 70 °C were rich in protein and antioxidants.

The effect of different ultrasound pretreatment powers (0–500 W) before hot air drying on the moisture migration and quality of Cantharellus cibarius (C. cibarius) was investigated in this study. The results showed that the ultrasound pretreatment accelerated the drying rate. When the ultrasound power was 400 W, the drying time of C. cibarius was reduced by 18.90% compared with the control group. The low-field nuclear magnetic resonance (LF-NMR) and magnetic resonance imaging (MRI) results showed that the ultrasound pretreatment increased the water mobility in C. cibarius. The scanning electron microscopy (SEM) results revealed that the ultrasound pretreatment promoted the expansion of intercellular pores. In addition, the rehydration capacity and quality characteristics of the ultrasound-pretreated dried C. cibarius were better than those of the control group. Overall, this study concluded that ultrasound pretreatment is a promising pretreatment method for the hot air drying of C. cibarius products to reduce the total drying time significantly and improve the retention rate of the total phenolics and flavonoids of dried C. cibarius. [ABSTRACT FROM AUTHOR]

Consumption of fresh and healthy vegetables in our diets aids protection from chronic diseases in humans. This study determined the effects of ultrasound as a pre-treatment technique on vitamin C, betacarotene contents, and the weight loss of frozen African spinach (Amaranthus hybridus), and thereafter compared with the control. All the samples except the control were subjected to the ultrasound effects prior to freezing at frequency, time, and power ranges of 40-120 kHz, 10-30 min, and 50-150 W respectively. Result obtained indicated that the maximum vitamin C (99.5%) was obtained from the sample stored for 5 days under the treatment condition of 40 kHz, 50 W, and 20 min. However, the same sample retained more vitamin C within 5-20 days' storage, while the pre-treated sample at 80 kHz, 100 W, and 10 min retained the maximum (80.9%) at 25 days of storage. The sample under the treatment condition of 80 kHz, 100 W, and 20 min lost more vitamin C (67.6, 66.6, and 59.2%) between 15-25 storage days. While for the beta-carotene, the sample with the treatment condition of 40 kHz, 50 W, and 20 min before freezing had the highest retention (99.8%) when stored for 5 days, and the same sample retained more at 10, and 15 days than others (97.6, and 92.4%). All pre-treated samples retained more beta-carotene at 25 days of storage when compared to the control with the least retention between 15-25 days. Furthermore, the least obtained content from the pre-treated samples was 64.9%, that is, a sample treated at 80 kHz, 100 W, and 20 min. The result revealed that Amaranthus hybridus was best preserved in pre-treated Amaranthus hybridus leaves. The optimum quality response occurs at 80kHz, and 50 W for 30 min. This gives a vitamin C content of 31.1 mg/100g and a Betacarotene content of 10.5 mg/g at 0.694 desirability. [ABSTRACT FROM AUTHOR]

The heat and moisture sensitivity of spices and a consistent supply of electrical energy is the challenging factors in developing a relevant drying system for rural applications. A novel solar‐assisted fluidized bed dryer was developed for drying locally harvested unique spices like bird's eye chili (Capsicum frutescens L.). The chili was pretreated by the osmosonication method prior to drying to expedite the elimination of intercellular and intracellular moisture. In order to make the dryer more reliable, the recirculation strategy and dehumidified air supplied by liquid desiccant were acclimatized to constrict the heat loss through outflowing moist drying air. The experiments were conducted up to the permissible water activity (0.4–0.6) under variable drying conditions (50–70°C). By raising the ambient inlet temperature (maximum 25.9°C), the developed solar FBD was able to supply the drying air up to 50°C (in continuous mode) and a maximum of up to 65°C without aiding any heat energy sources except solar. It was found that osmosonication opened up the possibility of reducing the required drying temperature (↓10°C) and energy consumption (up to ↓31.7%). The dried red chili was fortified by pretreatment, as it could retain more capsaicin (>6%) and reddishness (>5%) compared to untreated samples. The Fourier transform infrared (FTIR) analysis showed the structural integrity of pretreated samples. The relative humidity of the drying air could be reduced by as much as 5% using the composite lithium chloride and calcium chloride (35% + 5%) desiccant dehumidifier. Dehumidification of air was found advantageous, with an inclination to shorten the drying duration (about ↓0.5 h) and energy (↓12.43%). Practical Applications: There are various commercially valuable unique agro‐products that are exclusively being produced in rural areas. The inaccessibility of relevant drying technology and inconsistency of grid electricity are the main constraints in the value addition of those products. Open sun drying is most popular in rural areas; however, it is not reliable, and the product quality can't maintain. The developed solar‐assisted fluidized bed dryer utilizing dehumidifying air and integrated with osmosonication pretreatment could be a relevant technology for drying heat and moisture‐sensitive products like spices. Cost‐effective drying using locally accessible solar energy compared to open sun drying and superior dried product quality can be achieved by using the current drying system. [ABSTRACT FROM AUTHOR]

The request for alternative sources of energy has led to evaluating untapped routes for energy production, such as using abundant and low-cost waste materials, e.g., lignocellulosic wastes, as the substrate for biological processes aimed at biofuel production. This study focused on peanut shells (PS) valorisation via anaerobic digestion (AD). Two emerging pretreatments, i.e., organosolv and ultrasounds, were investigated to unlock the full AD potential of PS. The impact of a substrate-to-solvent ratio in organosolv pretreatment was investigated (i.e., 1:5 vs. 1:10 vs. 1:20). Different exposure times were tested for ultrasound pretreatment, corresponding to applied energy densities of 30,000, 12,000, and 6000 kJ/kg VS, respectively. Organosolv pretreatment achieved the maximal polyphenol solubilisation, i.e., 4.90 mg/g TS, when increasing the substrate-to-solvent ratio, whereas methane production did not benefit from the pretreatment, being comparable with that of raw PS at most (i.e., 55.0 mL CH4/g VS). On the other hand, ultrasounds mainly affected sugar solubilisation (up to 37.90 mg/g TS), enhancing methane production up to an extra 64%, achieved with the highest energy density. The organosolv route would benefit from further downstream steps to recover the biomolecules released in the liquid fraction, whereas ultrasounds pretreatment provided a slurry suitable for direct AD. [ABSTRACT FROM AUTHOR]

In this study, we investigated the effects of different high-intensity ultrasound (HIU) pretreatment times (0–60 min) on the structure of β-conglycinin (7S) and the structural and functional properties of 7S gels induced by transglutaminase (TGase). Analysis of 7S conformation revealed that 30 min HIU pretreatment significantly induced the unfolding of the 7S structure, with the smallest particle size (97.59 nm), the highest surface hydrophobicity (51.42), and the lowering and raising of the content of the α-helix and β-sheet, respectively. Gel solubility showed that HIU facilitated the formation of ε-(γ-glutamyl)lysine isopeptide bonds, which maintain the stability and integrity of the gel network. The SEM revealed that the three-dimensional network structure of the gel at 30 min exhibited filamentous and homogeneous properties. Among them, the gel strength and water-holding capacity were approximately 1.54 and 1.23 times higher than those of the untreated 7S gels, respectively. The 7S gel obtained the highest thermal denaturation temperature (89.39 °C), G′, and G″, and the lowest tan δ. Correlation analysis demonstrated that the gel functional properties were negatively correlated with particle size and the α-helix, while positively with Ho and β-sheet. By contrast, gels without sonication or with excessive pretreatment showed a large pore size and inhomogeneous gel network, and poor properties. These results will provide a theoretical basis for the optimization of HIU pretreatment conditions during TGase-induced 7S gel formation, to improve gelling properties. [ABSTRACT FROM AUTHOR]

Ultrasonic pretreatment could improve the accessibility of enzymes to cellulosic fibers, hence expanding the access of enzymes to effectively remove ink from paper. In this study, enzymes were isolated from paddy rice husks and utilized for biodeinking process. The characterizations of deinking from the pulp filtrate and paper samples were carried out to understand the effect of bacterial cellulases and ultrasonic pretreatment with time variables. The results showed that cellulases from bacterial isolates had the ability to hydrolyze cellulose at 1.78 U/mL enzyme activity. Ink content measurement showed 2310 ppm of ink was removed in the paper samples with 15 min of ultrasound pretreatment and 2% cellulases. Meanwhile, morphological analysis showed significant differences in the surface areas between treated and untreated paper samples. The highest crystallinity index achieved was 70.9%, and thermal resistance was 21.0%. Other paper qualities such as stain decrease, and brightness level improvement were observed. The combination of 2% cellulases with optimum ultrasonication duration resulted in exceptional wastepaper recycling process. [ABSTRACT FROM AUTHOR]

Protein hydrolysates and peptides can show biological activities, and pulsed ultrasound improves bioactivities. Among matrices from which protein hydrolysates can be obtain, chickpea is an excellent source. The objective of this research was to evaluate the effect of pulsed ultrasound on globulin concentrate to obtain chickpea hydrolysate (HGb) and peptide fractions and their bioactivity. Antioxidant activity by ABTS (2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt), FRAP (Ferric Reducing Antioxidant Power) and human erythrocyte assays was determined. The electrophoretic profile, amino acid profile, and antimicrobial activity of hydrolysates were also determined. Two hydrolysates had the highest antioxidant activity: HGb (91.44% ABTS inhibition, 73.04% hemolysis inhibition and 5185.57 µmol TE/g dried sample in FRAP assay) and HGb-20 (48.25% ABTS inhibition, 100% hemolysis inhibition and 2188.53 µmol TE/g dried sample in FRAP assay). Peptide fractions inhibited 100% of the hemolysis on human erythrocytes. The hydrolysates from chickpea proteins obtained with savinase have antioxidant activity through the SET and HAT mechanisms. The application of the obtained compounds for the development of functional foods or for food preservation should be considered. [ABSTRACT FROM AUTHOR]

BACKGROUND: The production of Russian sturgeon is expanding rapidly in China but it is necessary to adopt measures to extend the shelf life of sturgeon meat. Previous studies found that sous vide cooking (SVC) at 60 °C increased the protein and lipid oxidation. The addition of antioxidant substances reduced the acceptance of the product. The effect of combination SVC and ultrasound pretreatment was therefore investigated. RESULTS: Results showed that SVC at 50 °C combined with ultrasound effectively restrained the growth of total viable counts (TVC) in samples. Meanwhile, the main dominant genera changed from Pseudomonas to Carnobacterium and the number of microbial species decreased. The odor profile of Russian sturgeon meat was more stable and the lipoxygenase (LOX) activity decreased more rapidly after treating with SVC and ultrasound. Importantly, more stable protein aggregates were formed in samples treated by SVC 50 °C together with ultrasound pretreatment, so the protein and lipid oxidation were slowed during storage. Higher springiness values were obtained and the color of sturgeon meat was lighter under these conditions. CONCLUSION: The combination of SVC 50 °C and ultrasound pretreatment effectively inhibited the microbial growth of Russian sturgeon meat at lower oxidation levels. These findings theoretically support the preservation and development of sturgeon meat, and the application of SVC technology. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Ultrasound has been widely used as a green and efficient non-thermal processing technique to assist with enzymatic hydrolysis. Compared with traditional enzymatic hydrolysis, ultrasonic-pretreatment-assisted enzymatic hydrolysis can significantly improve the efficiency of enzymatic hydrolysis and enhance the biological activity of substrates. At present, this technology is mainly used for the extraction of bioactive substances and the degradation of biological macromolecules. This review is focused on the mechanism of enzymatic hydrolysis assisted by ultrasonic pretreatment, including the effects of ultrasonic pretreatment on the enzyme structure, substrate structure, enzymatic hydrolysis kinetics, and thermodynamics and the effects of the ultrasonic conditions on the enzymatic hydrolysis results. The development status of ultrasonic devices and the application of ultrasonic-assisted enzymatic hydrolysis in the food industry are briefly described in this study. In the future, more attention should be paid to research on ultrasound-assisted enzymatic hydrolysis devices to promote the expansion of production and improve production efficiency.

The anaerobic digestion, AD, process presents a solution for sustainable waste management, greenhouse gas mitigation and energy production for growing population needs and requirements. Adopting a biorefinery approach that utilises different feedstock may enhance energy production and support optimisation of the anaerobic digestion process. Algae is a promising feedstock that could be used for energy production via the anaerobic digestion process. Microalgal biomass is rich in carbohydrates and lipids; however, many species of algae exhibit tough cell walls that could also be difficult to digest and may influence or inhibit the efficiency of the AD process. This study concentrated on the comparison of AD remediation of two marine algal biomass species, Tetraselmis suecica and Nannochloropsis oceanica. The two species were pre-treated with an ultrasound technique and compared for their methane production using biochemical methane potential tests. For Tetraselmis, a specific methane production of 0.165 LCH4/KgVS was observed; however, for Nannochloropsis, a value of 0.101 LCH4/KgVS was observed for the samples treated with ultrasound. The BMP results from this study show that among the two micro-algae species tested, Tetraselmis suecica is found to be a better substrate for methane production potential. Contrary to increasing the specific methane production, ultrasound cavitation caused a slight decrease in the specific methane production values for both Nannochloropsis oceanica and Tetraselmis suecica biomass residues. The pre-treatment of the biomass using ultrasound techniques provided comparable results and can be recommended for effective bioenergy production. However, further research is required for the optimisation of the pre-treatment of microalgae and for the integration of microalgal biorefineries for circular economy. [ABSTRACT FROM AUTHOR]

The aim of this work was to investigate the effects of ultrasonic treatment during soaking of potatoes on the physicochemical properties of starches obtained after 16 weeks of germination. The ultrasonic treatment showed a direct correlation between sprout length and ultrasonic time. The protein content decreased from 0.63 to 0.38 % and the fat content decreased significantly from 0.31 to 0.01 % after germination. The amylose content changed depending on the ultrasonic treatment, and increased from 36.27 to 40.92 % after 16 weeks of germination, which was related to the amylopectin debranching and the duration of the ultrasonic treatment. X-ray diffraction showed that the nanocrystals with hexagonal structure were not affected by the germination and the duration of ultrasonic treatment. Scanning electron microscopy showed that the surface of the starch granules was not affected by the enzymatic treatment. The sprouted potato starch resulted in films with better tensile strength and lower water vapor permeability (WVP) compared to the native potato starch films. In addition, the films produced with ultrasound stimulated potato starch exhibited better properties (high strength and low permeability), which is desirable when it comes to controlling moisture exchange between a food product and the surrounding atmosphere. • Ultrasound stimulate the germination of potatoes. • Germination has no influence on the nanocrystals structure with hexagonalarrangement that occur in potato starch. • Ultrasonic stimulation prior to potato germination increased the viscosity of the starch pastes. • Germinated potato starch reduces the water vapor permeability in thin films. [ABSTRACT FROM AUTHOR]

In this study, double enzyme hydrolysis significantly enhanced the DPP-IV inhibition rate compared to single enzyme. The α + K enzymes exhibited the highest inhibition rate. Ultrasonic pretreatment for 30 min improved the hydrolysis efficiency and DPP-IV inhibition rate, potentially due to the structural changes in hydrolysates, such as the increased surface hydrophobicity, and reduced particle size, α-helix and β-turn. Six peptides were screened and verified in vitro. QPY, WPEYL, and YPPQVM displayed competitive inhibition, while LPAAP and IPAPSFPRL displayed mixed competitive/non-competitive inhibition. The interactions between these six peptides and DPP-IV primarily occurred through hydrogen bonds, electrostatic and hydrophobic interactions. Network pharmacological analysis indicated that LPAAP might inhibit DPP-IV activity trough interactions with diabetes-related targets such as CASP3, HSP90AA1, MMP9, and MMP9. These results uncover the potential mechanism of regulating blood glucose by camel milk hydrolysates, establishing camel milk peptide as a source of DPP-IV inhibitory peptide. • Combination of double enzymatic and ultrasonication improved DPP-IV inhibition. • Six peptides were screened based on the predicted results and in vitro test. • LPAAP exhibited highest active against DPP-IV, with IC 50 values 199.66 ± 6.77 μM. • Molecular docking and network pharmacology predicted DPP-IV inhibition mechanism. [ABSTRACT FROM AUTHOR]

Objectives:This study examined the effect of ultrasonic pretreatment on primary sewage sludge (raw sludge) solubilization and its subsequent microbial electrolysis cells (MECs) operation performance. Methods:To compare the effect of ultrasound on raw sludge solubilization, ultrasonic pretreatment was conducted at 1~4 W/mL energy density for 5~30 min. In MECs operation, raw sludge was used as a control group, and ultrasound pretreated sludge was used as an experimental group. For comparing MECs performance, biogas production, and organic matter removal were analyzed. Results and Discussion:The optimal experimental condition for ultrasonic pretreatment were 30 min of sonication time at 3 W/mL. In methane production, MEC with ultrasound pretreatment (MEC 3W) produced 243 mL/L more methane than that of unpretreated MEC (MEC) by 4,970 mL/L at 1, 3 cycles. In the modified Gompertz model analysis, the lag phase of MEC 3W was 0.46 days, which was 0.12 days longer than MEC. The maximum methane production rate of MEC 3W by 938.5 mL/L/day was also higher than MEC. MEC 3W showed a 1.8% higher TS removal rate, 2.4% VS removal rate than MEC. COD removal rate also improved by 2.0% when ultrasound pretreatment was applied. The methane yield of MEC with ultrasound pretreatment (377.4 mL/g VSin.) was 0.4% higher than that of MEC without pretreatment. Conclusion:Ultrasonic pretreatment of sewage sludge improved the methane production and organic removal in microbial electrolysis cells. It is necessary to find the optimal operating conditions to obtain the maximize the performance.

Nanofibrils, an effective method to modulate the functional properties of proteins, can be promoted by ultrasound pretreatment. This study investigated the effect of ultrasound pretreatment on the structure, functional property, antioxidant activity and digestibility of soy protein isolate (SPI) nanofibrils. The results showed that high amplitude ultrasound had a significant effect on structure of SPI nanofibrils. SPI nanofibrils pretreated by 80% amplitude ultrasound showed a blueshift of the amide II band in Fourier transform infrared spectroscopy (FTIR), resulted in more tryptophan residues being buried and increased the crystallinity. Low amplitude ultrasound (20%) pretreatment significantly improved the solubility, emulsifying activity index (EAI) and water absorption capacity (WAC) of SPI nanofibrils, but 80% amplitude ultrasound pretreatment of SPI nanofibrils reduced emulsifying stability index (ESI). High amplitude ultrasound (60% and 80%) pretreatment of SPI nanofibrils improved the foaming capacity and foaming stability and decreased denaturation temperature. DPPH radical scavenging activity of SPI nanofibrils were significantly improved by ultrasound pretreatment. 20% amplitude ultrasound pretreatment improved DPPH, ABTS radical scavenging activity and ferric reducing antioxidant power of SPI nanofibrils. The digestion rate of 80% amplitude ultrasound-pretreated nanofibrils were consistently higher, and SPI nanofibrils pretreated by ultrasound were more fragmented and shorter after simulating gastrointestinal digestion. This study would expand the application of food-grade protein nanofibrils in the food industry.

The effect of different ultrasound pretreatment powers (0–500 W) before hot air drying on the moisture migration and quality of Cantharellus cibarius (C. cibarius) was investigated in this study. The results showed that the ultrasound pretreatment accelerated the drying rate. When the ultrasound power was 400 W, the drying time of C. cibarius was reduced by 18.90% compared with the control group. The low-field nuclear magnetic resonance (LF-NMR) and magnetic resonance imaging (MRI) results showed that the ultrasound pretreatment increased the water mobility in C. cibarius. The scanning electron microscopy (SEM) results revealed that the ultrasound pretreatment promoted the expansion of intercellular pores. In addition, the rehydration capacity and quality characteristics of the ultrasound-pretreated dried C. cibarius were better than those of the control group. Overall, this study concluded that ultrasound pretreatment is a promising pretreatment method for the hot air drying of C. cibarius products to reduce the total drying time significantly and improve the retention rate of the total phenolics and flavonoids of dried C. cibarius.

The request for alternative sources of energy has led to evaluating untapped routes for energy production, such as using abundant and low-cost waste materials, e.g., lignocellulosic wastes, as the substrate for biological processes aimed at biofuel production. This study focused on peanut shells (PS) valorisation via anaerobic digestion (AD). Two emerging pretreatments, i.e., organosolv and ultrasounds, were investigated to unlock the full AD potential of PS. The impact of a substrate-to-solvent ratio in organosolv pretreatment was investigated (i.e., 1:5 vs. 1:10 vs. 1:20). Different exposure times were tested for ultrasound pretreatment, corresponding to applied energy densities of 30,000, 12,000, and 6000 kJ/kg VS, respectively. Organosolv pretreatment achieved the maximal polyphenol solubilisation, i.e., 4.90 mg/g TS, when increasing the substrate-to-solvent ratio, whereas methane production did not benefit from the pretreatment, being comparable with that of raw PS at most (i.e., 55.0 mL CH4/g VS). On the other hand, ultrasounds mainly affected sugar solubilisation (up to 37.90 mg/g TS), enhancing methane production up to an extra 64%, achieved with the highest energy density. The organosolv route would benefit from further downstream steps to recover the biomolecules released in the liquid fraction, whereas ultrasounds pretreatment provided a slurry suitable for direct AD.

In this study, we investigated the effects of different high-intensity ultrasound (HIU) pretreatment times (0–60 min) on the structure of β-conglycinin (7S) and the structural and functional properties of 7S gels induced by transglutaminase (TGase). Analysis of 7S conformation revealed that 30 min HIU pretreatment significantly induced the unfolding of the 7S structure, with the smallest particle size (97.59 nm), the highest surface hydrophobicity (51.42), and the lowering and raising of the content of the α-helix and β-sheet, respectively. Gel solubility showed that HIU facilitated the formation of ε-(γ-glutamyl)lysine isopeptide bonds, which maintain the stability and integrity of the gel network. The SEM revealed that the three-dimensional network structure of the gel at 30 min exhibited filamentous and homogeneous properties. Among them, the gel strength and water-holding capacity were approximately 1.54 and 1.23 times higher than those of the untreated 7S gels, respectively. The 7S gel obtained the highest thermal denaturation temperature (89.39 °C), G′, and G″, and the lowest tan δ. Correlation analysis demonstrated that the gel functional properties were negatively correlated with particle size and the α-helix, while positively with Ho and β-sheet. By contrast, gels without sonication or with excessive pretreatment showed a large pore size and inhomogeneous gel network, and poor properties. These results will provide a theoretical basis for the optimization of HIU pretreatment conditions during TGase-induced 7S gel formation, to improve gelling properties.

Abstract Main objectives of this work were to investigate the influences of ultrasound pretreatment (UP) and microwave pretreatment (MP) on extraction kinetics, chemical composition, and antioxidant activity of Kumquat peel essential oil (EO) obtained by hydrodistillation extraction (HDE). The effects of ultrasound power and processing time, and microwave power and processing time were evaluated. As compared with HDE individually, UP and MP decreased the extraction time, increased the yield and DPPH radical‐scavenging activity but did not noticeably affect chemical composition of the EO. For UP and MP, the highest EO yield was obtained when the ultrasonic power and processing time, and microwave power and processing time were 210 W and 30 min, 300 W and 6 min, respectively. In comparison with MP, UP gave a higher yield and DPPH radical‐scavenging activity of the EO. Overall, UP and MP are promising techniques for HDE of EO from kumquat peel.

The purpose of this study was to evaluate the effects of ultrasound-assisted saucing on the quality of chicken gizzards. The results showed that with the prolonging of the saucing time, the yield, water holding capacity (WHC), lightness (L*), redness (a*) and springiness of chicken gizzards significantly decreased, while the shear force, hardness and chewiness significantly increased (P

Natural deep eutectic solvents (NADES) have emerged as green extracting solvents in recent years. In this study, a variety of choline chloride (ChCl)-based natural deep eutectic solvents (NADES) were used as co-solvents for the hydrodistillation of nutmeg with the aim to obtain M. fragrans essential oil (EO) in higher yield and with a lower content of toxic phenylpropenoids (e.g. myristicin and safrole). The influence of ChCl-based NADES as additives in the hydrodistillation process was studied. The results showed that NADES additives improved the yield of the extracted essential oil and influenced its composition leading to a decrease in toxic phenylpropenoids. Best results were achieved by using ChCl-CA NADES ultrasound-assisted pretreatment coupled with traditional 2 ​h Clevenger hydrodistillation that increased the yield of the EO from 0.98% (traditional) to 1.41% and a decrease of the phenylpropenoids amount in the essential oil.

The effects of different ultrasonic pretreatments (120–600 W, 20 min; 360 W, 10–30 min) on the gel properties of shrimp surimi were investigated. Gel properties and protein functional properties were analysed to clarify the mechanism of action of ultrasound. The gel strength, water holding capacity and surface hydrophobicity of shrimp surimi gel increased initially and then decreased with the increase in ultrasound power or time, but the change in total sulfhydryl content showed the opposite trend, which indicated that proper ultrasound pretreatment could improve the gel properties of shrimp surimi, expand the protein to a greater extent and expose more SH groups and hydrophobic groups. According to scanning electron microscopy observation, ultrasound made shrimp surimi gel form a denser gel network. Fourier transform infrared analysis indicated that the α-helix content in shrimp surimi gel decreased initially and then increased with the increase of in ultrasound power or time, whereas the change in β-sheet content showed the opposite trend. And the protein was the most stable in 360 W/20 min pretreatment. SDS-PAGE patterns showed that proper ultrasound inhibited the degradation of actin and troponin C. In addition, dynamic rheology illustrated that the G′ values of the ultrasonic pretreatment group were higher than that of the control group, indicating that ultrasound could improve the elasticity and stability of shrimp surimi gel. The results suggested that the shrimp surimi gel pretreated by 360 W/20 min ultrasound showed the best gel properties. Furthermore, the correlation between the indexes affecting the properties of the gel was analyzed. This study provides a new technical means to improve the gel properties of shrimp surimi.

In order to better utilize the proteins in squid viscera (Dosidicus gigas), the effects of different pretreatments on the degree of hydrolysis (DH) and volatile compounds of hydrolysates were studied. The DH was used as an indicator to select alkaline protease as the optimal protease from 8 types of proteases. The hydrolysis conditions of alkaline protease and the flavor of the hydrolysates were investigated through single-factor, response surface methodology, and pretreatment-assisted hydrolysis experiments. The results showed that alkaline protease had the highest DH (42.08 ± 0.58%), with enzyme dosage of 1.5%, hydrolysis temperature of 45 °C, hydrolysis time of 5 h, and liquid-solid ratio of 4:1. The DH of the ultrasound group was significantly higher than other groups, with the highest DH (45.67 ± 0.34%) after ultrasound for 40 min (U40). The proportion of molecular weight < 1 kDa and the content of free amino acids (1613.64 mg/100 g) were the highest at U40. The electronic nose results indicated that the composition of organic sulfur and aliphatic compounds in U40 showed significant differences compared to other products. The U40 sample had the highest type and content of volatile compounds (especially benzaldehyde), which was more conducive to the volatilization of flavor substances. In conclusion, U40 pretreatment can effectively improve the DH and flavor of hydrolysates. • Hydrolysis conditions of squid viscera were optimized. • Effects of heat and ultrasound pretreatments on hydrolysis were investigated. • Ultrasound pretreatment enhanced the hydrolysis efficiency. • Ultrasound pretreatment improved the flavor of squid viscera hydrolysates. [ABSTRACT FROM AUTHOR]

• US-OH method was proposed as the optimal plant bioactive extraction technique. • EY, TPC, and antioxidant activity of US-OH extract were higher than other methods. • US-OH and MW-OH methods showed an improvement in the extract quality compared to the HAE method. The present study was carried out to investigate and optimize the recovery of Burdock (Arctium lappa L.) root extract (BRE) using Ohmic-assisted (OH) extraction method with ultrasonic (US-OH) and microwave (MW-OH) pretreatments. Initially the optimized OH condition was obtained with the aim of maximizing the extraction efficiency and total phenol content. Then, the effect of pretreatment time (20, 40 and 60 min), ultrasonic amplitude (50 and 100 %) and temperatures (30, 40 and 50 °C) in US-OH, and powers (100, 300 and 450 W) in MW-OH were investigated. Finally, optimized OH, US-OH, and MW-OH extraction methods were compared with the heat assisted extraction method (HAE). The results showed that all the main and interaction effects were significant in OH, US-OH, and MW-OH extraction methods (p < 0.05) and only the interaction effects on total phenolic content (TPC) were not significant in the OH method (p > 0.05). The voltage gradient equal to 12.8 V/cm, extraction time equal to 20.72 min and extraction temperature equal to 50 °C were obtained as optimal conditions in the OH extraction of BRE. Ultrasonic amplitude, extraction temperature and ultrasonic time 100 %, 50 °C and 40 min respectively were obtained as the optimum US-OH extraction method. According to the results of chemical compounds, microbial and morphological assays, extraction using pretreatment methods of ultrasound, microwave in ohmic heating, respectively, showed an improvement in the quality of the extraction compared to the conventional (HAE) method. [Display omitted] [ABSTRACT FROM AUTHOR]

Protein hydrolysates and peptides can show biological activities, and pulsed ultrasound improves bioactivities. Among matrices from which protein hydrolysates can be obtain, chickpea is an excellent source. The objective of this research was to evaluate the effect of pulsed ultrasound on globulin concentrate to obtain chickpea hydrolysate (HGb) and peptide fractions and their bioactivity. Antioxidant activity by ABTS (2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt), FRAP (Ferric Reducing Antioxidant Power) and human erythrocyte assays was determined. The electrophoretic profile, amino acid profile, and antimicrobial activity of hydrolysates were also determined. Two hydrolysates had the highest antioxidant activity: HGb (91.44% ABTS inhibition, 73.04% hemolysis inhibition and 5185.57 µmol TE/g dried sample in FRAP assay) and HGb-20 (48.25% ABTS inhibition, 100% hemolysis inhibition and 2188.53 µmol TE/g dried sample in FRAP assay). Peptide fractions inhibited 100% of the hemolysis on human erythrocytes. The hydrolysates from chickpea proteins obtained with savinase have antioxidant activity through the SET and HAT mechanisms. The application of the obtained compounds for the development of functional foods or for food preservation should be considered.

Enzymolysis kinetics, thermodynamics and molecular conformation of brewer’s spent grain protein (BSGP) pretreated with ultrasound were examined. Results showed that ultrasound pretreatment significantly reduced Michaelis constant (Km) and the thermodynamic parameters, including activation energy (Ea), enthalpy (ΔH), entropy (ΔS) and Gibbs free energy (ΔG) of BSGP during enzymolysis. Moreover, the initial reaction rate (Vi), association constant (Ka) and reaction rate constants (k) of BSGP pretreated with ultrasound were higher than those of native BSGP. The spectral analysis with Ultraviolet-visible (UV–vis) and Fourier transform infrared (FTIR) manifested that ultrasound pretreatment exposed hydrophobic groups and induced molecular unfolding of BSGP. Particle size analysis and scanning electron microscopy (SEM) showed that ultrasound pretreatment decreased particle size while increasing flexibility of BSGP. All these structural changes resulted in the improvement on enzymolysis efficiency of BSGP pretreated with ultrasound. Therefore, ultrasound pretreatment could be an efficient method to enhance the enzymolysis sensibility of BSGP. [ABSTRACT FROM AUTHOR]

Waste or by-product use is in focus for reducing the environmental threat and acquiring wealth out of waste. The current study aim was to investigate the effects of ultrasound pretreatment on the extraction of bioactive compounds and composition of essential oils extracted from citrus waste. The response surface methodology (RSM) was used to optimize higher yield extraction parameters. Pretreatment of ultrasound-assisted extraction recovered 33% enhanced yield with reduced time and was economical as compared to conventional hydro-distilled process. The functional quality of essential oil was determined using FTIR and GC-MS. Antioxidants from citrus peel and pulp/pomace were extracted and analyzed by spectroscopic techniques. The quantification of bioactive compounds from citrus waste was performed using high performance liquid chromatography (HPLC). Mass transfer rate of antioxidants from peel and pomace were 30% increased as a result of ultrasound-assisted treatment. The significantly (p ≤ 0.05) higher TPC (735.54 mg/100 g) and antioxidant activity (44.26%) was recorded in Citrus sinensis Pulp and peel respectively. The bioactive compounds such as hesperidin (31.52 mg/100 g) was significantly higher in (p ≤ 0.05) in Citrus sinensis pulnd extract. Vanillin was found 1.21 mg/100 g in peel extract of citrus fruit, moreover vanillin was not detected in pulp extract. Myrecitin was not detected in both the samples. The bioactive natural compounds extracted from citrus peel can be used in food and pharma sector as natural anti-oxidant compounds. [ABSTRACT FROM AUTHOR]

In our study, the effects of high-power (400 W) and low-frequency (20 kHz) ultrasound pretreatment applied for different durations (5, 10, and 20 min) and proteases (alcalase and flavourzyme) on the physicochemical, structural, and antioxidant properties of lupin protein hydrolysates (LPH) were examined. Changes in structural characteristics of the isolates and the resulting hydrolysates were measured using circular dichroism (CD), Fourier-transform infrared (FTIR), and UV–Vis spectroscopic techniques. Antioxidant activities of the LPH were assessed using 2,2-diphenyl-1picrylhydrazyl (DPPH) and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) assays. Physicochemical properties including the yield of hydrolysate, relative crystallinity, and surface charge were also evaluated. FTIR analysis revealed that ultrasound pretreatment altered the secondary structure of the proteins as indicated by the movement of absorption peaks to higher wavelength. Also, CD studies showed a reduction in α-helix and increase in the β-sheet component of LPH samples after ultrasound pre-treatment except hydrolysates prepared using flavourzyme. The particle size, zeta potential, and relative crystallinity of the hydrolysates were significantly affected by ultrasonication time and enzyme type. Also, ultrasonication had a noticeable impact on the antioxidant activity as maximum DPPH activity was recorded after 10 min sonication in hydrolysates prepared using alcalase and flavourzyme. In addition, yield of hydrolysate increased significantly (p < 0.05) after ultrasonication pretreatment. Principal component analysis also produced a two-principal component model that explained 65.33% of total data variation. It may be suggested that application of ultrasound treatment to lupin protein could enhance the various characteristics including physicochemical and antioxidant activities of its hydrolysate. [ABSTRACT FROM AUTHOR]

Abstract The effects of ultrasound power on extraction kinetic model, and physicochemical and structural characteristics of collagen from chicken lung were studied. Ultrasound power caused a significant increase in extraction rate and equilibrium concentration, with the maximum extraction yield (31.25%) at 150 W. The experimental data were consistent with the predicted ones in this empirical equation, in which the percentage error differences was 0.026–4.159%. Besides, ultrasound treatment did not affect their triple-helical structure. The thermal stability of pepsin-soluble collagen by ultrasound pre-treatment (UPSC) was higher, due to the higher imino acid content (20.76%). UPSC also exhibited better solubility and fibril forming capacity. Overall, the kinetic model of UPSC from chicken lung could serve the purpose of obtaining collagen, which displayed a potential alternative source to mammal collagens for application in food, biomaterials and biomedical fields. Graphical abstract

The objective of the present study was to assess the effects of ultrasound pretreatment on the quality of dry-cured yak meat. The ultrasonic power with 0, 200, 300 and 400 W (ultrasonic frequency of 20 kHz) were used to assist processing of dry-cured yak meat. The meat quality, nutrient substances, sensory quality, electronic nose, electronic tongue and volatile compounds of dry-cured yak meat were determined. The results indicated that the moisture content and hardness value of ultrasonic treatment group was significantly lower compared to the control group (P

The anaerobic digestion, AD, process presents a solution for sustainable waste management, greenhouse gas mitigation and energy production for growing population needs and requirements. Adopting a biorefinery approach that utilises different feedstock may enhance energy production and support optimisation of the anaerobic digestion process. Algae is a promising feedstock that could be used for energy production via the anaerobic digestion process. Microalgal biomass is rich in carbohydrates and lipids; however, many species of algae exhibit tough cell walls that could also be difficult to digest and may influence or inhibit the efficiency of the AD process. This study concentrated on the comparison of AD remediation of two marine algal biomass species, Tetraselmis suecica and Nannochloropsis oceanica. The two species were pre-treated with an ultrasound technique and compared for their methane production using biochemical methane potential tests. For Tetraselmis, a specific methane production of 0.165 LCH4/KgVS was observed; however, for Nannochloropsis, a value of 0.101 LCH4/KgVS was observed for the samples treated with ultrasound. The BMP results from this study show that among the two micro-algae species tested, Tetraselmis suecica is found to be a better substrate for methane production potential. Contrary to increasing the specific methane production, ultrasound cavitation caused a slight decrease in the specific methane production values for both Nannochloropsis oceanica and Tetraselmis suecica biomass residues. The pre-treatment of the biomass using ultrasound techniques provided comparable results and can be recommended for effective bioenergy production. However, further research is required for the optimisation of the pre-treatment of microalgae and for the integration of microalgal biorefineries for circular economy.

The effect of ultrasound (US) pretreatment (0, 200, 400, 600, and 800 W) on the physicochemical, emulsification, and gelatinization characteristics of citric acid (CA)-treated whey protein isolate (WPI) was investigated. Size exclusion chromatography demonstrated that when compared with untreated WPI, US pretreatment promoted production of more molecular polymers in the CA-treated WPI. There was a reduction in particle size of CA-treated WPI with the increase of US power (0–800 W), whereas its free sulfhydryl content, surface hydrophobicity, and intrinsic fluorescence strength increased. Furthermore, compared with untreated WPI, emulsifying ability index and emulsifying stability index of CA-treated WPI were increased by 14.04% and 10.10%, respectively, at 800 W. Accordingly, US pretreatment promoted the gel formation of CA-treated WPI, and its gel hardness was increased by 28.0% with US power ranging from 0 to 800 W. Therefore, US and CA treatment can be considered as an effective way to improve the emulsifying and gelatinization characteristics of WPI. [Display omitted] [ABSTRACT FROM AUTHOR]