High-intensity Ultrasound Research Articles

Use of high-intensity ultrasound as a pre-treatment for complex coacervation from whey protein isolate and iota-carrageenan.

The aim of this work was to evaluate the influence of high intensity ultrasound (HIUS) treatment on the molecular conformation of whey protein isolated (WPI) as a previous step for complex coacervation with iota carrageenan (IC) and its effect on the surface functional properties of complex coacervates (CC). Both biopolymers were hydrated (1% w/w) separately. A WPI suspension was treated with an ultrasonic bath (40 kHz, 600 W, 30 and 60 min, 100% amplitude). A non-sonicated protein was used as a control. Coacervation was achieved by mixing WPI and IC dispersions (10 min). FTIR-ATR analysis (400-4000 cm-1) detected changes after sonication on WPI secondary structure (1600-1700 cm-1), electrostatic interaction between WPI and IC by electronegative IC charged groups like sulfate (1200-1260 cm-1), anhydrous oxygen of the 3.6 anhydro-D-galactose (940-1066 cm-1) and the electropositive regions of WPI. Rheology results showed pseudoplastic behavior of both IC and WPI-IC with a significant change in viscosity level. Further, HIUS treatment had a positive effect on the emulsifying properties of the WPI-IC coacervates, increasing the time foaming (30 min) and emulsion stability (1 month) percentage. HIUS and complex coacervation proved to be an efficient tool to improve the surface functional properties of WPI.

Effects of High-Intensity Ultrasound Treatments on the Physicochemical and Structural Characteristics of Sodium Caseinate (SC) and the Stability of SC-Coated Oil-in-Water (O/W) Emulsions.

The effects of high-intensity ultrasound treatment (0, 3, 6, 9 min) on physicochemical and structural characteristics of SC and the storage, thermal and freeze–thaw stability of SC O/W emulsions were investigated. The results showed that ultrasound treatment reduced the particle size of SC, although there were no obvious changes in zeta potential, profiles and weights. Ultrasound treatment improved surface hydrophobicity and fluorescence intensity of SC and changed ultraviolet–visible (UV–Vis) spectroscopy but had no influence on the secondary structure of SC. This indicates that ultrasounds might destroy the tertiary structure but leave most of the integral secondary structure. A scanning electron microscope (SEM) also showed that ultrasound-treated SC presented small aggregates and a loose structure. The physicochemical and structural changes of SC benefited the ability of protein adsorbing oil droplets and emulsion stability. Under stresses such as storage, thermal and freeze–thawing, the oil droplets of treated emulsions were still uniform and stable, especially at 6 min and 9 min. Overall, the high-intensity ultrasounds made the SC present small aggregates and a loose structure improving the SC O/W emulsions stability under storage, thermal and freeze–thawing environment and have great potential to stabilize the SC prepared O/W emulsions.

The effects of high-intensity ultrasound and oil types on the physicochemical properties of egg white protein emulsions

This study aimed to evaluate the impact of high-intensity ultrasound (HIUS) and types of oil on the emulsion of egg white proteins (EWPs). Dispersions (2%, w/v) of (EWPs) with (corn, sunflower, and soybean) oils were homogenized and then sonicated at 320 -watts for 4, 12 and 20 min. Emulsions were described by microscopy, ζ-potential, particle size, rheology, viscosity, and interfacial tension. The results showed that extending the time of sonication considerably reduced particle size and interfacial tensions in emulsions. Additionally, increasing the sonication period reduced the viscosity and increased the elasticity of EWP emulsions. Moreover, results indicated sunflower oil had better emulsion stability than all oils. Ultrasound improved the microstructural of EWP emulsions. The droplet sizes of emulsions increased after heat treatment. Meanwhile, after 4 min of sonication, emulsions produced showed better stability against ionic strengths. The results confirmed that HIUS showed promising stabilized EWPs emulsions with different oils.

Influence of ultrasound and enzymatic cross-linking on freeze-thaw stability and release properties of whey protein isolate hydrogel.

This study investigated the effect of ultrasound and enzymatic cross-linking on the freeze-thaw (FT) stability and release properties of whey protein isolate hydrogels. We evaluated the FT stability by the changes in the microstructure, riboflavin retention, syneresis, water holding capacity (WHC), and texture of gels subjected to 3 FT cycles. High-intensity ultrasound (HUS) and transglutaminase (TGase)-mediated cross-linking improved the FT stability of whey protein isolate hydrogels loaded with riboflavin (WPISAR), as demonstrated by a more uniform and denser porous structure, significantly higher riboflavin retention, WHC, and textural properties, and lower syneresis after 3 FT cycles than those of untreated hydrogels. Furthermore, HUS- and TGase-mediated cross-linking decreased protein erosion and swelling ratio of WPISAR in simulated gastrointestinal fluids (SGIF) and reduced the riboflavin release rate in SGIF both with and without the addition of digestive enzymes. After 3 FT cycles, faster riboflavin release occurred due to a more porous structure induced by ice crystal formation compared with their unfrozen counterparts as detected by confocal laser scanning microscopy. High-intensity ultrasound- and TGase-mediated cross-linking alleviated the FT-induced faster riboflavin release rate in SGIF. High-intensity ultrasound- and TGase-treated gel samples showed that both diffusion and network erosion were responsible for riboflavin release regardless of FT. These results suggest that HUS- and TGase-mediated cross-linking improved the FT stability of WPISAR with a high riboflavin retention, and might be a good candidate as a controlled-release vehicle for riboflavin delivery to overcome undesired FT processing.

High-Intensity Ultrasound Processing Enhances the Bioactive Compounds, Antioxidant Capacity and Microbiological Quality of Melon (Cucumis melo) Juice.

The bioactive compounds, antioxidant capacity and microbiological quality of melon juice processed by high-intensity ultrasound (HIUS) were studied. Melon juice was processed at two ultrasound intensities (27 and 52 W/cm2) for two different processing times (10 and 30 min) using two duty cycles (30 and 75%). Unprocessed juice was taken as a control. Total carotenoids and total phenolic compounds (TPC) were the bioactive compounds analyzed while the antioxidant capacity was determined by DPPH, ABTS and FRAP assays. The microbiological quality was tested by counting the aerobic and coliforms count as well as molds and yeasts. Total carotenoids increased by up to 42% while TPC decreased by 33% as a consequence of HIUS processing regarding control juice (carotenoids: 23 μg/g, TPC: 1.1 mg GAE/g), gallic acid and syringic acid being the only phenolic compounds identified. The antioxidant capacity of melon juice was enhanced by HIUS, achieving values of 45% and 20% of DPPH and ABTS inhibition, respectively, while >120 mg TE/100 g was determined by FRAP assay. Further, the microbial load of melon juice was significantly reduced by HIUS processing, coliforms and molds being the most sensitive. Thus, the HIUS could be an excellent alternative supportive the deep-processing of melon products.

Improved water solubility of myofibrillar proteins by ultrasound combined with glycation: A study of myosin molecular behavior

The poor water solubility of myofibrillar proteins (MPs) limits their application in food industry, and is directly related to the molecular behavior associated with myosin assembly into filaments. This study aims to explore the effect of high-intensity ultrasound (HIU) combined with nonenzymatic glycation on the solubility, structural characteristics, and filament-forming behavior of MPs in low ionic strength media. The results showed that the HIU (200–400 W) application could promote the subsequent glycation reaction between MPs and dextran (DX) and interfere with the electrostatic balance between myosin rods, suppressing the formation of filamentous myosin polymers. Glycated MPs pretreated by 400 W HIU had the highest solubility, which corresponded to the smallest particle size, highest zeta potential, and optimum storage stability (P < 0.05). Structure analysis and microscopic morphology observations suggested that the loss of the MP superhelix and the depolymerization of filamentous polymers were the main mechanisms for MP solubilization. In conclusion, HIU combined with glycation can effectively improve the water solubility of MPs by destroying or suppressing the assembly of myosin molecules.

The Effect of High-Intensity Ultrasound and Natural Oils on the Extraction and Antioxidant Activity of Lycopene from Tomato (Solanum lycopersicum) Waste.

The extraction of lycopene was carried out with three types of vegetable oils (grape, extra virgin olive, and peanut) by means of two methods: agitation and high-intensity ultrasound with a frequency of 20 kHz at an amplitude of 80% with periods of 40 s of sonication for 20 min at a temperature of 40 °C. The antioxidant determination by inhibition of ABTS and DPPH radicals showed no significant differences (p > 0.05) for inhibition of the ABTS radical in native oils and oils with lycopene. However, the radical DPPH showed that the native oils presented significant differences (p ≤ 0.05) compared to the samples with lycopene. FTIR spectra revealed the characteristic functional groups of lycopene exhibiting two characteristic peaks at 2923 cm−1 and 2957 cm−1. The DSC thermograms showed that the higher the degree of oil unsaturation, the lower the melting temperatures. Olive oil was the least unsaturated with the highest amount of oleic fatty acid. Grapeseed oil reported the lowest melting temperature at around −24.64 °C. Extra virgin olive oil showed the lightest values (L* = 41.08 ± 0.45) of brightness, and the peanut oil with lycopene was the darkest (L* = 16.72 ± 0.05). The extraction of lycopene from organic wastes treated with agitation and ultrasound was satisfactory reducing the use of conventional solvents. However, extraction with olive oil under agitation showed the best results.

Integrated multivariate analysis as a tool to evaluate effects of ultrasound on beef quality

AbstractAn important controversy in the effect of high‐intensity ultrasound (HIU) on beef physicochemical properties exists among studies. This study aimed to analyze physicochemical data from several experiments in order to determine the most effective HIU treatment for the quality improvement of meat. Multivariate analysis was used to define the main effects attributed to the application of HIU, packaging, and storage of beef. A data set containing 104 individual records of color parameters (L*, a*, b*, C* and Hue*), drip loss, water‐holding capacity, and shear force from beef muscles under different treatments (HIU, packaging, storage) was constructed. All the evaluated variables presented changes by the effect of the treatments. The cluster analysis in the MANOVA analysis showed the formation of 12 groups with significant differences (p &lt; .05) among them. Each variable had an important role in explaining the data, and all variables should be considered in future studies about the HIU effect on meat quality. Multivariate analysis indicated that beef sonicated at 16–28 W/cm2 for 20–40 min and packed in modified atmosphere had the best physicochemical quality. This study confirmed the efficacy of multivariate statistical techniques in assessing the quality of beef and in indicating the HIU parameters associated with the technological quality of the product.Practical applicationsHIU as an alternative processing technique to conventional methods of beef preservation is considered a green emerging technology. The application of HIU to beef is effective for improving the technological quality of fresh and processed beef. Multivariate data analysis as a complementary discipline in meat processing can generate useful results to make decisions on the equipment design and the application of ultrasound for enhancing the beef technological quality and shelf life, benefiting to the meat industry.

The influence of high pressure homogenization and high-intensity ultrasound on the functional properties of whey-protein/canola oil nanoemulsions during storage

The current work was conducted in order to explore the influence of two non-thermal technologies (high pressure processing (HPH) and high-intensity ultrasound (HIU) on the droplet size, turbidity and lipid oxidation of whey protein / canola oil nanoemulsions (WPN) during a week. The outcomes exhibited that the HIU process have a significant impact on both droplet size and lipid oxidation (p&amp;lt;0.05) of WPNs. A smaller droplet size was obtained for HPH treated WPNs compared to the control (untreated) WPNs. On the other hand, the smallest droplet sizes were obtained for the samples exposed to 10 min HIU at 100% amplitude (614.7 nm). The same sample also showed the least lipid oxidation during 7 days of storage (124 mmol/kg). There is a positive relationship between the variables of droplet sizes and turbidities. All HIU-treated WPN samples exhibited less turbidity and smaller droplet size where the control WPN samples demonstrated most turbid structure (5.97) with the biggest droplet sizes (985.4 nm). Similar positive relationship was also figured out between the variables of droplet size and lipid oxidation. All HIU-treated WPN samples exhibited less lipid oxidation and smaller droplet size where the control WPN samples demonstrated most lipid oxidation with the biggest droplet sizes.

Modification of grass pea protein isolate (Lathyrus sativus L.) using high intensity ultrasound treatment: Structure and functional properties

In this study the effect of different high intensity ultrasound (HIU) amplitudes (25, 50 and 75%) and sonication times (5, 10 and 20 min) on the structure and functional properties of grass pea protein isolate (GPPI) was investigated. A higher sonication amplitude and longer time improved the protein solubility and surface hydrophobicity and reduced the particle size of GPPI. These physicochemical alterations in GPPI enhanced the protein adsorption at the oil–water interface, reduced the interfacial tension and increased the EAI and ESI values. SDS-page demonstrated that sonication did not change the primary structure of the protein. However, CD spectroscopy indicated a reduction in α-helix and an increase in the content of β-sheet and random coil structures in the sonicated GPPI. The free SH groups content and UV–vis absorbance intensity increased after the sonication. However, prolonged sonication up to 20 min reduced the free SH content in GPPI due to the oxidation of susceptible SH groups. HIU increased the thermal degradation of GPPI and lowered the least concentration needed for gelatinization of GPPI (LGC). Therefore, less protein powder was needed to form a strong gel compared to the non-sonicated GPPI. Sonicated GPPIs showed higher gel strength especially when 75% amplitude used for 10 min. These results showed that the HIU is a promising approach for modification of the functional properties of GPPI for food applications.

Fabrication of emulsions prepared by rice bran protein hydrolysate and ferulic acid covalent conjugate: Focus on ultrasonic emulsification

The aim of the paper was to investigate the effect of ultrasonic emulsification treatment on the fabrication mechanism and stability of the emulsion. The covalent conjugate made with rice bran protein hydrolysate (RBPH) and ferulic acid (FA) was used as the emulsifier. The effects of high intensity ultrasound (HIU) power with different level (0 W, 150 W, 300 W, 450 W and 600 W) on the stability of emulsion were evaluated. The results showed that ultrasonic emulsification can significantly improve the stability of the emulsions (p < 0.05). The emulsion gained better stability and emulsifying property at 300 W. It was able to fabricate emulsion with smaller particle size, more uniform distribution and higher interfacial protein content. It was confirmed by fluorescent microscopy and cryo-scanning electron microscopy (cryo-SEM) furtherly. And it was also proved that the emulsion treated by proper HIU treatment at 300 W had better storage stability. Excessive HIU treatment (450 W, 600 W) had negative effects on the stability of emulsion. The stability of emulsion (300 W) against different environmental stresses was further explored, which established a theoretical basis for the industrial application of emulsion in food industry.

Positive effects and mechanism of ultrasound on chitin preparation from shrimp shells by co-fermentation

The objective of this study is to explore the effect and mechanism of ultrasound on chitin extraction from shrimp shells powder (SSP) by the co-fermentation of Bacillus subtilis and Acetobacter pasteurianus. After pre-treating the SSP with high-intensity ultrasound (HIU) at 800 W, the protease activity in the fermentation solution reached 96.9 U/mL on day 3, which was significantly higher than for SSP that had not been pre-treated with ultrasound (81.8 U/mL). The fermentation time of the chitin extraction process was 5.0 d without ultrasound pre-treatment, while it was shortened to 4.5 d when using ultrasound at 800 W to treat SSP. However, there were no obvious differences when we applied ultrasound at low power (200 W, 400 W). Furthermore, chitin purified from shrimp shells pre-treated with HIU at 800 W exhibited lower molecular weight (11.2 kDa), higher chitin purity (89.8%), and a higher degree of deacetylation (21.1%) compared to SSP with no ultrasound pre-treatment (13.5 kDa, 86.6%, 18.5%). Results indicate that HIU peels off the protein/CaCO3 matrix that covers the SSP surface. About 9.1% of protein and 4.7% of Ca2+ were released from SSP pre-treated with HIU at 800 W. These figures were both higher than with no ultrasound pre-treatment (4.5%, 3.2%). Additionally, the amount of soluble protein extracted from SSP through HIU at 800 W was 50% higher than for the control sample. SDS-PAGE analysis indicated that the soluble protein was degraded to the micromolecule. It also revealed that HIU (600, 800 W) induced the secondary and tertiary structure destruction of protein extracted from SSP. In conclusion, HIU-induced degradation and structural damage of protein enhances the protein/CaCO3 matrix to be peeled off from SSP. Also, in the co-fermentation process, an increase of protease activity further accelerates deproteinization.

Effect of low-frequency high-intensity ultrasound (HIU) on the physicochemical properties of chickpea protein

The aim of this study was to improve the functional properties of chickpea protein for its potential application in the food industry. The effects of low frequency high intensity ultrasound (HIU) at different power (0–300 W) and time (15–30 min) on the rheological properties, gelation, thermal stability, solubility and microstructure of chickpea protein were tested and analyzed. Based on the analysis, it was found that HIU caused the disruption of non-covalent bonds between protein chains leading to the unfolding of chickpea. The HIU-treated chickpea isolate protein aggregates were smaller and more uniformly dispersed, with increased orderly structure, thermal stability, and exposure of hydrophobic and charged groups originally buried in the interior. The experimental results also showed that the effect of HIU did not become more pronounced with increasing power and time, as the power exceeding 150 W for 30 min led to the formation of new polymers by the interactions between the exposed non-covalent groups, which were more ordered and homogeneous than those without HIU.

High‐intensity ultrasound processed acerola juice containing oligosaccharides and dextran promotes Lacticaseibacillus casei NRRL B‐442 growth

SummaryIn the present study, a prebiotic acerola juice containing gluco‐oligosaccharides and dextran was produced and processed by high‐intensity ultrasound (HIUS). After a simulated in vitro digestion, the gluco‐oligosaccharides and dextran maintained 90% and 80% of their initial concentration in all prebiotic’s juices. At the same time, Vitamin C and phenolic compounds concentration increased significantly by 19% and 7% (P &lt; 0.05). After the in vitro digestion, the prebiotic juice HIUS processed by 10 min showed the highest increase in gluco‐oligosaccharides and bioactive compound concentrations. The HIUS processing imparted some dextran hydrolysis and improved its fermentability by Lacticaseibacillus casei. Gluco‐oligosaccharides were extensively consumed as substrate in simulated intestinal conditions, promoting the L. casei NRRL B‐442 growth and production of organic acids and short‐chain organic acids. The prebiotic juice HIUS processed for 6 min showed the best responses regarding the metabolism of L. casei NRRL B‐442. The results showed high‐intensity ultrasound processed acerola juices containing gluco‐oligosaccharides and dextran as a prebiotic food.

Ultrasound accelerates pickling of reduced-sodium salted duck eggs: An insight into the effect on physicochemical, textural and structural properties

In this work, high-intensity ultrasound (HIU) was used to accelerate the pickling of the reduced-sodium salted duck eggs (RSSDE). Meanwhile, it was evidenced that HIU treatment was also helpful to improve the overall quality of RSSDE. When the optimized HIU at 80 W was used, it resulted in favorably higher hardness (1.83 N), springiness (4.20 mm), and chewiness (4.83 mJ) of RSSDE whites, while the lowest hardness (1.12 N) of RSSDE yolks. The average particle size of RSSDE whites was significantly reduced (230.37 nm, 7.14%) as well. Apart from that, the absolute zeta potential and hydrophobicity were increased to −8.63 mV by 14.30% and 164.70 μg by 3.12%, respectively, attributed to the destruction of protein aggregation by cavitation effects. The oil exudation showed an obvious rising during the 14 days of the salting. HIU treatment at 80 W destroyed the emulsification state of lipid droplets and led to higher oil exudation (39.30%). The structural analysis of RSSDE proteins revealed marked alterations following HIU, with a reduction in α-helix and an increase in β-turn and random coil. The highest r-value reached 1.32 after HIU treatment at 80 W, which was attributed to the exposure of both tyrosine and tryptophan residues caused by the hydrophobic rearrangement of RSSDE protein. Scanning electron microscopy revealed that HIU altered the architecture of RSSDE proteins, resulting in more irregular pores. This work proved that HIU was a promising tool to shorten the salting period of RSSDE with much better quality.

Degree of oxidation of sonicated soybean oil using various sonication process parameters

SummaryThis research aimed to examine the effect of high‐intensity ultrasound (HIU) on the oxidation of soybean oil (SBO). Samples (5, 100, and 250 g) were sonicated at 25 °C using various sonication conditions: power level (settings 1, 5, and 9), tip size (12.7, 3.2, and 2 mm), and duration (5, 10, and 60 s). After sonication, the degree of oxidation of samples (sonicated and non‐sonicated SBO) were analysed using peroxide value (PV), oil stability index (OSI), and volatile compounds. Sonication was applied to obtain a range of absolute power (0–123.5 W), power density (0–14.2 W cm−3), and power intensity (0–1,120 W cm−2) values. The highest power density and power intensity were obtained with the highest HIU setting with the 3.2 mm tip. The highest power was obtained when HIU was applied using a 12.7 mm tip and setting 9 in 250 g of sample. No significant difference (P &gt; 0.05) was observed in PV (0.20 ± 0.01 mEq kg−1) nor OSI (10.05 ± 0.04 h), among the various sonication conditions tested. In addition, no differences were observed in the volatile compounds obtained. These results show that HIU can be used under mild sonication conditions such as the ones needed to change the physical properties of lipids without causing oxidative deterioration.

Structure and properties of egg white protein films modified by high-intensity ultrasound: An effective strategy

Edible films based on egg white protein (EWP) were prepared, and it were modified by high-intensity ultrasound (HIUS) to improve the functional properties. The findings indicated the properties of EWP films were improved at the appropriate time of HIUS treatment. With the increase of ultrasonic time, water vapor permeability (WVP) and tensile strength (TS) of EWP films ascended and then declined, and the best performance (3.30 g·mm/ m2·h·KPa for WVP, and 7.28 MPa for TS) was achieved when ultrasonic time was 10 min. Thermogravimetric analysis exhibited ultrasound could enhance the thermal stability of EWP films. The SEM reflected moderate ultrasonic treatment could make the EWP films smoother. The FTIR spectroscopy and X-ray diffraction patterns of EWP films were changed by HIUS, which illustrated the secondary structure of the protein was altered. The transverse relaxation curve obtained by LF-NMR analysis showed the tightness between water and the films.

Ultrasound emulsification energy strategies impact the encapsulation efficiency of essential oils in colloidal systems

In the last years, high-intensity ultrasound (HIUS) technology has shown consistent growth as a smart alternative for developing processes and innovative products, such as emulsified systems. However, there is still a lack of standard process protocols for designing HIUS-assisted colloidal systems, such as essential oil (EO)-based emulsions. In this work, we reported the impact of different homogenization strategies using ultrasound energy on the production of oil-in-water emulsions containing different EOs (clove, orange, and rosemary) and gum Arabic as an emulsifier. We evaluated the effect of applying a given HIUS specific energy (300 J g−1) on emulsion kinetic stability and encapsulation efficiency, using an acoustic power and process time binomial approach, analogously to conventional thermal pasteurization processes, in two ways: low power and long time (LPLT) and high power and short time (HPST). Emulsions presented kinetic stability after 72 h of storage, except for emulsions containing orange EO and high encapsulation efficiency (EE) values (81.5–100%, approximately). Furthermore, kinetic stability was associated with low droplet sizes (<1 μm). The use of different HIUS processes did not influence the kinetic stability of emulsions. However, the HPST process led to higher EE. This effect was more significant for emulsions containing clove and rosemary EOs. Additionally, different EOs resulted in emulsions with different physicochemical properties and EE. These results suggest that the way of applying ultrasound specific energy may be less significant for emulsion stabilization but might be considered for HIUS-assisted encapsulation. Therefore, the acoustic power and processing time binomial might be a useful approach for designing HIUS-assisted colloidal systems, such as EO-based emulsions.

Ultrasound as a Potential Technology to Improve the Quality of Meat Produced from a Mexican Autochthonous Bovine Breed

The objective of this study was to evaluate the effect of high-intensity ultrasound (HIU) on the physicochemical and textural properties of meat from Rararumi Criollo, a Mexican autochthonous bovine breed. After slaughter, Longissimus dorsi and Triceps brachii muscles were separated from carcasses, cut into 2.5 cm slices and treated with HIU, except the control group, which was not sonicated. After treatment, samples were vacuum-sealed and stored at 4 °C for 0, 3, 6, 9, 12 and 15 d. HIU increased (p &lt; 0.05) the luminosity and yellowness (b*) of meat. Higher b* (p &lt; 0.05) was observed in L. dorsi than in T. brachii muscles. No effect (p &gt; 0.05) of HIU was detected on drip loss, pH, the water holding capacity and the total collagen of meat. The shear force of HIU-treated meat was lower (p &lt; 0.05) than control samples, indicating a tenderizing effect. There were differences between muscles. L. dorsi was more tender (p &lt; 0.05), and it had higher pH and WHC values than T. brachii. Overall, HIU is a potential method for tenderizing Raramuri Criollo cattle meat without negative impacts on other quality characteristics. HIU is an emerging technology that could add value to indigenous breeds and provide a new opportunity for the growing meat market.

High‐intensity ultrasound treatment to produce and preserve the quality of fresh‐cut kiwifruit

In this study, high intensity ultrasound (HIU), antibrowning chemicals (calcium chloride and ascorbic acid), water bath were used to avoid the browning of kiwifruit pieces, and the shelf-life of fresh-cut was measured (two weeks). The treated fresh-cut kiwi samples were evaluated in terms of color, enzyme activities, bioactive compounds, microbial and sensory studies. The study shown that HIU treatment restricted (p<0.05) the microbial growth (bacteria, yeats & mold) in fresh-cut kiwi samples at 4 °C. Moreover, kiwi samples exposed to HIU exhibited significant (p<0.05) enhancements in bioactive metabolites as well as improvements in the physical features with the comparison of all other applications. Similarly, the lowest browning index (BI) values were observed for kiwifruit samples by HIU at the end of storage (180.04). Furthermore, the lowest scores for decay (0.5/3.0 and 0.9/3.0 in days 7 and 14, respectively) and off-odor (1/7 and 2/7 in days 7 and 14, respectively) were determined for the fresh-cut kiwifruit subjected to HIU. It has been proposed that HIU application is a possible choice to take the place of chemical and physical approaches to extend the product life and maintain quality characteristics in fresh-cut kiwifruit at cold storage conditions.