Degradation behavior and products of malathion and chlorpyrifos spiked in apple juice by ultrasonic treatment

Apple juice (13 °Brix) spiked with malathion and chlorpyrifos (2–3 mg l⁻¹ of each compound) was treated under different ultrasonic irradiations. Results showed that ultrasonic treatment was effective for the degradation of malathion and chlorpyrifos in apple juice, and the output power and treatment time significantly influenced the degradation of both pesticides (p < 0.05). The maximum degradations were achieved for malathion (41.7%) and chlorpyrifos (82.0%) after the ultrasonic treatment at 500 W for 120 min. The degradation kinetics of both pesticides were fitted to the first-order kinetics model well (R²  0.90). The kinetics parameters indicated that chlorpyrifos was much more labile to ultrasonic treatment than malathion. Furthermore, malaoxon and chlorpyrifos oxon were identified as the degradation products of malathion and chlorpyrifos by gas chromatography–mass spectrometry (GC–MS), respectively. The oxidation pathway through the hydroxyl radical attack on the PS bond of pesticide molecules was proposed.     

Use of pulsed-high hydrostatic pressure treatment to decrease patulin in apple juice

This study was aimed at reducing patulin content of apple juice using a non-thermal method, namely pulsed-high hydrostatic pressure (p-HHP). Commercially available clear apple juice was contaminated artificially with different concentrations of patulin (5, 50 and 100?ppb). Then, the samples were processed 5?min at different pressure treatments (300–500?MPa) in combination with different temperatures (30–50°C) and pulses (6 pulses?×?50?s and 2 pulses?×?150?s). To compare the impact of pulses, single pulse of high hydrostatic pressure (HHP) treatment was also applied with the same pressure/temperature combinations and holding time. Results indicated that pressure treatment in combination with mild heat and pulses reduced the levels of patulin in clear apple juice up to 62.11%. However, reduction rates did not follow a regular pattern. p-HHP was found to be more effective in low patulin concentrations, whereas HHP was more effective for high patulin concentrations. To the best of our knowledge, this is the first study using p-HHP to investigate the reduction of patulin content in apple juice.     

Microbial inactivation in cloudy apple juice by multi-frequency Dynashock power ultrasound

The study determined the efficacy of Dynashock wave power ultrasound as an alternative processing technique for apple juice against a number of pathogenic and spoilage microorganisms. The effects of several implicit, intrinsic and extrinsic properties on the Dynashock wave inactivation of the microorganisms were also investigated. Results showed that acid adaptation increased the resistance of Escherichia coli O157:H7 and Salmonella spp. but decreased that of Listeria monocytogenes. Spoilage yeast mixed inoculum composed of Debaryomyces hansenii, Torulaspora delbrueckii, Clavispora lusitaniae, Pichia fermentans and Saccharomyces cerevisiae was found to be more resistant than any of the adapted or non-adapted pathogens. Among the individual, acid-adapted E. coli O157:H7, the MN-28 isolate was found most resistant; while three other individual isolates had greater resistance than the composited E. coli inoculum. Increased in pulp content decreased the efficacy of Dynashock waves, but co-treatment with ultraviolet-C rays significantly enhanced inactivation in the cloudy apple juice. The results demonstrated the potential of Dynashock wave technology, together with other antimicrobial hurdles as alternative juice processing technique/s.     

Effect of sonication on eliminating of phorate in apple juice

The degradation of phorate in apple juice by sonication was investigated in the present study. Results showed that sonication was effective in eliminating phorate in apple juice, and the ultrasonic power and sonication time significantly influenced the degradation of phorate (p < 0.05). The degradation of phorate followed the first-order kinetics model well. Phorate-oxon and phorate sulfoxide were identified as the degradation products of phorate by gas chromatography-mass spectrometry (GC-MS). Moreover, the toxicity of apple juice samples spiked with phorate was significantly reduced by sonication (p < 0.05). The quality indexes of apple juice including pH, titratable acidity (TA), electrical conductivity (EC), total soluble solids (TSS), and the contents of sucrose, glucose and fructose were not affected by sonication, and no visible difference in color was observed between the sonicated samples and the control.     

Degradation of reactive brilliant red in aqueous solution by ultrasonic cavitation

Degradation of reactive brilliant red K-BP in aqueous solution by means of ultrasonic cavitation was investigated for a variety of operating conditions. It is found that the degradation of reactive brilliant red K-BP in aqueous solution follows pseudo-first-order reaction kinetics and the degradation rate is dependent on the initial concentration of reactive brilliant red K-BP, the temperature and acidity of the aqueous medium. The effects of Fe2+, Fenton reagent and NaCl addition on the sonochemical degradation of reactive brilliant red K-BP were also investigated. The results obtained here indicate that the degradation rate of brilliant red K-BP in aqueous solution was substantially accelerated by Fe2+, NaCl or Fenton reagent addition.     

Degradation of dissolved diazinon pesticide in water using the high frequency of ultrasound wave

This article aims to apply the ultrasound technique in the field of clean technology to protect environment. The principle of sonochemistry is conducted here to degrade pesticides in simulated industrial wastewater resulted from a factory manufacturing pesticides namely diazinon. Diazinon pesticide selected in this study for degradation under high frequency ultrasound wave. Three different initial concentrations of diazinon (800, 1200, and 1800 ppm), at different solution volumes were investigated in to degrade dissolved diazinon in water. Ultrasound device with 1.7 MHz, and 0.044 cm diameter, was used to study the degradation process.

It is found that as the concentration of diazinon increased, the degradation is also increasing, and when the solution volume increases, the ability to degraded pesticides decreases. The experimental results showed an optimum condition achieved for degradation of diazinon at 1200 ppm as initial concentration and 50 ml solution volume. Kinetic modeling applied for the obtained results showed that the degradation of diazinon by high ultrasound frequency wave followed a pseudo-first-order model with apparent rate constant of around of 0.01 s⁻¹.     

Effect of ultrasound on different quality parameters of apple juice

Fresh apple juice treated with ultrasound (for 0, 30, 60 and 90 min, at 20 °C, 25 kHz frequency) was evaluated for different physico-chemical, Hunter color values, cloud value, antioxidant capacity, scavenging activity on 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical, ascorbic acid, total phenolics, flavonoids, flavonols and microbial characteristics. No significant effect of sonication was observed on pH, total soluble solids (°Brix) and titratable acidity of apple juice. Sonication significantly improved ascorbic acid, cloud value, phenolic compounds, antioxidant capacity, DPPH free radical scavenging activity and differences in Hunter color values. Moreover, significant reduction in microbial population was observed. Findings of the present study suggested that sonication treatment could improve the quality of apple juice. It may successfully be employed for the processing of apple juice with improved quality and safety from consumer’s health point of view.     

Thermosonication as a potential quality enhancement technique of apple juice

Enzymatic browning and microbial growth lead to quality losses in apple products. In the present study, fresh apple juice was thermosonicated using ultrasound in-bath (25 kHz, 30 min, 0.06 W cm⁻³) and ultrasound with-probe sonicator (20 kHz, 5 and 10 min, 0.30 W cm⁻³) at 20, 40 and 60 °C for inactivation of enzymes (polyphenolase, peroxidase and pectinmethylesterase) and microflora (total plate count, yeast and mold). Additionally, ascorbic acid, total phenolics, flavonoids, flavonols, pH, titratable acidity, ^°Brix and color values influenced by thermosonication were investigated. The highest inactivation of enzymes was obtained in ultrasound with-probe at 60 °C for 10 min, and the microbial population was completely inactivated at 60 °C. The retention of ascorbic acid, total phenolics, flavonoids and flavonols were significantly higher in ultrasound with-probe than ultrasound in-bath at 60 °C. These results indicated the usefulness of thermosonication for apple juice processing at low temperature, for enhanced inactivation of enzymes and microorganisms.     

Degradation of m-xylene solution using ultrasonic irradiation

This study is to apply ultrasound to remove m-xylene, a volatile compound from aqueous solutions which causes environmental damage. High frequency ultrasound was used to investigate the effect of different operational parameters, such as m-xylene initial concentration, ultrasonic frequency and ultrasonic power. The degradation rate of m-xylene was increased with decreasing initial concentration of m-xylene and increasing frequency and power. Optimal conditions include 26.07 mg/L, 806.3 kHz and 70±1 W, in which MnO(2), Cu(2+), Fe(2+), and H(2)O(2) had little or no effect on the degradation. Moreover, the effect of radical scavengers such as Na(2)CO(3) and t-butyl was not obvious, which indicates that direct pyrolysis inside the collapsing bubbles has an important role in m-xylene ultrasonic removal. In addition, the degradation of m-xylene was observed to behave under pseudo-first-order kinetics with different experimental conditions tested in the present work.     

Degradation of Acid Orange 7 in aqueous solution by zero-valent aluminum under ultrasonic irradiation

Degradation of azo dye Acid Orange 7 (AO7) by zero-valent aluminum (ZVAl) in combination with ultrasonic irradiation was investigated. The preliminary studies of optimal degradation methodology were conducted with sole ultrasonic, sole ZVAl/air system, ultrasonication + ZVAl/air system (US-ZVAl). In ZVAl/air system, the degradation of AO7 could almost not be observed within 30 min. The degradation of AO7 by ZVAl/air system was obviously enhanced under ultrasound irradiation, and the enhancement is mainly attributed to that the production of hydroxyl radicals in ultrasound-ZVAl process was much higher than that in sole ultrasonic or in sole ZVAl/air system. The variables considered for the effect of degradation were the power of ultrasound, the initial concentration of AO7, as well as the initial pH value and the dosage of zero-valent aluminum. The results showed that the decolorization rate increased with the increase of power density and the dosage of ZVAl, but decreased with the increase of initial pH value and initial concentration of AO7. More than 96% of AO7 removal was achieved within 30 min under optimum operational conditions (AO7: 20 mg/L, ZVAl: 2 g/L, pH: 2.5, ultrasound: 20 kHz, 300 W). This study demonstrates that ultrasound-ZVAl process can effectively decolorize the azo dye AO7 in wastewater.     

Degradation,isomerization and stabilization of three dicaffeoylquinic acids under ultrasonic treatment at different pH

Dicaffeoylquinic acids (diCQAs) are found in a variety of edible and medicinal plants with various biological activities. An important issue is the low stability of diCQAs during extraction and food processing, resulting in the degradation and transformation. This work used 3,5-diCQA as a representative to study the influence of different parameters in ultrasonic treatment on the stability of diCQAs, including solvent, temperature, treatment time, ultrasonic power, duty cycle, and probe immersion depth. The generation of free radicals and its influence were investigated during the treatment. The stability of three diCQAs (3,5-diCQA, 4,5-diCQA and 3,4-diCQA) under the certain ultrasonic condition at different pH conditions was evaluated and found to decrease with the increase of pH, further weakened by ultrasonic treatment. Ultrasound was found to accelerate the degradation and isomerization of diCQAs. Different diCQAs showed different pattern of degradation and isomerization. The stability of diCQAs could be improved by adding epigallocatechin gallate and vitamin C.     

Computational mesomechanics of titanium surface-hardened by ultrasonic treatment

This paper studies plastic strain localization and stress-strain evolution in commercial titanium specimens with an ultrasonically treated surface. A dynamic plane strain boundary-value problem is numerically solved by the finite difference method. The microstructure and mechanical properties of the composition are specified in the calculations based on microhardness measurements, mechanical tensile tests, and metallographic studies. The dependences of the plastic flow localization characteristics on the geometry and mechanical properties of ultrasonically treated surface layers have been established. Plastic strain localization is found to depend on the geometry and mechanical properties of ultrasonically treated surface layers.     

Drying characteristics and quality attributes of apple slices dried by a non-thermal ultrasonic contact drying method

Drying is one of the most prevalent methods to reduce water activity and preserve foods. However, it is also the most energy-intensive food processing unit operation. Although a number of drying methods have been proposed and tested for the purpose of achieving a time- and energy-efficient drying process, almost all current drying methods still rely on thermal energy to remove moisture from the product. In this study, a novel use of power ultrasound was explored for drying of apple slices without the application of heat. The non-thermal ultrasound contact drying (US-CD) was performed in the presence of an air stream (26–40 °C) flowing over product surface to remove mist or vapor produced by the ultrasound treatment. The effects of the non-thermal US-CD, hot-air drying (HAD), and freeze drying (FD) on the changes in rehydration ratio, pH, titratable acidity, water activity, color, glass transition temperature, texture, antioxidant capacity, total phenols, and microstructures of the samples were evaluated. The moisture content of the apple slices reached below 5% (w.b.) after 75–80 min of US-CD, which was about 45% less than that of the HAD method. The antioxidant capacity and total phenol contents of the US-CD samples were significantly higher than that of the AD samples. The non-thermal ultrasonic contact drying is a promising method which has the potential to significantly reduce drying time and improve product quality.     

Ultrasonic and other sterilization methods on nutrition and flavor of cloudy apple juice

Sterilization plays an important role in extending the shelf-life of apple juice; however, it also affects the nutritional and flavor profile of the juice. This study was initiated to evaluate the effects of several common sterilization methods (conventional pasteurization, microwave sterilization, ultrasonic sterilization, and ultra-high-pressure sterilization) on some important quality parameters of apple juice. The results showed that the content of soluble pectin and soluble protein in juice decreased significantly after ultra-high-pressure sterilization. Sonication was found to be effective in increasing the level of ascorbic acid in apple juice. The sugar:acid ratio increased significantly after pasteurization, microwave sterilization, and ultra-high-pressure sterilization, which changed the taste of juice. Microwave sterilization caused the highest volatile compound loss, while ultra-high-pressure sterilization led to a higher retention rate of volatile compounds in juice. This study could be helpful in seeking suitable sterilization methods retaining the quality of cloudy apple juice.     

Impact of applied ultrasonic power on the low temperature drying of apple

Low temperature drying (LTD) allows high-quality dried products to be obtained, preserving the nutritional properties of fresh foods better than conventional drying, but it is a time-consuming operation. Power ultrasound (US) could be used to intensify LTD, but it should be taken into account that process variables, such as the level of applied power, have an influence on the magnitude and extension of the ultrasonic effects. Therefore, the aim of this work was to assess the influence of the level of applied ultrasonic power on the LTD of apple, analyzing the drying kinetics and the quality of the dried product. For that purpose, apple (Malus domestica cv. Granny Smith) cubes (8.8 mm side) were dried (2 m/s) at two different temperatures (10 and −10 °C), without and with (25, 50 and 75 W) US application. In the dried apple, the rehydration kinetics, hardness, total phenolic content, antioxidant capacity and microstructure were analyzed to evaluate the impact of the level of applied ultrasonic power.At both temperatures, 10 and −10 °C, the higher the ultrasonic power level, the shorter the drying time; the maximum shortening of the drying time achieved was 80.3% (at −10 °C and 75 W). The ultrasonic power level did not significantly (p < 0.05) affect the quality parameters analyzed. Therefore, US could be considered a non-thermal method of intensifying the LTD of fruits, like apple, with only a mild impact on the quality of the dried product.     

Sonication enhances polyphenolic compounds,sugars, carotenoids and mineral elements of apple juice

A study was initiated with the objective of evaluating the effects of sonication treatment on quality characteristics of apple juice such as polyphenolic compounds (chlorogenic acid, caffeic acid, catechin, epicatechin and phloridzin), sugars (fructose, glucose and sucrose), mineral elements (Na, K, Ca, P, Mg, Cu and Zn), total carotenoids, total anthocyanins, viscosity and electrical conductivity. The fresh apple juice samples were sonicated for 0, 30 and 60 min at 20 °C (frequency 25 kHz and amplitude 70%), respectively. As results, the contents of polyphenolic compounds and sugars significantly increased (P < 0.05) but the increases were more pronounced in juice samples sonicated for 30 min whereas, total carotenoids, mineral elements (Na, K and Ca) and viscosity significantly increased (P < 0.05) in samples treated for 60 min sonication. Losses of some mineral elements (P, Mg and Cu) also occurred. Total anthocyanins, Zn and electrical conductivity did not undergo any change in the sonicated samples. Findings of the present study suggest that sonication technique may be applied to improve phytonutrients present naturally in apple juice.     

Application of ultrasound in grape mash treatment in juice processing

Recently, application of ultrasound has attracted considerable interest as an alternative approach to traditional methods. In this study, response surface methodology (RSM) was used to optimize the conditions for grape mash treatment by ultrasound and by combination of ultrasound and enzyme. The results indicated that optimal conditions were the temperature of 74 °C and the time of 13 min for sonication treatment; and were the enzyme concentration of 0.05% and the time of 10 min for combined ultrasound and enzyme treatment. In comparison with traditionally enzymatic treatment, sonication treatment increased extraction yield 3.4% and shortened treatment time over three times; combined ultrasound and enzyme treatment increased extraction yield slightly, only 2%, but shortened treatment time over four times. After sonication treatment, enzymatic treatment increased extraction yield 7.3% and total treatment time of this method was still shorter than that of traditionally enzymatic treatment method. Besides, application of ultrasound improved the grape juice quality because it increased contents of sugars, total acids and phenolics as well as color density of grape juice.     

Application of ultrasonication at different microbial growth stages during apple juice fermentation by Lactobacillus plantarum: Investigation on the metabolic response

In this work, low-intensity ultrasonication (58.3 and 93.6 W/L) was performed at lag, logarithmic and stationary growth phases of Lactobacillus plantarum in apple juice fermentation, separately. Microbial responses to sonication, including microbial growth, profiles of organic acids profile, amino acids, phenolics, and antioxidant capacity, were examined. The results revealed that obvious responses were made by Lactobacillus plantarum to ultrasonication at lag and logarithmic phases, whereas sonication at stationary phase had a negligible impact. Sonication at lag and logarithmic phases promoted microbial growth and intensified biotransformation of malic acid to lactic acid. For example, after sonication at lag phase for 0.5 h, microbial count and lactic acid content in the ultrasound-treated samples at 58.3 W/L reached 7.91 ± 0.01 Log CFU/mL and 133.70 ± 7.39 mg/L, which were significantly higher than that in the non-sonicated samples. However, the ultrasonic effect on microbial growth and metabolism of organic acids attenuated with fermentation. Moreover, ultrasonication at lag and logarithmic phases had complex influences on the metabolism of apple phenolics such as chlorogenic acid, caffeic acid, procyanidin B2, catechin and gallic acid. Ultrasound could positively affect the hydrolysis of chlorogenic acid to caffeic acid, the transformation of procyanidin B2 and decarboxylation of gallic acid. The metabolism of organic acids and free amino acids in the sonicated samples was statistically correlated with phenolic metabolism, implying that ultrasound may benefit phenolic derivation by improving the microbial metabolism of organic acids and amino acids.