Effects of sonication on the kinetics of orange juice quality parameters

One-step ultrasound-assisted recovery of yellow-orange-red natural coloring from defatted annatto seeds: A cleaner processing alternative

The interest in natural colorants derived from sustainable processes has prompted research into obtaining bixin from defatted annatto (Bixa orellana L.) seeds. Bixin is a compound that imparts yellow-orange-red coloration, known for its high biodegradability, low toxicity, and wide industrial applicability. Meanwhile, high-intensity ultrasound (HIUS) technology has emerged as a promising method for extracting natural colorants, offering higher yields through shorter processes and minimizing thermal degradation. Although some studies have demonstrated the efficiency of HIUS technology in bixin extraction, research on the effects of acoustic cavitation on the properties of the colorant remains limited. Therefore, this study aimed to investigate the influence of HIUS-specific energy levels (0.02, 0.04, 0.12, and 0.20 kJ/g) on the chemical, physical, and morphological characteristics of annatto extracts containing bixin and geranylgeraniol. Single-step extractions of bixin using ethanol as a solvent were evaluated at various acoustic powers (4.6, 8.5, 14.5, and 20 W) and extraction times (0.5, 1, 3, and 5 min) to determine their impact on the yield of natural colorant extraction. Increasing the acoustic power from 4.6 to 20 W and extending the extraction time from 0.5 to 5 min resulted in higher yields of natural colorant, likely due to the effects of acoustic cavitation and increased heat under more intense conditions. However, elevated levels of mechanical and thermal energy did not affect the chemical properties of the colorant, as indicated by UV-Vis and FTIR spectra. Conversely, higher specific energies yielded colorants with a more intense red hue, consistent with increased bixin content, and altered the microstructure and physical state, as observed in X-ray diffractograms. Nevertheless, these alterations did not impact the solubility of the colorant. Therefore, employing a cleaner extraction procedure aided by one-step ultrasound facilitated the recovery of natural colorants and contributed to the biorefining of annatto seeds, enabling the production of a rich geranylgeraniol colorant through a sustainable approach.

Gas barrier coating based on cellulose nanocrystals and its preservation effects on mango

Mango is the "king of tropical fruits" because of its attractive appearance, delicious taste, rich aroma, and high nutritional value. However, mango keeps fast metabolizing after harvest, leading to water loss, starch conversion into sugar, texture softening, and decay. Here, a gas barrier coating based on cellulose nanocrystals (CNCs) is proposed to control the post-harvest metabolism of mango. The results of gas barrier permeability show that CNCs enhance the barrier ability of the chitosan (CS) membrane on mango by 202 % and 63 % for oxygen and water vapor, respectively. The gas-barrier coating reduces the climb in pH and the decrease in firmness by 84.9 % and 45.8 %, respectively, decelerating the conversion process from starch to sugar. Besides, introducing clove essential oil (CEO), the CEO mainly adsorbs and crystalizes on the hydrophobic facets of CNCs, presenting high compatibility, increases the antibacterial rate to nearly 100 %. As a consequence, the preservation period of the mango coated by the CNC-based membrane is at least 7-day longer than the control group. Such a gas-barrier coating based on eco-friendly composites must have excellent potential in the preservation of mango, and even for other tropical fruits.

Application of thermosonication for guava juice processing: Impacts on bioactive, microbial, enzymatic and quality attributes

The present work explores different conditions of thermosonication (TS) processing that would ensure microbiological and enzymatic safety for guava juice while simultaneously maximizing the preservation of its quality attributes. The guava juice was subjected to TS treatment (frequency: 40 kHz; power: 200 W; Temperature: 40, 60, and 80 °C; Time: 2, 6 and 10 min) and was compared with fresh and pasteurized (90 °C/60 s) juice samples. The objectives of the research work were to determine the effect of thermosonication on the quality attributes such as total soluble solids (TSS), pH, titratable acidity, cloud value, color attributes, total phenolic contents, total flavonoid contents, antioxidant activity, ascorbic acid levels, enzymatic, microbiological, and sensory properties. The thermosonicated and pasteurized samples showed no significant (p > 0.05) changes in pH, total soluble solids, and titratable acidity. TS improved the cloud value and color attributes. Furthermore, TS enhanced total phenols (10 to17%), flavonoids (5 to 25%), antioxidant activity (10.45% to 14.55%) and retention of ascorbic acid (61.98-83.32%) relative to control. Thermosonicated sample at 80 °C/10 min gives the maximum inactivation of Pectin methyl esterase (PME), Peroxidase (POD) and Polyphenol oxidase (PPO) enzymes. While both thermosonication and pasteurization drastically decreased the microbial count to undetectable levels, only TS exhibited modest improvement in sensory qualities. The results demonstrated that TS can enhance the overall safety, quality, and commercial viability of guava juice as a practical substitute to pasteurization.

Processing of verjuice by ultrasound-assisted microwave heating: An assessment on the enzyme activity retention, technological parameters, and bioactive properties

The present study evaluated the effect of ultrasonication prior to microwave heating applied at 60 °C, 70 °C, and 80 °C on the quality characteristics of verjuice. The sole microwave heating and conventional heating were also performed at the same temperature levels, and effectiveness of three different treatments were evaluated. The required treatment times were decided based on obtaining <10% pectin methylesterase (PME) activity, and ultrasound pretreatment provided the least heating durations. Turbidity, browning index, and viscosity values increased by 3.4 to 14.8-fold, 0.24 to 1.26-fold, and 9.2% to 48.0%, respectively, after all thermal treatments, while Brix values decreased by 1.4% to 15.7%. Ultrasound pretreatment revealed relatively lower browning index in all temperature levels, and almost the highest viscosity values were obtained in sonication pretreated microwave heating as compared with sole microwave and conventional heating. The minimum turbidity value (0.035) was determined in ultrasound-assisted microwave heating at 60 °C. The highest antioxidant capacity (DPPH and ABTS) values were achieved by ultrasound-assisted microwave heating (up to 4.96 and 28.4 mmol Trolox equivalent (TE)/kg, respectively) followed by microwave heating (up to 4.30 and 27.0 mmol TE/kg) and conventional heating (up to 3.72 and 26.8 mmol TE/kg). Furthermore, ultrasonication resulted in better retentions of PME residual activity during 60 days of refrigerated storage (4 °C). Ultrasound pretreatment prior to microwave heating could be a convenient approach for juice processing by reducing the required treatment time and by conserving the quality parameters.

Inactivation of Escherichia coli in an Orange Juice Beverage by Combined Ultrasonic and Microwave Treatment

The inactivation of Escherichia coli is one of the major issues in the food industry. The present study focuses on the application of a combined microwave-ultrasound system for the optimization of the inactivation of Escherichia coli ATCC 25922 in an orange juice drink. Using response surface methodology (RSM), trials were planned with a Box-Behnken Design (BBD) to maximize the impact of microwave power (A: 300-900 W), microwave treatment time (B: 15-35 s), and time of ultrasound (C: 10-30 min) on E. coli inactivation. Analysis of variance (ANOVA) was carried out and E. coli inactivation was expressed with a mathematical equation depending on the factors. The results showed that both the microwave treatment time and the time of ultrasound were effective as independent variables in eliminating the E. coli strain. However, the effect of these two variables, ultrasound and microwave exposure time, in combination was significantly greater than when examined separately. RSM modeling determined that optimal treatment conditions include 900 W microwave power, 33 s microwave treatment time, and 20 min time of ultrasound to achieve an 8-log reduction of E. coli, constituting total inactivation. The results of this study showed that ultrasound-microwave treatment is a potential alternative processing method for an orange juice beverage.

Equivalent processing for pasteurization of a pineapple juice-coconut milk blend by selected nonthermal technologies

Identifying equivalent processing conditions is critical for the relevant comparison of food quality attributes. This study investigates equivalent processes for at least 5-log reduction of Escherichia coli and Listeria innocua in pineapple juice-coconut milk (PC) blends by high-pressure processing (HPP), pulsed electric fields (PEF), and ultrasound (US) either alone or combined with other preservation factors (pH, nisin, and/or heat). The two blends (pH 4 and 5) and coconut milk (pH 7) as a reference were subjected to HPP at 300-600 MPa, 20°C for 0.5-30 min; PEF at an electric field strength of 10-21 kV/cm, 40°C for 24 µs; and US at 120 µm amplitude, 25 or 45°C for 6 or 10 min. At least a 5-log reduction of E. coli was achieved at pH 4 by HPP at 400 MPa, 20°C for 1 min; PEF at 21 kV/cm, 235 Hz, 40°C for 24 µs; and US at 120 µm, 45°C for 6 min. As L. innocua showed greater resistance, a synergistic lethal effect was provided at pH 4 by HPP with 75 ppm nisin at 600 MPa, 20°C for 5 min; PEF with 50 ppm nisin at 18 kV/cm, 588 Hz, 40°C for 24 µs; and US at 45°C, 120 µm for 10 min. The total soluble solids (11.2-12.4°Bx), acidity (0.47%-0.51% citric acid), pH (3.91-4.16), and viscosity (3.55 × 10^-3 -4.0 × 10^-3  Pa s) were not significantly affected under the identified equivalent conditions. HPP was superior to PEF and US, achieving higher ascorbic acid retention and lower color difference in PC blend compared to the untreated sample.

Effect of combined ultrasonic and enzymatic extraction technique on the quality of noni (Morinda citrifolia L.) juice

In order to obtain noni juice with high yield and good quality, the effect of combined extraction technique of enzymatic treatment (EZ) and ultrasonication (US) on the overall quality of noni juice was investigated. Moreover, the extraction performance of the EZ-US combined extraction technique was compared with that of EZ-based extraction and the US-based extraction. Response surface methodology (RSM) was designed to optimize the parameters of ultrasonic treatment, by taking consideration of the extraction efficiency, quality parameters and bioactive ingredients of noni juice. The results indicated that combined ultrasonic and enzymatic treatment achieved a synergistic effect on promoting the quality of noni juice. The maximum juice yield of 67.95 % was obtained under ultrasonication for 10 min at 600 W after enzymatic treatment (EZU). In addition, EZU-treated juice exhibited the highest contents of total phenolic and flavonoid, which were 148.19 ± 2.53 mg gallic acid/100 mL and 47.19 ± 1.22 mg rutin/100 mL, respectively, thus contributing to better antioxidant activity. Moreover, the EZU treatment significantly reduced the particle size of noni juice, and improved its suspension stability and rheological properties. FTIR results indicated that the treatments did not bring major changes in the chemical structure and the functional groups of compounds in noni juice. Therefore, EZU treatment can be successfully applied to the extraction of noni juice with better nutritional properties and overall quality.

Sensory evaluation of microwave-ultrasound treated bottle gourd juice using hybrid features of fuzzy logic and proportional odd modelling approach

In the present investigation, sensory evaluation of bottle gourd juice (BGJ) samples, obtained from microwave-ultrasound based combined treatment was performed. The raw (sample-1) and conventionally treated (sample-2) alongside microwave-ultrasound treated (sample-3) were considered for the assessment of sensory evaluation. An innovative approach of hybrid fuzzy logic and proportional odd modelling (FL-POM) was implemented for the analysis of the sensory scores. The similarity values for the juice samples and their quality attributes were resolved from the results obtained by fuzzy logic. These values were considered as input for hybridization with the POM approach. The assessed coefficients obtained from the results of POM were considered for the ranking of the samples and quality traits. The ranking of the BGJ samples was observed in the order of sample-1 > sample-3 > sample-2, and their related quality attributes ranked in the order color > taste > aroma > mouth feel. The microwave-ultrasound treated BGJ evinced as the best sample in comparison to the raw one.

Treatment of Fresh Meat, Fish and Products Thereof with Cold Atmospheric Plasma to Inactivate Microbial Pathogens and Extend Shelf Life

Assuring the safety of muscle foods and seafood is based on prerequisites and specific measures targeted against defined hazards. This concept is augmented by 'interventions', which are chemical or physical treatments, not genuinely part of the production process, but rather implemented in the framework of a safety assurance system. The present paper focuses on 'Cold Atmospheric pressure Plasma' (CAP) as an emerging non-thermal intervention for microbial decontamination. Over the past decade, a vast number of studies have explored the antimicrobial potential of different CAP systems against a plethora of different foodborne microorganisms. This contribution aims at providing a comprehensive reference and appraisal of the latest literature in the area, with a specific focus on the use of CAP for the treatment of fresh meat, fish and associated products to inactivate microbial pathogens and extend shelf life. Aspects such as changes to organoleptic and nutritional value alongside other matrix effects are considered, so as to provide the reader with a clear insight into the advantages and disadvantages of CAP-based decontamination strategies.

Design consideration and modelling studies of ultrasound and ultraviolet combined approach for shelf-life enhancement of pine apple juice

Although both ultraviolet (UV) radiation and ultrasound (US) treatment have their capabilities in microbial inactivation, applying any one method alone may require a high dose for complete inactivation, which may affect the sensory and nutritional properties of pineapple juice. Hence, this study was intended to analyse and optimise the effect of combined US and UV treatments on microbial inactivation without affecting the selected quality parameters of pineapple juice. US treatment (33 kHz) was done at three different time intervals, viz. 10 min, 20 min and 30 min., after which, juice samples were subjected to UV treatment for 10 min at three UV dosage levels, viz. 1 J/cm², 1.3 J/cm², and 1.6 J/cm². The samples were evaluated for total colour difference, pH, total soluble solids (TSS), titrable acidity (TA), and ascorbic acid content; total bacterial count and total yeast count; and the standardization of process parameters was done using Response Surface Methodology and Artificial Neural Network. The results showed that the individual, as well as combined treatments, did not significantly impact the physicochemical properties while retaining the quality characteristics. It was observed that combined treatment resulted in 5 log cycle reduction in bacterial and yeast populations while the individual treatment failed. From the optimization studies, it was found that combined US and UV treatments with 22.95 min and1.577 J/cm² ensured a microbiologically safe product while retaining organoleptic quality close to that of fresh juice.

Influence of guar gum and chitosan enriched with lemon peel essential oil coatings on the quality of pears

Pear is a typically climacteric fruit and highly perishable with a low shelf life owing to extreme metabolic activity after harvesting. The present study aimed to reduce weight loss and improve the firmness of pear during storage. The lemon peel essential oil (LPEO) has gained considerable attention due to being the richest source of bioactive compounds that behaved as a natural antioxidant agent, being cost‐effective, and being generally recognized as safe. Edible coatings equipped with a natural antioxidant agent and renewable biopolymers have gained more research fame owing to their involvement in the direction of biodegradability and food safety. In this work, edible skin coating materials (ESCMs) embedded by chitosan (1%) and guar gum (2%) were fabricated, and afterward, five concentrations of LPEO (1, 1.5, 2, 2.5, and 3.0%) were incorporated individually into the ESCMs. Findings revealed that LPEO–ESCMs significantly reduced the weight loss and improved the firmness of pear up to 45 days of storage at 4 ± 2°C. Furthermore, the LPEO–ESCMs have enhanced the antioxidant capacity, antibacterial efficiency, and malondialdehyde level of pear during storage time. It was concluded that 3% of LPEO–ESCMs improved the overall acceptability of pear fruits. Taken together, the novel insights of guar gum and chitosan‐based ESCMs entrapped with LPEO will remain a subject of research interest for researchers in the future.

Enhancing the Efficacy of Microwave Blanching-cum-black Mould Inactivation of Whole Garlic (Allium sativum L.) Bulbs Using Ultrasound: Higher Inactivation of Peroxidase, Polyphenol Oxidase, and Aspergillus niger at Lower Processing Temperatures

The freshly harvested whole garlic bulbs require the inactivation of peroxidase (POD), polyphenol oxidase (PPO), and Aspergillus niger. However, the conventional hot water blanching and modern pretreatment like ultrasound (US) and microwave (MW) cannot individually inactivate both the enzymes and Aspergillus niger to the desired levels without compromising the quality of the garlic due to either of the higher process temperatures (> 85 °C) or prolonged treatment times. Therefore, a two-stage sequential US followed by MW pretreatment for garlic bulbs was developed for simultaneous inactivation of POD, PPO, and Aspergillus niger to the desired levels and overcome the individual pretreatment drawbacks. The separate experiments were conducted for US and MW pretreatment using central composite design, and optimization was carried out using response surface methodology. When temperature constraint was considered during optimization, the US was able to reduce POD, PPO, and Aspergillus niger by 80.87%, 93.80%, and 2.60 logs, respectively, whereas MW reduced POD, PPO, and Aspergillus niger by 77.84%, 77.04%, and 1.90 logs, respectively. The US treatment (58.43 WL⁻¹ ultrasound power density for 40 min with an initial bath temperature of 60 °C) followed by MW treatment (3 Wg⁻¹ MW power density for 120 s) resulted in 90.37% POD and 92.38% PPO inactivation with 2.62 log reduction in Aspergillus niger. The maximum temperature reached in US + MW process was 83 °C which ensured no severe thermal damage to the garlic bulbs. The scanning electron microscopic images indicated that ultrasonication induced the porous structure in garlic and helped microwaves increase the product temperature rapidly and achieve the higher inactivation of enzymes and Aspergillus niger. Thus, the US was found to be enhancing the efficacy of the MW heating process.

Evaluating ultrasound pre-treatment as a tool for improving the process of a fermented beverage made from pineapple by-products

Abstract Fermentation has the potential of converting fruit by-products into value-added products via an efficient, sustainable, and low-cost process. Traditionally, Mexicans use pineapple residues to produce a fermented beverage called tepache. As this soft drink is increasingly consumed in restaurants, it is necessary to develop an effective and reliable process to yield a final product with desirable physicochemical properties. In this work, tepache was prepared using an ultrasound pre-treatment to enhance the fermentation process and improve the end-product quality. The ultrasound was provided by a probe (25 kHz, 400 W) submerged in pineapple preparations before fermentation. Characterization of physicochemical properties was performed on samples processed under different types of amplitude (20 and 100%) and sonication time (5 and 10 min). In all samples, the pH, acidity, and ºBrix values were similar to those in commercial tepaches. On the other hand, microscopy revealed that 5 min of sonication induced positive changes in the suspended matter responsible for the physical stability of fruit beverages. The tepaches obtained with this method had color uniformity. Indeed, 5 min of sonication at the highest amplitude (16.34 kJ・cm-2) augmented the soluble solids during the initial phases of fermentation. Moreover, the results from IR spectroscopy proved that ultrasound helped the ethanol release from yeasts. The maximum ethanol yield, calculated by model fitting, had a positive variation of 35%. These findings prove that ultrasound is capable to induce physicochemical changes useful for the industrial production of tepache.

Ultrasound assisted modulation of yeast growth and inactivation kinetics

The yeast Saccharomyces cerevisiae is well known for its application in the food industry for the purpose of developing fermented food. The ultrasound (US) technology offer a wide range of applications for the food industry, including the enhancement of fermentation rates and inactivation of microbial cells. However, a better understanding and standardization of this technology is still required to ensure the scaling-up process. This study investigated the effect of the US technology on the growth of S. cerevisiae using frequencies of 20, 25, 45 and 130 kHz, treatment periods from 2 to 30 min. Furthermore, yeast kinetics subjected to US treatments were evaluated using modelling tools and scanning electron microscopy (SEM) analysis to explore the impact of sonication on yeast cells. Yeast growth was monitored after different US treatments plotting optical density (OD) at 660 nm for 24 h at 30 ⁰C. Growth curves were fitted using models of modified Gompertz and Scale-Free which showed good parameters of the fit. In particular, US frequencies of 45 and 130 kHz did not have a disruptive effect in lag phase and growth rate of the yeast populations, unlike the frequency of 20 kHz. Moreover, inactivation curves of yeast cells obtained after exposure to 20 and 25 kHz also observed the best fit using the Weibull model. US frequency of 20 kHz achieved significant reductions of 1.3 log cfu/mL in yeast concentration and also induced important cell damage on the external structures of S. cerevisiae. In conclusion, the present study demonstrated the significant effect of applying different US frequencies on the yeast growth for potential application in the food industry.

Ultrasonication of Thawed Huyou Juice: Effects on Cloud Stability, Physicochemical Properties and Bioactive Compounds

In order to remove the flocculent precipitation in Huyou juice after frozen storage and thawing process, the thawed juice was ultrasonically treated with different power (45-360 W) and time (10-60 min) in ice bath (~0 °C), and its sedimentation behavior during storage was observed. After optimization, the cloud stability of juice could be improved by ultrasonic treatment with ultrasonic power of 360 W or more for at least 30 min, which could be stable during 7 days of storage at 4 °C. Under this optimal condition (360 W, 30 min), the effects of ultrasound on the physicochemical properties and bioactive compounds of thawed Huyou juice during storage were investigated. The results showed that with smaller particle size and lower polymer dispersity index, ultrasonic treatment did not significantly change the color, soluble solids, titratable acidity, and bioactive compounds including flavonoids and other phenolics. In addition, all properties of samples were at the same level during storage. Thus, ultrasound was applicable since it can improve the cloud stability of Huyou juice with minimal impact on its physicochemical properties and nutritional quality compared to the untreated one.

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.

Effect of high frequency ultrasound pre-treatment on nutritional and technological properties of tomato paste

This study investigates the separate effect of sonication (US, carried out for 5 and 15 min) and thermal treatment (90 °C for 5 min) on nutritional and technological properties of tomato paste. US treatments did not affect the colour parameters and decreased the level of total acidity. Ascorbic acid content was slightly reduced after 5 min US but halved by pasteurization, while total carotenoids (TCC) and lycopene (LC) decreased in non-pasteurized samples after 15 min US. Neither the TCC nor the LC significantly changed in US-pasteurized samples if compared to controls. Microscopic analyses suggested a possible increased bioaccessibility of lycopene in US treated samples due to an enhancement of free lycopene clusters. Viscosity decreased as a consequence of thermal stress, although sonication contributed as well. The present findings suggest that 5 min sonication before pasteurization can enhance the nutritional characteristics of tomato paste, besides improving its texture.

Solubility study and intensification of extraction of phenolic and anthocyanin compounds from Oryza sativa L. 'Violet Nori'

Oryza sativa L. 'Violet Nori' is an Italian cultivar of spontaneous growing aromatic purple rice which is particularly rich in polyphenolic compounds, especially anthocyanins, conferring it an excellent antioxidant capacity. The present study aimed at increasing the extraction yields of its antioxidant compounds with green strategies and it is divided into two steps. The first step concerned a solubility study of the targeted polyphenols in different ethanol:water mixtures by means of a theoretical prediction method, using the simulation program COSMO-RS, and the subsequently confirmation of the computational results by practical experiments. Once the best extraction mixture was identified, the second step of the work was performed, with the purpose of intensifying the extraction yield. Therefore, various innovative green extraction techniques, including ultrasound, using both the probe system and the ultrasonic bath, bead milling, microwave and accelerated solvent extractions were tested and compared to conventional maceration. Results, expressed in terms of total phenolic and total monomeric anthocyanin contents, showed that the best extracting solvent for 'Violet Nori' rice was the mixture ethanol:water (60:40 v/v), being COSMO-RS computational predictions in good correlation with the experimental results. Moreover, the most efficient techniques to extract the antioxidant compounds resulted to be both ultrasound-assisted extraction probe and bead milling, that in only 5 min got the same extractive efficiency obtained after 3 h of conventional maceration.

Effect of Stand-Alone and Combined Ultraviolet and Ultrasound Treatments on Physicochemical and Microbial Characteristics of Pomegranate Juice

The objective of this study was to determine the combined usage possibilities of ultraviolet (UV) and ultrasonic (US) processes in the pasteurization of pomegranate juice. For this purpose, UV, US, and combined UV+US pasteurization of pomegranate juice were optimized using experimental designs, such as the Central Composite Design (CCD) and Factorial Design (FD), and compared with the conventional pasteurization process. Total phenolic content (TPC), color a*, water-soluble dry matter (°Brix), turbidity, anthocyanin, DPPH, HPLC TPC, and yeast and mold count were used as quality parameters during all of the processes. The results showed that the application of 50 °C, 3.5 L/min flow rate and 5.1 mW/cm2 UV dose, and 10 min US (200 Watt) together reduced the microbial population below the detection limits. The integration of UV+US processes into the pasteurization process could limit microbial activity at lower temperatures and times than the conventional pasteurization process, thus preserving the existing bioactive compounds.

Lactobacillus plantarum-derived biosurfactant: Ultrasound-induced production and characterization

The aim of the present study was to investigate the effect of ultrasonic treatment (25 kHz) on biosurfactant production by Lactobacillus plantarum ATCC 8014. The impacts of the ultrasonication (with a frequency of 25 kHz and power of 7.4 W for 30 min time duration) were examined at different stages of the fermentation process to obtain the optimum stimulation instant(s). The optimum scenario was found to be one-time sonication at the 12^th hour of fermentation which can be beneficial from an economic point of view (compared with multiple applications of sonication). Ultrasonic treatment at this time resulted in enhancement of the productivities of biomass (4.5 g/L) and biosurfactant (2.01 g/L) which was almost 1.3 times higher than those of the non-sonicated control samples. According to our results, it was clearly observed that glucose consumption increased after ultrasonic treatment representing the improved substrate uptake and progression of the cellular metabolism. Furthermore, the transmission electron microscopic images immediately after sonication clarified the pore formation on the cell surfaces. The results also indicated the enhancement of plasma membrane permeability of the sonicated cells. Fourier transform infrared spectroscopy and scanning electron microscopy coupled with energy dispersive x-ray spectroscopy analyses also disclosed respectively no structural differences before and after ultrasonic exposure in the produced biosurfactant and bacterial cell membrane. The biosurfactant was characterized to be a mixture of carbohydrate (28%), protein (23%) and lipid (specified by gas chromatography-mass spectrometry) known as glycolipoprotein. The sustainable critical micelle concentration and the stability of the synthesized biosurfactant can feature its potential applicability in various processes in the food and pharmaceutical industries.

Impact of Different Pasteurization Techniques and Subsequent Ultrasonication on the In Vitro Bioaccessibility of Carotenoids in Valencia Orange (Citrus sinensis (L.) Osbeck) Juice

The effects of traditional pasteurization (low pasteurization, conventional pasteurization, hot filling) and alternative pasteurization (pulsed electric fields, high pressure processing), followed by ultrasonication on the carotenoid content, carotenoid profile, and on the in vitro carotenoid bioaccessibility of orange juice were investigated. There was no significant difference in the total carotenoid content between the untreated juice (879.74 µg/100 g juice) and all pasteurized juices. Significantly lower contents of violaxanthin esters were found in the high thermally-treated juices (conventional pasteurization, hot filling) compared to the untreated juice, owing to heat-induced epoxy-furanoid rearrangement. The additional ultrasonication had almost no effects on the carotenoid content and profile of the orange juices. However, the in vitro solubilization and the micellarization efficiency were strongly increased by ultrasound, the latter by approximately 85.3-159.5%. Therefore, among the applied processing techniques, ultrasonication might be a promising technology to enhance the in vitro bioaccessibility of carotenoids and, thus, the nutritional value of orange juice.

Infrared drying of dill leaves: Drying characteristics, temperature distributions, performance analyses and colour changes

Thin-layer drying behaviour of dill leaves samples under three different infrared radiation power intensities was investigated. Diffusion Approach was found to be the best model that describes the drying behaviour of dill leaves. Effective diffusivity values were 6.97 × 10^-9, 6.84 × 10^-9 and 8.96 × 10^-9 m²/s for power intensities of 1790, 1970 and 2070 W/m², respectively. According to the first and second law efficiencies, the infrared drying system was more efficient at higher power intensities (p < 0.05). However, the total colour change was maximum at the highest power intensity. For the investigated infrared drying conditions, 1970 W/m² was recommended as the best-infrared power intensity applied for drying of dill leaves by taking into account both performance analyses and quality changes.

Effect of particle size on the stability and flavor of cloudy apple juice

Different particle sizes in cloudy apple juice were obtained following filtration with different mesh sizes (100, 200, 300, and 400-mesh). The effects of cloud particle size on the stability, nutrient content, and volatile flavor of cloudy apple juice were evaluated. With increasing mesh number, particle size decreased (p < 0.05) and particle shape changed. Particle size had an effect on volatile flavor compounds, especially nitrogen oxides, alcohols, and aromatic compounds. The content of pectin and total phenol decreased with decreasing particle size, while the content of soluble protein was not affected. The reduction of cloud particle size increased absolute value of ζ-potential, cloud stability, and apparent viscosity and decreased turbidity and cloud values. Pearson correlation analysis showed that there was a strong correlation between particle size and quality indicators, except for soluble protein.

Xylooligosaccharides chemical stability after high-intensity ultrasound processing of prebiotic orange juice

The effects of the high-intensity ultrasound (HIUS) technology at the nominal powers of 300, 600, 900, and 1200 W were evaluated on the chemical stability of xylooligosaccharides (XOS) used to enrich orange juice. The ultrasound energy performance for each nominal power applied to the XOS-enriched orange juice was determined by calculating acoustic powers (W), HIUS intensity (W/cm²), and energy density (kJ/mL). Physicochemical properties (pH and soluble solid content), organic acid content (ascorbic, malic, and citric acids), total phenolic content (TPC), antioxidant activity by the FRAP (Ferric reducing ability of plasma) method, sugar (glucose, fructose, and sucrose), and XOS (xylobiose, xylotriose, xylotetraose, xylopentaose, and xylohexaose) content were determined. The pH and soluble solid content did not change after all HIUS treatments. The HIUS process severity was monitored by quantifying ascorbic acid content after the treatments. A significant linear decrease in the ascorbic acid content was observed in prebiotic orange juice with the HIUS process intensification by increasing nominal power. The malic acid and citric acid contents had similar behavior according to the HIUS process intensification. The nominal power increase from 300 to 600 W increased the concentration of both organic acids, however, the intensification up to 1200 W reduced their concentration in the functional beverage. The TPC and FRAP data corroborated with the results observed for the ascorbic acid content. However, the HIUS processing did not alter sugar and XOS contents. The XOS chromatographic profiles were not modified by the HIUS treatment and presented the same amount of all prebiotic compounds before and after the HIUS treatment. Overall, HIUS technology has been evaluated as a promising stabilization technique for prebiotic beverages enriched with XOS due to their high chemical stability to this emerging technology under severe process conditions.

Recent nano-, micro- and macrotechnological applications of ultrasonication in food-based systems

There is a neoteric and rising demand for nutritional and functional foods which behooves food processors to adopt processing techniques with optimal conservation of bioactive components in foods and with minimal pernicious impacts on the environment. Ultrasonication, a mechanochemical technique has proven to be an efficacious panacea to these concerns. In this review, an analytic exploration of recent researches and designs regarding ultrasound methodology and equipment on diverse food systems, technological scales, procedural parameters and outcomes of such experimentations optimally scrutinized. The relative effects of ultrasonication on food formulations, components and attributes such as nanoemulsions, nanocapsules, proteins, micronutrients, sensory and mechanical characteristics are evaluatively delineated. In food systems where ultrasonication was employed, it was found to have a remarkable effect on one or more quality parameters. This review is a supplementation to the pedagogical awareness to scholars on the suitability of ultrasonication for research procedures, and a call to industrial food brands on the adoption of this technique for the development of foods with optimally sustained nutrient profiles.

Interaction and multi-objective effects of multiple non-thermal treatments of sour cherry juice: pesticide removal, microbial inactivation, and quality preservation

BACKGROUND

The consumption of pesticide-contaminated sour cherries as fruit or juice has become a major health concern, and so the search for alternative processing technologies, such as pulsed electric fields (PEF), ozone (O), and ultrasonication (US) has intensified. The objectives of this experimental study of sour cherry juice were fourfold: (1) to quantify the removal efficiency of new processing technologies (PEF, O, US), and their combinations, for the pesticides chlorpyrifos ethyl, τ-fluvalinate, cyprodinil, pyraclostrobin, and malathion; (2) to detect their impact on physical, bioactive, and sensory properties; (3) to determine their microbial inactivation levels for Escherichia coli O157:H7, Bacillus cereus, Pseudomonas syringae subs. Syringae, and Penicillum expansum; and (4) to jointly optimize multiple responses of physical, quality, and sensory properties, pesticides, and microbial inactivation.

RESULTS

Except for all the O treatments, the physical, bioactive and sensory properties of sour cherry juice were not adversely affected by the treatments. The joint optimization suggested PEF1 (24.7 kV cm^-1 for 327 μs), PEF2 (24.7 kV cm^-1 for 655 μs), PEF2 + O + US, US, and PEF2 + O as the five best treatments. PEF2 + O + US best achieved both pesticide removal and microbial inactivation.

CONCLUSION

PEF2 + O + US provided promising reductions in pesticide and microbial loads. © 2019 Society of Chemical Industry.

Ultrasound-assisted forward osmosis desalination using inorganic draw solutes

Internal concentration polarization (ICP) represents a serious challenge in forward osmosis (FO) desalination since it causes a significant decline in the water flux across the membrane. Mitigation of ICP is cumbersome since the phenomenon occurs within the membrane porous support layer and mitigation procedures such as inducing turbulence or changing the hydrodynamic conditions tend to be ineffective. In this study, the effect of 40 kHz ultrasound on FO desalination of synthesized brackish and seawater was investigated. The studied process utilizes two different inorganic draw solutes (magnesium and copper sulfate) that are available commercially, can generate high osmotic pressures, and can be easily separated from the product water. Different concentrations of the draw solutions were considered. Results show that the applied ultrasound was effective in partially mitigating the ICP effects and enhancing the water flux. Depending on the feed and the draw solution concentration, flux enhancements of up to 34.6% and 43.9% were observed with magnesium sulfate and copper sulfate draw solution, respectively. In addition, it was observed that the effect of ultrasound on flux enhancement was more evident at lower draw solution concentrations. Although water flux was enhanced, ultrasound resulted in an increased reverse draw solute flux across the membrane.

Comparison of High Hydrostatic Pressure, Ultrasound, and Heat Treatments on the Quality of Strawberry-Apple-Lemon Juice Blend

Changes in the microbial, physicochemical, and sensory properties of blended strawberry–apple–lemon juice were investigated to comparatively assess the influence of three processing treatments, namely high hydrostatic pressure (HHP) (500 MPa/15 min/20 °C), ultrasound (US) (376 W/10 min/35 °C), and heat treatment (HT) (86 °C/1 min) over 12 days of storage at 4 °C. The results showed that the total aerobic bacteria (TAB) counts in the HHP-, US-, and HT-treated juice blends were less than 2 log₁₀ CFU/mL, the yeast and mold (Y & M) counts were less than 1.3 log₁₀ CFU/mL, and the coliforms most probable number (MPN/100 mL) was less than 3 after 10 days at 4 °C. Anthocyanins were maintained by HHP, but decreased by 16% and 12% after US and HT, respectively. Total phenols increased by 18% and 7% after HHP and US, respectively, while they were maintained by the HT. Furthermore, better maintenance of total phenols, total anthocyanins, ascorbic acid, antioxidant capacity, color, and sensory values were observed in the HHP-treated juice blend stored for 10 days at 4 °C, compared to both the US- and HT-treated samples. Therefore, HHP was proposed to be a better processing technology for juice blend.

Chemical-free and synergistic interaction of ultrasound combined with plasma-activated water (PAW) to enhance microbial inactivation in chicken meat and skin

In general, the poultry industry uses 0.5–1 ppm chlorine solution in the meat sanitization process. However, chlorine can react with organic material and produce halogenated organic compounds, notably chloroform, which causes bladder and rectal cancer in humans. For this reason, many industries try to avoid chlorine. This study investigated the efficacy of ultrasound and plasma-activated water (PAW) on the inactivation of Escherichia coli and Staphylococcus aureus in chicken muscle, rough skin, and smooth skin. Samples inoculated with bacteria suspension were treated by ultrasound alone and PAW–ultrasound. The Taguchi method and desirability function approach were used for the experimental design and optimization. Combined ultrasound and PAW inactivated up to 1.33 log CFU/ml of E. coli K12 and 0.83 log CFU/ml of S. aureus at a sample thickness of 4 mm, at 40 °C for 60 min, while PAW alone only reduced E. coli K12 by 0.46 log CFU/ml and S. aureus by 0.33 log CFU/ml under the same condition. The muscle topography showed a porous structure, which facilitated the penetration of PAW. The color measurements of muscle treated with ultrasound and PAW–ultrasound were dramatically different from the untreated sample, as also perceived by the sensory evaluation panel. Therefore, the synergistic interaction of combined PAW–ultrasound could be used to enhance microbial inactivation in meat.

Effects of combination treatments of lysozyme and high power ultrasound on the Salmonella typhimurium inactivation and quality of liquid whole egg

An investigation was conducted into the utilization of treatments combining ultrasound and lysozyme (US + Lys) to deactivate Salmonella typhimurium (S. typhimurium) in the liquid whole egg (LWE). Furthermore, US + Lys and heat treatment (HT) with a similar microbial inactivation effect were comparatively evaluated by examining their impact on the quality attributes of LWE. The LWE was treated with US at 35-45 °C and 605-968 W/cm² for 5-35 min, and with HT at 58-64 °C for 3-4 min. Lysozyme (Lys) alone achieved a minimal degree of inactivation in S. typhimurium, while it was enhanced with the application of US alone when the treatment temperature, time, and energy were increased. Furthermore, US and US + Lys caused a reduction of 3.31 and 4.26 log₁₀ cycles in S. typhimurium, respectively at 968 W/cm² and 35 °C for 20 min, indicating a synergistic relationship between US and Lys for the effective inactivation of S. typhimurium. Similarly, HT and HT + Lys achieved a reduction of 4.10 and 4.75 log₁₀ cycles at 64 °C/3 min, respectively. The L* and b* values of the LWE following US and US + Lys application were significantly higher than untreated and heat-treated LWE, indicating that US treated LWE had a brighter and yellower appearance. The protein solubility (PS) slightly decreased after all treatments, while the pH increased. Furthermore, the foaming capacity (FC) and foam stability (FS) were decreased, revealing that LWE had a lower FC and unstable foam after all treatments. Therefore, US and US + Lys could increase the viscosity and gelation temperature (Tg) of LWE, indicating that LWE exhibited higher heat resistance after US treatment. These results indicated that US + Lys might be a promising pasteurization technology in the processing of LWE.

Ultrasound-Assisted Enzyme-Catalyzed Hydrolysis of Collagen to Produce Peptides With Biomedical Potential: Collagenase From Aspergillus terreus UCP1276

Ultrasound has been applied for varied purposes as it provides additional mechanical energy to a system, and is still profitable and straightforward, which are advantages for industrial applications. In this work, ultrasonic treatments were applied to purified collagenase fractions from a fermented extract by Aspergillus terreus UCP 1276 aiming to evaluate the potential effect on collagen hydrolysis. The physical agent was evaluated as an inductor of collagen degradation and consequently as a producer of peptides with anticoagulant activity. The sodium dodecyl sulphate-polyacrylamide gel electrophoresis analyses were also carried out to compare the hydrolysis techniques. The ultrasound (40 kHz, 47.4 W/L) processing was conducted under the same conditions of pH and temperature at different times. The ultrasound-assisted reaction was accelerated in relation to conventional processing. Collagenolytic activity was enhanced and tested in the presence of phenylmethanesulfonyl fluoride inhibitor. Underexposure, the activity was enhanced, reaching more than 72.0% of improvement in relation to the non-exposed enzyme. A period of 30 min of incubation under ultrasound exposure was enough to efficiently produce peptides with biological activity, including anticoagulation and effect on prothrombin time at about 60%. The results indicate that low-frequency ultrasound is an enzymatic inducer with likely commercial applicability accelerating the enzymatic reaction. Bioelectromagnetics. 2020;41:113-120. © 2019 Bioelectromagnetics Society.

Stimulation of biosurfactant production by Lactobacillus plantarum using ultrasound

Due to their nonpathogenic status, biosurfactants produced by Lactobacillus strains have been shown to have potential applicability in several industrial sectors, particularly food and pharmaceutical industries. However, products with high efficiency are needed to fulfill the demand for these biosurfactants. Therefore, the present study investigated kinetic parameters, biomass and biosurfactant production of Lactobacillus plantarum ATCC 8014 applying standard MRS and modified MRS (supplemented standard MRS by nitrogen and carbon sources) culture medium under various ultrasonic frequencies of 20, 25, 35, 45, 130 and 950 kHz to obtain more efficient conditions. The optimum conditions were found when using the modified MRS treated by the frequency of 25 kHz (the power of 7.4 W) for 30 min, which led to a significant effect on the growth rate (µ_max, h^-1) rather than control. Furthermore, this condition caused the highest population (10.07 ± 0.1 log CFU/mL) and biomass concentration (4.33 ± 0.06 g/L), and lowest surface tension (39.26 ± 0.5 mN/m), leading to higher biosurfactant production. Hence, given the results of the present study, it can be established that controlled ultrasound exposure and supplementation of culture media using the main growth factors can intensify the microbial activity and the productivity of biological processes.