Ultrasound treatment: effect on physicochemical, microbial and antioxidant properties of cherry (Prunus avium)

Fabrication of millet starch nanocapsules loaded with beta carotene using acid hydrolysis and ultrasonication: Characterisation, release behaviour and bioactivity retention

The acid hydrolysis process was used to create novel millet starch-based nanoparticles from three different sources: sorghum, foxtail millet and pearl millet. An environment-friendly, risk-free ultrasonication technique was used for encapsulating beta carotene in starch nanoparticles to create nanocapsules that will shield the bioactivity of beta carotene in gastrointestinal conditions and increase its accessibility after consumption. Formulated nanocapsules were examined for zeta potential, particle size and encapsulation efficiency. The particle dimensions of beta carotene-loaded sorghum (SSB), foxtail millet (FSB), and pearl millet (PSB) starch nanoparticles were 416, 399 and 587 nm with zeta potential of -17.98, -19.03 and -22.31 mV respectively. Encapsulation efficiencies of nanocapsules were found to be 85.83, 89.65 and 78.32 % for SSB, FSB and PSB respectively. Scanning electron microscopy (SEM) was also harnessed as a confirmatory tests towards the presence of beta carotene in nanocapsules. Beta carotene encapsulation in starch nanoparticles was also demonstrated using ATR-FTIR which revealed broad characteristic peaks at 3000, 1086 and 885 cm-1 that occur without any discernible interaction. Intestinal juice with higher beta carotene content ensured controlled release in the intestine. Encapsulated beta carotene showed more bioactive properties in terms of antioxidant activity as compared to free beta carotene form.

Formulation of Functional Liquid Diets Under IDDSI Levels 0 to 2 for Dysphagia Patients: Physico-Chemical, Sensory, Antioxidant and Electromyographic Oral Processing Analyses

Dysphagia is a significant health concern especially amongst the old age population. It is an ailment brought on by the weakening of the swallowing muscles. To reduce the risk of choking in dysphagia patients, the food is usually diluted to suit their swallowing ability. But dilution results in reducing the nutritional density of the foods thus causing undernutrition and malnutrition in patients. In this study, functional liquid diets were formulated under International Dysphagia Diet Standardization Initiative (IDDSI) levels 0-2. The developed diets were analysed for their proximate composition, colour, antioxidant and sensory properties. Antioxidant activities were determined using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+), 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and total phenolic content (TPC) methods. The highest ABTS+ value was observed in pumpkin puree (level-2) i.e. 98.59%. Black carrot juice (level-1) showed the highest DPPH free radical scavenging activity and FRAP value viz. 88.43% and 689.33 µM TE/g, respectively. Electromyography (EMG) is an upcoming technique of food texture evaluation which provides real-time information about food oral processing. In this study, an EMG was conducted to measure the myoelectrical activity of human suprahyoid and masseter muscles by placing electrodes on the skin's surface during the oral processing of liquid. The EMG parameters correlated significantly with viscosity, ease of swallowing and IDDSI levels of the formulated diets. Hence EMG can be used as a tool for design and development of textured-modified diets for dysphagia patients. The sensory scores of formulated diets in this study were high indicating that these liquid diets may be incorporated into the diet plans of dysphagia patients.

Improvement of shelf-life of cherry (Prunus avium L.) by combined application of modified-atmosphere packaging and antagonistic yeast for long-distance export

BACKGROUND

The last decade has seen a growing interest in reducing the use of chemical fungicides for postharvest decay control. In the research for new, safe alternatives, the combined application of biocontrol agents and passive modified-atmosphere packaging (MAP) has been shown to be a promising strategy to extend fruit quality. Therefore, the aim of this work was to evaluate the effect of the combined application of MAP and two antagonistic yeasts, Metschnikowia pulcherrima L672 and Pichia kudriavzevii PK18, on sweet cherry shelf life.

RESULTS

Microbiological, physico-chemical, and quality fruit analysis from batches treated with antagonistic yeast were compared with a control batch without yeast application and a batch to which fludioxonil (Scholar®) was applied. The composition of the atmosphere and physico-chemical traits showed similar values among the different batches during cold storage. However, interestingly, the combination of MAP with the antagonistic yeasts M. pulcherrima L672 and P. kudriavzevii PK18 increases the control of microbiological spoilage with results comparable to the application of fludioxonil. In addition, these batches experienced a slight decrease in volatile compounds associated with fresh fruit aroma, whereas in the control batch an increase of altered fruit aromas was observed. The same effect of control of spoilage was observed during the shelf life period.

CONCLUSION

These results showed the positive effect of the combination of antagonistic yeasts and MAP, obtaining similar results in terms of control of microbiological spoilage and physico-chemical quality compared with the application of fludioxonil. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Effect of ultrasound assisted cleaning on pesticide removal and quality characteristics of Vitis vinifera leaves

In this study, the pesticide (acetamiprid, deltamethrin, and pyridaben) removal and physicochemical quality improvement of vine (Vitis vinifera) leaf were examined using ultrasonic and traditional cleaning for 5, 10, and 15 min. After an ultrasonic cleaning procedure at 37 kHz for 10 min, acetamiprid, deltamethrin, and pyridaben in vine leaf were reduced by 54.76, 58.22, and 54.55 %, respectively. Furthermore, the total phenolic content (TPC) in vine leaf increased to 13.45 mg GAE/g DW compared to that in control samples using traditional cleaning (10.37 mg GAE/g DW), but there were no significant differences in DPPH radical scavenging activity. After 15 min of conventional cleaning, the total chlorophyll and total carotenoid content of leaves were found to be lowest among all samples, at 6.52 mg/kg and 0.48 mg/kg, respectively. In conclusion, when compared to conventional cleaning methods, ultrasonic cleaning with no chemicals or heat treatment has proven to be a successful and environmentally friendly application in reducing commonly used pesticides and improving the physicochemical qualities of leaves.

Transcriptomic and physiological analysis reveals the possible mechanism of ultrasound inhibiting strawberry (Fragaria × ananassa Duch.) postharvest softening

Ultrasound effectively inhibited strawberry softening but the mechanism was not clear. In this study, physical data including firmness, soluble pectin (SP) contents, pectin esterase (PE), polygalacturonase (PG) activity and transcriptome sequencing data were analyzed to explore the mechanism of strawberry response to ultrasonic treatment. After 24 days storage, the firmness reduction rate and soluble contents (SP) increased rate of the strawberry treated with ultrasound (25 kHz, 0.15 W/cm2) for 3 min decreased 41.70 and 63.12% compared with the control, respectively. While the PG and PE enzyme activities of ultrasound-treated strawberries were significantly lower than control after storage for 18 days. A total of 1,905 diferentially expressed genes (DEGs) were identified between ultrasound-treated and control, with 714 genes upregulated and 1,254 genes downregulated, including 56 genes in reactive oxygen species (ROS), auxin (AUX), ethylene (ETH) and jasmonic acid (JA) signaling pathways. At 0 h, 15 genes including LOX, JMT, ARP, SKP, SAUR, IAA, ARF, and LAX were significantly upregulated compared with the control group, which means reactive oxygen specie, auxin, ethylene and jasmonic acid-mediated signaling pathway respond to ultrasound immediately. ERF109, ERF110, and ACS1_2_6 downregulated before 2 days storage indicated ethylene signaling pathway was inhibited, while after 2 days, 9 genes including ERF027, ERF109, and ERF110 were significantly upregulated indicating that the response of the ethylene signaling pathway was lagging. Therefore, in strawberry ultrasound enhanced ROS scavenging and activated JA biosynthesis, which acts as a signal for delaying the activation of ET signaling pathway, thus suppressing the activity of pectin-degrading enzymes PE and PG, and ultimately inhibiting postharvest softening.

Use of Ultrasonic Cleaning Technology in the Whole Process of Fruit and Vegetable Processing

In an era of rapid technological development, ultrasound technology is being used in a wide range of industries. The use of ultrasound technology in fruit and vegetable processing to improve production efficiency and product quality has been an important research topic. The cleaning of whole fresh fruits and vegetables is an important part of fruit and vegetable processing. This paper discusses the development process of components of the ultrasonic equipment, the application of ultrasonic technology in fruit and vegetable cleaning, and the research advances in ultrasonic cleaning technology. Moreover, the feasibility of ultrasonication of fruits and vegetables for cleaning from the perspectives of microbial inactivation, commodity storage, and sensory analysis were discussed. Finally, the paper identified the inevitable disadvantages of cavitation noise, erosion, and tissue damage in fruit and vegetable processing and points out the future directions of ultrasonic fruit and vegetable cleaning technology.

Extending the Shelf Life of Fresh Khalal Barhi Dates via an Optimized Postharvest Ultrasonic Treatment

The Barhi date is a high-quality date cultivar whose fruits (dates) are plucked and eaten fresh when they reach the Khalal maturity stage due to their sweetness, crispiness, and yellow skin color. After harvesting, Khalal Barhi fruits rapidly matured to the Rutab stage, where their tissues become soft and their skin color browner. This results in a decrease in their market value and customer demand. This study aims at investigating the effectiveness of the postharvest ultrasonic treatment in conserving the physical, microbial, and nutritional quality of Barhi fruits and extending their shelf life. To achieve the goals of the present work, the response surface methodology (RSM) was used for the optimization of the ultrasonic intensity (50, 100, 150, and 200 W/cm²) and application time (5, 10, 15, and 20 min) to preserve the Barhi dates high quality features for varied storage temperatures (1, 5, 15, and 25 °C) and duration (1, 6, 16, and 21 days). In RSM, a four-factors-mixed-levels central composite rotatable design (CCRD) was applied to optimize the ultrasound treatment and storage environments for better-quality physical [total soluble solids (TSS), firmness, and total color changes (ΔE)], microbial [total viable count (TVC)], nutritional [total phenolic content (TPC), DPPH antiradical activity, glucose, and fructose] features of Barhi dates. The outcomes showed that ultrasound intensity and its application time, storage temperature, and storage period influence the physical, microbial, and nutritional quality attributes in different magnitudes. The ideal settings for lessening the changes in the physical attributes, eliminating the microbial growth, and improving the nutritional quality attributes were 140 W/cm², 5.2 min, 20.9 °C, and 21 days for ultrasound intensity, ultrasound exposure duration, storage temperature, and storage duration, respectively. In conclusion, this study proved the potential application of ultrasound for persevering the excellence aspects of Barhi dates and identified the ideal ultrasound environments for maintaining the physical, microbial, and nutritional quality features of Barhi dates during extended storing.

Application of ultrasonic incorporated with calcium gluconate maintains physicochemical quality of pink guavas during short-term storage at room temperature

The effectiveness of simultaneous calcium gluconate (0.5% w/v) (Ca-G) and ultrasonication (Ca-G + US) on physicochemical quality of pink guavas under room temperature (27 ± 1 °C) was monitored. The fruits were sonicated for 2, 4, 6 and 8 min and the untreated fruits were defined as control. Peel discoloration and black spot disease were evidently controlled by Ca-G + US for 4 min. The treatment delayed the loss of acidity and total chlorophylls content and the increase in total carotenoids content. The fruit softening and cell membrane permeability and peroxidation were retarded by Ca-G + US for 4 min. Ca-G + US for 4 min enhanced ascorbic acid content and maintained total phenols content and antioxidant activity. In conclusion, the application of Ca-G + US for 4 min is feasible approach maintaining physicochemical quality such as peel color, texture and nutritional value of pink guavas during the short-term storage.

Ultrasound and its combined application in the improvement of microbial and physicochemical quality of fruits and vegetables: A review

The eating safety and high quality of fruits and vegetables have always been concerned by consumers, so require a safe, non-toxic, environment-friendly technology for their preservation. The application of ultrasound is a potential technology in the preservation of fruits and vegetables. This paper describes the ultrasound mechanism for inactivating microorganisms, with the cavitation phenomena of ultrasound being considered as a main effect. Effect of ultrasound on microorganisms of fruits and vegetables was discussed. Ultrasound alone and its combined treatments can be an effective method to inactivate the spoilage and pathogenic microorganisms on the surface of fruit and vegetables. Effect of ultrasound on physicochemical quality of fruits and vegetables was reviewed. Ultrasound and its combined treatments reduced mass loss, decreased color change, maintained firmness, enhanced and inhibited enzyme activity as well as preserving nutritional components such as total phenolic, total flavonoids, anthocyanin, and ascorbic acid.

Impact of high-intensity thermosonication treatment on spinach juice: Bioactive compounds, rheological, microbial, and enzymatic activities

To study the impacts of thermosonication (TS), the spinach juice treated with TS (200 W, 400 W, and 600 W, 30 kHz, at 60 ± 1 °C for 20 mint) were investigated for bioactive compounds, antioxidant activities, color properties, particle size, rheological behavior, suspension stability, enzymatic and microbial loads. As a result, TS processing significantly improved the bioactive compounds (total flavonols, total flavonoids, total phenolic, carotenoids, chlorophyll, and anthocyanins), antioxidant activities (DPPH and FRAP assay) in spinach juice. Also, TS treatments had higher b*,L*, hue angle (h0), and chroma (C) values, while minimuma* value as compared to untreated and pasteurized samples. TS processing significantly reduced the particle size, improved the suspension stability and rheological properties (shear stress, apparent viscosity, and shear rate) of spinach juice as compared to the untreated and pasteurized sample. TS plays a synergistic part in microbial reduction and gained maximum microbial safety. Moreover, TS treatments inactivated the polyphenol oxidase and peroxidase from 0.97 and 0.034 Abs min-1 (untreated) to 0.31 and 0.018 Abs min-1, respectively. The spinach juice sample treated at a high intensity (600 W, 30 kHz, at 60 ± 1 °C for 20 mint, TS3) exhibited complete inactivation of microbial loads (<1 log CFU/ml), the highest reduction in enzymatic activities, better suspension stability, color properties, and highest bioactive compounds. Collectively, the verdicts proposed that TS processing could be a worthwhile option to pasteurize the spinach juice to enhance the overall quality.

Thermosonication effect on bioactive compounds, enzymes activity, particle size, microbial load, and sensory properties of almond (Prunus dulcis) milk

The object of this research was to appraise the physicochemical characteristics of almond milk and consumer acceptability after the thermosonication (TS) processing. The almond milk was subjected to TS processing (frequency: 40 kHz; power: 600 W; Temperature: 30, 45, and 60 °C; Time: 10, 20, 30, and 40 min) and pasteurization (for 60 s at 90 °C). After treatments, all samples were analyzed for bioactive compounds, antioxidant activities, microbial, enzymatic, and sensory attributes. The results showed a non-significant difference in total soluble solids and pH while TS processing at 45 and 60 °C significantly increased the cloudiness, viscosity, browning index, and color properties. TS processing increased the bioavailability of total phenolic, flavonols, flavonoids, condensed tannin contents, and antioxidant activity as compared to untreated and pasteurized samples. TS processing also significantly reduced the particle size distribution through acoustic cavitation. Microbial inactivation with TS at 60 °C resulted in ≥ 5 log reduction oftotal plate count and ≥ 4 log reduction ofyeast & moldwas achieved. The highest inhibition of lipoxygenase (LOX) and peroxidase (POD) were observed at 60 °C for 30 min. Moreover, the best sensorial properties were observed after TS processing at 60 °C. Thus; TS processing can increase the almond milk quality and safety as a viable substitute for thermal processing.

Quality attributes optimization of orange juice subjected to multi-frequency thermosonication: Alicyclobacillus acidoterrestris spore inactivation and applied spectroscopy ROS characterization

This is the first time to investigate the synergistic inactivation effect and mechanism of multifrequency ultrasound (MTUS) on A. acidoterrestris (AAT) vegetative cells and spores, nutrients and enzymes of orange juice. The optimized results of MTUS (using Box Behnken design- surface responsemethodology) and further comparison with different mode of ultrasound (mono-and multi-frequency) revealed that 20/40 kHz, 24 min and 64 °C were the best optimum results. The AAT spores and vegetative cells were inactivated by 2 and 4 logs, respectively, without deteriorating orange juice contents. In addition, AAT inactivation indicated an inversely proportional relationship with ROS production. FT-IR and UV-Vis spectroscopy characterization confirmed the existence of ROS in treated orange juice and LF-NMR analysis confirmed the inactivation of AAT spores. The findings illustrated the successfully used dual-frequency ultrasound technology for fruit beverages, promoting beneficial changes in physical properties without any significant effects on the quality of ascorbic acid.

Effect of thermosonication on quality attributes of hog plum (Spondias mombin L.) juice

The use of thermosonication (TS) technique to preserve the qualities of fruit juice as an alternative to conventional pasteurization has attracted research interest in recent times. In the present study, freshly prepared hog plum juice (control), and the juice samples subjected to pasteurization (90 °C for 60 s) and thermosonication (40 kHz, 400 W at 40, 50 and 60 °C each for 5, 10, 20 and 30 min) were each analyzed for physicochemical, bioactive, microbial and sensory properties. After treatment, no significant changes in pH, total soluble solids and titratable acidity were observed. Notably, TS at 40 and 50 °C significantly (p < 0.05) improved color parameters, cloudiness and browning index. Furthermore, thermosonication increased ascorbic acid (11.40-18.55%), total phenolic content (17.98-18.35%), carotenoids (2.19-4.30%), flavonoids (10-16%) and antioxidant activity (32.52-48.5%) relative to the control. Both treatments significantly reduced the microbial count to non-detectable level after processing, while sensory attributes slightly improved. However, TS treatment at 60 °C decreased most of the quality parameters. Results showed that TS can improve quality, safety and economic potential of hog plum juice as a feasible alternative to pasteurization.

Application of ultrasonic technology in postharvested fruits and vegetables storage: A review

It has been an important research topic and a serious applicable issue to extend storage time of fruits and vegetables using advanced scientific and effective technology. Among various approaches, ultrasound has been regarded as one of the most pollution-free and effective technical means to significantly improve the preservation of fruits and vegetables. This paper summarizes the application of ultrasonic technology in fruits and vegetables storage in recent years, including removal of pesticide residues and cleaning, sterilization, enzyme inactivation, effect on physico-chemical indexes. Additionally, we also discussed limitations and negative effects of ultrasonic treatment on fruits and vegetables such as damages to tissues and cells. Furthermore, a proper application of ultrasonic technology has been proven to effectively extend the storage period of postharvest fruits and vegetables and maintain the quality. Moreover, the combination of ultrasound and other conventional preservation technologies can further improve the preservation in a coordinate manner and even have a broader application prospect.

Inactivation of Salmonella Enteritidis on cherry tomatoes by ultrasound, lactic acid, detergent, and silver nanoparticles

Ultrasound (US) combined with chemical agents could represent an effective method for decontaminating fruits and vegetables. This study aimed to evaluate the use of US (40 kHz for 5 min) alone or with 1% lactic acid (LA), 1% commercial detergent (DET), or 6 mg/L silver nanoparticles (AgNP, average diameter 100 nm) as an alternative treatment to 200 mg/L sodium dichloroisocyanurate for inactivating Salmonella enterica serovar Enteritidis present on cherry tomatoes. The interfacial tension between sanitizing solutions and bacterial adhesion was investigated. Sanitizers in solutions with DET and AgNP had lower surface tension. All treatments, except that with DET, reduced Salmonella Enteritidis by more than one logarithmic cycle. There was no significant difference between the mean values of log colony-forming units (CFU)/g reduction in all treatments. Transmission electron microscopy revealed the loss of the Salmonella Enteritidis capsule following treatment with US and with US + LA. Salmonella Enteritidis counts (2.29 log CFU/g) in cherry tomatoes were markedly reduced to safe levels by treatment with the combination of AgNP and US + LA (2.37 log CFU/g).

Ultrasonicated resveratrol loaded starch nanocapsules: Characterization, bioactivity and release behaviour under in-vitro digestion

In this study, the resveratrol was nano-encapsulated in three different sources of starch like Water chestnut Horse chestnut and Lotus stem to safeguard it from gastric conditions and to improve its bioavailability and bioactivity upon digestion. The nano-capsules were prepared using safe and eco-friendly ultra-sonication method and studied for encapsulation-efficiency, particle-size and zeta-potential measurement. These were also characterized by ATR-FTIR, SEM, XRD and DSC. The release behaviour of resveratrol and its activity against anti-diabetic and anti-obesity were also studied. The particle size of HSR, LSR and WSR was found to be 419, 797 and 691 nm with a zeta potential of -16.09, -24.28 and -14.77 and encapsulation efficiency of 81.46, 75.83 and 79.37 %, respectively. The nanoparticles showed porous or film-like structures with decreased crystallinity and higher transition temperatures. The maximum percentage of resveratrol was released in intestinal juice and exhibited higher anti-obesity and anti-diabetic activities than free resveratrol after digestion.

Influence of ultrasound on the functional characteristics of indigenous varieties of mango (Mangifera indica L.)

The present study was conducted to evaluate the effect of ultrasonic (US) treatment on chemical characteristics and antioxidant potential of pulps obtained from eight mango varieties indigenous to Pakistan. There was a significant (p < 0.05) effect of varieties and US treatment on chemical characteristics i.e. pH, acidity, TSS, vitamin C contents, total sugars (%), reducing sugars (%) and non-reducing sugars (%). Microstructure evaluation of pulp from all mango varieties showed deshaped middle lamella and cell wall of cells after 8 min of US treatment. At 4 min of US treatment as per shaped cell wall and middle lamella, the chemical characteristics and antioxidant potential were higher. The total phenolics (TP), flavonoids (TF) and total antioxidant activity (TAA) of pulp from most varieties increased significantly (p < 0.05) after US treatment for 4 min but decreased successively after each treatment i.e. 8 and 12 min. The maximum value (314.17 μg AAE/mL pulp) of DPPH was shown by pulp from Dosehri and the minimum (158.67 μg AAE/mL pulp) was found in pulp from Langra before US treatment. The DPPH values of pulp from most of the varieties increased significantly (p < 0.05) after US treatment for 4 min but decreased successively after each treatment but pulp from Langra showed increasing trend after 8 min of US treatment which decreased after 12 min of treatment. The total anthocyanin (TA) values of pulp from Chaunsa, Dosehri, Sindhri, Gulab Khas and Langra increased abruptly after US treatment for 4 min but decreased successively after subsequent treatment. The pulp from Desi, Anwar Ratol, Gulab Khas and Langra showed an abrupt decrease in TA after 8 min of US treatment. An increasing trend of values of total carotenoids (TC) was shown by pulp from all mango varieties after 4 min of US treatment but decreasing trend was observed with subsequent increase in time of US treatment.

Storage effects on the quality quartet of orange juice submitted to moderate thermosonication: Predictive modeling and odor fingerprinting approach

The effects of moderate thermosonication (MTS) on the quality quartet: physico-chemical, microbial, nutritional and sensory qualities of orange juice (OJ) inoculated with Alicyclobacillus acidoterrestris (AAT) were studied during 24 days of storage at ambient and refrigerated temperatures. The bioactive compounds and antioxidant activity of OJ decreased with storage, while the pectin methyl esterase (PME) increased. Nonetheless, noticeable changes were observed from the 12th day of storage. There was no obvious (p > 0.05) variation in pH and total soluble solids. To determine the nutritional and microbial quality characteristics of OJ during storage, non-linear kinetic curves were successfully fitted with least square fitting polynomial and four-parameter log-logistic distribution models. The E-nose sensors succeeded in discriminating between the aroma of non-treated and treated OJ based on linear discriminant analysis (LDA). Furthermore, terpenes, alcohol and partially aromatic compounds were the main spoilage indicators of OJ during storage based on E-nose analysis and confirmed by HS-SPME-GC/MS analysis. Thus, MTS significantly extended the shelf life of the quality quartet of natural OJ at 4 °C. E-nose-GC/MS fusion offered odor fingerprints to AAT microorganisms that can be used as spoilage index without using traditional food analysis techniques. The proposed approach can be used as an alternative tool for rapid detection of spoilage microorganisms in OJ.

The Role of Extracting Solvents in the Recovery of Polyphenols from Green Tea and Its Antiradical Activity Supported by Principal Component Analysis

Green tea contains a variety of biologically active constituents that are widely used in the pharmaceutical and food industries. Among them, simple catechins constitute a major group of compounds that is primarily responsible for the high biologic activity of green tea extracts. Therefore, the application of optimized extraction conditions may result in obtaining high value extracts. The main purpose of the study was to compare the content of polyphenols, mainly catechins, and the antioxidant activity of green tea extracts obtained by three different extraction methods: simple maceration, ultrasound extraction and accelerated solvent extraction using six various solvent systems. The quality of the extracts was evaluated by LC-ESI-Q-TOF-MS methodologies and spectrophotometric determinations. The obtained results revealed that catechins' extraction efficiency was identical for the three techniques studied. However, larger quantitative differences among the samples were observed when using different solvents. The total content of major catechins and gallic acid was within a very wide range of 10.2-842 mg/L. Ethyl acetate was by far the least effective extractant, regardless of the extraction technique used. After all, the solvent system composed of ethanol:water (1:1 v/v) was proven to be the best to recover catechins and to deliver extracts with the highest antiradical activity.

In vitro gastrointestinal evaluation of a juçara-based smoothie: effect of processing on phenolic compounds bioaccessibility

In the present work, the bioaccessibility of the main phenolic compounds of a juçara, banana and strawberry homogenized smoothie (control), subjected to pasteurization and sonication, was evaluated. The smoothie was also evaluated in terms of its main chemical and physical characteristics. Pasteurized smoothie showed higher apparent viscosity, as well as higher initial shear stress when compared to the control and sonicated samples. The increase in the apparent viscosity of the pasteurized smoothie was associated with the smaller particle size of this sample (68 μm). These characteristics conferred to the pasteurized smoothie higher physical stability than the control and sonicated smoothies. Phenolic compounds bioaccessibility was higher in the pasteurized and sonicated smoothies than in the control sample, which confirmed the positive effect of the treatments for the preservation of these compounds after gastrointestinal digestion. Compared to the sonication process, the pasteurization provided higher total phenolic compounds bioaccessibility (47%), as well as of ferulic (16%) and ellagic (80%) acids. Antioxidant capacity was higher in gastric digest for all the samples evaluated by ABTS assay. These results confirm the importance of processing on the physical stability and phenolic compounds bioaccessibility of the juçara-based smoothie, standing out the thermally treated product.

Influence of power ultrasound on the main quality properties and cell viability of osmotic dehydrated cranberries

The aim of the study was to investigate the effect of ultrasound treatment in two osmotic solutions, carried out at different time, on some physical properties, antioxidant activity and cell survival of cranberries. Ultrasound treatment was conducted at 21kHz for 30 and 60min in liquid medium: 61.5% sucrose solution and 30% sucrose solution with 0.1% steviol glycosides addition. Some samples before the ultrasound treatment were subjected to cutting or blanching. The results showed that dry matter content and concentration of the dissolved substances increased during ultrasound treatment in osmotic solution, however higher value was observed for treatment in 61.5% sucrose solution and for longer time. Water activity and volume of cranberries did not change after the ultrasonic treatment. Combined treatment led to colour and antioxidant activity alterations as well. A cell viability of whole and cut samples decreased after 60min of osmotic treatment and completely lost in the blanched samples.

Changes of Mechanical and Thermal Properties of Cranberries Subjected to Ultrasound Treatment

The aim of the study was to investigate the effect of ultrasound treatment in osmotic solution, carried out at different time and solutions, on mechanical and thermal properties of cranberries. Ultrasound treatment was applied for 30 and 60 min in liquid mediums such as 61.5 % sucrose solution and 30 % sucrose solution with 0.1 % steviol glycosides addition. Before the ultrasound treatment samples were subjected to traditional operations (cutting, blanching). The traditional operations and ultrasonic treatment of whole fruits did not influence or slightly influenced dry matter content and mechanical properties. The cutting had impact on thermal properties to the highest extent due to the exposition of fruits’ flesh. The combination of cutting and sonication decreased thermal conductivity which suggests that mass transfer was more pronounced. The sonication had greater influence when compared to only ultrasonic treatment. Combined both cutting and blanching with ultrasonic treatment led to greater changes in cranberries properties.