Juice Samples Research Articles

Acid Adaptation Enhances Tolerance of Escherichia coli O157:H7 to High Voltage Atmospheric Cold Plasma in Raw Pineapple Juice.

Pathogens that adapt to environmental stress can develop an increased tolerance to some physical or chemical antimicrobial treatments. The main objective of this study was to determine if acid adaptation increased the tolerance of Escherichia coli O157:H7 to high voltage atmospheric cold plasma (HVACP) in raw pineapple juice. Samples (10 mL) of juice were inoculated with non-acid-adapted (NAA) or acid-adapted (AA) E. coli to obtain a viable count of ~7.00 log10 CFU/mL. The samples were exposed to HVACP (70 kV) for 1-7 min, with inoculated non-HVACP-treated juice serving as a control. Juice samples were analyzed for survivors at 0.1 h and after 24 h of refrigeration (4 °C). Samples analyzed after 24 h exhibited significant decreases in viable NAA cells with sub-lethal injury detected in both NAA and AA survivors (p < 0.05). No NAA survivor in juice exposed to HVACP for 5 or 7 min was detected after 24 h. However, the number of AA survivors was 3.33 and 3.09 log10 CFU/mL in juice treated for 5 and 7 min, respectively (p < 0.05). These results indicate that acid adaptation increases the tolerance of E. coli to HVACP in pineapple juice. The potentially higher tolerance of AA E. coli O157:H7 to HVACP should be considered in developing safe juice processing parameters for this novel non-thermal technology.

Preparation of microelectrode based on molecularly imprinted monolith using ionic liquids as functional monomers for specific separation and enrichment of phenolic acids

Efficient and specific isolation and capture of phenolic acids (PAs) in complex samples is challenging due to its high polarity. In this study, combining the merits of porous monolith, ionic liquids, molecularly imprinted polymer and electroenhanced solid-phase microextraction (EE-SPME), a new sample pretreatment method was developed for the selective isolation and extraction of PAs. Using vanillic acid (VA) as template molecule, mixed ionic liquids including 1-allyl-3-methylimidazoliumbis[(trifluoromethy)sulfonyl]imide and N,N,N-trimethyl-1-(4-vinylphenyl)methanaminium chloride were chosen as dual functional monomers, a molecularly imprinted monolith-based microelectrode (MBM) was in-situ fabricated. Under the EE-SPME format, the extraction behaviors and specific recognition performance of MBM towards VA and its structural analogues were investigated in detail. Results revealed that the exertion of electric field during extraction period increased the imprinted factors from 1.57–1.77 to 1.87–2.23. Under the beneficial parameters, a sensitive and reliable approach for the quantification of PAs contents in water and fruit juice samples by the combination of MBM/EE-SPME with HPLC technique was developed. The achieved limits of detection ranging from 0.012 μg/L to 0.11 μg/L and 0.042 μg/L to 0.15 μg/L for waters and juices, respectively, and the recoveries with different spiked concentrations in actual sample were 83.1–110 %. In comparison with the existing approaches, the established method presented some characteristics in the analysis of PAs, such as simplicity, high cost-effectiveness, good anti-interference performance, satisfactory sensitivity and low consumption of solvent.

Investigation of the formation of furfural compounds in apple products treated with pasteurization and high pressure processing

The thermal treatment carried out in the processing of apple products is very likely to induce Maillard reaction to produce furfurals, which have raised toxicological concerns. This study aimed to elucidate the formation of furfural compounds in apple products treated with pasteurization and high pressure processing (HPP). The method for simultaneous determination of five furfural compounds including 5-hydroxymethyl-2-furfural (5-HMF), furfural (F), 4-hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF), 2-acetylfuran (FMC), and 5-Methyl-2-furfural (MF) using high performance liquid chromatography equipped with diode array detector (HPLC-DAD) was successfully developed and validated. All five furfurals exhibited an increasing trend after the pasteurization treatment of apple clear juice, cloudy juice, and puree. 5-HMF, F, FMC, and MF were increased significantly during the precooking of apple puree. Whereas there was no significant change in the furfurals formation after apple products treated with high pressure processing (HPP) with 300 MPa and 15 min. Based on the variation of the fructose, glucose and sucrose detected in apple products after thermal treatment, it revealed that the saccharides and thermal treatment have great effect on the furfural compounds formation. The commercial fruit juice samples with different treatments and fruit puree samples treated with pasteurization were also analyzed. Five furfurals were detected more frequently in the fruit juice samples treated with pasteurization or ultra-high temperature instantaneous sterilization (UHT) than those treated with HPP. 5-HMF and FMC were detected in all fruit puree samples treated with pasteurization, followed by F, MF, and HDMF with the detection rate of 79.31 %, 72.41 %, and 51.72 %. The results could provide a reference for risk assessment of furfural compounds and dietary guidance of fruit products for human, especially for infants and young children. Moreover, moderate HPP treatment with 300 MPa and 15 min would be a worthwhile alternative processing technology in the fruit juice and puree production to reduce the formation of furfural compounds.

Effects on quality characteristics of ultrasound-treated gilaburu juice using RSM and ANFIS modeling with machine learning algorithm

Gilaburu (Viburnum opulus L.) is a red-colored fruit with a sour taste that grows in Anatolia. It is rich in various antioxidant and bioactive compounds. In this study, bioactive compounds and ultrasound parameters of ultrasound-treated gilaburu water were optimized by response surface methodology (RSM) and adaptive neuro-fuzzy inference system (ANFIS). As a result of RSM optimization, the independent ultrasound parameters were determined as an ultrasound duration of 10.7 min and an ultrasound amplitude of 53.3, respectively. The R2 values of the RSM modeling level were 99.93%, 98.54%, and 99.80%, respectively, and the R2 values of the ANFIS modeling level were 99.99%, 98.89%, and 99.87%, respectively. Some quality parameters of gilaburu juice were compared between ultrasound-treated gilaburu juice (UT-GJ), thermal pasteurized gilaburu juice (TP-GJ), and control group (C-GJ). The quality parameters include bioactive compounds, phenolic compounds, minerals, and sensory evaluation. Bioactive compounds in the samples increased after ultrasound application compared to C-GJ and TP-GJ samples. The content of 15 different phenolic compounds was determined in Gilaburu juice samples, and the phenolic compound of UT-GJ samples increased compared to TP-GJ and C-GJ samples, except for gentisic acid. Ultrasound treatment applied to gilaburu juice enabled its bioactive compounds to hold more in the juice.

Decoding the Effects of High Hydrostatic Pressure and High-Temperature Short-Time Sterilization on the Volatile Aroma Profile of Red Raspberry Juice.

The loss of distinctive aromas due to sterilization significantly hinders efforts to enhance the sensory quality of fruit and vegetable juices. This study aimed to elucidate the impacts of high-hydrostatic pressure (HHP) and high-temperature short-time (HTST) sterilization methods on the loss of C6 aldehyde aroma-active compounds in red raspberry juice. External standard quantification and quantitative descriptive analysis (QDA) revealed a notable decline in the levels of hexanal and (Z)-3-hexenal following the HHP and HTST treatments (p < 0.05), resulting in a marked attenuation of the grassy aroma characteristic of red raspberry juice. Furthermore, a comprehensive examination of the precursors, pivotal enzymes, intermediates, and downstream aromas within the fatty acid metabolism pathway in different raspberry juice samples indicated that the C6 aldehydes loss induced by HHP and HTST sterilizations was primarily ascribed to the competitive inhibition of β-oxidation and the hindered enzymatic oxidation of fatty acids. These insights suggest that modifying sterilization protocols and enhancing enzymatic stability may help preserve the aroma integrity of raspberry juice. Our findings offer practical guidance for optimizing juice processing techniques to maintain flavor.

Gold nanoparticles decorated kaolinite mineral modified screen-printed electrode: Use for simple, sensitive determination of gallic acid in food samples

The current study offers the nanomolar quantification of gallic acid (GAL) based on gold nanoparticles (AuNps) and kaolinite minerals (KNT) modified on a screen-printed electrode (SPE). The electrochemical behavior of GAL was performed using differential pulse voltammetry (DPV) in Britton Robinson (BR) buffer solution at pH 2.0 as a supporting electrolyte. Under the optimized DPV mode parameters, the oxidation peak current of GAL (at 0.72 V vs Ag/AgCl) increased linearly in the range between 0.002 μmolL−1 and 40.0 μmolL−1 with a detection limit of 0.50 nmolL−1. The effect of common interfering agents was also investigated. Finally, the applicability of the proposed method was verified by quantification analysis of GAL in black tea and pomegranate juice samples.

Determination of Azole Fungicide Residues in Fresh Juice by Magnetic Solid Phase Extraction Based on Fe3O4@ZnAl-LDH@MIL-53(Al) Sorbent in Combination with High-Performance Liquid Chromatograph.

In this work, a magnetic adsorption material based on metal-organic framework (Fe3O4@ZnAl-LDH@MIL-53(Al)) was synthesized and used as an adsorbent in the process of magnetic solid phase extraction. Then, a high-performance liquid chromatograph was used to quantitatively detect triazole fungicides in samples. In order to verify the successful preparation of the material, a series of characterization analyses were carried out. Besides, the key parameters that may affect the extraction efficiency have been optimized, and under optimal conditions the three triazole fungicides showed good linearity in the range of 10-1000μg/L (R2 ≥ 0.9796); Limit of detections were ranged from 0.013 to 0.030μg/mL. Finally, the established method was applied to the detection of triazole fungicides in four fresh juice samples. The results showed that the target analyte was not detected in all the test samples. By detecting the recoveries (73.3-104.3%) and coefficient variation (RSD ≤ 6.8%) of triazole fungicides in fortified samples, it proved that this established method meets the requirements of pesticide residue analysis and showed excellent application potential.

Music attributes and the perception of orange juice

There has been a recent growth of interest in understanding whether sound (specifically music) in the dining environment can enhance the taste perception of food and drink. Most of the previous research within the music-taste association utilized music soundtracks which were specifically designed to correspond to taste characteristics, for example, sweet taste/sweet music or sour taste/sour music. However, only a few studies have focused on the effect of each music attribute on aroma and taste. Moreover, freshness and thickness, as an oral somatosensory aspect, are concepts that lack the multisensory research of their sensory perception. This study investigated the effect of music on the taste of orange juice in a multisensory and controlled indoor environment laboratory (Sens i-Lab). In this current study, participants tasted orange juice samples while listening to eight music soundtracks and one silent sound. The music soundtracks were designed by combining two levels in each of three sonic attributes: Articulation (Legato, Staccato), Tempo (70 and 120 Bpm), and Pitch (Low, High). Overall, results showed that the variety in music attributes influences the orange juice about aroma, sweetness, sourness, bitterness, freshness, and thickness perceptions. The findings of this research can contribute to the development of multisensory design strategies for interactive design innovation in the context of food service. Moreover, the music stimuli in the dining experience can exalts the sensory perception of food and beverage as a part of creative gastronomic experience.

In situ formation of an adsorbent using a mixture of ibuprofen and choline chloride for the extraction of Cu(II) and Cd(II) ions from water and fruit juice samples combined with dispersive liquid–liquid microextraction

In situ formation of an adsorbent using a mixture of ibuprofen and choline chloride for the extraction of Cu(II) and Cd(II) ions from water and fruit juice samples combined with dispersive liquid–liquid microextraction

A magnetic imprinted polymer nano-adsorbent with embedded quantum dots and mesoporous carbon for the microextraction of triazine herbicides

A magnetic molecularly imprinted polymer (MMIP) adsorbent incorporating amino-functionalized magnetite nanoparticles, nitrogen-doped graphene quantum dots and mesoporous carbon (MIP@MPC@N-GQDs@Fe3O4NH2) was fabricated to extract triazine herbicides from fruit juice. The embedded magnetite nanoparticles simplified the isolation of the adsorbent from the sample solution. The N-GQDs and MPC enhanced adsorption by affinity binding with triazines. The MIP layer provided highly specific recognition sites for the selective adsorption of three target triazines. The extracted triazines were determined by high-performance liquid chromatography (HPLC) coupled with diode-array detection (DAD). The developed method exhibited linearity from 1.5 to 100.0 µg L−1 with a detection limit of 0.5 µg L−1. Recoveries from spiked fruit juice samples were in the range of 80.1– 108.4 %, with a relative standard deviation of less than 6.0 %. The developed MMIP adsorbent demonstrated good selectivity, high extraction efficiency, ease of fabrication and use, and good stability.

Effect of bile reflux on gastric juice microbiota in patients with different histology phenotypes

Background/aimsBile reflux (BR) can influence the gastric environment by altering gastric acidity and possibly the gastric microbiota composition. This study investigated the correlation between bile acids and microbial compositions in the gastric juice of 50 subjects with differing gastric pathologies.MethodsThis study included 50 subjects, which were categorized into three groups based on the endoscopic BR grading system. The primary and secondary bile acid concentrations in gastric juice samples were measured, and microbiota profiling was conducted using 16 S rRNA gene sequencing.ResultsSignificant differences were observed in each bile acid level in the three endoscopic BR groups (P < 0.05). The Shannon index demonstrated a significant decrease in the higher BR groups (P < 0.05). Analysis of the β-diversity revealed that BR significantly altered the gastric microbiota composition. The presence of neoplastic lesions and the presence of H. pylori infection impacted the β-diversity of the gastric juice microbiota. The abundance of the Streptococcus and Lancefielfdella genera exhibited positive correlations for almost all bile acid components(P < 0.05). In addition, the abundance of Slobacterium, Veillonella, and Schaalia showed positive correlations with primary unconjugated bile acids (P < 0.05).ConclusionChanges in microbial diversity in the gastric juice were associated with BR presence in the stomach. This result suggests that the degree of BR should be considered when studying the gastric juice microbiome.

Influence of Growing Region on Targeted Anthocyanin Profile, Color, Phenolics, and Antioxidant Activity of Grape Juice

Influence of Growing Region on Targeted Anthocyanin Profile, Color, Phenolics, and Antioxidant Activity of Grape Juice cv. Manjari Medika (MM) were examined. The prevailing environmental conditions affect chemical composition or metabolites of grapes. The MM grape berries were harvested from three environmentally different locations in India i.e. Pune (MMJP), Vijayapura (MMJV), and Nashik (MMJN). MMJV, grown in region with high average temperatures and low rainfall showed higher levels of (393.65 ± 8.18 g/L) reducing sugar with lower levels of color intensity (49.69±0.55%), juice recovery (68.70±0.54%), and acidity (6.98±0.04 g/L) followed by flavonoids (0.023 g/L) than the regions with relatively low temperatures and high rainfall ((MMJP) and (MMJN)). In UHPLC-Oribitrap MS analysis, a total of 11 anthocyanins, which includes delphinidin-3-galactoside (Dp3Ga), cyanidin (Cy), peonidin-glucoside-4-Vinylphenol (Pn3Glu4VP), petunidin-3-glucoside (Pt3Glu), malvidin-3-glucoside (Mv3Glu), pelargonidin (Pg), petunidin-3-acetyl glucoside (Pt3ace), peonidin-3-acetyl glucoside (Pn3ace), malvidin-3-acetyl glucoside (Mv3ace), delphinidin (Dp) and petunidin (Pt) were detected in grape juice samples. MMJV. It is interesting to note that among the 11 anthocyanins detected, two compounds, petunidin-3-acetyl glucoside (Pt3ace) and peonidin-3-acetyl glucoside (Pn3ace), have been reported only in specific grape juice samples, i.e., Pt3ace in MMJV and Pn3ace in MMJN. Discriminatory compounds among the regions were petunidin-3-acetyl glucoside (Pt3ace), peonidin-3-acetyl glucoside (Pn3ace), and cyanidin (Cy) according to principal component analysis (PCA). UHPLC-MS results showed that the total anthocyanin content of the fresh juice in the cultivar tended to increase with altitude from sea level.

Glutathione‑iron hybrid nanozyme-based colorimetric sensor for specific and stable detection of thiram pesticide on fruit juices

Given the potential dangers of thiram to food safety, constructing a facile sensor is significantly critical. Herein, we presented a colorimetric sensor based on glutathione‑iron hybrid (GSH-Fe) nanozyme for specific and stable detection of thiram. The GSH-Fe nanozyme exhibits good peroxidase-mimicking activity with comparable Michaelis constant (Km = 0.551 mM) to the natural enzyme. Thiram pesticides can specifically limit the catalytic activity of GSH-Fe nanozyme via surface passivation, causing the change of colorimetric signal. It is worth mentioning that the platform was used to prepare a portable hydrogel kit for rapid qualitative monitoring of thiram. Coupling with an image-processing algorithm, the colorimetric image of the hydrogel reactor is converted into the data information for accurate quantification of thiram with a detection limit of 0.3 μg mL−1. The sensing system has good selectivity and high stability, with recovery rates in fruit juice samples ranging from 92.4% to 106.9%.

Susceptibility to antibiotics and virulence profiling of Proteus mirabilis among foodstuff

Proteus mirabilis is a genus of bacteria that can cause foodborne diseases. We collected 100 canned food samples from local supermarkets in Hillah (Iraq), including juice (23%), milk products (22%), beef (20%), fish (14%), milk (12%), and tomato paste (9%) samples. We subsequently characterized some virulence factors of P. mirabilis found in these foodstuff, including biofilm formation, protease activity, motility, haemolysis, adhesion, urease production, lipase pro¬duction, and antibiotic susceptibility. In a total of 32 foodstuff samples of positive culture, P. mirabilis was isolated in 15 (46.8%), including 3 juice samples, 4 milk product samples, 2 beef samples, 1 fish sample, 3 milk samples, and 2 tomato paste samples. All isolates exhibited swarming motility (100%) and urease production (100%), while none of the isolates was found to produce haemolysin. The results of the antibiotic susceptibility test revealed a higher re¬sistance against ampicillin (86.6%).

BIOCHEMICAL INDICATORS OF GASTRIC JUICE IN INCOMPETENCE OF THE PHYSIOLOGICAL GASTRIC CARDIA

Aim. This study aimed to evaluate the biochemical characteristics of gastric juice in cases incompetence of the physiological cardia (IPC) at the gastroesophageal junction. Methods. Gastric juice samples were collected from 42 patients diagnosed with hiatal hernia (HH) at the State Institution "Institute of Gastroenterology of the National Academy of Medical Sciences of Ukraine". Patients were classified into type I (sliding) HH (n=26) and type II (paraesophageal) HH (n=16), with a control group of healthy volunteers (n=9). Results. Analysis included pH, pepsin concentration, bile acids, total calcium and stable metabolites of nitric oxide (NOx). In type I HH, gastric juice showed increased pH (3.73±0.49) and elevated pepsin concentration (1.33±0.22 mg/ml) compared to controls (p&lt;0.01 and P&lt;0.05 respectively), indicating hypoacidity and hyperfunction of chief cells. Type II HH exhibited pH levels (2.34±0.72) similar to controls and no significant difference in pepsin concentration. NOx levels in type I HH were lower (P&lt;0.05) compared to controls, suggesting reduced NOergic system activity. Calcium concentration in gastric juice did not significantly differ between groups. Conclusions. These findings suggest that type I HH is associated with disturbances in gastric secretion regulation, possibly unrelated to duodenogastric reflux. Further investigation is warranted to elucidate the underlying pathophysiological mechanisms.

Vortex-assisted dispersive micro-solid-phase extraction using silica-supported Fe2O3-modified khat (Catha edulis) biochar nanocomposite followed by GC-MS for the determination of organochlorine pesticides in juice samples

In this paper, dispersive micro-solid phase extraction technique was developed for the purpose of extracting and preconcentrating organochlorine pesticide residues in juice samples before their separation and quantitative analysis by gas chromatography-mass spectrometry. A sorbent composed of a silica-supported Fe2O3-modified khat leftover biochar nanocomposite (SiO2-Fe2O3-KLBNC) was implemented in the process. To improve the dispersion of the sorbent in the solution, vortex mixer was employed. Experimental parameters influencing the performance of the method were optimized, and the optimal conditions were established. With these conditions, linear dynamic ranges ranged from 0.003 to 100.0 ng/mL were achieved, with a correlation coefficient (r2) ≥ 0.9981. The limits of detection and quantification, determined by signal-to-noise ratios of 3 and 10, respectively, were found to be in the ranges of 0.001–0.006 ng/mL and 0.003–0.020 ng/mL. Intra- and inter-day precision, values ranging from 0.3–4.8% and 1.7–5.2% were obtained, respectively. The matrix-matched extraction recoveries demonstrated favorable outcomes, falling within the range of 83.4–108.3%. The utilization of khat leftover as an adsorbent in contemporary sample preparation methodologies offers a cost-effective alternative to the currently available, yet expensive, adsorbents. This renders it economically viable, particularly in resource-constrained regions, and is anticipated to witness widespread adoption in the coming future.

Facile synthesis of magnetic layered double hydroxide/metal–organic framework MIL-100(Fe) for simultaneous extraction and enantiomeric determination of three chiral triazole fungicides in water and juice samples

For the first time, magnetic layered double hydroxide/metal–organic framework (Fe3O4@CuZnAl-LDH@MIL-100(Fe)) was successfully fabricated and applied for enrichment of triazole fungicides from water and juice samples prior to chiral HPLC-UV analysis. Several key parameters influencing the extraction efficiency including extraction time, desorption time, sample solution pH, the ionic strength of sample solution, adsorbent amount, desorption volume, desorption solvent and sample volume were investigated by Plackett-Burman design and Box-Behnken design. Under the optimum conditions, the limit of detections (LODs) and limit of quantifications (LOQs) were in the ranges of 0.35 to 1.20 μg L−1 and from 1.00 to 3.80 μg L−1, respectively. The average spiked recoveries and enrichment factors ranged from 86.28-98.22 % and 21.6–23.8, respectively. The linearity was in the range of (5–1000 μg L−1) with satisfactory correlation coefficients (R2) values (0.9987–0.9999) and a good precision (RSDs ≤ 5.74 %). Moreover, the computational simulation was first employed to analyze adsorption properties of MIL-100(Fe) against triazole fungicides. This work provides a promising method for trace chiral pesticide analysis in aqueous samples.

Distinguishing methicillin-resistant Staphylococcus aureus from methicillin-sensitive strains by combining Fe3O4 magnetic nanoparticle-based affinity mass spectrometry with a machine learning strategy

Pathogenic bacteria, including drug-resistant variants such as methicillin-resistant Staphylococcus aureus (MRSA), can cause severe infections in the human body. Early detection of MRSA is essential for clinical diagnosis and proper treatment, considering the distinct therapeutic strategies for methicillin-sensitive S. aureus (MSSA) and MRSA infections. However, the similarities between MRSA and MSSA properties present a challenge in promptly and accurately distinguishing between them. This work introduces an approach to differentiate MRSA from MSSA utilizing matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) in conjunction with a neural network-based classification model. Four distinct strains of S. aureus were utilized, comprising three MSSA strains and one MRSA strain. The classification accuracy of our model ranges from ~ 92 to ~ 97% for each strain. We used deep SHapley Additive exPlanations to reveal the unique feature peaks for each bacterial strain. Furthermore, Fe3O4 MNPs were used as affinity probes for sample enrichment to eliminate the overnight culture and reduce the time in sample preparation. The limit of detection of the MNP-based affinity approach toward S. aureus combined with our machine learning strategy was as low as ~ 8 × 103 CFU mL−1. The feasibility of using the current approach for the identification of S. aureus in juice samples was also demonstrated.Graphical

Assessing the impact of isochoric freezing as a preservation method on the quality attributes of orange juice.

Isochoric (constant volume) freezing is a novel food preservation technology that has demonstrated the ability to preserve food products at subfreezing temperatures in an unfrozen state, thereby avoiding the detrimental effects of ice formation. It minimizes the quality loss of fresh fruits and juices, increases their nutrient content, and reduces microbial counts. Orange juice (OJ) samples were subjected to conventional freezing (CF) and isochoric freezing (IF) for 7 days and then stored at 4°C for an additional 7 days. We evaluated the microbiological and physicochemical quality of CF and IF OJ before and after storage. The IF was performed at three different conditions: -5°C/73MPa, -10°C/93MPa, and -15°C/143MPa. The results indicate that the total aerobic count of OJ remained below the detection limit after heat treatment, 7 days of CF and 7 days of IF. Yeast and mold counts increased in fresh and CF OJ after 7 days of storage at 4°C, whereas IF OJ remained below the detection limit. Less color difference was observed in IF (-15°C/143MPa) OJ compared to heat-treated and CF OJ. Heat treatment inactivated 42% of pectin methylesterase (PME), whereas 7-day long IF increased PME activity up to 150%. Additionally, IF (-15°C/143MPa) OJ showed reduced pulp sedimentation, which can be advantageous, as sedimentation in juices has been a recognized technological issue in the juice industry. Ascorbic acid level was significantly higher in IF (-15°C/143MPa) OJ compared to fresh and CF OJ after storage.

Impact of Ultrasound Pretreatment on Juice Yield and Bioactive Content in Juice Produced from Selected Berries Fruit.

The aim of the work was to investigate the effect of ultrasound application during juice pressing. The impact on pressing yield and extraction of bioactive compounds during production of juice from strawberry, blackcurrant and raspberry was evaluated. Juice pressing was carried out after four kinds of mash pretreatment. The tested objects were heated to 55 °C, treated by ultrasound, and/or macerated with an enzyme. The obtained juices were analyzed for the content of bioactive compounds and compared to the 'Control' sample, which was the juice pressed without any pretreatment. Although the results presented here do not conclusively show that enzymatic maceration can be completely replaced by the use of ultrasound, in the case of strawberry and raspberry fruit, juice yield after ultrasound treatment increased almost as much as after enzymatic maceration. Additionally, in the case of raspberry fruit, the antioxidant activity of the juice samples was definitely improved when ultrasound was used. The results from this experiment also showed that it is possible to separate the effect of temperature from the effect of mechanical and chemical actions in ultrasound treatment.