Juice Clarity Research Articles

Dual effects of whey protein isolates on the inhibition of enzymatic browning and clarification of apple juice

The inhibition was studied of enzymatic browning occurring in apple juice by whey protein isolates as compared to ascorbic acid and l-cysteine. A further comparison of different filter-aid pretreatments, such as whey protein isolates (WPI), pectinase and whey protein isolates – pectinase pretreatments, alone and combined with ultrafiltration was also made. The results indicated that WPI demonstrated a concentration-dependent inhibitory activity on polyphenoloxidase (PPO). At lower concentrations (0.005–0.01 g/l), the suppression effect of WPI on PPO activity was higher than that of both ascorbic acid and l-cysteine. WPI exhibited intermediate inhibition on PPO activity at the concentrations of 0.01–0.1 g/l, as compared to ascorbic acid and l-cysteine. The comparison of different clarification treatments suggested that WPI acted more effectively on clarification than pectinase. In addition, combined WPI-pectinase pretreatment significantly increased the clarity of apple juice, indicating a synergistic effect between WPI and pectinase. The subsequent ultrafiltration after WPI and pectinase pretreatments alone or combined could further improve the clarity and colour and reduce the turbidity of clear apple juice with non-significant influence on its typical characteristics.  

Impact of ultraviolet radiation treatments on the physicochemical properties, antioxidants, enzyme activity and microbial load in freshly prepared hand pressed strawberry juice.

Freshly prepared, hand-pressed strawberry fruit juice was exposed to ultraviolet radiation (254 nm) at room temperature (25 ℃ ± 1 ℃) for 15, 30 and 60 min with 0 min serving as control. Results revealed decrease in pH, total soluble solids and titratable acidity, while colour parameters (L*, a* and b* values) and clarity of juice (% transmittance) increased significantly. All the results corresponded to exposure time to ultraviolet radiation. Bioactive compounds (total phenolics, ascorbic acid and anthocyanins) decreased along with a recorded reduction in polyphenol oxidase enzyme and 1,1-diphenyl-2-picryl hydrazyl radical scavenging activities, which were again dependent on exposure time. Results on the microbial studies showed significant reduction by 2-log cycles in aerobic plate count as well as in total yeast and mould counts. Though negative results were observed for certain parameters, this is the first time it was endeavoured to demonstrate the impact of ultraviolet radiation radiation on freshly prepared, hand-pressed strawberries juice.

Effective clarification of pomegranate juice: A comparative study of pretreatment methods and their influence on ultrafiltration flux

The aim of this study was to introduce an effective pre-clarification step in order to improve performance of subsequent ultrafiltration (UF) and to obtain a high quality pomegranate juice (PJ) with improved clarity. The effects of various pre-clarification treatments utilizing gelatin, bentonite and polyvinyl polypyrrolidone (PVPP) on UF performance were evaluated comparatively through analysis of flux behavior and membrane fouling. Quality attributes of the PJs (pH, total acidity, total phenolic content, total monomeric anthocyanins, individual phenolic acids, organic acids, total antioxidant activity and color characteristics) following various pre-clarification treatments were also investigated. On the whole, pre-clarification treatments that included PVPP exhibited a higher overall adsorption capacity, especially of low molecular weight phenolics. The best results with regard to both the fouling behavior of the UF membrane and the juice clarity were achieved by sequential application of PVPP and bentonite. Since lesser amounts of fining agents were used in the pre-clarification treatments, quality attributes of PJ were well preserved comparing conventional clarification applications.

Effect of enzymatic treatment on juice yield, viscosity and clarity of banana juice

The effect of pectinase enzyme concentration (0.05–0.15%), incubation temperature (30–50°C) and incubation time (60–180 min) on juice yield, viscosity and clarity of banana juice were studied. A Central Composite Design was used to optimize the conditions for enzymatic clarification of banana pulp to maximize juice yield and clarity and to minimize pulp viscosity. Significant regression model describing the changes of juice yield, viscosity and clarity of juice with respect to hydrolysis parametres were established with the coefficient of determination, R2 = 0.9881, 0.9951 and 0.9722 respectively. The recommended enzymatic clarification condition for the banana pulp of maturity stage 7 was 0.11% enzyme concentration at 39.8°C and incubation time of 143 min to achieve maximum juice yield (75.11%), clarity (94.05%) and minimum pulp viscosity (372 cps).

Pectin Methylesterase of Datura species, purification, and characterization from Datura stramoniumand its application

Pectin methylesterases (PME; EC 3.1.1.11) involved in de-esterification of pectin and have applicability in food, textiles, wines, pulp, and paper industries. In the present study, we compared PME activity of different parts of 3 Datura species and found that fruit coat showed maximum PME activity followed by leaf and seed. PME from leaves of D. stramonium (DsPME) was purified and characterized. DsPME showed optimum activity at 60 °C and pH 9 in the presence of 0.3 M NaCl. DsPME was stable at 70 °C and retained more than 40% activity after 60 min of incubation. However, enzyme activity completely abolished at 80 after 5 min of incubation. It follows Michaelis-Menten enzyme kinetics. Km and Vmax with citrus pectin were 0.008 mg/ml and 16.96 µmol/min, respectively. DsPME in combination with polygalactourenase (PGA) increased the clarity of orange, apple, pomegranate and pineapple juices by 2.9, 2.6, 2.3, and 3.6 fold, respectively in comparison to PGA alone. Due to very high de-esterification activity, easy denaturation and significant efficacy in incrementing clarification of fruit juice makes DsPME useful for industrial application.

Immobilization of tomato (Lycopersicon esculentum) pectinmethylesterase in calcium alginate beads and its application in fruit juice clarification

Clarity of fruit juices is desirable to maintain an aesthetically pleasing quality and international standards. The most commonly used enzymes in juice industries are pectinases. A partially-purified pectinmethylesterase from tomato was entrapped in calcium alginate beads and used for juice clarification. The activity yield was maximum at 1 % (w/v) CaCl2 and 2.5 % (w/v) alginate. The immobilized enzyme retained ~55 % of its initial activity (5.7 × 10(-2) units) after more than ten successive batch reactions. The Km, pH and temperature optima were increased after immobilization. The most effective clarification of fruit juice (%T620 ~60 %) by the immobilized enzyme was at 4 °C with a holding time of 20 min. The viscosity dropped by 56 % and the filterability increased by 260 %. The juice remains clear after 2 months of storage at 4 °C.

بهینه یابی شرایط شفاف سازی آب کیوی با استفاده از آنزیم پکتیناز، بنتونیت و پلی وینیل پلی پرولیدون

In order to prevent the turbidity during storage of kiwifruit juice, clarification is necessary. Through proper clarification, flavor and taste of the product is also improved. Therefore, the purpose of the present study was to present a method to determine the optimum amount of clarifying agents (Pectinase enzyme, Bentonite and polyvinyl poly pyrolidone) for producing kiwifruit juice with stable clarity. For this purpose, effect of Pectinase enzyme (2-8 g/kg), Bentonite (200-350 g/Ton) and polyvinyl poly pyrolidone (70-110 g/100 lit) on viscosity, turbidity, clarity and total phenolics compound of kiwifruit juice was investigated. For each response a second order polynomial model was developed using a multiple linear regression analysis. Results showed that R2 for viscosity, turbidity, clarity and the total amount of phenolics were more than 0.90. The statistical analysis indicates that viscosity, turbidity and clarity (P<0.01) were significantly correlated with enzyme, Bentouite and PVPP. The effect of PVPP concentration on the total phenolics were reported to be significant (p<0.01). With regard to the experimental model obtained through response surface methodology, the relationship between the variables studied was appropriate. The final optimal amounts of clarifying agents under simultaneous consumption condition were reported as follows: Pectinase enzyme, Bentouite and PVPP were specified 5.83g/kg, 306.05 g/ton, and 70g/100 lit, respectively.

Comparing characteristic of banana juices from banana pulp treated by high pressure carbon dioxide and mild heat

High pressure carbon dioxide (HPCD) was a novel non-thermal technology in fruit juice processing recently. Characteristics of banana juices from banana pulp treated by HPCD at 20 MPa and mild heat (MH) at atmospheric pressure were investigated. The temperatures were 45, 50, 55, and 60 °C, and treatment time was 30 min. Residual polyphenol oxidase (PPO) in the juice from HPCD-treated banana pulp was lower than that from MH-treated banana pulp and its minimum was 11.6% at 60 °C. L* value and clarity of juice from HPCD-treated banana pulp was greater than that from MH-treated banana pulp, however, a* value, b* value, viscosity, pectin and protein were lower. As compared with MH treatment, the particle size and Zeta-potential of juice from HPCD-treated banana pulp respectively became smaller and more negative, and all their reduction increased with increasing treatment temperature. Moreover, a slight decrease in the juice yield, pH, and total soluble solids of banana juice from HPCD-treated banana pulp was observed as compared with juice from mild heat-treated banana pulp. The study is relevant to banana juice processing. Many studies indicated that high pressure carbon dioxide (HPCD) is a novel non-thermal technology for pasteurization of microorganisms and the inactivation of enzymes. In this study, results shown HPCD can also be used in clarification of banana juice.

Enzymatic clarification of fruit juices (Apple, Pineapple, and Tomato) using purified Bacillus pumilus SV-85S xylanase

The xylanase obtained from a hyper-producer Bacillus pumilus SV-85S was purified and characterized to evaluate its potential in industrial applications. Xylanase was purified to homogeneity 25.3-fold with 63.2% recovery using cation-exchange chromatography through CMSephadex C-50. The purified xylanase showed a single band on Native-PAGE and a single peak in RP-HPLC confirming its homogeneity. The purified enzyme revealed a single band on SDS-PAGE with a molecular mass of 23.6 kDa, which was confirmed with gel filtration chromatography through Sepharose 6B. The Km and Vmax of the purified xylanase was 1.0 mg/mL and 333.3 IU/mL, respectively. The temperature and pH profiles of the purified xylanase revealed that it was thermo and alkali stable. In recent years due to the overall increase in natural fruit juice consumption, juices have become important from a consumption point of view. However, raw juice is turbid and viscous which tends to settle during storage. Therefore, it must be clarified before commercialization. The efficacy of absolutely purified xylanase was studied on juice enrichment of apples (Malus domestica), pineapples (Ananas comosus L.) and tomatos (Lycopersicum esculentum). The treatment with xylanase lead to an increased juice yield by 23.53% (apple), 10.78% (pineapple), and 20.78% (tomato) as well as having a significant effect on juice clarity by an increase of % transmittance of 22.20, 19.80, and 14.30, respectively. The turbidity and viscosity was also decreased without affecting acid neutrality significantly.

Improved Control of Sucrose Losses and Clarified Juice Turbidity with Lime Saccharate in Hot Lime Clarification of Sugarcane Juice and other Comparisons with Milk of Lime

A comparative investigation of adding milk of lime (MOL) versus lime saccharate (SACCH) in the hot lime clarification of juice at a U.S. sugarcane factory was undertaken to quantify performance across the 2009 processing season, after a preliminary factory study in 2008. SACCH was prepared by adding hydrated lime to hot clarified juice (CJ) in a greater than 1:7 ratio. The lime treatment was added to flash heated limed juice (FHLJ) to obtain a target CJ pH of 7.3. Samples of FHLJ and CJ were collected six times every 30 min, taking into account the retention time of the clarification tank. Results from the preliminary study suggested that SACCH caused lower turbidity in CJs with better control, as well as higher and better controlled CJ pHs. Across the 2009 season, SACCH factory mud volumes tended to be slightly (no significant difference) higher than for MOL, but no greater than 8.5%. In 2009, CJ turbidities with SACCH were, generally, lower and better controlled than MOL. Lower median particle sizes in CJs with MOL across the season at least partially explain the higher CJ turbidities with MOL than SACCH. For the same amount of hydrated lime added, SACCH produced a higher pH than MOL and this, generally, allowed SACCH to achieve the target CJ pH better than MOL and reduce sucrose losses from acid inversion. No significantly (P < 0.05) extra lime had to be added in the SACCH than MOL treatment, and there were no significant differences between the color of either FHLJ or CJ from SACCH or MOL. Overall, the use of SACCH over MOL improved hot lime clarification especially with respect to the achievement and control of target pH values that saved a considerable amount in sucrose losses and improved turbidity values of clarified juices. Practical Applications This paper is highly practical because in recent years there has been a shift in the U.S.A. and worldwide from the harvesting of burnt to green (unburnt) sugarcane, which has meant that more sugarcane leaves and tops are being processed at factories and have made clarification and sucrose losses worse. The work represented here offers a solution to this by proving that the addition of lime saccharate (SACCH) instead of the traditional milk of lime (MOL), during clarification of sugarcane juice, can improve turbid particle removal and be used as a tool by sugar processors to reduce expensive sucrose losses. This paper reports the performance of MOL and SACCH lime treatments on both the laboratory and factory clarification of sugarcane juices and puts forward explanations for the differences observed.

Bioconversion of shrimp shell waste for the production of antioxidant and chitosan used as fruit juice clarifier

SummaryThe pH, proteolytic activity, extent of demineralisation and deprotenisation of shrimp waste were studied during 7 days of fermentation using Pseudomonas aeruginosa A2. After 3 days, pH dropped from 7.0 to 4.4 and then remained constant. Simultaneously, a demineralisation of 92% was achieved. However, protease activity reached its highest level (1230 U mL−1) after 1 day of incubation, and a protein removal of 90% was achieved. Chitin obtained was converted to chitosan. This chitosan, with 73% deacetylation, was tested for clarification of different fruit juices. It was observed that low concentrations of chitosan (below to 1%) greatly increase the clarity of juices without affecting the nutritional value. The antioxidant activity of the hydrolysates produced during fermentation was tested. Hydrolysate obtained after 3 days showed the strongest scavenging activity (90%), which was comparable to the positive control BHA; however, that obtained after 1 day exhibited the highest ferric‐reducing antioxidant power (OD 700 nm = 1.7).

Optimization of Enzymatic Clarification of Green Asparagus Juice Using Response Surface Methodology

Enzymatic clarification conditions for green asparagus juice were optimized by using response surface methodology (RSM). The asparagus juice was treated with pectinase at different temperatures (35 °C-45 °C), pH values (4.00-5.00), and enzyme concentrations (0.6-1.8 v/v%). The effects of enzymatic treatment on juice clarity and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging capacity were investigated by employing a 3-factor central composite design coupled with RSM. According to response surface analysis, the optimal enzymatic treatment condition was pectinase concentration of 1.45%, incubation temperature of 40.56 °C and pH of 4.43. The clarity, juice yield, and soluble solid contents in asparagus juice were significantly increased by enzymatic treatment at the optimal conditions. DPPH radical-scavenging capacity was maintained at the level close to that of raw asparagus juice. These results indicated that enzymatic treatment could be a useful technique for producing green asparagus juice with high clarity and high-antioxidant activity. Treatment with 1.45% pectinase at 40.56 ° C, pH 4.43, significantly increased the clarity and yield of asparagus juice. In addition, enzymatic treatment maintained antioxidant activity. Thus, enzymatic treatment has the potential for industrial asparagus juice clarification.

Insights to the Clarification of Sugar Cane Juice Expressed from Sugar Cane Stalk and Trash

Processing of juice expressed from green sugar cane containing all the trash (i.e., tops and leaves, the nonstalk component) of the sugar cane plant during sugar manufacture has been reported to lead to poor clarified juice (CJ) quality. Studies of different liming techniques have been conducted to identify which liming technique gives the best clarification performance from juice expressed from green cane containing half of all trash extracted (GE). Results have shown that lime saccharate addition to juice at 76 °C either continuous or batchwise gives satisfactory settling rates of calcium phosphate flocs (50-70 cm/min) and CJ with low turbidity and minimal amounts of mineral constituents. Surprisingly, the addition of phosphoric acid (≤ 300 mg/kg as P₂O₅), prior to liming to reduce juice turbidity (≤ 80%), increased the Mg (≤ 101%) and Si (≤ 148%) contents particularly for clarified GE juices. The increase was not proportional with increasing phosphoric acid dose. The nature of the flocs formed, including the zeta potential of the particles by the different liming techniques, has been used to account for the differences in clarification performance. Differences between the qualities of the CJ obtained with GE juice and that of burnt cane juices with all trash extracted (BE) have been discussed to provide further insights into GE processing.

RESPONSE SURFACE OPTIMIZATION OF CONDITIONS FOR THE CLARIFICATION OF GUAVA FRUIT JUICE USING COMMERCIAL ENZYME

ABSTRACT Response surface methodology was employed to optimize the incubation temperature (36.6–53.40C), incubation time (0.95–11.05 h) and enzyme concentration (0.16–0.84 mg/100 g guava pulp) on ascorbic acid retention, clarity, viscosity and color (L value) of guava juice. A central composite rotatable design was used. Significant regression models describing the changes of ascorbic acid, clarity, viscosity and color with respect to the independent variables (enzyme concentration, temperature and incubation time) were established with the coefficient of determination, R2, greater than 0.8. The results indicated that incubation temperature was the most significant (P &lt; 0.01) variable in ascorbic acid retention, changes in clarity and color, whereas the incubation time showed the most significant (P &lt; 0.01) effect on the viscosity of juice. The compromised optimum condition obtained by numerical integration for clarifying guava juice were: incubation temperature 45.35C, incubation time 7.23 h and enzyme concentration 0.70 mg/100 g guava pulp with ascorbic acid 77.71 mg/100 g, clarity 34.54% transmittance, viscosity 1.24 cps and color (L value) 23.33.PRACTICAL APPLICATIONSConsumption of natural fruit juice as an alternative to the traditional caffeine‐containing beverages such as coffee, tea or carbonated soft drinks has increased in recent years in Asian countries. Guava juice when extracted are mostly cloudy due to colloidal suspension and is needed to be clarified as clear juice is preferred. For increased juice yield, the fungal enzymes (pectinases) assist in pectin hydrolysis, causing a significant increase in juice yield. However, the effect of enzyme treatment on guava juice clarification has not been systematically studied. If the enzyme treatment also helps in juice clarification, it will be advantageous to the guava juice process industries. Therefore, the present study was aimed to optimize the hydrolysis pretreatment parameters (incubation temperature, time of treatment and enzyme concentration) for the maximal retention of ascorbic acid, clarity and color with minimal viscosity for the development of clarified guava juice for better acceptability of the product.

EFFECTIVE CLARIFICATION OF POMEGRANATE JUICE USING LACCASE TREATMENT OPTIMIZED BY RESPONSE SURFACE METHODOLOGY FOLLOWED BY ULTRAFILTRATION

ABSTRACT Phenolic compounds of pomegranate juice, which are responsible for haze formation and browning during storage, could be selectively removed by combined enzyme‐ultrafiltration process. The pomegranate juice was treated with Fomes fomentarius laccase at various enzyme concentrations (0.5–5 U/mL), temperatures (20–50C) and times (30–300 min). The effect of these enzymatic treatments on total phenol content and clarity of the juice were evaluated using a central composite design. The optimum treatment conditions were: enzyme concentration 5 U/mL; time 300 min; and temperature 20C. Their application led to a 40% reduction of total phenols but induced a threefold decrease of the juice clarity. This drawback was overcome by ultrafiltration of the laccase‐treated juice. The pomegranate juice obtained was clear, stable and characterized by total phenolics = 864 mg/L, clarity (A650 nm × 1,000) = 86 and color (A420 nm × 1,000) = 236 versus 1,681, 127 and 382, respectively, for untreated juice.PRACTICAL APPLICATIONSThe tendency for hazes to develop in pomegranate juices during storage is a persistent problem in the fruit juice industry. In this work, laccase treatment optimized by response surface methodology followed by ultrafiltration was used to clarify the pomegranate juice. The application of the optimum enzymatic treatment conditions (enzyme concentration 5 U/mL; time 300 min; and temperature 20C) followed by ultrafiltration (cutoff value 15 KDa) decreases the total phenolics of about 50% and the antioxidant capacity of about 20% and, increases the clarity of about 30% versus untreated juice.

Improving Blended Carrot-Orange Juice Quality by the Addition of Cyclodextrins During Enzymatic Clarification

The purpose of this study was to evaluate the effect of cyclodextrins (CDs) on carotene content and quality of blended carrot-orange juice after enzymatic clarification. The blended carrot-orange juice was treated with 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) and gamma cyclodextrin (γ-CD) in different concentrations (1–5 g/100 mL of juice) prior to enzymatic clarification. The results showed that in non-homogenized juice added with HP-β-CD, juice acidity was generally increased from 0.83 to 1.05 g/100 mL. In the homogenized juice added with 3% (w/v) HP-β-CD, the carotene content was also increased to 5.34 mg/mL, meaning two to six times compared to control samples. However, the addition of HP-β-CD prior to juice enzymatic clarification decreased the juice clarity more than that added with γ-CD; both CDs showed wider effect on the ascorbic acid content in non-homogenized than in homogenized, when compared to control samples. The non-enzymatic browning was significantly enhanced by the addition of CDs; though, the total polyphenol content increased with the addition of HP-β-CD from 32.59 to 37.09 and from 29.20 to 35.44 mg GAE/mL in non-homogenized and homogenized juice, respectively. The juice color turned red-yellow with increase in the carotene content of the juice. In conclusion, the addition of HP-β-CD in homogenized juice improved the nutritional and some physico-chemical parameters of the juice.

Improved Sugar Cane Juice Clarification by Understanding Calcium Oxide-Phosphate-Sucrose Systems

It is accepted that the efficiency of sugar cane clarification is closely linked with sugar juice composition (including suspended or insoluble impurities), the inorganic phosphate content, the liming condition and type, and the interactions between the juice components. These interactions are not well understood, particularly those between calcium, phosphate, and sucrose in sugar cane juice. Studies have been conducted on calcium oxide (CaO)/phosphate/sucrose systems in both synthetic and factory juices to provide further information on the defecation process (i.e., simple liming to effect impurity removal) and to identify an effective clarification process that would result in reduced scaling of sugar factory evaporators, pans, and centrifugals. Results have shown that a two-stage process involving the addition of lime saccharate to a set juice pH followed by the addition of sodium hydroxide to a final juice pH or a similar two-stage process where the order of addition of the alkalis is reversed prior to clarification reduces the impurity loading of the clarified juice compared to that of the clarified juice obtained by the conventional defecation process. The treatment process showed reductions in CaO (27% to 50%) and MgO (up to 20%) in clarified juices with no apparent loss in juice clarity or increase in residence time of the mud particles compared to those in the conventional process. There was also a reduction in the SiO2 content. However, the disadvantage of this process is the significant increase in the Na2O content.

Efficacy of xylanase purified from Aspergillus niger DFR-5 alone and in combination with pectinase and cellulase to improve yield and clarity of pineapple juice

Pineapple is one of the fruits having xylan rich hemicellulose content more than pectin. Therefore, the efficacy of absolutely purified xylanase from A. niger DFR-5 alone and in combination with pectinase and cellulase on juice yield and clarity was studied. Xylanase provided maximum yield (71.3%) and clarity (64.7%) of juice in comparison to control responses (61.8% yield and 57.8% clarity). When used together, a synergistic effect of xylanase, pectinase and cellulase on process responses was observed indicating the necessity of a cock-tail of hydrolytic enzymes for complete cell wall degradation. Overall, an increase in juice yield by 52.9% was observed. The process was numerically optimized with the constraint of 'minimum' pectinase and cellulase and 'maximum' xylanase and incubation time for 'maximum' juice yield and clarity. The closeness of observed response (90.2% yield and 80.9% clarity) to the predicted one (89.6% yield and 80.3% clarity) indicated the validity of developed model.

Aspergillus carbonarius polygalacturonases purified by integrated membrane process and affinity precipitation for apple juice production

Aspergillus carbonarius, when grown by submerged and solid-state fermentation, produces different molecular forms of polygalacturonase (PG; EC 3.2.1.15), among them a 42 kDa PG with a high specific activity of 7000 U/mg protein. When the enzymes were purified by integrated membrane process (IMP) and alginate affinity precipitation (AAP), the two processes concentrated different forms of the enzyme. The AAP process selectively purified and concentrated the high active PG whereas the IMP yielded different PGs and also amylase and protease. Evaluation of the AAP enzyme preparations for apple juice preparation under conditions usually employed commercially demonstrated that the high activity PG did not result in good juice clarity. With IMP processed enzymes, juice yields and clarity were similar to that obtained with commercial PG from A. niger.

Impact of apple processing modes on extracted juice quality: Pressing assisted by pulsed electric fields

The purpose of this study was to compare the effects of pulsed electric field (PEF) on apple juice characteristics (turbidity, polyphenolic content and antioxidant capacities). The pressing was used as a standard method for juice extraction. Experiments were carried out at a constant pressure ( P = 3 bar) using a laboratory press cell. Two different methods for PEF application at 400 V/cm were investigated (PEF treatment of whole samples before cutting and PEF treatment of apple slices after cutting). PEF treatment resulted in increase of the juice yield from 44 g/100 g apple (untreated samples) to 58 g/100 g apple (treatment of whole apples) and 64 g/100 g apple (treatment of slices) after 30 min of pressing. The analysis of pH and conductivity showed no significant difference between untreated and PEF-treated samples. However, the total soluble matter content of juice increased after PEF treatment. The obtained turbidity and transmittance data evidence a noticeable improvement of juice clarity for PEF-treated samples. The PEF pre-treatment was accompanied by an increase of the content of polyphenols and intensification of the antioxidant capacities of juice. Most of these effects (juice clarity and content of antioxidants) were more pronounced for the whole treated apples as compared to untreated apples and PEF-treated apple slices. The evolution of apple browning before and after PEF treatment was more pronounced for whole samples. PEF treatment accelerates browning. The obtained data can contribute to the determination of an optimum time for PEF application. The results evidence that PEF-enhanced expression is promising for production of higher quality juices. PEF treatment of whole apples reduces the energy consumption and is advantageous for industrial applications as compared to the treatment of apple slices. PEF combined with pressing can become a good alternative to traditional process.