INTRODUCTIONApple juice is one of the most popular fruit juicesin Russia. Therefore, domestic food industry needsreliable methods for its nutritional value and riskassessment. The beneficial properties of apple juice areassociated with various biologically active compounds.Recent antioxidant studies show that apple juice is richin such antioxidants as polyphenols, e.g. quercetin,phloretin, chlorogenic acid, and epicatechin. A fruit andvegetable diet reduces oxidative stress, thus preventingchronic diseases and slowing down aging. Apples andapple products are known to reduce the risk of cancer,cardiovascular diseases, asthma, and type II diabetes[1]. The chemical composition of juices depends on thevariety of apples, their ripeness, climate, cultivationmethod, etc. Apple juice production involves a widevariety of apple cultivars but gives preference to winterand autumn varieties because they are juicy, firmfleshed,and rich in aromatic and phenolic substances.Consumers see apple juice as a source of biologicallyactive compounds that are beneficial to human health.As a result, the volume of its industrial productionkeeps increasing. Food processing determines thenutritional value of the finished product [2]. Crushing,heat treatment, fermentation, and clarification ofapples affect the phytochemical composition of applejuice. These processes decrease the amount of phenoliccompounds. After heat treatment and direct extraction,fruit juice had 10% of the antioxidant properties offresh fruits. After pulp fermentation, this figure was 3%.Pulp fermentation decreased the content of phloridzin,Copyright © 2022, Samoylov et al. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 InternationalLicense (http://creativecommons.org/licenses/by/4.0/), allowing third parties to copy and redistribute the material in any medium or format and to remix,transform, and build upon the material for any purpose, even commercially, provided the original work is properly cited and states its license.Foods and Raw Materials, 2022, vol. 10, no. 1E-ISSN 2310-9599ISSN 2308-4057177Samoylov A.V. et al. Foods and Raw Materials, 2022, vol. 10, no. 1, pp. 176–184chlorogenic acid, and catechin by 31, 44, and 58%,respectively. Most of the active compounds remained inapple pomace [3].Another study compared polyphenols in apple juiceafter heat and high pressure treatments [4]. The phenolicprofile of the resulting apple juice changed significantly.The epicatechin concentration was 0.42 mg/100 mL inthe raw juice; it decreased to 0.31 mg/100 mL at 25°Cand increased to 0.39 mg/mL at 65°C. Heat treatmentincreased the amount of catechin and chlorogenicacid, while pressure treatment decreased the amountof polyphenols. The authors linked this phenomenonto structural destruction because the rapid release ofcarbon dioxide led to pressure gradient.Various plant assays of antioxidants propertiesreceive more and more scientific attention each year.Unfortunately, different antioxidant tests use differentterms and measurements [5]. Moreover, antioxidantsmay respond differently to different radicals or theirsources. Phytochemical compounds are present innumerous products and possess numerous mechanismsof action on metabolic processes. Thus, the foodindustry has a wide choice of adequate antioxidantassessment methods [6]. Therefore, an objective analysisof data on bioactive compounds needs specificallytailored markers. Finally, the bioactivity of plant foodproducts depends on a whole complex of phytochemicalcompounds. Lipid peroxidation is measured by thelevels of malondialdehyde (MDA), β-carotene, and dieneconjugates [6].Other methods determine the total antioxidantpotential according to the concentration of freeradicals, e.g. 2,2-diphenyl-1-picrylhydrazyl radical(DPPH), pre-generated radical cation 2,2’-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ironreducing/antioxidant (FRAP), ferrous complex andxylenol orange (FOX), iron(III) thiocyanate complex(FTC), alkyl carboxylic acid (ACA), etc.These approaches make it possible to analyze thelevel of antioxidant activity both in food productsand in living organisms after consumption. However,bioassays seem to be the most informative and accuratemethods, since all nutritionally valuable substancesare bioavailable and bioactive. Testing food matriceson laboratory animals or human cell lines is expensiveand labor-consuming. Therefore, plant assays are morepreferable.Scientists compared the level of lipid peroxidationin onion roots after their treatment with apple juice anda model aqueous solution of fructose, glucose, sucrose,D-sorbitol, and malic acid. After incubation, the contentof MDA in root tissues was 1.7 times higher in themodel solution than in the apple juice [7]. Such resultsproved that the juice possessed some antioxidant activity,which lowered the carbohydrate-induced lipid oxidationalmost to the control values, i.e. those of water.Domestic regulations ban synthetic additives fromjuice production. Unfortunately, these measures failto eliminate juice-related safety risks. Therefore, foodproducers have to check raw materials for variouscontaminants, such as heavy metals, pesticides,and herbicides, as well as to monitor the safety oftechnological production means, e.g. detergents,lubricants, packaging material, etc. Moreover,technological methods of juice processing requireexposure to high temperatures during pasteurization,sterilization, etc., which can result in accumulationof toxic compounds and adducts. For example, somephytochemical compounds of plant products are knownto react with cellular macromolecules during storage,thus causing cellular toxicity or even genotoxicity if theyreact with DNA [7, 8].Almost all higher plants contain such naturalmutagens as pyrolizidine alkaloids and some flavonoids[9]. In fact, recent studies linked the consumptionof fruits and juices to cancer and asthma in children[10–13]. Finally, juices are rich in carbohydrates, andfructose and sucrose produce adverse metabolic effectson human health [14, 15]. Food scientists have developednumerous physicochemical assay methods for thesetoxic agents. However, bioassays seem to be the onlymethod that gives an integrated assessment of theirsynergetic effect.In this regard, the Allium cepa test is especiallypromising. This test is recommended by WHO expertsas a standard for cytogenetic monitoring. The A. cepaassay is a popular method to define the bioindicator ofcyto- and genotoxicity of xenobiotics in food productsand their components [16]. The A. cepa test provides aprompt comparative analysis of individual compoundsand their combinations. A. cepa cells share metabolicmechanisms with all eukaryotes, but unlike animal andhuman cell lines, they are not subject to transformationand can be useful in detoxification modeling. This testcan screen biomarkers that determine the negativepotential of food matrix toxicants for metabolicprocesses in onion root tissues [17].Taking into account these indicators and the dataon antioxidant activity, plant bioassays can logically beapplied to various brands of apple juice [7]. However,research databases seem to contain no publications onthe Allium-based comparative evaluation of variousdomestic brands of apple juice. The present researchobjective was to compare the antioxidant activity,cytotoxicity, and genotoxicity of various domestic applejuice brands.STUDY OBJECTS AND METHODSPreparation of bioassay solutions. The researchfeatured samples of processed and clarified apple juicesfrom four producers. The juices were purchased from aretail chain and marked as A, B, C, and D. The juiceswere within the expiration date, with intact packaging.The juices were diluted with bottled water in ratios 1:5,1:9, and 1:20. Sorbic acid (Thermo Fisher Scientific,USA) simulated oxidative stress. Solutions of sorbicacid (100 and 50 mg/L) included bottled water and178Samoylov A.V. et al. Foods and Raw Materials, 2022, vol. 10, no. 1, pp. 176–184were prepared in a water-bath by heating to 78°C withconstant stirring.Bioassay. The bioassay featured peeled onion bulbsof the same weight (5–7 g) and diameter (≥ 3 cm). Theonions were placed in 2-mL test tubes with bottledwater and left for two or three days, depending on theexperimental conditions, in a thermostat (24 ± 1°C)in total darkness. After two days of preliminarygermination, the onions with a root length of ≥ 1 cmwere placed in experimental solutions with apple juice,sorbic acid, or their mix. They were incubated in thethermostat for the next 24 or 48 h. Bottled water wasused as a negative control. Ten onions were selectedfrom each group of experimental and control samples.After preliminary three days of germination and twodays of treatment with solutions of different juices, someonions were thoroughly washed and then incubated inbottled water for another 48 h at 25 °C to be tested forrestorative germination. After the experiment, all rootswere cut off, dried with filter paper, and weighed. Theweight gain was determined as the arithmetic mean foreach solution.Staining and microscopy. A 2% solution ofacetoorcein was used to stain the preparations of onionapical root cells. The solution included 1 g of orceindye per 50 mL of 45% acetic acid. A 70% solutionof ethyl alcohol facilitated the long-term storage inthe refrigerator. The experiment involved the instantpressure method. A root end of 2–4 mm in length wascut off from the root and washed in distilled water.The piece was placed in a drop of 45% acetic acid andcrushed with a glass spatula under a coverslip. Thecells were observed in interphase, prophase, metaphase,anaphase, and telophase in an Axioskop 40 (Zeiss) lightmicroscope under 40× magnification (Fig. 1).Cytogenetic indicators. The mitotic index, % wascalculated by the following formula:Mitotic index = (1)The chromosomal aberration analysis revealeddisorganization, adhesion, overlap, lagging, colchicinemitosis, and a small percentage of bridging andmicronuclei formation (Fig. 2).For a quantitative description, the index ofchromosome aberrations, % was calculated as follows:Chromosome aberrations =The cytogenetic studies revealed on average 10 000cells per variant.Concentration of malondialdehyde in the onionroot cells. The lipid peroxidation in root tissues wasdetermined by the amount of malonic dialdehyde(MDA) interacting with 2-thiobarbituric acid (MDAin fresh mass) [18]. During the experiment, 0.2–0.9 gof onion roots were placed into a polymer 15-cm3tube (weighing error ± 0.0001 g). After that, 1 cm3 oftrichloroacetic acid (Merck, Germany) with a massconcentration of 200 g/dm3 was added to the sample.The mix was stirred and diluted with 3 cm3 of thesame trichloroacetic acid solution. The tubes werecentrifuged for 15 min at 1000×g at 4°C. Then, 1 cm3of the upper liquid layer was transferred to another tube.After that, 4 cm3 of a thiobarbituric acid solution (0.5 gof thiobarbituric acid (Diam, Russia)) was poured into100 cm3 of trichloroacetic acid solution (200 g/dm3).The tubes were placed in a 95°C water-bath for 30 minfollowed by an ice bath. Next, the tubes were placed ina centrifuge for 10 min at 1000×g at 20°C. The resultingsolutions were subjected to spectrophotometry in aCary WinUV 100 spectrophotometer (Varian, USA) atwavelengths of 600 and 532 nm.Statistical analysis. Statistical processing involvedMicrosoft Excel 2016 and Statistica 12 software.The root mass indicator was calculated using thenonparametric Mann-Whitney test to compare twomeans (P ≤ 0 .05). F isher’s t est ( P ≤ 0.05) quantifiedthe differences in data with a binomial distribution, i.e.mitotic index and frequency of chromosome aberrations.RESULTS AND DISCUSSIONThe research tested the antioxidant effect of waterdilutedapple juice on Allium cepa roots after sorbicacid-induced oxidative stress. Antioxidants of plantorigin could delay or prevent lipid oxidation becausethey inhibited the development and accumulation of freeradicals [19]. However, sorbic acid is known to triggerthe dose-dependent development of oxidative stressand increase the malonic dialdehyde (MDA) content inroot tissues [20]. Concentrated solutions of apple juiceactivated lipid oxidation during the A. cepa test [7].Therefore, the initial task was to select the optimalconcentrations of sorbic acid and juice to obtain themaximal antioxidant effect. The onion samples spent48 h incubating in solutions of sorbic acid and applejuice: 100 mg/L of sorbic acid was diluted with brand Aapple juice as 1:2, 1:5, and 1:9. After the incubation, theFigure 1 Mitosis phases, from left to right: prophase, metaphase, anaphase, and telophase179Samoylov A.V. et al. Foods and Raw Materials, 2022, vol. 10, no. 1, pp. 176–184Figure 2 Chromosome aberrations: a) lagging in telophase; b) detachment in metaphase; c) lagging in anaphase; d), e), andi) disorganization in metaphase; f) multipolar mitosis and disorganization in metaphase; g) disorganization in metaphase;h) detachment in metaphase; j) k-mitosis* statistically significant difference from control (P < 0.05); error bars determine the value of the standard deviationFigure 3 Decrease in weight gain of onion roots after treatment with brand A juice and sorbic acid (100 mg/L)0 20 100 120Juice 1:2 + sorbic acidJuice 1:5 + sorbic acidJuice 1:9 + sorbic acidControlPre-test control40 60 80Root weight gain, % of control0 20 100 120Juice 1:2 + sorbic acidJuice 1:5 + sorbic acidJuice 1:9 + sorbic acidControlPre-test control40 60 80Root weight gain, % of control0 20 100 120Juice 1:2 + sorbic acidJuice 1:5 + sorbic acidJuice 1:9 + sorbic acidControlPre-test control40 60 80Root weight gain, % of controlFigure 4 MDA in the roots treated brand A apple juice and sorbic acid (SA, 50 mg/L)05101520253035Control Juice1:20+SAJuice 1:9+SA Juice 1:5+SA Juice 1:9 SAMDA concentration,μmoL/g wet weight05101520253035Control Juice1:20+SAJuice 1:9+SA Juice 1:5+SA Juice 1:9 SAMDA concentration,μmoL/g wet weight05101520253035Control Juice1:20+SAJuice 1:9+SA Juice 1:5+SA Juice 1:9 SAMDA concentration,μmoL/g wet weightaeib c df g hj180Samoylov A.V. et al. Foods and Raw Materials, 2022, vol. 10, no. 1, pp. 176–184mass of the roots remained the same. In fact, they turnedyellow and mucous, which meant that the doses had anacute toxic effect (Fig. 3).In the next experiment, the treatment time and theacid concentration were halved, and the juice sampleswere diluted as 1:20, 1:9, and 1:5. Figure 4 shows that the1:9 juice solution provided the maximal protective effectunder oxidative stress caused by a 50 mg/mL solutionof sorbic acid. In these samples, the level of MDAwas lower by 43% than in the samples with the sameconcentration of sorbic acid.The obtained data confirmed the results described in[21], where apple juice in rats’ diet decreased the levelof MDA in their blood plasma. The phenolic compoundsand dietary fiber of apple juice proved to reduce the lipidoxidation in humans as well [1, 22, 23].The dose-dependent decrease in MDA was revealedonly in the first two, more diluted juice solutions(Fig. 4). In 1:5 juice samples, this indicator increasedagain. This effect was associated with carbohydrates,which are known to have prooxidant propertiesat this concentration during the A. cepa test [7].Therefore, these data also confirmed that the maximalantioxidant activity of apple juice depended not onlyon its biologically active compounds, but also on theconcentration of carbohydrates.Some recent research featured the effect of fructoseon the redox balance in the organs of the centralnervous system. Rat studies revealed an increase inlipid oxidation of brain tissues after both short-term andlong-term intake of this carbohydrate [24]. These animalmodels showed the same results as the abovementionedplant bioassays for the prooxidant properties of applejuice carbohydrates. Therefore, the A. cepa test provedto be a reliable research method for the molecularmechanisms of antioxidant and prooxidant properties ofapple juice.Growth indicators demonstrated no significantdifferences after the onions were treated with solutionsof juice and sorbic acid (Table 1). However, previousresearch revealed that the increase in juice concentrationhad an adverse effect on onion root cell proliferation[7]. However, the decrease in the mitotic index againstthe increase in the juice proportion was not dosedependent(Table 1). Both juice concentrations, 1:20 and1:9, had the same values of this indicator. Probably, themaximal antioxidant status of the samples diluted 1:9had protected the proliferative processes by reducing theeffects of oxidative stress.Similar conclusions were reported in a publicationabout the effect of antioxidants on bisphenolinducedoxidative stress in mouse spermatozoa [25].Antioxidants preserved the motility of these germcells, improved the fertilization process, and preventedpremature development of the resulting fetus.The low values of the mitotic index meant a lowproportion of dividing cells in the experimental sampleswith mixes of juice and sorbic acid (Table 1). Therefore,no comparative analysis of chromosomal aberrationswas necessary.The next stage featured the antioxidant potential ofvarious juice brands diluted 1:9 after 24 h of sorbic acidinducedoxidative stress. Juice brands A, B, and C inthe mix reduced the level of MDA by 23, 26, and 26%,respectively (Fig. 2). Juice brands B and C also revealedsome antioxidant activity; however, the differencesbetween the experimental samples in MDA values wereinsignificant (3%). In the experimental mixes, the rootmasses were very similar and minimal, while the valuesof the mitotic index showed some statistically significantdifferences (Table 2).Phenolic compounds are mainly to be found in applepeel and pulp cell walls [1, 26]. Therefore, the processedand clarified juices had some residual differencesin antioxidant activity in relation to lipid oxidation.Nevertheless, the bioassay was able to register a ratherhigh antioxidant activity even in these non-pulp juices.The similar MDA values could also be explained bythe absence of the pulp as the main source of phenoliccompounds.The results indicated an acute toxic effect (Fig. 3)and an increase in the levelЦ of lipid oxidation (Fig. 5)in the mixes of various juices and sorbic acid atconcentrations of 100 and 50 mg/L, respectively.For some juice-containing drinks, domestic regulatorydocuments state much greater permissibleconcentrations of this preservative, ≥ 1 g/kg. Therefore,sorbic acid can reduce the initial antioxidant potentialof these products, but not the content of phytochemicalcompounds. These data are important if the productionTable 1 Root weight gain, mitotic activity, and frequency of chromosome aberrations in onion root meristem cells after incubationin solutions of brand A juice, sorbic acid (SA), and their mixes*SE – standard error, ** – values marked by the same letter have no significant statistic difference (P < 0.05)Experiment Root weight gain, g/onion,mean ± SE*Mitotic index, %,mean ± SEChromosome aberrationsper total cells, %, mean ± SEControl 0.296 ± 0.048a** 8.70 ± 0.24a 0.26 ± 0.04aJuice 1:20 + SA, 50 mg/L 0.189 ± 0.034ab 1.08 ± 0.11b 0.02 ± 0.02bJuice 1:9 + SA, 50 mg/L 0.162 ± 0.029bc 1.01 ± 0.08b 0.08 ± 0.02cJuice 1:5 + SA, 50 mg/L 0.138 ± 0.032bcd 0.40 ± 0.06c 0.04 ± 0.02bcJuice 1:9 0.109 ± 0.012bcd 1.40 ± 0.09d 0.21 ± 0.03adSA, 50 mg/L 0.243 ± 0.021ab 5.86 ± 0.21e 0.18 ± 0.04d181Samoylov A.V. et al. Foods and Raw Materials, 2022, vol. 10, no. 1, pp. 176–184technology provides for this preservative. However, onlybioassay can determine how these effects interact.Our experiments on the toxic potential of differentjuice brands were aimed at a comparative assessmentof their side effects on the growth and the cytological,cytogenetic, and biochemical parameters of onionroots. We found no scientific publications that featuredthe A. cepa test as a means of researching the toxic0510152025303540Control SA Ju ice A J uice B Juice C Juice A* Juice B* Juice C*MDA μmoL/g wet weight0510152025303540Control SA Ju ice A J uice B Juice C Juice A* Juice B* Juice C*MDA concentration, μmoL/g wet weight0510152025303540Control SA Ju ice A J uice B Juice C Juice A* Juice B* Juice C*MDA concentration, μmoL/g wet weightFigure 5 MDA in roots treated with various apple juice brandsNote: Vertical error bars indicate the value of the standard deviation; * marks the incubation experiments with mixes of juices and sorbic acid(SA, 50 mg/L)Table 2 Root weight gain, mitotic activity, and frequency of chromosome aberrations in onion root meristem cells after incubationin solutions of juices and their mixes with sorbic acid (SA)* SE – standard error, ** – values marked by the same letter have no significant statistic difference (P < 0.05)Table 3 Root weight gain, mitotic activity, and frequency of chromosome aberrations in onion root meristem cells before and afterrestorative germination in juice solutionseffect of apple juice. The main task was to obtain dataon possible irreversible violations of these processes.In case of complete or partial irreversibility after thejuice treatment, the detoxification systems of the plantorganism failed to cope with the load, and these negativephenomena might progress in the future.The previous experiments had a high toxic loadbecause of sorbic acid (Table 2). In this experiment,Experiment Root weight gain, g/onion,mean ± SE*Mitotic index, %, mean ± SE Chromosome aberrations pertotal cells, %, mean ± SEControl 0.236 ± 0.030a** 8.75 ± 0.24a 0.29 ± 0.05aSA, 50 mg/L 0.211 ± 0.034ab 5.17 ± 0.19b 0.18 ± 0.04bJuice А 0.139 ± 0.016bc 2.55 ± 0.13c 0.05 ± 0.02cJuice B 0.146 ± 0.016bcd 1.10 ± 0.09d 0.11 ± 0.03bJuice C 0.184 ± 0.024abcde 0.99 ± 0.08d 0.01 ± 0.01dJuice А +SA, 50 mg/L ЦЦ0.155 ± 0.021bcdef 0.48 ± 0.05e 0.020 ± 0.001cdJuice B + SA, 50 mg/L 0.143 ± 0.030bcdefg 0.58 ± 0.07ef 0.02 ± 0.01eJuice C + SA, 50 mg/L 0.171 ± 0.012abcdefg 0.56 ± 0.07ef 0.04 ± 0.02eExperiment Root weight gain, g/onion,mean ± SE*Mitotic index, %, mean ± SE Chromosome aberrations per total cells, %,mean ± SEBefore restorative germinationControl 0.799 ± 0.089a** 8.52 ± 0.27a 0.02 ± 0.01aJuice А 0.561 ± 0.056ab 3.06 ± 0.19b 0.12 ± 0.04bJuice C 0.540 ± 0.048bс 3.64 ± 0.18c 0.08 ± 0.03bcJuice D 0.597 ± 0.060abc 3.95 ± 0.20c 0.15 ± 0.04abcAfter restorative germinationControl 1.060 ± 0.082a 7.82 ± 0.28a 0.16 ± 0.04aJuice А 0.791 ± 0.088ab 7.99 ± 0.25ab 0.43 ± 0.06bJuice C 0.827 ± 0.094abc 8.08 ± 0.27ab 0.99 ± 0.10cJuice D 0.944 ± 0.095abc 6.93 ± 0.25c 0.41 ± 0.06b182Samoylov A.V. et al. Foods and Raw Materials, 2022, vol. 10, no. 1, pp. 176–184Figure 6 shows the chromosome aberrations found inthe apical meristem of the onion roots after incubationin juice solutions, as well as after incubation andsubsequent regeneration in bottled water. No statisticallysignificant differences (P ≤ 0.05) in chromosomaldisorders were revealed before or after restorativegermination in bottled water. However, juice A samplesdemonstrated all kinds of aberrations after restorativegermination.Thus, all the experimental samples revealedirreversible significant genotoxic effects (Table 3),represented mostly by chromosome disorganization0102030405060708090100Control Juice A Juice C Juice DAfter incubation in juice solutionsControl Juice A Juice C Juice D% of total abberations revealed1 2 3 4After restorative germination024681012141618Control Juice A Juice C Juice D Control* Juice A* Juice C* Juice D*MDA concentration, μmoL/g wet weightFigure 6 Chromosomal aberrations in meristem cells of onion roots before and after restorative germination in juice solutions: 1)disorders of chromosome segregation (overlap, lag); 2) anomalies of mitotic apparatus (adhesion, multipolar mitosis); 3) aberrationsof clastogenic character (bridges, fragments); 4) miscellaneous (fragmentation, agglutination, pulverization)Note: Vertical error bars indicate the value of the standard deviation, * – marks incubation in acid solutions followed by germination in bottledwaterFigure 7 MDA in roots treated with aqueous solutions of juicesthe treatment time with juice solutions reached 48 h.After restorative germination, the average weight ofthe roots was by 11–25% lower than in the controlsamples, but this difference was not significant (Table 3).Mitotic index had the same trend, except for the brandD juice samples, although this indicator differed fromthe control by only 11%. However, the cytogeneticanalysis showed a significant increase in chromosomalaberrations in all the experimental groups, while themaximal growth by more than six times was recorded inthe brand C juice samples.183Samoylov A.V. et al. Foods and Raw Materials, 2022, vol. 10, no. 1, pp. 176–184in metaphase, lagging in anaphase, detachmentin metaphase, and lagging in telophase (Fig. 6).Disorganization of chromosomes in metaphase, forinstance, was a typical irreversible side effect of benzoicacid on onion roots [20].After restorative germination, MDA content washigher in all the experimental variants by 21–51%compared with the control values (Fig. 7). Thisindicator also demonstrated the irreversible nature ofthe identified adverse effects after exposure to juicesolutions.Thus, the maximal negative effects after restorativegermination were recorded when analyzing the valuesof the mitotic index and MDA in the D juice samplesand the level of chromosome aberrations in the C juicesamples. If the first two indicators differed from thecontrol only by tens of percent, the latter differed byseveral times in all the experimental variants. In thejuice C samples, the level of cytogenetic disorders wastwo times higher compared to samples A and D. Thisbiomarker requires more attention when assessing thegenotoxic potential of this product, both phytochemicaland technological.CONCLUSIONThe research featured a new bioassay method fordetermining the antioxidant potential of processedapple juice. The juice reduced the lipid oxidation inonion roots to 40% after oxidative stress induced bysorbic acid. The antioxidant potential in juice solutionsdepended on the ratio of biologically active compoundsand carbohydrates.The research included a comparative analysis ofthree juice brands. Sorbic acid had a possible negativeeffect on the quality of juice-containing products: even50 mg/L reduced the antioxidant profile of the finishedproduct. When the concentration of sorbic acid reached100 mg/L, its effect became toxic, and onion roots died.No side toxic subchronic effects on the weight gain wereregistered after onion roots were treated with three juicebrands. However, one of the three juices demonstratedan irreversible decrease in the proliferative index by11%.The cytogenetic analysis of the root meristemrevealed the maximal adverse side effect: chromosomalaberrations increased in all experimental groups. Forone brand, these disorders increased by more than sixtimes. In general, the Allium cepa bioassay of toxicsubchronic effects provided reliable results for sideeffects in apple juice production.CONTRIBUTIONThe authors were equally involved in writing themanuscript and are equally responsible for plagiarism.CONFLICT OF INTERESTThe authors declare that there is no conflict ofinterests regarding the publication of this article.