ENGINEERING FOR RURAL DEVELOPMENT

Transcription

1 Ltvi University of Life Sciences nd Technologies Fculty of Engineering 17 th Interntionl Scientific Conference ENGINEERING FOR RURAL DEVELOPMENT Proceedings, Volue 17 My 23-25, 218 Jelgv 218

2 ENGINEERING FOR RURAL DEVELOPMENT Jelgv, EFFECT OF PRESS CONSTRUCTION ON YIELD OF PRESSING AND SELECTED QUALITY CHARACTERISTICS OF APPLE JUICE Zigniew Kous 1, Rfl Ndulski 1, Alexndros Sotirios Anifntis 2, Frncesco Sntoro 2 1 University of Life Sciences in Lulin, Polnd; 2 University of Bri Aldo Moro, Itly zigniew.kous@up.lulin.pl, rfl.ndulski@up.lulin.pl, lexndrossotirios.nifntis@uni.it, frncesco.sntoro@uni.it Astrct. The process of fruit juices production should e chrcterised y high efficiency, while the finl product should hve high content of solule solids, low cidity nd high content of helth-prooting coponents. Currently, screw presses re ecoing incresingly populr especilly on sll frs nd households. Their construction hs gret ipct on yield pressing nd qulity chrcteristics of juice. The priry ojective of this study ws to deterine the effect of the press type on juice extrction efficiency nd on the totl ount of relesed polyphenols. The scope of the study included lso the deterintion of the juice qulity preters such s the content of solule solids, ph, viscosity nd density. Apple fruits were pressed using two types of chines: nd twin ger juice extrctor. Study results deonstrte tht the pressing efficiency depends on the press construction. The highest yield of extrction ws otined for the twin-screw press. Under the experientl conditions, there ws no influence of the press type on the qulity properties of the juice, except for its viscosity. However, the qulity chrcteristics of the juice depended on the pple vriety. Higher contents of the extrct nd polyphenols were otined in juice fro the pple vr. Jongold juice nd viscosity in juice fro the pple vr. juice. The use of the press offers the possiility of producing juices with desirle qulity trits. Keywords: juice, yield, juice qulity, press construction. Introduction A growing interest of consuers hs recently een oserved in helth-prooting foods, which lower the risk of developent of certin diseses nd disorders [1]. One of the clsses of cheicl copounds with docuented helth-prooting properties re polyphenols [2].In Europe, coon source of these copounds re pples. They re eten either fresh or processed, inly in the for of juices. In recent yers, there hs een n increse in the consuption of nturl juices (NFC not fro concentrte), i.e. with low degree of processing [3]. The technologicl process of pple juice production on the industril scle includes wshing, inspection, shing, enzytic liquefction, extrction, therl tretent, depectinistion, clrifiction, filtrtion, psteuristion, nd pcking [4]. Under industril conditions, juices re produced with the pressing ethod inly y using the horizontl rotry press, s well s elt nd screw presses nd with the help of centrifugl seprtion of juice fro continuous fruit sh stre. In this industry, gret ttention is pid to workers sfety nd helth evlution like in other groindustry nd griculturl sectors [5-7]. The ethod of pulp processing nd the ethod of juice production s well s the preters of these processes hve jor influence on the efficiency nd qulity of the juice otined [8]. The helth-prooting vlue of pples is relted ong others to the content of polyphenols nd solule frctions of dietry fire. Iproperly selected production technology cn significntly reduce the helth-prooting vlue of juices. Tody, juice producers, especilly those operting on sll scle (orchrdists, locl entrepreneurs), specilize in the production of nturl cloudy juices. Their processing does not involve enzytic tretent of pulp, clrifiction nd filtrtion, which llows for the preservtion of greter ount of pectins nd polyphenols thn in cler juices produced fro the se rw teril [9]. The process of fruit juices production should e chrcterised y high efficiency, nd result in the finl product with high content of solule solids, low cidity nd high content of helthprooting coponents. Nowdys, screw presses re ecoing incresingly populr especilly on sll frs (in which renewle energy cn e used to supply energy [1]) nd in households. The construction of these presses hs gret ipct on the pressing yield nd proly on the qulity chrcteristics of juice. Currently, there re liited reports concerning the physico-cheicl coposition of pple juices processed y different extrction techniques. The i of this study ws to deterine the effect of the press type on juice extrction efficiency nd the totl ount of relesed polyphenols. The scope of the study included lso the deterintion of the juice qulity preters such s the content of solule solids, ph, viscosity nd density. Fruits DOI: /ERDev N36 652

3 ENGINEERING FOR RURAL DEVELOPMENT Jelgv, of pples of two vrieties: Jongold nd, were pressed using two types of chines: singlescrew press nd twin ger juice extrctor. Mterils nd ethods The reserch ws conducted with pplies of nd Jongold vrieties purchsed fro the Rylex Group sp. z o.o. (Błędów, Polnd). The tests were conducted on helthy fruits, without ny echnicl dge. Prior to the tests, the fruits were wshed, dried on lotting pper, nd divided into portions of 2 g ech. Two kinds of presses were used for juice extrction: (Zeler, Polnd) nd twin ger juice extrctor (Green Str Elite 3, Triest). The extrcted juice ws collected in continers nd stored in cold plce. Pressing yield For oth presses, two types of pressing yield: pressing yield for rw juice (Y r ) nd pressing yield for filtered juice (Y f ) were deterined in ccordnce with the following foruls: where Y r pressing yield for rw juice j ss of rw juice ss of pple where Y f pressing yield of juice fter filtrtion f ss of filtrted juice ss of pple j Y r = 1 % (1) f Y f = 1 % (2) Totl phenolic content The totl phenolic content ws deterined ccording to the FC ethod [11]. The sornce ws esured using spectrophotoeter (UV-18 Shidzu, Jpn) t wvelength of λ = 76. The results were expressed s g gllic cid equivlent per 1 l pple juice (g GAE per 1 l). Antioxidnt ctivity (AA) Antioxidnt ctivity (AA) of juices wsdeterined y the ethod of reduction of the synthetic 2.2-diphenyl-1-picrylhydrzyl (DPPH) rdicl nd y spectrophotoetric sornce ssy ccording to the odified ethod of Brnd-Willis et l. [12]. The sornce of the solutions ws esured t wvelength of λ = 517 n. Degree of inhiition ws clculted fro the following forul: where AA ntioxidnt ctivity, % A c control sornce A s sple sornce ( ) ( A A ) c s AA % = 1 % (3) A Solule solids content, juice cidity nd density Solule solids content in the juice ws deterined with refrctoetric ethod (PN-9/A- 7511/2), using n ATAGO PAL-3 refrctoeter (Atgo, Tokyo, Jpn). Juice cidity ws deterined with ph-etric ethod (EN 1132: 1994), using CP-411 ph-eter (Eletron, Zrze, Polnd). Juice density ws deterined with the use of pycnoetric ethod t teperture of 22 ºC, using distilled wter s odel liquid. Dynic viscosity The viscosity of juice ws deterined using rottionl type Brookfield Viscoeter (Model LVDV-II Pro +, Brookfield Engineering Lortories, USA). A juice sple of 16 l ws pouredinto s 653

4 ENGINEERING FOR RURAL DEVELOPMENT Jelgv, cylindricl cher (ULA) nd llowed to equilirte t the desired teperture using circulting wter th. The viscosity of pple juice ws esured t teperture of 22 ºC t 5 rp. Methods of sttisticl nlysis Sttisticl nlysis of the dt ws perfored with Sttistic softwre (Sttistic 12, SttSoft Inc., Tuls, Okl., U.S.A.) using nlysis of vrince for fctoril designs (ANOVA). The significnce of differences ws tested using the Tukey LSD test (p.5). Results The sttisticl nlysis of the results reveled sttisticlly significnt (p.5) effect of the press type on the yield of the pressing process. Generlly, the juice extrcted with the screw presses is chrcterized y high content of pulp prticles in coprison to the juice produced on sket or lyer presses. Hence, the juice needs to e filtered efore further processing. Under the conditions of the experient, in the cse of rw juice, juice pressing with twin-screw press resulted in n increse of the process efficiency y pprox % in coprison to single screw press (Fig. 1). However, in the cse of filtered juice, n increse in the pressing yield ws oserved y pprox. 63 %, if copred to single screw press (Fig. 2). The higher efficiency of pressing is due to different nd ore effective wy of fruit grinding in the two-screw press. The twin ger press (or the triturting juicer) crushes nd grinds the teril into very sll prticles (sller thn in the cse of the singlescrew press). Also, the triturting extrctor cuses wider opening of the cell ernes nd relese of greter ounts of their deep-seted nutrients. There ws no influence of vrietl chrcteristics of the tested pples on the pressing yield. 1 8 Jongold Y r, % doule-screw press Fig. 1. Effect of press type on yield of pressing Y r (unfiltrted juice) 1 8 Jongold Y f, % doule-screw press Fig. 2. Effect of press type on pressing Y f (filtrted juice) 654

5 ENGINEERING FOR RURAL DEVELOPMENT Jelgv, The conducted nlyses showed no influence of the type of the press on the content of polyphenolic copounds in the extrcted juices (Fig. 3). The content of these copounds ws ffected only y the vrietl chrcteristics of pples. This is consistent with the literture dt [13; 14]: regrdless of the type of the press used, the content of polyphenolic copounds in the pple juice fro the Jongold vriety ws y out 2 % higher copred to the juice fro the vriety. 1 8 Jongold TPC, % doule-screw press Fig. 3. Effect of press type on totl phenolic content (TPC) in juice (filtrted juice) The ntioxidnt cpcity is very iportnt qulity chrcteristic of juices. The effect of pulp pre-tretent on the ntioxidnt power is presented in Fig. 4. There ws no influence of the type of the press on the ntioxidnt ctivity in the otined juices.the content of polyphenols nd their ntioxidnt ctivity cn e esure of the oxidtion process nd degrdtion of ioctive coponents during the extrction of fruit juices. According to Donldson [18], very sensitive wy to esure the extentof oxidtion nd degrdtion is lso the ctivity of selected enzyes (lph-ylse nd peroxidse). Reserch crried out y Donldson [18] showed very siilr enzytic ctivity of juices otined using single nd twin screw press. This oservtion confirs the high qulity of juices otined using oth screw presses. 1 AA, % Jongold 2 doule-screw press Fig. 4. Effect of press type on ntioxidnt ctivity (AA) of juice (filtrted juice) The type of the press used did not ffect the extrct content in the nlysed juices. However, the juice produced fro the tested vrieties ws chrcterised y different solule solids content. The extrct content in pple juices pressed industrilly in Polnd is t the level of ºBx [15]. The extrct content in the otined juices exceeded the vlue of 1 Bx, which indictes its suitility for juice production [16]. Acidity is one of the ost iportnt criteri in ssessing the suitility of fruit for juice production. The sttisticl nlysis showed tht the type of press used did not ffect the cidity of the 655

6 ENGINEERING FOR RURAL DEVELOPMENT Jelgv, juices otined. Generlly, the cidity of juices is significntly ffected y vrietl chrcteristics nd fruit vegettion conditions [17]. Juices de of the tested pple vrieties were chrcterised y n verge ph of 3.66 ±.9 on the ph scle. According to literture dt, the ph of pple juice vries fro 3.37 to 4.24 [17] (Fig. 5) Jongold SSC, o Brix doule-screw press Fig. 5. Effect of press type on solule solids content ( o Bx) in juices (filtrted juice) The rw juice ieditely fter pressing on the screw presses contins echnicl suspensions of vrious specific grvities fored fro prts of tissues nd cells. Although it contins ny helthprooting ingredients, the juice requires filtrtion even during producing of cloudy juices. After filtrtion, the density of the tested juice ws t siilr level regrdless of the vriety s well s the ethod of pressing nd ounted to pproxitely ± 3.73 kg Jongold d v, P*s 3 2 c 1 doule-screw press Fig. 6. Effect of press type on viscosity (ph) of (filtrted juice) The study results deonstrted the effect of vrietl chrcteristics of pples on the viscosity of the juice otined. Regrdless of the press type, higher viscosity ws deterined in the juice fro the vriety. The viscosity of the juices otined depended on the press type (Fig. 6). Viscosity of pple juice fro the Jongoldvriety ws higher y 12.9 %, when the juice ws otined y ens of the twin-screw press copred to the juice fro. In the cse of juice, the difference ws greternd ounted to 19.4 %.The higher viscosity of the juice extrcted with the twin-screw press cn e cused y greter reking down nd relese of solule phytocheicl ingredients fro pples. Conclusions The study indictes tht the pressing efficiency depends on the design of the press. The highest yield of extrction ws otined for the twin-screw press. Under the experientl conditions, there 656

7 ENGINEERING FOR RURAL DEVELOPMENT Jelgv, ws no influence of the press type on the qulity properties of the juices, except for their viscosity. However, the qulity chrcteristics of the juice depended on the pple vriety. Higher contents of the extrct nd polyphenols were otined in Jongold juice nd higher viscosity in the cse of juice. The conducted reserch indictes the necessity of further reserch on the use of screw presses for the production of juices with helth-prooting properties. References [1] Shhidi F., Aigipln P. Phenolics nd polyphenolics in foods, everges nd spices: Antioxidnt ctivity nd helth effects A review. J Funct Foods 18, 215, pp [2] Yo L.H., Jing Y.M., Shi J., Toás-Brerán F.A., Dtt N., Singnusong R., Cheng S.S. Flvonoids in food nd their helth enefits. Plnt Food Hu Nutr 59, 24, pp [3] Gwóźdź E., Gęczyński P. Prozdrowotne włściwości owoców, wrzyw i ich przetworów (Prohelthy properties of fruits, vegetles nd their preserves), Post Fitoter., nr (16)4, 215, pp (In Polish). [4] Mrkowski J., Bron A., Le Quéeré J.M., Plochrski W. Coposition of cler nd cloudy juices fro French nd Polish pples in reltion to processing technology. LWT- Food SciTechnol 62, 215, pp [5] Pscuzzi S., Sntoro F. Anlysis of possile noise reduction rrngeents inside olive oil ills: A cse study. Agriculture (Switzerlnd), 7(1), 217, [6] Pscuzzi S., Sntoro F. Evlution of frers OSH hzrd in opertion nery oile telephone rdio se sttions. 16th Interntionl Scientific Conference Engineering for rurl developent Proceedings, Volue 16. Jelgv, Ltvi, My 24-26, 217, pp ISSN: , [7] Pscuzzi S., Sntoro F. Exposure of fr workers to electrognetic rdition fro cellulr network rdio se sttions situted on rurl griculturl lnd. Interntionl Journl of Occuptionl Sfety nd Ergonoics, 21(3), 215, pp [8] Ndulski, R., Kous, Z., Wilczyński, K., Zwiślk, K., Grochowicz, J., Guz, T. Appliction of freezing nd thwing in pple (Mlus doestic) juice extrction. Journl of Food Sciences, 81(11), 216, E2718-E2725. [9] Tetik N., Krhn M., Turhn I., Aksu M., Oziyci H.R. A lrge-scle study on storge stility of cloudy pple juice treted y N2 nd scoric cid. J Food Qulity 36, 213, pp [1] Anifntis A.S., Colntoni A., Pscuzzi S., Sntoro F. Photovoltic nd Hydrogen Plnt Integrted with Gs Het Pup for Greenhouse Heting: A Mtheticl Study. Sustinility 218, 1, [11] Singleton V.L., Orthofer R., Luel-Rventos R.M. Anlysis of totl phenols nd other oxidtion sustrtes nd ntioxidnts y ens of Folin-Cioclteu regent. Methods Enzyol 299, 1999, pp [12] Brnd-Willis W., Cuvelier M.E., Berset C.L.W.T. Use of free rdicl ethod to evlute ntioxidnt ctivity. Food Science nd Technology, 28, 1995, pp [13] Vrhovsek U., Rigo A., Tonon D., Mttivi F. Quntittion of polyphenols in different pple vrieties. J. Agric. Food Che. 52, 24, pp [14] Wojdyło A., Oszinski J., Lskowski P. Polyphenolic copounds nd ntioxidnt ctivity of new nd old pple vrieties. J. Agric. Food Che. 56, 28, pp [15] Kowlczyk R. Wydjność tłoczeni i wskźnik zużyci jłek w procesie wytwrzni zgęszczonego soku jłkowego (The pressing cpcity nd the rte of pple consuption in the process of producing concentrted pple juice). Prol Inż Spoż 12, 2, pp. 2-3 (In Polish). [16] Gsik A., Mitek M., Ginlski Z., Krysztoforski M.A., Lesisz J.T., Słt B., Szońsk B., Śliw A. Przetwórstwo owoców n pozioie gospodrstw (Fruit processing t fr level). Centru Dordztw Rolniczego w Brwinowie Oddził w Rdoiu, s. 8, 212, ISBN (In Polish). [17] Eisele T.A., Drke S.R. The prtil copositionl chrcteristics of pple juice fro 175 pple vrieties. J Food Copos Anl 18, 25, pp [18] Donldson M., Coprison of juice extrctors: Enzyes, Hllelujh Acres Foundtion, Shely, NC