UV-C irradiation reduces breakdown and chilling injury of peaches during cold storage

Transcription

1 Journl of the Siene of Foo n griulture J Si Foo gri 84:4 4 (online: 4) DOI:./jsf.67 UV-C irrition reues rekown n hilling injury of pehes uring ol storge Gustvo Gonzlez-guilr, Chien Y Wng n George J ut Centro e Investigión en limentión y Desrrollo, C (CID, C), Direion e Tenologi e limentos e Origen Vegetl, Crreter l Vitori Km.6, L Vitori, Hermosillo, Sonor (8) Méxio Proue Qulity n Sfety Lortory, griulturl Reserh Servie, US Deprtment of griulture, ltimore venue, eltsville, MD 7-, US strt: Pre-storge exposure of pehes (Prunus persi v Jefferson) with UV-C irrition for, or min signifintly reue hilling injury fter 4 n ys of storge t C plus 7 ys of shelf-life t C. Similr reution in fungl ey ws lso foun y these tretments. Skin rowning n UV mge were foun to e moerte to severe in pehes fter the or min of UV-C tretments. The min of exposure elerte eteriortion. Fruit trete with UV-C for, or min remine firmer n softene more slowly thn the ontrol n those trete with longer urtions of exposure. No ifferenes were foun in weight loss or respirtion rtes mong the tretments. However, ethylene proution ws stimulte y ll of the UV-C tretments ompre with the ontrol. Putresine levels inrese initilly fter or min of exposure to UV-C. teneny towr higher umultion of spermiine n spermine ws foun in pehes fter UV exposure. These higher levels of polymines pprently re response to the UV-C irrition n might e enefiil in inresing the resistne of fruit tissue to eteriortion n hilling injury. 4 Soiety of Chemil Inustry Keywors: UV-C irrition; ey; hilling injury; polymines INTRODUCTION hevy reline on syntheti fungiies hs een neessry to ontrol posthrvest ey of proue, whih results in out % loss of fruits n vegetles in the US. In eveloping ountries, these losses n exee %. Fungiie resiues hve een foun to pose potentil helth thret to the onsumer, n prtiulrly to hilren. euse of this prolem, reserhers hve ttempte to fin lterntives to hemil pestiies for ontrolling posthrvest iseses of hortiulturl prouts. 6 mong the lterntive methos use for ontrolling ey, ultrviolet-c irrition (UV-C, 9 8 nm wvelength) offers interesting possiilities. UV tretment, espeilly with rition t 4 nm, n use wek stress responses, often ssoite with the phenomenon of inuile pthogen resistne. 7,8 This tretment enhnes the iosynthesis of phenols (toxi to pthogens) y inresing the tivity of the phenylnine mmoni-lyse enzyme. 9 The inreses of soprone n sopoletin in itrus fruit inue y UV-C irrition my lso e relte to enhne resistne ginst pthogens. UV-C irrition lso inrese the levels of ntioxints (α-toopherol, β-rotene n sori i) in severl green vegetles. It hs een reporte tht the umultion of the polymines, putresine n spermiine, n e onsiere s n initor of stresses on fruit inluing the effets of low temperture storge. We reently oserve tht UV-C tretment inrese the polymine levels in skin tissue of mngo fruit. The optiml storge temperture of pehes is.6 C. 4 However, storge t C hs een reporte to enhne internl rekown n evelopment of hilling injury symptoms. UV-C irrition hs een shown to ely ripening n reue ey of CVS Elert n Loring pehes store t C, 8 ut, no stuies hve een reporte using omintion of UV-C tretment n susequent low temperture storge. The im of this stuy ws to etermine the effetiveness of UV-C tretment in reuing ey n preventing other physiologil isorers while mintining the qulity of pehes store t hilling temperture ( C) n/or shelf-life temperture ( C). Corresponene to: Gustvo Gonzlez-guilr, Centro e Investigión en limentión y Desrrollo, C (CID, C), Direion e Tenologi e limentos e Origen Vegetl, Crreter l Vitori Km.6, L Vitori, Hermosillo, Sonor (8) Méxio E-mil: gustvo@sel.i.mx (Reeive 4 Otoer ; epte 4 Deemer ) Pulishe online Ferury 4 4 Soiety of Chemil Inustry. J Si Foo gri 4/4/$. 4

2 G Gonzlez-guilr, CY Wng, GJ ut MTERILS ND METHODS Plnt mterils n experiments Pehes (Prunus persi v Jefferson) were otine on the y of hrvest from MLeo Frms In, SC, US. Fruit of US Extr #9 gre use for this experiment initilly h firmness of 8 6 N n solule solis ontent of. rix. Fruits were sorte n rnomize. Fruits of uniform size, shpe n mturity n free from efets were use, n were ivie into six lots of 6 fruits eh for UV-C irrition. Tretments use were: () ontrol (nontrete); () UV-C irrition for min; () UV-C irrition for min; (4) UV-C irrition for min; () UV-C irrition for min; (6) UV-C irrition for min. Temperture hnges uring irrition were negligile n, even with the highest ose teste, i not exee C. fter irrition, the fruits were trnsferre to rkness immeitely n store for 4 or ys t C plus 7 ys t C. Non-trete fruits store uner the sme onitions were use s the ontrol. During the storge perio, hnges in qulity were etermine. fter ol storge (4 or ys t C) five fruits per tretment were tken n hel t C to mesure respirtion rte n ethylene proution. fter 4 or ys t C n susequent shelf-life perio (7 ys t C), fruits from eh tretment were evlute for weight loss, flesh firmness, hilling injury (CI) symptoms, rowning inex, ey, shriveling n UV-C mge. Smples ( g) of skin tissue were tken from eh of four fruits initilly, fter UV-C tretment, fter ol storge ( C) n shelf life perio for polymine nlysis. Polymine quntities were etermine oring to Gonzlez-guilr et l. 6 UV-C irrition The UV-C irrition tretment ws pplie using unfiltere Generl Eletri -W G T8 germiil lmps. Of the irrine emitte y these lmps, 8% ws in the UV-C ( 8 nm) region. 7 Groups of pehes were ple on wie-mesh sreen n irrite on oth upper n lower surfes t istne of m from the sreen. t.-,.-, -, 7.- n -min intervls, thefruitswererotte8 to hieve omplete irrition for -, -, -, - n -min UV-C tretments, respetively. The UV-C setup ws ple in fume hoo to remove ny ozone generte uring irrition. s sfety preutions, polyronte femsk n protetive gloves n lothing were use. UV mesurements were tken with n Optroni Moel 7 UV-VIS spetroriometer (Optroni Lortories In, Orlno, FL, US) to etermine the spetrl irrine of the re lmp. The integrl vlue of spetrl irrine for the wvelength rnge of 8 nm ws etermine s 8 mw m. Qulity ttriutes Pehes were weighe efore n fter the storge perio to lulte perentge of fresh weight loss. Flesh firmness ws etermine t three ifferent positions on eh fruit (skin remove) using firmness tester, Pressure Tester Moel EPT-R (Lke City Tehnil Prouts In, Kelown, C, Cn) with n 8-mm ylinril plunger. The extent of ey ws ssesse visully se on the re of ey. Overll pperne ws rte on sle of, where = very poor, = poor, = fir, 4 = goo n = exellent. Softening ws etermine y soring ( ) the egree of tissue yiel y pplying finger pressure: = very firm, = firm, = moertely firm, 4 = slightly firm, n = soft. The sore of hilling injury (CI) n rowning ws se on the perentge of totl surfe re n flesh ffete y sheet pitting n rowning; = no injury, = slight, = moerte, n = severe oring to Gonzlez- guilr et l. 6 Shriveling n UV-C mge were evlute oring to Erkn t l. 7 The ph, totl solule solis n titrtle iity were etermine oring to OC 8 methoology. The nlysis of vrine n Tukey s multiple rnge test for omprison of mens n lest signifint ifferenes (LSD) (P <.) were performe on the t using the SS 6. system. 9 Sujetive evlutions were trnsforme to rsine vlues efore sttistil nlysis. RESULTS ND DISCUSSION Figure shows respirtion rte n ethylene proution t C fter 4 or ys t C, in pehes trete with UV-C for ifferent perios of time. The highest respirtion rte ws oserve in fruit trete with UV-C for min fter 4 ys of storge t C. stle respirtion rte ws mintine fter trnsferring the pehes to storge t C. fter ys of storge, only fruits trete with UV-C for or min showe higher respirtion rte thn tht of the ontrols. The lowest respirtion rte ws oserve in fruits trete with UV-C for min (Fig n ). UV-C tretments inrese ethylene proution of pehes. ll UV-C tretments use in this stuy enhne ethylene proution of pehes t Cfteroth4 n ys of storge t C. fter ol storge for 4 ys, ethylene proution in ontrol fruits inrese ontinuously upon trnsferring to C(FigC). similr pttern of ethylene proution ws oserve in fruits trete with UV-C fter 4 ys t C. The highest ethylene proution ws oserve in fruits trete for or min, followe y those trete for, or min, respetively. However, fter ys t C, fruits trete with UV-C for min showe the highest inrese in ethylene proution, followe y the min UV-C tretment. fruits h signifintly the lowest ethylene proution, fter 4 or ys t C(FigCnD). k et l reporte tht UV-C tretment suppresses respirtion rte n ethylene proution of strwerries store t 4 n C. However, we foun tht UV-C tretment inrese respirtion rte n 46 J Si Foo gri 84:4 4 (online: 4)

3 enefits of UV-C irrition of pehes uring ol storge UV-C UV-C UV-C UV-C UV-C ys t C ys t C 8 7 Respirtion rte (ml CO kg h ) Respirtion rte (ml CO kg h ) 4 C D 4 Ethylene proution (µl C H 4 kg h ) Ethylene proution (µl C H 4 kg h ) Hours t C fter eing store t C Figure. Effet of UV-C irrition on respirtion rte n ethylene proution of pehes, fter eing store for 4 n ys t Cn trnsferre to C. Eh vlue is the men of four replitions ± stnr evition. ethylene proution of pehes fter eing store for 4 n ys t C (Fig ). Crisosto et l reporte tht pehes v Summer Ly trete with pulste ultrviolet light h n inrese in the respirtion rte n ethylene proution of 8% n %, respetively. It hs een oserve tht UV-C irrition inreserespirtion rte of Cuurit pepo tissue without signifintly ffeting ethylene proution. 7 The UV-C tretment elye respirtion rte n ethylene proution in tomtoes uring storge t 6 C. Figure shows the weight n firmness loss of pehes, fter eing store for 4 or ys t C plus 7 ys t C. s expete, weight loss inrese with longer storge perio n ws more notiele in ll the tretments fter ys t C plus 7 ys t C. The ontrol fruits h higher losses of weight thn those fruits trete with UV-C. No signifint ifferenes in weight loss were oserve mong trete fruits with ifferent tretment lengths. Firmness loss woul e more the result of the UV-C tretment or physiologil ripening uring ol storge n shelf-life perio. Softening of ontrol fruits oul e ssoite with the higher metoli proesses (eteriortion), whih in turn enhne senesene of the pehes. Mhrj et l reporte tht UV-C irrition (.7 Jm ) prevente firmness loss n elye senesene proesses of tomto fruits store t 6 C. In generl, UV-C tretment reue firmness loss of pehes uring ol storge n shelf-life perio. However, UV-C tretments for or min were the most effetive in mintining the firmness of pehes uring storge. No signifint ifferenes were otine fter ys t C plus 7 ys t C etween ontrols n those trete with UV- C for, or min. Stevens et l 8 reporte tht UV-C tretment mintine firmness n reue weight loss of pehes n pples. lso, the ontent of sori i ws higher in UV-C-trete fruit thn in ontrols. It hs een reporte y severl uthors for ifferent fruits tht the lower the sori i loss, the higher qulity of fruit uring ol storge n shelf-life. Chilling injury symptoms, mesure s rowning of the skin n internl rekown, were signifintly iminishe y the -, - n -min UV-C tretments (Fig ). This reution ws more evient for longer storge perios ( ys t C plus 7 ys t C). The effetiveness of the UV-C tretment ws reue with length of pplition, the - n -min UV-C tretments eing lest effetive. fruit exhiite severe hilling injury symptoms n ey, ut the UV-C trete fruit remine free from rowning or fungl ey exept for the min tretment (Fig ). UV-C tretment for n min enhne rowning of skin n pulp. It hs een reporte tht J Si Foo gri 84:4 4 (online: 4) 47

4 G Gonzlez-guilr, CY Wng, GJ ut 4 ys t C 4 ys t C 7 ys t C ys t C ys t C 7 t C LSD. =.6 UV-C- UV-C- UV-C- UV-C- UV-C- Weight loss (%) Firmness (Nw) LSD. =.47 UV-C minutes Figure. Effet of UV-C irrition on weight loss (%) n firmness (N) of pehes fter eing store for 4 n ys t Cplus 7yst C. Eh vlue is the men of replitions ± stnr evition. LSD (P <.) = lest signifint ifferene. pehes evelop hilling injury symptoms more rpily t Cthnt C. UV-C tretment prevente evelopment of hilling injury symptoms of pehes store for up to ys t C 7 ys t C. The most effetive tretments in reuing ey symptoms were n min in urtion (Fig ). UV-C tretments for n n min reue oth ey n rowning, ut the min tretment le to moerte UV-C mge t the en of the storge perio (Figs n 4). Fruits trete with UV-C for min n ontrol fruits evelope ey to similr extent (Fig ). The rowning inex of the pehes ws signifintly reue y the -, - n -min UV-C tretments (Fig 4). However, n -min tretments enhne rowning of the skin n ffete the qulity. The -min tretment resulte in the lowest sores in ll of the sujetive evlutions. Pehes trete with UV-C for longer thn min exhiite signifintly higher UV-C mge, this eing more evient fter longer storge perios (Fig 4). The longer the tretment, the greter the UV-C mge to the skin, oserve s pink re strns throughout the surfe of the fruit. Chilling injury Dey 4 4 ys t C 7 ys t C ys t C 7 ys t C Figure. Effet of UV-C irrition on hilling injury inex n ey of pehes fter eing store for 4 n ys t Cplus7ys t C. Eh vlue is the men of replitions. Mens with the sme letter t the sme storge perio re not signifintly ifferent oring to Tukey s test (P <.). It ppers tht the effetiveness of UV-C tretment is relte to the ose pplie, mturity stge n type of skin tissue of the fruit. This stuy grees with previous reports where UV-C tretment ws very effetive in preventing fungl ey use y vrious miroorgnisms in tle grpes, itrus fruit, kumqut, strwerries n mngos. 6,6,4, However, the optiml ose of UV-C for ontrolling infetions in vrious rops seems to vry gretly. In the se of pehes, the ose ppers to e quite smll n is similr to those reporte for inuing isese resistne in rrots n peppers. 6,7 Higher oses were use for inuing isese resistne in tomtoes n lemons. 6,8 Port et l 9 reporte the UV-Cinue resistne in grpefruit ginst Peniillium igittum is ssoite with inreses in the hitinse n β-,-enoglunse tivities in peel tissue. The enhnement of the resistne of itrus fruit y UV-C irrition ws expline in prt y inution of key enzymes in the seonry metolite pthwy, suh s phenyllnine mmoni lyse (PL) n peroxise, n umultion of ntifungl ompouns. UV-C 48 J Si Foo gri 84:4 4 (online: 4)

5 enefits of UV-C irrition of pehes uring ol storge Softening 4 4 UV-C- UV-C- UV-C- UV-C- UV-C- rowning inex UV-C- UV-C- UV-C- UV-C- UV-C- Shrivelling UV-C Dmge 4 ys t C 7 ys t C ys t C 7 ys t C 4 ys t C 7 ys t C ys t C 7 ys t C Figure 4. Effet of UV-C irrition on softening n shriveling of pehes fter eing store for 4 n ys t Cplus7yst C. Eh vlue is the men of replitions. Mens with the sme letter t the sme storge perio re not signifintly ifferent oring to Tukey s test (P <.). Figure. Effet of UV-C irrition on rowning inex n UV-C mge of pehes fter eing store for 4 n ys t Cplus 7yst C. Eh vlue is the men of replitions. Mens with the sme letter t the sme storge perio re not signifintly ifferent oring to Tukey s test (P <.). irrition for n min signifintly reue miroil tivity n eteriortion of Cuurit pepo fruit tissue. 7 Sujetive ssessment of qulity ttriutes emonstrte tht UV-C tretment signifintly reue eteriortion symptoms (Figs 4 n ). Sujetive mesurements of softening n shriveling were orrelte with ojetive t of firmness n weight loss (Fig n Figs ). Softening n shriveling ws signifintly more evient in ontrol n fruits trete with UV-C for min, fter ys t C 7 ys t C (Fig ). Pehes trete for n min with UV-C presente signifintly the lowest softening vlues followe y the - n -min tretments (Fig ). UV-C tretment for n min signifintly inrese the putresine ontent initilly (Fig 6). However, ontrol fruits h signifintly the highest putresine levels, followe y those trete with UV- C for n min, fter 4 ys t C plus 7 ys t C. fterwrs, putresine levels erese only in the ontrols, ut inrese for the UV-C tretments of, n min n were mintine t onstnt levels in fruits trete with UV-C for n min. No signifint ifferenes were foun in putresine ontent mong tretments fter ys t C 7 ys t C. Spermiine levels, in generl, inrese initilly fter UV-C tretment (Fig 6). This inrese ws signifintly higher in pehes trete with the UV-C tretments for n min. fter ol storge, the spermiine ontent only inrese in fruits trete with UV-C for min. Spermiine levels were mintine t onstnt levels in the other tretments fter 4 n ys t C plus 7 ys t C. ll UV-C tretments inrese spermine levels to the sme extent. However, these levels were signifintly reue fter ol storge n shelfstorge in most of the tretments, exept in tht of fruit trete with UV-C for min. In generl, no signifint hnges in spermine ontent were oserve in the ontrol n UV-C tretments, fter ys t C plus 7 ys t C(Fig6C).UV- C tretment for min resulte in signifintly the highest levels of spermine fter ol storge n shelf storge. J Si Foo gri 84:4 4 (online: 4) 49

6 G Gonzlez-guilr, CY Wng, GJ ut Spermiine (nmol g fresh mss) Putresine (nmol g fresh mss) 4 UV-C- UV-C- UV-C- UV-C- UV-C- 7 C Spermine (nmol g fresh mss) 6 4 Initil 4 ys t C 7 ys t C ys t C 7 ys t C Figure 6. Effet of UV-C irrition on polymine ontent of pehes fter eing store for 4 n ys t Cplus7yst C. Eh vlue is the men of four replitions. Mens with the sme letter t the sme storge perio re not signifintly ifferent oring to Tukey s test (P <.). The inrese firmness of UV-C trete fruit ompre with the ontrols oul e ssoite with inrese levels of polymines. Polymines re ssume to funtion vi mehnisms similr to tht of lium, involving the formtion of tion rosslinks with peti i n other polyshries, thus limiting essiility of the ell wll to egrtive enzymes. Rstogi n Dvis reporte tht the high putresine levels in lo tomtoes were relte to slower ripening n thus prolonge keeping qulity. In ition, Krmer et l hve shown tht polymines inhiit softening y reuing the tivity of ell wll egring enzymes suh s polyglturonse. Levels of polymines usully erese with ge in plnts ut UV tretment ppers to ontriute 4 J Si Foo gri 84:4 4 (online: 4)

7 enefits of UV-C irrition of pehes uring ol storge to the mintenne of higher levels of putresine n spermiine in pehes (Fig ). It hs een reporte tht inresing ethylene proution oul reue polymine synthesis. 4 However, in this stuy we oserve tht UV-C tretment inrese oth ethylene n polymine synthesis. These results ontrst with those reporte y Mhrj et l where UV-C irrition reue softening, respirtion rte n ethylene proution n susequently elye senesene of tomto fruits. It hs een oserve tht UV-C irrition of tle grpes n e enefiil in terms of inresing the ontent of potentilly helthpromoting phenols. 4 Reutions in eteriortion n hilling symptoms were oserve in v Tommy tkins ripe mngos trete with UV-C irrition fter previous storge t C. The effetiveness of the tretment ws orrelte with the higher levels of polymine foun in the skin tissue. 6 The effetiveness of UV-C irrition in ontrolling ey of pehes, even t the lowest ose ( min), my e orrelte with the inution of polymines. lthough the inution of efense mehnisms y UV- C in pehes ws not speifilly stuie, resistne inue y UV-C ginst fungl ey oul lso e ssoite with other efensive ompouns. It hs een oserve tht resistne ginst ey inue in ornges y UV-C tretment is relte to inreses of phytolexins, soprone n sopoletin. Droy et l reporte mrke inhiition of sporultion of fungi in grpefruit s well s signifint inrese in phenyllnine mmoni lyse (PL) n peroxise in the peel. Other effets of UV-C tretment relte to qulity loss hve een oserve in other hortiulturl prouts. UV-C irrition t.7 mw m for min inrese y two- or threefol the vitmin D ontent in mushrooms. However, enhne surfe isolortion tht might influene the eptility of the prout in the fresh mrket ws seen. We onlue tht UV-C tretments for n min n e use to reue hilling injury symptoms, eteriortion n prolong the shelf-life of pehes uring storge t C. UV-C ppers to e new option to reue physiologil isorers of pehes uring ol storge. However, further stuies re neessry to eluite the moe of tion of this tretment. REFERENCES Slunkhe DK n Km SS, Hnook of Vegetle, Siene n Tehnology, Proution, Composition, Storge n Proessing, e y DK Slunkhe n SS Km, Vol, Introution, Mrel Dekker, New York, pp (998). Ntionl Reserh Counil, Reommene Dietry llownes th en, Ntionl emi Press, Wshington, DC (989). Wilson CL n Pusel PL, Potentil for iologil ontrol of posthrvest plnt iseses. Plnt Dis 69:7 78 (98). 4 Lu JY, Stevens C, Khn V n Kwe M, The effet of ultrviolet irrition on shelf-life n ripening of pehes n pples. J Foo Qulity 4:99 (99). Wilson CL, Ghouth El, Uphurh, Stevens C, Khn V, Droy S n Chlutz E, Using n on-line UV-C pprtus to tret hrveste fruit for ontrolling posthrvest ey. HortTehnology 7:78 8 (997). 6 en-yehoshu S, Roov V, Kim J n Crmeli S, Preforme n inue ntifungl mterils of itrus fruits in reltion to the enhnement of ey resístnse y het n ultrviolet tretments. J gri Foo Chem 4:7 (99). 7 Wilson CL, El Ghouth, Chlutz E, Droy S, Stevens C, Lu JY, Khn V n rul J, Potentil of inue resistne to ontrol posthrvest iseses of fruits n vegetles. Plnt Dis 78: (994). 8 Stevens JL, Wilson CL, Lu JY, Khn V, Chlutz E, Droy S, Kwe MK, Hung Z, eyeye O, Pusey PL, Wisniewski ME n West M, Plnt hormesis inue y ultrviolet light- C for ontrolling posthrvest iseses of tree fruits. Crop Prot :9 4 (996). 9 Frietzenheimer KH n Kinl H, Coorinte inution y UV light of stilene synthse, phenyllnine mmoni-lyse n innmte 4-hyroxylse in leves of Vitee. Plnt :48 (98). D hllewin G, Shirr M, Mnueu E, Pig n en- Yehoshu S, Soprone n sopletin umultion n ultrviolet-c inue resistne to posthrvest ey in ornges s influene y hrvest te. JmSoHortSi 4:7 77 (999). Higshio H, Ippoushi H, Ito H n zum K, Inution of n oxitive efense system ginst UV-stress n pplition to improve qulity of green vegetles, Pro Int Symp on Qulity of fresh n Fermente Vegetles, Lee JM, Gross KS, Wt E n Lee SK (es). t Hort 48:99 (999). Fust M n Wng SY, Polymines in hortiulturl importnt plnts. Hort Rev 4: 6 (99). González-guilr G, Wng CY, ut JG n Krizek DT, Use of UV-C irrition to prevent ey n mitin posthrvest qulity of ripe Tommy tkins Mngoes. Int J Foo Si Tehnol 6: (). 4 Mithell FG n Ker, Ftors ffeting eteriortion rte, in Pehes, plums n netrines: growing n hnling for fresh mrket, e y LRue, JH n Johnson RS, University of Cliforni, Pulition, pp 6 78 (989). Lushinger LE n Wlsh CS, Chilling injury of pehes fruit uring storge. t Hort 464: (998). 6 González-guilr G, Zrís L, Muls M n Lfuente MT, Temperture n urtion of wter ips influene hilling injury, ey n polymine ontent in Fortune mnrins. Posthrvest iol Tehnol :6 69 (997). 7 Erkn M, Wng CY n Krizek DT, UV-C exposure reues miroil popultions n eteriortion in Cuurit pepo fruit tissue. Environ Exp ot 4: 9 (). 8 OC, Offiil Methos of nlysis of the OC th e, ssoition of Offiil griulturl Chemists, Wshington, DC, US (99). 9 SS Institute, SS user s guie: sttistis version 6., SS institute In, Crey, NC, US (99). k M, Merier R, Coruff F, Cstigne J n rul J, Photohemil tretment to improve storility of fresh strwerries. J Foo Si 64:68 7 (999). Crisosto CH, Mithel FG n Ju Z, Suseptiility to hilling injury of peh, netrine, n plum ultivrs grown in Cliforni. HortSiene 4:6 8 (999). Mhrj R, rul J n Neu P, Effet of phytohemil tretment in the preservtion of fresh tomto (Lyopersion esulentum v Cpello) y elying senesene. Posthrvest iol n Tehnol : (999). Crisisto CH, Seguel X n Mihilies T, Compring pulste ultrviolet light n posthrvest fungiie for peh fruit ey ontrol. t Hort 46: (998). 4 Cntos E, Espín JC n Tomás-rern F, Posthrvest inution moeling metho using UV irrition pulses for otining resvertrol-enrihe tle grpes: new Funtionl fruit. J gri Foo Chem 49: 8 (). J Si Foo gri 84:4 4 (online: 4) 4

8 G Gonzlez-guilr, CY Wng, GJ ut Nigro F, Ippolitto n Lim G, Use of UV-C light to reue otrytis storge rot of tle grpes. Posthrvest iol Tehnol :7 8 (998). 6 Merier J, k M, Rey, Coruff R n rul J, Shortwve ultrviolet irrition for the ontrol of ey use y otrytis inere in ell pepper: Inue resistne n germiil effets. JmerSoHortSi6:8 (). 7 Merier J, rul J n Cohen C, Effet of UV-C on phytolexin umultion n resistne to otrytis inere in store rrots. J Phytopthol 9:7 (99). 8 Chrles MT, Coruff R, Roussel D n rul J, Effet of mturity n storge onitions on rishitin umultion n isese resistne to otrytis inere in UV-C trete tomto fruit. t Hort (ISHS) 99:7 76 (). 9 PortR,Lers,DoriS,CohenL,Weiss,Dus,WilsonCL n Droy S, Inution of hitinse n -,-enoglunse proteins y UV irrition n wouning in grpefruit peel tissue. Phytoprsiti 7: 6 (999). Droy SE, Chlutz, Horver L, Cohen V, C, Wilson L n Wisniewski ME, Ftors ffeting UV-inue resistne in grpefruit ginst green moul ey use y Peniillium igittum. Plnt Pthol 4:48 44 (99). Rstogi R n Dvis PJ, Polymine metolism in ripening tomto fruit, II Polymine metolism n synthesis in reltion to enhne putresine ontent n storge life of l tomto fruit. Plnt Physiol 9:4 4 (99). Krmer GF, Wng CY n Conwy WS, Correltion of reue softening n inrese polymine levels uring low-oxygen storge of MIntosh pples. JmSoHortSi4: (989). Sloum RD, Kur-Swnhey R n Glston W, The physiology n iohemistry of polymines in plnts. rh iohem iophys :8 (984). 4 Wng SW n Fust M, Ethylene iosynthesis n polymine umultion in pples with wterore. JmSoHortSi 7: 8 (99). Mu JL, Chen Pr n Yng JH. Ultrviolet irrition inrese vitmin D ontent in eile mushrooms. J gri Foo Chem 46: 69 (998). 4 J Si Foo gri 84:4 4 (online: 4)