Contents: Evlution of Ozone Gs Penetrtion Through Citrus Commercil Pckges nd Control of Green nd Blue Molds Sporultion During Cold Storge Tble Grpe Cooling Future Events COOPERATIVE EXTENSION University of Cliforni Kerney Agriculturl Center 9240 South Riverbend Avenue Prlier, CA 93648 / USA 559/646-6500 September 2002 Vol. 11, No. 3 Crlos H. Crisosto, Editor Visit our websites http://www.uckc.edu http://posthrvest.ucdvis.edu http://pomology.ucdvis.edu EVALUATION OF OZONE GAS PENETRATION THROUGH CITRUS COMMERCIAL PACKAGES AND CONTROL OF GREEN AND BLUE MOLDS SPORULATION DURING COLD STORAGE Lluís Plou, Joseph L. Smilnick, Monir Mnsour, Crlos H. Crisosto, Tom J. Clrk Introduction In recent work we reported the bility of gseous ozone continuously relesed t low doses (0.3 or 1 ppm, v/v) to inhibit the This newsletter is posted on our website t www.uckc.edu/posthrv. You must subscribe to receive miled copy. sporultion of severl importnt posthrvest pthogens of tble grpes, stone fruit, nd citrus fruit (Plou et l., 2001, 2001b, 2002). Sporultion of Penicillium digittum nd P. itlicum on cold-stored ornges or lemons ws suppressed without injuring the fruit. In those trils, however, exposure of the fruit to the gs ws unimpeded nd we did not evlute the effectiveness of ozone pplied to commercilly-pcked citrus fruit. The objectives of this work were to test the bility of ozone gs to penetrte into different commercil citrus fruit pckges nd to evlute the effectiveness of the gs in The University of Cliforni prohibits discrimintion ginst or hrssment of ny person employed by or seeking employment with the University on the bsis of rce, color, ntionl origin, religion, sex, physicl or mentl disbility, medicl condition (cncer-relted or genetic chrcteristics), ncestry, mritl sttus, ge, sexul orienttion, citizenship, or sttus s covered vetern (specil disbled vetern, Vietnm-er vetern or ny other vetern who served on ctive duty during wr or in cmpign or expedition for which cmpign bdge hs been uthorized). Inquiries regrding the University s nondiscrimintion policies my be directed to the Affirmtive Action/Stff Personnel Services Director, University of Cliforni, Agriculture nd Nturl Resources, 1111 Frnklin, 6th Floor, Oklnd, CA 94607-5200. Telephone (510) 987-0096.
Pge 2 Centrl Vlley Posthrvest Newsletter controlling sporultion on commercillypcked citrus fruit. Mterils nd methods Fruit inocultion. Lne lte nvel ornges (Citrus sinensis (L.) Osbeck) from commercil orchrds in the Sn Joquin Vlley (Cliforni) were used in the experiments before ny commercil posthrvest tretments were pplied. P. digittum nd P. itlicum were grown on PDA in petri dishes t 25ºC for 7 to 10 dys. Spores were rubbed from the gr surfce nd high-density spore suspension (pproximtely 10 6 spores ml -1 ) ws prepred. Ornges were inoculted 1-cm deep into the flesh in the equtor of two opposite fces with plstic syringe with 20-mm needle. Approximtely 0.25 ml of the spore suspension ws pplied t ech inocultion point. Fruit pckging. The following types of pckges were prepred seprtely with fruit inoculted with ech pthogen. See Tble 1 for chrcteristics of ech pckge. 1) Crton (nked): stndrd corrugted fiberbord citrus crtons with vents were filled with 60-70 ornges. Inoculted fruit were plced in the four corners nd t the center of the crton t both the bottom nd top levels of the crton. Ten inoculted ornges per crton were used. Crtons were stored with the lids on. 2) RPC (nked): returnble plstic boxes were filled with pproximtely 50 ornges. Inoculted fruit were plced in the four corners nd t the center of the box t both the bottom nd top levels of the box. Ten inoculted ornges per box were used. 3) RPC (bgged): 5 lb polyethylene bgs with smll vents were filled with ornges, 4 were inoculted nd 10 were not inoculted. Eight bgs were plced in ech RPC. 4) Mster crton (bgged): polyethylene bgs were filled with inoculted nd non-inoculted ornges s previously described nd plced in mster crtons. Ten bgs were plced in ech crton. Crtons were stored with the lids on. Six pckges of ech type were prepred with fruit inoculted with P. digittum nd six with fruit inoculted with P. itlicum. Mster crtons were only prepred with fruit inoculted with P. itlicum. For ech pthogen, three of these six pckges (replictes) were rndomly stcked on one pllet nd the other three on nother pllet. Pcked fruit ws held t 55 ± 2ºF for 24 h before ozone exposure. Tble 1. Chrcteristics of the different pckges used in the experiments. Pckge Dimensions (inches) (long x wide x tll) Volume (in 3 ) Lid Box vented re (%) Crton 17.3 x 11.9 x 11.7 2,408.7 Yes 2.6 RPC 23.5 x 15.5 x 10.1 3,678.9 No 35.9 Mster crton 19.5 x 13 x 14.5 3,675.7 Yes 2.9 Plstic bg 21 x 10.5 0.7
Centrl Vlley Posthrvest News Pge 3 Continuous exposure to gseous ozone. A wter-cooled coron dischrge ozone genertor (Model Genesis CD-25G, Del Industries, Sn Luis Obispo, CA) ws instlled in n djcent non-ozonted room nd set to produce 2.5 g h -1 ozone. The gs ws continuously relesed to 23,940 ft 3 cold storge room with constnt temperture of 55 ± 2ºF (12.8 ± 1ºC) through 0.2-inch dimeter Teflon tube nchored to the wll of the room. The room ws erted through 105 ceiling cones (with 6 inch outlet) spced 5 ft from ech other. About 24 h fter inocultion nd pckging, the pllet contining one hlf of the pcked fruit ws stored in this room for 13 dys. The pllet contining the other hlf of the pcked fruit ws stored t the sme temperture nd for the sme time in n identicl non-ozonted room (ir tmosphere, control room). The ozone concentrtion in the room nd inside some of the pckges on the pllet ws continuously monitored by 6-chnnel UV bsorption ozone nlyzer (Model 450 Nem, API Inc., Sn Diego, CA) with minimum detection limit of 0.001 ppm. Air from the smpling points in the ozonted room ws pumped through 0.15 inch internl dimeter tubes to the nlyzer, which ws locted in the djcent room ner the genertor. The smpling points re specified in Tble 2. Sporultion ssessment. Green nd blue mold sporultion on Lne lte nvel ornges pcked nd stored in both ozonted nd control rooms were recorded for ech inoculted fruit fter 13 dys of storge t 55ºF. A sporultion index ws used where numbers 0, 0.5, 1, 2, 3, 4, nd 5, respectively, indicted soft lesion but no spores or mycelium present, mycelium but no spores present, < 5%, 6 to 30%, 31 to 60%, 61 to 90%, nd > 91% of the fruit surfce covered with spores. Sttisticl nlysis. Scores in the sporultion index were considered s quntittive vrible. Ech vlue in the dt set ws trnsformed to the squre root of the vlue plus 0.5. An nlysis of vrince ws pplied to the trnsformed dt nd mens were seprted by Fisher s Protected Lest Significnt Difference test (LSD, P = 0.05). Results nd discussion Averge levels of the ozone concentrtion for the entire storge period re given for ech smple point (Tble 2) nd type of pckge (Tble 3). Ozone penetrtion in ech type of pckge, clculted s percentge of the ozone concentrtion in the room mbient, is lso presented (Tble 3). Tble 2. Averge ozone levels for the entire storge period t the different smpling points. Anlyzer chnnel Chnnel 1 Chnnel 2 Chnnel 3 Chnnel 4 Chnnel 5 Chnnel 6 Smpling point Inside plstic bg in RPC box Inside RPC box (nked fruit) Inside crton (nked fruit) Inside plstic bg in Mster crton Inside crton (nked fruit) In the room mbient Position in the pllet Ozone levels (ppm, v/v) Middle 0.12 Middle 0.59 Middle 0.03 Middle 0.07 Top 0.11 0.72 A comprison between ozone concentrtions inside the different pckges indicted tht the gs penetrted more esily into RPC boxes thn into crtons or Mster crtons. Nevertheless, ozone concentrtion in RPC boxes ws significntly higher in the spces surrounding the nked fruit thn inside plstic bgs (Tble 3).
Pge 4 Centrl Vlley Posthrvest Newsletter Tble 3. Averge ozone levels nd percentge of ozone penetrtion (bsed on the verge level in the room) for the entire storge period inside the different types of pckges. Pckging system Ozone levels (ppm, v/v) Ozone penetrtion (%) Crton (nked) 0.07 9.7 RPC (nked) 0.59 81.9 nd P. itlicum on ornges pcked nked in RPC boxes. The gs ws not ble to penetrte properly through corrugted fiberbord crton or polyethylene bgs. Therefore, it ws not ble to control sporultion on ornges pcked in stndrd crtons, Mster crtons, or plstic bgs. Effective control of sporultion relied on ctul physicl contct between the gs nd the decyed re of the fruit. RPC (bgged) 0.12 16.7 Mster (bgged) 0.07 9.7 Ozone penetrtion ws relted to the vented re of ech pckge (Tble 1), indicting tht the gs ws not ble to go through corrugted fiberbord crton or polyethylene bgs. Ozone penetrtion ws cceptble only in RPC boxes with nked fruit (82%, Tble 3). On the other hnd, the position of the box on the pllet lso influenced the ozone concentrtion; ozone levels inside mid-plced crton were in generl lower thn inside top-plced crton (chnnel 3 vs. chnnel 5, Tble 2). Sporultion of both P. digittum nd P. itlicum ws significntly inhibited by ozone exposure on ornges pcked nked in RPC boxes, but it ws not on ornges pcked following the other pckging methods (Fig. 1). According to the percentges of ozone penetrtion inside the pckges (Tble 3), this result confirmed the need for good penetrtion nd full contct to the decyed re on the fruit for ozone gs to be effective in controlling sporultion. Conclusions Gseous ozone continuously generted in cold storge room t rtes rnging 0.5 to 1 ppm (v/v) effectively penetrted nd controlled sporultion of both P. digittum Sporultion index (score) 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 Control Ozone b b Crton (nked) RPC (nked) RPC (bgged) Mster (bgged) Pckging system Green mold No dt Blue mold Fig. 1. Sporultion index on Lne lte ornges rtificilly inoculted with Penicillium digittum or P. itlicum, pcked following different pckging systems, nd stored t 55ºF for 13 dys in n ir tmosphere (control) or in n ozonted tmosphere (0.5-1 ppm O 3 v/v). Within pckging systems, columns with the sme letter re not significntly different ccording to Fisher s Protected LSD test (P < 0.05) pplied fter n nlysis of vrince to the squre root trnsformed dt. Non-trnsformed mens re shown.
Centrl Vlley Posthrvest News Pge 5 References Plou, L., Crisosto, C. H., Smilnick, J. L., Adskveg, J. E., nd Zoffoli, J. P. 2001. Evlution of the effect of ozone exposure on decy development nd fruit physiologicl behvior. Act Hort. 553: 429-430. Plou, L., Smilnick, J. L., Crisosto, C. H., nd Mnsour, M. 2001b. Effect of gseous ozone exposure on the development of green nd blue molds on cold stored citrus fruit. Plnt Dis. 85: 632-638. Plou, L., Crisosto, C. H., Smilnick, J. L., Adskveg, J. E., nd Zoffoli, J. P. 2002. Effects of continuous 0.3 ppm ozone exposure on decy development nd physiologicl responses of peches nd tble grpes in cold storge. Posthrvest Biol. Technol. 24: 39-48. TABLE GRAPE COOLING Crlos H. Crisosto, Jmes F. Thompson nd Dvid Grner University of Cliforni, Dvis The time required to force-ir cool grpes is determined by the temperture of the incoming product, the finl temperture desired, the temperture of the cooling medium (ir), irflow nd the box design nd inner pckging. A typicl reltionship between initil product temperture, cooling medium temperture nd cooling time is illustrted in Figure 1. Notice tht the product cools rpidly t first nd the rte of cooling slows s the product temperture pproches the cooling medium temperture. Since the rte of cooling becomes quite slow s product temperture ners the cooling medium temperture, most opertors re stisfied with reducing the temperture 7/8ths of the difference between initil product nd cooling medium temperture. This is clled the 7/8ths cooling point. Frction of initil produce to ir temperture difference 1 ---- 1/2 ---- 1/4 ---- 1/8 ---- 1/16 ---- 0 ---- TEMPERATURE (ºF) 75 Initil produce temperture 70 65 60 55 50 45 40 Air temperture 1/2 Cool 3/4 Cool 7/8 Cool 35 0 3 6 9 12 HOURS OF COOLING 15/16 Cool Fig. 1. Typicl reltionship between initil product temperture, cooling medium temperture nd cooling time. Incoming grpe temperture. Initil grpe temperture ffects cooling rte nd stem qulity. However, it is not s importnt fctor s the temperture of the cooling ir medi. For exmple, using Figure 1 the totl time needed to cool the grpes to 40ºF (7/8ths cooling) would be incresed by 1/3 (3 hours) if the incoming product were of 105ºF rther thn 75ºF (30ºF chnge). On the other hnd, reducing the finl fruit temperture from 40ºF to 35.5ºF (only 4.5ºF difference), using 35ºF ir temperture, would lso tke 3 hours extr cooling time (12 hours totl). Thus the difference between finl product temperture nd the cooling medium generlly hs greter effect on cooling time thn initil product temperture. Air temperture. In the exmple given in Figure 1, when incoming fruit temperture ws 75ºF nd ir temperture ws 35ºF, 7/8ths cooling to product temperture of 40ºF ws reched in 9.0 hours. If 32ºF ir temperture ws used insted, 7/8ths cooling to product temperture of 37.4ºF would be reched in 8.4 hours. Finlly, if 30ºF ir temperture ws used, 7/8ths cooling to product temperture 35.6ºF would be reched in 8.0 hours (Tble 1). The rte of cool irflow. Incresing irflow rtes decreses cooling times (Tble 2). As rule of thumb, for forced ir cooling the irflow 15
Pge 6 Centrl Vlley Posthrvest Newsletter rte must be doubled or tripled to reduce cooling times by one hlf. This rule will not necessrily pply to irflow rtes bove 2 cfm/lb of produce, but most forced ir coolers operte below this level. The price pid for decresed cooling time is greter energy use by the fn (with forced ir cooling) nd greter refrigertion cpcity requirement. Box design nd inner pckging. The system for pckging the product cn increse cooling times if it retrds irflow through the box or prevents the ir from hving direct contct with the product (convection). For forced-ir cooling, boxes should hve vent re equl to bout 5% of the end re of the boxes. Venting res less thn this will retrd irflow through the boxes, increse cooling times, nd result in uneven cooling throughout the pllets. Venting greter thn 5.0% excessively wekens stndrd fiberbord boxes. The use of pper wrps, pdding mteril, cluster bgs (Fig. 2), nd box liners increses cooling times, requires higher sttic pressures, nd my cuse uneven cooling throughout the pllets. Thus, their use should be considered crefully. If these inner pckging mterils re used, they should be vented or rrnged to llow the cooling medium good ccess to the produce. The reltionship between box venting nd inner pckging should be crefully studied. Attempts to improve the Chilen corrugted box hve been strted (Tble 2D). In our preliminry evlutions, we found the 7/8ths cooling times rnged from 11 to 23 hours, nd sttic pressures from 0.7 to 4.4 depending upon irflow. The gretest decrese in cooling time nd sttic pressure ws mde by reducing inner pckging (pper wrps, etc.). The use of box liners in Cliforni reduces grpe wter losses, but cn increse cooling time nd my reduce pssive sulfur dioxide penetrtion to dngerous levels. We re currently trying to find the idel perforted box liner with vented re tht is compromise between wter loss, cooling time nd sulfur dioxide penetrtion for Cliforni grpes tht will be exported. In this system, inner pckging is being minimized. In our previous tests, Chilen grpes pcked using the Cliforni system nd shipped to Long Bech, CA rrived in excellent condition (Crisosto et l., 1994). A good illustrtion of the effect of box liner venting pttern on cooling time hs been developed for kiwifruit (Wiley nd Crisosto, 1999). For fruit pcked using different perforted box liners, sttic pressure, 7/8ths cooling nd wter loss vried ccording to box liner vented re (Tble 3). In generl, fst cooling occurred when fruit were exposed to high rtes of irflow. However, sttic pressure hd to be incresed to mintin the sme irflow nd hve uniform cooling when using box liners with less venting. Prediction of cooling time. In prctice, it my not be fesible to ccurtely predict the cooling time of lot of produce. During the dy produce of vrying tempertures will be rriving t the cooler. Vrying rtes of deliveries often dictte tht ir coolers be loded with different quntities of product, which will ffect the rte of irflow per box nd consequently cooling times. In light of this, cooler opertors need to control cooling times on the bsis of ctul product pulp temperture. By experience, the mnger should determine which box loctions tend to cool the slowest nd terminte cooling when fruit in these res hve reched the desired temperture. The loction of the slowest cooling product is determined by mesuring tempertures t mny positions for severl cooling runs. In generl, the wrmest product pulp temperture is locted t the end of the pth of the cooling medi through the product. Boxes locted on the inside of the corridor of forced ir system will be the slowest to cool. No produce should leve cooling system until ctul product temperture is mesured nd recorded in log.
Centrl Vlley Posthrvest News Pge 7 It is sometimes necessry to estimte the volume of irflow (CFM) through the product (flow rte). Unfortuntely, this is not esily done in commercil cooling sitution. In forced ir cooler, the flow rte through continer is estimted by determining the totl ir volume produced by the cooling fn. The flow through n verge box is equl to the totl ir volume produced by the fn divided by the totl number of boxes minus 10% to 20% to ccount for ir lekge. The ir volume produced by the fn is determined by mesuring the totl negtive or positive pressure tht is cusing ir to flow. Fn performnce dt provided by the mnufcturer lists the reltionship between sttic pressure, fn speed nd fn irflow. The irflow rte through the box cn be used to estimte the cooling time with the id of Tbles 2A-D. The following eqution cn be used to clculte the time required to cool box of product to specific temperture: where T = 1.107 V Log S M F M T = time (minutes) to cool to temperture F V = 7/8ths cooling time (minutes) S temperture (ºF) of the incoming product F temperture (ºF) of product when cool (finl temperture) M temperture (ºF) of cooling ir entering box This eqution cn be used to estimte totl cooling time to ny temperture given the 7/8ths cooling time, ir temperture nd the incoming temperture of the product. If 7/8ths cooling time (V) cnnot be found in Tble 1, the following formul cn be used to clculte V: V = 0.903 T S M log F M where T, S, F, M re mesured under ctul operting conditions. In the initil plnning of new cooling fcility, it is often desirble to estimte the size of refrigertion system needed for cooler. As rule of thumb, the size cn be estimted from the following formul: P x (T initil T finl ) = refrigertion tonnge 10,000 where P = mximum lbs. of product cooled per hour (including weight of continers T initil = mximum expected temperture of incoming product T finl = temperture of product t the end of the cooling cycle Actul selection of refrigertion equipment will require more detiled nlysis of other fctors such s: pek cooling rtes, het input from wlls, lights, nd mchinery nd product respirtion. See USDA Hndbook 66 for n exmple of more detiled clcultion. Refrigertion lods for storge rooms (without cooling cpbility) require n nlysis similr to the detiled computtions for cooling nd there is not simple rule of thumb clcultion. Finl Recommendtions Keep in mind tht cooling is strted in the field. Pick, pck nd hul the grpes to the cold storge s soon s possible. If hrvested fruit is temporrily stored in the orchrd, it should be covered or plced in the shde.
Pge 8 Centrl Vlley Posthrvest Newsletter Rpid cooling should be done s soon s possible fter hrvest. Keep ir temperture constnt during forced ir cooling. Keep dt log nd control your cooling opertion. When pckging, lign liners nd vents. Do not over or under fill pckges. For shed pcking opertions, if fruit is hrvested fster thn the pckinghouse cpcity, fruit should be forced ir cooled nd held in storge before pcking. Pcking low temperture grpes cn cuse condenstion on the berries. This concentrtes dust into spots tht look bd. Therefore, do not cool below the dew point or ir-condition pcking sheds. Fruit will rewrm in the pckinghouse nd will need to be cooled gin. Use of forced ir initil fumigtion in combintion with cooling is dvised. Remove the fruit from the precooler s soon s the fruit reches the desired temperture in the wrmest position or just turn the fn off. Fruit should be stored t 30 to 32.0ºF pulp temperture throughout its posthrvest life. Highest berry freezing point is 28.1ºF. Highest stem freezing point is 28.4ºF. Inspect your grpes frequently during storge. Determine nd record product tempertures during loding. Check loding ptterns for trnsporttion. Keep trnsit times to n bsolute minimum by voiding unnecessry delys en route. If you need to repck grpes in storge, the newly repckged grpes should be promptly forced-ir cooled nd fumigted. Forced-ir cooling will not only cool the grpes, but it will ccelerte the drying of condenstion tht will excerbte decy. When decyed berries re removed, workers hnds will spred gry mold to other berries quickly unless fumigtion follows promptly. Consider redesigning your inner pckging nd boxes. References Crisosto, C.H., J.L. Smilnick, N.K. Dokoozlin, nd D. Luvisi. 1994. Mintining tble grpe posthrvest qulity for long distnce mrkets. In: J.M. Rntz [ed.]. Interntionl Symposium on Tble Grpe Production. Anheim, CA, 28-29 June, 1994. Pges 195-199. Ksmire, R.F., T. Hinsch nd J.F. Thompson. 1996. Mintining perishble product tempertures in truck shipments. Univ. of Clif. Posthrvest Hort. Series No. 12. 12 pp. Nelson, K. E. 1978. Precooling Its significnce to the mrket qulity of tble grpes. Int. J. Refrig. 1:207-215. Prsons, R.A. 1972. Forced ir cooling of tble grpes. Unpublished report. 5 pp. Thompson, J., F.G. Mitchell, T.R. Rumsey, R.F. Ksmire, nd C.H.Crisosto. 1998. Commercil cooling of fruits, vegetbles, nd flowers. Univ. of Clif. Div. of Agric. nd Nt. Res. Pub. 21567. 62 pp. Wiley, P. nd C.H. Crisosto. 1999. Adpting perforted box liners to the Cliforni kiwifruit industry. In: J. Retmles, A.R. Ferguson, E.W. Hewett nd B. Defilippi [eds.]. Proceedings of the Fourth Interntionl Symposium on Kiwifruit. Sntigo, Chile, 11-14 Jnury, 1999. Act Hort. 498:299-306. Tble 1. Exmple of the effect of ir temperture on cooling rtes of tble grpes with n initil temperture of 75ºF t different ir tempertures 7/8ths cooling z Product temp. (ºF) 35 40.0 9.0 32 37.4 8.4 30 35.6 8.0 Air temp. (ºF) z Bsed on Figure 1. Time (hours)
Centrl Vlley Posthrvest News Pge 9 Tble 2A. Hours to 7/8 ths cool tble grpes mesured t the slowest cooling position within the pllet for different box types plced three deep nd in register. Numbers within prentheses re sttic pressures mesured s inches of wter column. Hours to 7/8ths cool downstrem grpes Continer type 1½ 2 3 4 6 9 12 TKV with no bottom clet, pper wrp TKV with ¾ bottom clet, pper wrp Full telescope 17-1/2 x 11 x 9, 3.7% side re vented Full telescope 17-1/4 x 15 x 6, 5.3% side re vented Prt telescope, CCA tough trveler, 2.7% side re vented Prt telescope, bliss style, 3.5% side re vented Kool mover, Intl. Pper, 4.1% side re vented CFM/lb z 2.8 x 1.6 0.71 0.37 0.25 Pressure y (>4) w (2-3) (0.4-0.7) (0.2) (0.1) CFM/lb 2.5 1.3 0.75 0.50 Pressure (0.75) (0.25) (0.10) (0.05) CFM/lb 1.4 1.0 0.62 0.43 0.27 0.17 Pressure (>5) (2.9) (1.2) (0.64) (0.27) (0.12) CFM/lb 1.4 1.0 0.62 0.43 0.27 0.17 Pressure (3.0) (1.7) (0.68) (0.36) (0.16) (0.07) CFM/lb 2.2 1.3 0.9 0.6 0.37 Pressure (>5) (2.5) (1.5) (0.6) (0.25) CFM/lb 1.55 1.15 0.72 0.53 0.34 0.22 Pressure (>4) (2.6) (1.1) (0.55) (0.23) (0.09) CFM/lb 2.2 1.4 0.80 0.60 0.32 0.22 Pressure (3.5) (1.6) (0.6) (0.32) (0.11) (0.05) z CFM/lb = Cubic feet per minute per pound of fruit. y Sttic pressure (inches wter column) shown is for ir pth through three tiers of continers stcked in register. For other stcking, multiply sttic pressure by: 1-tier = 0.05, 2-tiers = 0.3, 4-tiers = 2.3, 6-tiers = 7.0. x Numbers without prentheses re hours needed to rech 7/8 ths cooling of the product. w Numbers within prentheses re sttic pressures mesured s inches of wter column.
Pge 10 Centrl Vlley Posthrvest Newsletter Tble 2B. Hours to 7/8 ths cool tble grpes mesured t the slowest cooling position within the pllet for different box types, with nd without box liners, nd oriented end-to-end or side-to-side with respect to the direction of irflow. Numbers within prentheses re sttic pressures mesured s inches of wter column. Airflow (CFM/lb z ) Box Liner & Orienttion/ Box Type 0.25 0.50 0.75 1.0 1.5 Without box liners. Boxes oriented side-to-side. CHEP Box 8.5 y 5.4 4.3 3.5 3.8 (23.6 x 15.8 x 5 ) (0.13) x (0.49) (0.83) (0.95) (1.36) Corrugted Box 13.9 4.9 3.3 3.3 2.6 (20 x 16 x 5, 2.9% V.A.) (0.12) (0.48) (0.53) (0.78) (1.03) Fom-1 Box 10.9 4.9 3.4 2.4 2.8 (20 x 16 x 6.5, 3.9% V.A.) (0.13) (0.48) (0.83) (0.95) (2.09) Fom-1b Box 9.6 7.5 7.0 (20 x 12 x 8, 3.9% V.A.) (0.37) (1.15) (1.55) Fom-2 Box 12.0 7.5 5.0 1.5 (20 x 16 x 6.5, 2.9% V.A.) (0.09) (0.30) (1.07) (1.50) IFCO Box 10.2 8.2 6.7 5.6 4.8 (23.6 x 15.8 x 6 ) (0.22) (0.47) (0.83) (1.08) (1.55) TVK Box 7.7 5.3 4.4 3.7 3.9 (16 x 20 x 5.5 ) (0.10) (0.35) (0.39) (0.74) (1.06) Without box liners. Boxes oriented end-to-end. Fom-1b Box 18.7 15.0 9.3 7.5 (20 x 12 x 8, 3.9% V.A.) (0.15) (0.61) (0.70) (2.50) With box liners. Boxes oriented side-to-side. CHEP Box 17.0 13.6 14.3 13.8 (23.6 x 15.8 x 5 ) (0.20) (0.55) (1.50) (3.25) IFCO Box 14.0 10.5 12.1 (23.6 x 15.8 x 6 ) (0.43) (1.20) (3.30) With box liners. Boxes oriented end-to-end. CHEP Box 8.5 5.0 4.8 (23.6 x 15.8 x 5 ) (0.14) (0.48) (1.15) IFCO Box 10.0 7.5 5.5 (23.6 x 15.8 x 6 ) (0.13) (0.37) (0.94) z CFM/lb = Cubic feet per minute per pound of fruit. y Numbers without prentheses re hours needed to rech 7/8 ths cooling of the product. x Numbers within prentheses re sttic pressures mesured s inches of wter column.
Centrl Vlley Posthrvest News Pge 11 Tble 2C. Hours to 7/8 ths cool tble grpes mesured t the slowest cooling position within the pllet for different types of fom boxes plced three deep nd in register. Numbers within prentheses re sttic pressures mesured s inches of wter column. z Box type/ Dimensions/ Air flow (CFM/lb) z Vented re 1.5 1.0 0.5 0.25 Fish box 7/8ths cooling (hrs.) 2.8 x 4.0 6.0 10.0 20 x 11.5 x 7.5 Sttic pressure (in w.c.) y (1.8) w (0.7) (0.22) (0.07) 3.0% side V.A. Shoe box 7/8ths cooling (hrs.) 2.2 2.4 3.0 8.3 20 x 11.5 x 8.75 Sttic pressure (in w.c.) (2.2) (1.0) (0.54) (0.05) 2.9% side V.A. Metric box 7/8ths cooling (hrs.) 2.4 3.5 5.2 8.0 20 x 16 x 6.5 3.9% side V.A. Sttic pressure (in w.c.) (1.5) (1.0) (0.3) (0.09) CFM/lb = Cubic feet per minute per pound of fruit. y Sttic pressure (inches wter column) shown is for ir pth through three tiers of continers stcked in register. For other stcking, multiply sttic pressure by: 1-tier = 0.05, 2-tiers = 0.3, 4-tiers = 2.3, 6-tiers = 7.0. x Numbers without prentheses re hours needed to rech 7/8 ths cooling of the product. w Numbers within prentheses re sttic pressures mesured s inches of wter column. Tble 2D. Air flow rtes nd sttic pressures required to forced-ir cool tble grpes in Chilen corrugted boxes. Box dimensions/ Vented re/ Internl pckging 7/8ths cooling (hours) Sttic pressure (in. w.c.) Air flow (CFM/lb) z 19.75 x 11.75 x 6.5 23.4 0.7 0.5 2.6% V.A. 15.3 2.8 1.0 Clusters pper wrpped 11.0 4.2 1.5 19.75 x 11.75 /11.5 x 6.5 18.5 0.6 0.5 <1% V.A. 15.0 2.6 1.0 Clusters pper wrpped 11.0 4.4 1.5 19.75 x 11.75 /11.5 x 6.5 19.7 0.7 0.5 2.8% V.A. 19.6 2.4 1.0 Clusters pper wrpped 11.6 4.4 1.5 19.75 x 11.75 /11.5 x 6.5 2.8% V.A. Nked pck (no pper wrps) 9.6 1.3 1.5 z CFM/lb = Cubic feet per minute per pound of fruit.
Pge 12 Centrl Vlley Posthrvest Newsletter Tble 3. Effect of box liner vented re on the sttic pressure nd rte of kiwifruit cooling t two different rtes of irflow. Airflow/ Box liner Sttic Pressure (in. w.c.) Hours to 7/8ths cool 0.3 CFM/lb 0% V.A. (solid) 1.0 23 0.3% V.A. 0.4 22 0.6% V.A. 0.4 12 1.2% V.A. 0.5 9 Nked 0.2 7 0.7 CFM/lb 0% V.A. (solid) 4.0 21 0.3% V.A. 0.7 14 0.6% V.A. 0.5 9 1.2% V.A. 0.5 6 Nked 0.7 4 7/8 ths COOLING TIME (hours) 4 3 2 Plin Bgged 0.4 0.6 0.8 1.0 1.2 1.4 AIR FLOW (CFM/lb) Fig. 2. Reltionship between ir flow rte nd fruit bgging on forced ir cooling times bsed on lbortory simultion of pllet lods of grpes in vrious types of boxes.
Centrl Vlley Posthrvest News Pge 13 Fig. 3. Commercil (left) nd experimentl (right) Chilen corrugted boxes used in cooling tests. FUTURE EVENTS Winter Tree Fruit Meeting December 4, 2002, Dinub Memoril Hll, Dinub, CA, 8:00.m. until 12:00 noon. For further informtion, plese contct Kevin Dy, UCCE Tulre County, (559) 685-3309, Ext. 211, krdy@ucdvis.edu. You must subscribe to receive miled copy. (See Subscription Order Form on next pge.) If your subscription is bout to expire, the 4-digit dte code in the upper right corner of your ddress lbel will red 2002.
Pge 14 Centrl Vlley Posthrvest Newsletter Subscription rtes: Centrl Vlley Posthrvest Newsletter Published two times per yer Subscription Order Form Mil to: Lois Strole UC Kerney Ag Center 9240 S. Riverbend Ave. Prlier, CA 93648 USA Phone: (559) 646-6545 Fx: (559) 646-6593 United Sttes 1 yer = $25 2 yers = $48 3 yers = $72 4 yers = $95 Outside U.S. 1 yer = $40 2 yers = $76 3 yers = $114 4 yers = $150 Enclosed is U.S. Bnk Check mde pyble to UC Regents Plese bill my: VISA Mstercrd Account # Expires on: Signture Send subscription to: (Plese type or print netly) Nme: Compny: Address: City, Stte, Zip: Country: Phone: Emil: Fx: