The "Frozen-pack" Method of Preserving. Berries. The future of the frozen pack" seems assured when a product of unquestioned merit

Transcription

1 STATON BULLETN 278 MAY 1931 The "Frozen-pck" Method of Preserving Berries The future of the frozen pck" seems ssured when product of unquestioned merit is developed. This will result (1) when the grower produces product of uniform high qulity, (2) when the pcker by the use of modern improved mnufcturing methods mintins this qulity in frozen form until it finlly reches the consumer. The recommendtions contined in this Bulletin, if followed, will ssist in this development. Agricu1tur Experiment Sttion Oregon Stte Agriculturl College CORVALLS

2 OREGON STATE BOARD OF HGHER EDUCATON Hon. C. L. STARR, President Hon. Hermn Oliver Cnyon City Hon. Hon. C. C. Colt Portlnd Hon. Hon. B. F. rvine Portlnd Hon. Hon. E. C. Smmons Portlnd Hon. Dr. K. E. Lindsy, Executive Secretry W. J. Kerr, D.Sc., LL.D J. '1. Jrdine, U.S -. P. Brss, S.M...Plnt Pthologist in Chg. F. D. Biley, M.S...Asso. Pthologist, nsecticide nd Fungicide Bd., U. S. D. of A. i. S. Bessc, M.S Associte in Frm Mt. F. M. Bolin, D.V.M...Assistnt Veterinrin W. 11. Bollen, Ph.D Ass't Bcteriologist A. G. Bouquet, M.S Horticulturist (Vegetble Crops) ['. M. Brndt, AM...Diry Husbndnin in Chsrse E. N. Bressmn, Ph.D...4ssoc. Agronomist G. G. Brown, U.S Horticulturist, -food River Brnch Exp. Sttion, Hood River W. S. Brown, D.Sc Horticulturist in Chg. ). E. liullis, M.S Assistnt Chemist A. S. Hurrier, M.S Assistnt in Frm Mngement J. C. Burtner, B.S..Asso. Dir., News Service C. D. Byrne, M.S Director, News Service Leroy Childs, A.B Superintendent Hood River Brnch Exp. Sttion, Hood River Grce M. Cole, A.B Ass't Botnist Seed Lb., U. S. Dept. of Agric. (Seed Anlyst) ). Cooter Orchrd Foremn C. V. Copson, M.S...Bcteriologist in Chrge C. M. Drrow, Ph.D Sr. Ponsologist in Chrge Smll Fruit nves., Hort. Crops nd Dis., U. S. Dept. of Aqric.. K. Den, B.S superintendent Urntill Brnch Exp. Sttion, Hermistn M. Dickinson, D.V.M Assistnt Poultry Pthologist W. H. Dreesen, Ph.D Ag'! Economist '1'. P. ])ykstr, M.S Assistnt Plnt Pthologist, U. S. Dept. of Agriculture c. M. Edwrds, B.S Asst. Animl Him. bnd,nn, Est. Ore. Br. Exp. St., Union A. K. Engbretson, B.S Superintendent John Jcob Astor Br. Exp. St., Astori K. Fox, M.S...Asso. Poultry Husbndmn L. G.. Gentner, M.S...Associte Entornol. ogst. So. Ore. Br. Exp. Sttion, Tlent H. G. (.iillespie, M.S Asst. Entomologist Hood River Brnch Experiment Sttion 1... N. Goodding, BA., B.S Associte Plnt Pt hlo gist, U. S. Deprtment of Agric. H. M. Goode, B.A Associte Editor 3. K. Hg, Ph.D Chemist (Animl Nut.) H. Hrtrnn, M.S Horticulturist (Porn.) K. H. Hrvey, Ph.D -orticulturi.ct (Phys.) ). 1). Hill, M.S Associte Agronomist F. G. Hinmnn, M.S Jr. Entomologist, Stored Prod. nsects, U S. Dept. of Agrsc. C. J. Hurd, B.S Ass't Ag'! Engineer R. E. Hutchisn, D.S Assistnt to Sup!. of Hrney Vlley Br. Exp. St., Burns C,. t. Hyslop, U.S Agronomist in Chrge r. Johnson, D.V.M...Pouttry Pthologist. P. Jone5, Ph.D...Assoc. Diry Husbnd'n J. S. Jones, M.S.A Chemist in Chrge S. Jones, M.S Asst. Entomologist F. L. Knowlton, B.S...Poultry Husbndmn G. \V. Kuhlmn, M.S...Assistnt in Frm Mngement A.. Lrson, M.S Entomologist, Stored- Prod. nsects, U. S. Dept. of Agric. M. t. Lewis, C.E rrigtion nd Dringe Specilist; Agriculturl Engineer, Bureu of Public Rods, U. S. Dept. of Agric. A. C. Lunn, B.S Poultry Husbndmn in Chrge Portlnd Albert Burcli Medford C. Pese The Dlles K. çllister Albny Corneli Mrvin Pierce L Grnde.) le in STAFF OF AGRCULTURAL EXPERMENT STATON President Director A. M. McCpes..). V.M...4sst. Veterinrin F. P. McWhorter, Ph.D Asso. Plnt Pthologist J. F. Mrtin, B.S Jr. Agron., Office of Cerel Crops nd Diseses, U. S. D. of A. P. %V. Miller, Ph.D Assoc. Plnt Pthologist, Hrt. Crps nd Dss., U. S. D. of A. H. H. Millsp Agent. Bureu of Plnt ndustry, U. S. Dept. of Agric. G. A. Mitchell, U.S Assistnt Agronomist, Office of Dry-Lnd Agric., U..5. D. of A. D. C. Mote, Ph.D Entomologist in Chig.. H. Muth, D.V.M. Assistnt Veterinrin M. N. Nelson. Ph.!) Agriculturl Econo mist ioi Chrge. M. Nelson, M.S Ansnil Husbndmn A. W. Oliver, M.S Assistnt Animl Husbndniu M. M. Oveson. D.S Asst. to Supt., Slier. mn County Br. Exp Sb., Moro K. L. Potter, M.S Animl Husbndnin in Chrge W. L. Poivers, Ph.]) Soil Scientist in Chg. F. K. Price, U.S Agriculturl Engineer E. T. Reed, B.S., A.B Editor F. C. Reimer, M.S Superintendent Son. them Oregon Br. Exp. Sttion, Tlent R. H. Robinson, M.S Chemist, n. secticides nd Fungicides C. V. Ruzek, M.S Associte Soil Scientist (Fertility) H. A. Schoth. M.S Associte Agronomist, Forge Crops, U. S. Dept. of Agric. C. K. Schuster, M.S Horticulturist, Hort. Crops nd Dis., Bureu of Plnt ndustry, U. S. Dept. of Agric. H. H. Scudder, B.S...Chief in Frm Mn'g't. L. Sercy, B.S Technicin, Vet. Med. H. E. Selby, D.S Associte in Frm Mgt.. Shttuck, M.S Superintendent Hrney Vlley Brnch Experiment St., Burns J. N. Shw, B.S., D.V.M..Asst. Veterinrin J. E. Simmons, M.S Asso. Bcteriologist B. T. Sirnms, D.V.M...Veterinrin in Clig. t. Sprgue, Ph.D Assisitnt Pthologist, U. S. Dept. of Agric. H. E. Stephens, U.S Superintendent Sher. mn County Brnch Exp. Sttion, Moro t. K. Stephenson, Ph.D Associte Soil Scientist C. L. Sulerud, M.A Asst. Ag'! Economi.cb. G. Thompson, M.S Asst. Entomologist E. F. Torgerson, B.S Assistnt Soil Scien. list (Soil Survey) B. B. Webb B.S Agent, Cerel Crops nd Dis., U..'. Dept of Agric., Shermn Co. Br. Sttion C. F. Whitker, B.S Assistnt Chemist K. H. Wiegnd, B.S Horticulturist (Horticulturl Products) Joseph Wilcox. M.S Asst. Entomologist Mud Wilson, M.A Home Econo oust Gustv Wilster, Ph.D Associte in Diry Mnufcturing Robt. Withycombe, B.S Superintendent Estern Oregon Br. Exp. Sttion. Union t. A. Work, B.S...Asst. rrigtion Engineer, Div. of Ag'! Engineering, U. S. D. of M. Zeller. Ph.D Plnt Pthologist

3 TABLE OF CONTENTS Pge NTRODUCTON 5 PRESENT COMMERCAL METHODS 6 Grding nd Sizing 7 Addition of Sugr 7 Seling 8 Freezing 8 Results Unstisfctory 8 EARLY EXPERMENTS 8 EXPERMENTAL PROCEDURE 9 Continers 9 Generl Methods 1 Weight Vritions 1 Volume Determintions 1 Chnge in Solution Densities 1 Defrosting Time Stndrdized 1 Dry Sugr nd Sirups 1 Cold Storge nd Freezing Methods Used 11 Temperture Chnges in Cold Storge 12 Exmintion of the Frozen Fruit 12 DSCUSSON OF RESULTS 12 Acceptnce of Fruit 12 Mturity 12 Holding Fruit t Pcking Plnt 13 Wshing nd Grding 13 Sorting the Fruit 13 Dry Sugr nd Sirup Comprisons 15 Continers nd Their Chrcteristics 17 Precooling Effective in Preserving Fruit 2 Precooling Pcked Fruit Before Freezing 2 Quick Versus Slow Freezing 22 Freezing Berries in Cold Sirup 22 Cost of Pcking One-Pound Fiber Crtons 23 RECOMMENDATONS 24 Hrvesting nd Hndling 24 Type of Continers 24 Vrieties of Berries 24 Sugr Types 24 Sirup Densities 24 Precooling 24 Cold Storge 25 Quick Freezing mportnt 25 Usul Freezing Tempertures 25 ACKNOWLEDGMENT 25 LTERATURE CTED 25 APPENDXTABULATONS OF DATA (TABLES -XV) 27

4 1, The "Frozen-pck" Method of Preserving Berries By ERNEST H. WEGAND NTRODUCTON The Pcific Northwest frozen-fruit industry is stedily growing. Figures compiled by the Division of Crop Estimtes, United Sttes Deprtment of Agriculture, for 193, show 61-percent increse in yerly tonnge of fresh fruit frozen pcked" since Besides berries, this tonnge represents cherries, currnts, prunes, nd rhubrb. Although the tonnge incresed during the period bove mentioned, the pck vried somewht, with 1928 indicting the gretest totl output. The following tbultion gives detiled tonnge. t will be noted from these figures tht strwberries led throughout this six-yer period, which seems to indicte decided preference for this product. FROZEN PACK" N THE PACFC NORTHWEST (Oregon-Wshington) (Fresh fruit) Kind of Fruit Tons Tons 5 7 ons ions Tons Blckberries, cultivted 238 1, , Blckberries, wild Gooseberries Lognberries Rspberries, blck Rspberries, Cuthbert 4,531 1,333 4,94 2,82 4,932 Rspberries, other, red 664 1, Strwberries - 3,141 5,3u 11,18 14,636 1,44 7,876 Cherries, blck 5 7 Cherr,es, Royl Ann, pitted Cherries, sour, pitted Currnts Rhubrb totl 6,64 12,782 14,77 22,767 16,446 17,326 "Compiled by the D,v,sion of Crop Estinttes, United Sttes Deprtment of Agriculture, Portlnd, Oregon (Brnch Office). The Pcific Northwest hs the distinction of being the first to enter the field in both brreled nd smll-pckged frozen fruit. As indicted itt the following tble, the number of smll continers of vrious products pcked in Oregon rid Wshington hve incresed rpidly since their dvent in 1928:

5 6 AGRCULTURAL EXPERMENT STATON BULLETN 278 SMALL-PACKAGE OUTPUT NORTHWEST FROZEN BERRES AND FRUT One- nd Two-Pound Continers Fruit Rtio of fruit to sugr The pcking opertions s crried on in the vrious plnts throughout Oregon re essentilly the sme. There is only one plnt which diverges from the commonly prcticed methods. This one hs equipment mnufctured by Birdseye' for the express purpose of rpid pckging nd quick freezing t exceedingly low tempertures. Here the complete pckging nd freezing is done mechniclly. Most other orgniztions pck- Strwberries- 1_pound crton 3:1 34,415 1,114,853 1,672,536 1-pound crton 5:1 93,6 2-pound crton 5: pound cn 3:1 552,429 13,332 Red rspberries- 1-pound crton 3:1 84,28 182,498 Blck rspberries- 1-pound crton 3: ,84 Lognberries- 1-pound crton 3:1 24, Blckberries- 2-pound crton 3:1 185 Huckleberries- 1-pound crton -- 3:1 12 RS.P. cherries- 1-pound crton 1-pound crton 1-pound crton - Compiled by the Division of Crop Estimtes, United Sttes Deprtment of Agriculture, Portlnd, Oregon (Brnch Office). t ppers from study of the foregoing figures tht tile future seems fvorble for continued increse in the demnd for the smller-sized pckge. This will probbly be brought more in evidence s distribution of the frozen product is improved by low-temperture fcilities for holding nd distributing the frozen product to the consumer, To dte the processes of mnufcture hve dvnced fr beyond distribution fcilities. At present but few retilers re equipped to hndle the "frozen pck" fruit, temperture of F. being necessry to keep fruit in the best mrketing condition. This Bulletin presents the results of investigtions of vrious types of continers nd tretment given the fruit prior to freezing. Some considertion ws given to vrious tempertures for freezing, but the more importnt phses considered in these experiments were those tht tended to improve nd stndrdize the pcking of the product. PRESENT COMMERCAL METHODS 3:1 4:1 5:1 16,376 37, ,855 RJsubrb-- 1-pound crton 4:1 12 Totl 434,446 1,793,571 1,932,5

6 THE "FROZEN-PACK" METHOD OF PRESERVNG BERRES 7 ing berries for freezing use freezing rooms where the product fter pcking is frozen nd stored. The berries re brought from the field in crtes holding from 12 to 15 pounds. n the better-regulted orgniztions, the fruit is received on the dy it is picked. This prevents considerble deteriortion nd softening. The plump, fresh fruit pcks better nd hs finer ppernce upon defrosting. Before pcking, the fruit is thoroughly wshed in running wter either by system of flottion or by sprying. n the flottion system the fruit is dumped into circulting cold wter which conveys it to the grding equipment for sizing. Grding nd sizing. Grding is essentil, since it improves the ppernce nd mkes for more uniform pck. Some of the fruit is either too lrge or too smll for pckging in one-pound continers. Such fruit is usully grded out nd used for brreling, lter to be used in jm nd preserve mnufcture. Although the grding methods employed re numerous, sizing is usully done on either screen- or rod-type shker grder which sifts out fruit ccording to the perfortion of the screen or the spcing between the rods. The screen sizes therefore commonly used for strwberries re: No. 1 grde size 34/32-inch perfortions No. 2 grde size 24/32-inch perfortions No. 3 grde size more thn 24/32 inch perfortions The No. 1 screen is used to remove the lrgest berries tht re brreled; the No. 2 screen is used for berries put up in smll pckges; while the No. 3 screen is used to seprte the berries used for brreling. n lognberries nd red rspberries the screen sizes vry somewht. Lognberries No. size 19/32 to 21/32-inch perfortions No. 2 size 17/32 to 18/32-inch perfortions No. 3 size smllest, into pie or wter-cnned stock. Red,-.spberries 17/32 to 16/32-inch perfortions 14/32 to 15/32-inch perfortions The grded fruits fll from the grder upon conveyor belts which trvel t speed of bout 3 to 4 feet per minute. Sorting out imperfect fruit occurs long this belt nd is done by workers locted t one or both sides. The belt is well lighted to ssure proper sorting. As the belts move from the grder they crry fruit tht is directed either to brrels for freezing or to cns nd crtons. Filling rrngements t the end of the belt re designed to cut down to minimum the number of workers necessry to hndle the dily tonnge. Addition of sugr. All fruit going into the continers is crefully weighed before sugr is dded. This is importnt s considerble loss will likely occur through negligence in this opertion. The mnner of dding sugr vries with the opertors. Some prtly fill the pckge with berries, dd some sugr, then fill in the remining fruit with the lst sugr spred over the top. This method is prcticed where tll continers re used, but with shllow continers ll the sugr is plced on top. Pcking with dry sugr hs been crried on lmost universlly up to the present time. The proportions used re usully 3:1 (3 prts of berries to 1 prt of sugr) or 2:1 (2 prts of berries to 1 prt of sugr). The sugr

7 8 AGRCULTURAL EXPERMENT STATON BULLETN 278 used is generlly mnufcturers' grde tht vries in size, depending upon the mnufcturer. Usully this sugr is slightly corser thn the regulr tble grde of grnulted cne sugr. Seling. After the vrious types of continers re filled, they re either hnd or mechniclly seled. All prffined cups except the selright style re crimped. The seling device curls the fiber bord, t the sme time melting the prffin, which resets, mking firly tight closure. Where the fruit is pcked in tin, the cns re seled under vcuum t bout 22 to 25 inches. These smll continers re then pcked in fiberbord cses, twelve or twenty-four to cse. n some instnces the cses re immeditely seled. Often, however, the lid is left open to fcilitte freezing. Freezing. Freezing is crried on t tempertures rnging from -1 F'. to +1 F. 'vvhere ptented processes re used s previously meiffioned, freezing is done t tempertures s low s -45 F. t must be relized tht where berries re pcked in crtons plced in fiber-bord cses nd seled or even left open, freezing does not usully occur for few hours. n the Birdseye' process freezing tkes plce within forty-five minutes to one nd one-hlf hours, depending upon the product. After the product hs frozen, it cn be held in storge t higher tempertures if desired. t hs been the prctice of most pckers, however, to keep the product t tempertures of from 1 F. to not to exceed 15 F. Often in higher tempertures where the sugr-fruit rtio gives more dense solutions the sirup formed is not completely frozen. The trnsporttion of frozen products is not serious problem. The increse in temperture in refrigertor cr is very slight during shipment in the winter nd erly spring. n some instnces, conditions remin lmost identicl with those used during storge. With the new silic-gel refrigertor crs, the product cn be kept in excellent condition in trnsit. Results unstisfctory. t hs been found tht berries pcked in the mnner described bove lck color, firmness, nd flvor. When the rpid methods of freezing re used, the fruit ppers flt in tste nd lcks firmness fter defrosting. The berries pcked in crtons oxidize nd the flvor becomes impired. n mny cses molding nd discolortion of the fruit hve developed which my be ttributed to mny of the prctices previling in hndling, pcking, freezing, nd storing. The results of present methods hve been noted nd it ws the purpose of this experiment to show how these spoilge conditions my be reduced or eliminted. EARLY EXPERMENTS The first preliminry work crried on in freezing fruit for mrket dtes bck to 191 when some test pcks were mde in Slem, Oregon. Ten yers lter (192) Cruess, Overholser, nd Bjrnson conducted some preliminry investigtions with smll continers using glss nd tin. These experiments were first conducted where sirup ws indicted s desirble in ssisting nd mintining the chrcter of the fruit fter freezing. No further investigtions on the subject of smll continers were crried on until 1928 when McConkie' conducted series of experiments

8 THE "FROZEN-PACK" METHOD OF PRESERVNG BERRES 9 on the reltive merits of vcuum nd non-vcuum continers for preserving berries by freezing. His experiments proved conclusively tht vcuum retrded growth of molds nd ws more effective in mintining the nturl chrcteristics of the fruit s well s preventing swells. Diehl, Mgness, Gross, nd Bonney4 further pointed out tht the loss of color in brreled goods ws due to oxidtion on the surfce where the ir cme in contct with the fruit. Since these experiments, numerous others hve been strted nd much vluble dt will undoubtedly be evolved. EXPERMENTAL PROCEDURE Experimentl work on freezing berries ws strted t the Oregon Agriculturl Experiment Sttion in During the seson of 1929, the work ws done in coopertion with the Greshm Berry Growers, nc. The pcking ws done entirely with crtons. This preliminry experimenttion ws to note the effect of vrious fruit.sugr rtios for the different berries (strwberries, red rspberries, lognberries, nd blckberries), nd lso to determine the effect of style of continer on the resulting product. While the preliminry investigtions gve much informtion, the results indicted the need for further investigtions. The studies were continued in 193 with both the Greshm Growers nd the Apple Growers Cnning Compny of Hood River. Figure 1. Styles of continerstubs, tils, cylinders, nd vcuum tins. Continers. The first seson's opertions were confined to three styles of crtons. n 193 the tin continer ws dded to the list. These styles re illustrted in Figure 1. Ech style is designed to hold pound of mteril bsed on 2:1 or 3:1 fruit-sugr rtio. The first nd second styles hve flt lids tht fit into groove ner the top. The lid is further tightened by rolling the top edge of the cup down to hold the lid in. The groove in which the lids rest prevents the lids from dropping down deeper into the cup. These continers include squt type known s "tubs" nd lrger type known s "tils." A third style is closed with the lid mde the sme s the body except tht it hs

9 1 AGRCULTURAL EXPERMENT STATON BULLETN 278 lrger dimeter tht slips over the top of the opening. The union is firly tight nd is further improved by wrming the lids, which tighten the sel when the prffin hrdens on cooling. V.TitFi fourth style, tin continer, the lids re mechniclly crimped on, giving n ir-tight sel. n seling, the mchine first vcuumizes the cn, thus eliminting prcticlly ll the ir within the continer. Generl methods. The first seson's work ws confined to prffined crtons using sugr nd sirup solutions. As the work ws coopertive nd informtion on strwberries ws most importnt, the experiments were confined principlly to this product nd only smll pck of other berries ws stored. n 193, however, the lrgest pck ws put up in vcuum tins to get comprtive informtion with the work of the previous seson. The dt from the vrious experiments re incorported in the tbles ppended (pges 27-42). Weight vritions. All continers were filled by weight. The rtios of fruit nd sugr were vried to determine the effect of different sugr concentrtions. The weight of fruit nd sugr used ws the mximum nd minimum tht could be used in the continers designed for frozen pck. Fruit in ll cses ws tken directly from sorting belts. The crtons nd cns of berries pcked with sirup nd wter were filled with.75 pound (12 ounces) of fruit nd cc. (5 fluid ounces) of sirup. n 1929, before estblishing definite volume of in-going sirup, the mount ws vried s indicted in Tble (pge 26). n the crtons nd cns pcked with fruit nd dry sugr the weight ws 1 pound net. The sirup pcks were slightly in excess of this weight becuse of the extr wter dded. Volume determintions. n pcking the fruit, methods in vogue were pplied except where determintions for volume were mde. n such cses the berries were mesured for volume in lrge cylinder by the displcement of the wter. n testing the pcked product fter defrosting nd drining for two minutes on -inch-mesh screen, the berries were gin mesured in the sme wy to determine the shrinkge. Chnge in solution densities. To find the chnge in the density of sugr solutions in sirup-pcked berries, the sirup ws first crefully stndrdized nd known quntities dded to ech crton or cn. After defrosting, the sirup ws drined from the fruit nd redings mde. All such dt were compiled in lots of twelve or more nd verges tken of the whole. Defrosting time stndrdized. n n endevor to stndrdize defrosting, twenty-four-hour period ws tken s the time llowed for thwing out t room temperture. Although this seemed the best wy to hndle the observtions nd recording of dt, there were discrepncies due to elpsed time for exmintions nd records. During this time considerble osmotic chnge took plce which prevented uniform results, especilly with quickly frozen products where osmotic ction ws retrded until defrosting. Dry sugr nd sirups. The method of ppliction of dry sugr ws essentilly the sme s tht used in commercil prctice. The pckges were filled with one pound net of berries nd sugr. Berries nd sugr

10 THE "FROzEN-pAc" METHOD OF PRESERVNG BERRES 11 were vried to give the desired fruit-sugr rtio. t ws found tht, when freezing nd thwing took plce, however the rtios such s 7:1 (7 prts of berries nd prt of sugr) mde n exceptionlly full pckge before shrinkge. The closing of these crtons injured the fruit nd detrcted from the ppernce of the resulting product. Vrious sized grins of sugr were used in order to determine the effect of these sugrs on the product. Discussion of this will be presented in the results. Figure 2. Glvenometric thermometer used in mking freezing determintions. Sugr sirups were pplied in 1929 in quntities rnging s follows: 15 c.c., 175 cc., nd 2 cc. t ws found tht cc., or 5 fluid ounces, gve the best filled pckge for commercil purposes. This ws therefore dopted s stndrd for the experiments conducted during 193. Densities of sirups used were from 2 to 8 Blling nd wter. All these vrying sirup densities were not used on ll products becuse it ws felt tht in mny instnces the sirup ws too light or too hevy for the product. The lighter sirups were pplied only where comprtive dt were desired to show color chrcteristics. Cold storge nd freezing methods used. n some of the experiments conducted, storge t 3 to 31 F. ws used s preliminry to freezing nd storge t to 1 F. Where freezing ws pplied s it is normlly done, the usul room tempertures used were o to 6 F. Cold brine solutions t F. were used where cns were quickly frozen before being stored. Liquid ir ws used to obtin quick-freezing conditions for comprison. All fruit ws finlly stored t from 6 to 2 F. Storge plnts t Greshm, Hood River, nd the Oregon Experiment Sttion lbortory were used to obtin the necessry conditions.

11 12 AGRCULTURAL EXPERMENT STATON BULLETN 278 Temperture chnges in storge. To determine the rte of chnge in temperture of the fruit csed, glvenometric thermometer ws used (Figure 2). Thermocouples were inserted t different points within the cses, crtons, fruit, nd fruit sirups, to determine the effect of freezingroom condition on the fruit. The temperture grph indictes some of the results of this study. Exmintion of the frozen fruit. The fruit which ws used for freezing ws tken from regulr lots in the pcking plnts. Upon defrosting, color, flvor, texture, nd firmness were recorded by the following method. Color, one of the most importnt fetures, is indicted in the tbles by numericl vlue s follows: 1, excellent, bright, chrcteristic of fruit; 2, very good, chrcteristic; 3, good, color verge, lcks brillincy; 4, fir, lcking in brightness; 5, poor, wshed out or too drk. Flvor is recorded by the use of letters. A, excellent, flvor chrcteristic; B, good, flvor slightly sweet; C, fir, flvor too sweet; D, poor, flvor too sweet or flt. Texture nd firmness re considered together nd recorded s follows: 1A, very firm fine texture; 1B, firm, lcking somewht in texture; 1C, soft, poor texture; 1D, very soft nd of very poor texture. Vv'hile it is conceded tht this rbitrry scle is not perfect for indicting the condition of the product, ech product in the investigtion ws plced s ner its true position s could be determined by comprison. DSCUSSON OF RESULTS Acceptnce of fruit. The observtions on conditions of receiving fruit t pcking plnts indicted tht much improvement might be mde in creful nd rpid hndling. A distinct lck in system ws often indicted by the indefinite time nd mnner of delivery. n some instnces the fruit hrvested during the morning ws delivered t noon or erly fternoon. n other instnces the mjority of the fruit hrvested during the dy ws brought in lte in the fternoon. Fruit hrvested lte during tht dy ws left until the delivery of the following dy. t ws prticulrly noted tht, with some growers, ll the fruit hrvested one dy ws not delivered until the following morning. No dequte protection ws given this fruit, hence, s consequence, drkening occurred nd the fruit lcked plumpness nd freshness. Whenever the fruit hrvested ws delivered the sme dy nd pcked before the close of the dy's work, the resulting product ws usully good nd did not vry in qulity. Mturity. Mturity is n importnt considertion in frozen-pcked berries. t ws observed tht lck of mturity injured the color, flvor, nd cut-out condition of both the fruit nd the sirup. This is indicted very mrkedly throughout the entire set of tbles ppended (pges 27-42). Note especilly Tble, lines 3, 4, 6, 11, nd 15. The vritions in weight nd volume here recorded re, in mesure, cused by these vrying mturities. Loss of color is striking illustrtion of under-mturity. n mny instnces, vrition in sirup densities re most striking. n lmost every pck of blckberries the red under-mture berry gve n undesirble red color to the pck. This red color ws exceedingly prominent when the berry ws frozen. Only through creful supervision of hrvesting nd belt sorting cn the mount of under-mtured fruit be reduced to stisfctory proportions.

12 THE "FROZEN-PACK" METHOD OF PRESERVNG BERRES 13 Holding fruit t pcking plnt. Contrcting beyond the pcking fcilities of the plnt ws found to limit the qulity of the product. Where fcilities were indequte to hold the dily receipts nd no cold storge ws vilble in the plnt, the color nd qulity of the fruit suffered. t ws found more stisfctory to clen up ech dy's receipts by operting the plnt during the night when necessry. Wshing nd grding. n most plnts these opertions were crried on together. The dpttion of the flottion method for conveying the fruit to the grding equipment simplified nd effectively eliminted one opertion. There re some importnt fetures in this connection which were observed. n ll instnces, certin mount of the wter used for conveying nd wshing ws recirculted. Tests conducted on this wter showed tremendous increse in the bcteril count. The fcilities for clering out the wste from the wter were found indequte nd did not remove the lrge ccumultion of orgnisms brought in with ech new crte of fruit wshed. While on some crtoned products spoilge condition (mold growth) ws found tht probbly occurred before freezing, this ws not found to occur in the vcuumized tin continers. Probbly some of this spoilge ws in mesure the result of the wshing process, s the high percentge of contmintion in the wsh wter indicted. Excessively low tempertures within the freezer re necessry to retrd mold growth in pckges in which n exchnge of ir my tke plce. This is prticulrly true in dry-sugr pck where the sugr hs dissolved sufficiently to expose the berry without forming protective coting of sirup or dry sugr. To get the berries into the pckges s free from contmintion s possible is therefore importnt. Sorting the fruit. All fruit fter being sorted for size ws hnd-sorted before being pcked in order to remove, so fr s possible, ll immture nd blemished fruit. The immture fruit, which ffected the pck to the gretest extent, ws hrd to detect. n mny instnces, the exterior of the fruit did not indicte the interior immture chrcteristics. Especilly ws this true of strwberries nd red rspberries. The under-mture condition in the lognberry ws indicted by light-red color nd some greenness, while in the blckberry red berry distinctly indicted under-mturity. No better method thn thorough sorting by hnd could be worked out for the qulity grding of berries. When pcking the fruit with the vrious fruitsugr rtios it ws difficult to get one-pound pck with wide sugr rtio. This ws on ccount of the size of the stndrdized continer. With the greter mount of sugr shrinkge of from 25 percent to 48 percent in the volume of the fruit ws found fter defrosting nd the continer hd decided ppernce of slck fill (Figure 3). n mny instnces the shrinkge in the products (2:1 dry-sugr pck) mde difference of one-hlf to three-fourths inch in the fill of crtons nd cns. A few smples of more thn n inch hedspce were recorded, especilly in the tll crtons. This ppernce of excess shrinkge ws owing to the style of the continer. The tubs nd cns, being shllow, hd the lest hedspce. V,.Tith the sirup pcks for ll berries the rnge- ws one-eighth to onefourth inch hedspce. The generl ppernce ws t once improved s ws the generl chrcter of the fruit. The process of hndling sirup pcks in filling ws simplified. Where the density exceeded 4 percent Blling, the fruit hd very nturl ppernce nd tste.

13 C-; C; C H C N N z H H H z bi C -, N Pt H z Figure 3. Comprison between hed spce in dry-sugr pck nd sirup-pck strwberries. right, sirup pck. Note improved ppernce of sirup pck. At left, sugr pck; t

14 THE "FROzEN-PAcC" 1VETHOD OF PRESERVNG BERRES 15 Dry-sugr nd sirup comprisons. The dry-sugr pcks in crtons filed in most instnces to meet the stndrd Set for color, ppernce, nd flvor. This ws due to oxidtion nd in some instnces to the type of continer used. Oxidtion ws brought bout in the crton-pcked mteril by being subjected to tmospheric conditions. n mny instnces the sugr plced on top to protect the fruit hd melted nd dehydrting ction hd tken plce. This dehydrting ction ctised mrked drkening in the cells on the surfce, especilly in the cse of strwberries, while in the other berries the fruit becme somewht lighter in shde. The fruit hd the ppernce of hving been prtly dried nd wilted, except some berries in dense sirup ner the bottom of the continer; these hd much more nturl ppernce. Where the fruit ws not protected by sirup, hlf-inch of mteril on the top of the continer ws of very poor qulity nd would not meet the demnds of criticl buyers. n some instnces, however, where the freezing conditions were properly crried out nd the sugr tht hd been plced on the top did not dissolve, protective coting ws - formed ginst oxidtion (Figure 4). Here the fruit remined lmost norml except for the flvor, which seemed flt, owing to lck of sugr bsorption. Essentilly the ddition of sugr in ny form brings bout - preservtive effect s well s n improvement in tste due to incresed sweetness. Corse sugrs with lrge crystls such s confectioners' grde A nd AA were compred with fine grnulted or mnufcturers' grde. t ws noted tht the corser the sugr the more slowly it went into solution. The fruit retined much - of its nturl color beneth the cot- Figure 4. Showing undissolved sugr ing of undissolved sugr. Usully crton-pck berries, the effect ws not plesing, however, becuse of the lrge quntities of undissolved lrge-crystl sugr on top. The finer sugr crystls gve s much protection nd the solubility chrcteristics were incresed t the time the fruit ws defrosted. The ppernce of the pck ws improved by the fine crystls. Shrinkge of berries, mrked chrcteristic n pckges contining dissolved sugr, ws slightly more in evidence in the berries treted with the fine grnulted nd mnufcturers' grde sugr thn in the corse sugrs, s is indicted by the low shrinkge chrcteristics of the fruit for the confectioners' A nd AA shown in Tble XV. Here the shrinkge in weight of the blckberries vries from percent to percent. For fine grnulted sugr in 3:1- nd 2:1- pck blckberries, the shrinkge in weight vries from percent to percent (Tble XV), which is probbly slightly excessive for 2:1- pck, ewng to the mturity of the fruit.

15 16 AGRCULTURAL EXPERMENT STATON BULLETN 278 Fine, dry sugr hd nother detrimentl effect. After plcing the fruit (2:1) in freezing storge nd before freezing ctully occurred, vrying mounts of sugr went into solution. As the fruit juice dissolved the sugr, forming sirup of high density, shrinkge nd toughening took plce in the berry. n the pcks where the fruit sugr rtio ws 3:1 nd 2:1 this shrinkge vried from percent to 18.8 percent in Mrshll strwberries; percent for 3:1 No. 12's (Tble ); percent to percent in Clrk Seedlings (Tble V); percent to percent, percent to percent for red rspberries (Tbles V, V, nd X); percent to percent for 3:1 nd 2:1 lognberries (Tble /2 /,5. / s5torciy7e 7me (/%surs). 7Z 96 Figure 5. Effect of storge time t 3O to 31 F. on fruit shrinkge (cut-out) of sugr-pck strwberries. X). After complete shrinkge took plce only smll rection occurred in the opposite direction s will be noted in Figure 5 (showing Clrk Seedling strwberries). Shrinkge occurred in the sirup pck but the berries still retined decided plumpness chrcteristic of the fresh fruit. Shrinkges in weight of berries for sirup pcks rnge from percent to percent for strwberries in sirups of vrying degree (Tbles nd ). The sirup kept the fruit suspended, which prevented flttening such s often occurs in the sugr pck. n the sirups of hevier density the color ws fine but slightly drker. With very light sirup the color hd diluted ppernce. n generl, sirup densities rnging from 4 to 6 Blling seemed to give most stisfctory results. For the verge berry, however, 6 to 7 Blling might be considered the proper density for high-qulity pck. Hevy density sirups cuse undesirble texture owing to excessive volume

16 THE "FROzEN-pAcc" METHOD OF PRESERVNG BERRES 17 shrinkge s indicted in Tble. Weight shrinkge is illustrted in Figure 6, which brings out the comprison between 4 nd 7 sirups. Continers nd their chrcteristics. The continers used for pckging without vcuum were fiber impregnted with prffin. While these continers were quite successful there is considerble room for improvement. The experiments indicte tht the comnion types now used for berries re not perfectly seled either ginst bsorption of fruit juices or ir interchnge. When the liquids re bsorbed by the fiber, poor ppering crton is produced (Figure 7) nd n undesirble flvor dded 11 /2 8 -qc' 4-i, 4 2 '5torrg??7 c (i%ur) Z 96 Figure 6. Effect of storge time t 3 to 31 F. on fruit shrinkge (cut-out) sirup-pck Clrk Seedling. to the product. Only where it is possible to freeze the product quickly before bsorption occurs nd to hold it in frozen condition up to the time of consumption, cn this be prevented. n this sme wy mold growth nd some surfce dehydrtion cn be eliminted. Most generlly, however, storge-temperture conditions for holding my t some time rech 2 F. or higher nd then solution my occur with high sugr concentrtions in dry-sugr pck, in which cse protection is removed from the surfce fruit. The freezing point or ice-formtion point of 6 Blling solution s indicted by Josyln nd Mrsh is 6.8 F. Thus it is obvious tht considerble dissolving ction will occur unless the temperture of the storge room is kept quite low. n such cse, the protective gency of the sugr on top of the pck is lost s the sugr goes into solution. After exposure of the berries in crton pck, the ir cuses considerble oxidtion, especilly in the higher tempertures. Very low tempertures

17 18 AGRCULTURAL EXPERMENT STATON BULLETN 278 (-1 to F.) for storge were found effective in retrding oxidtion s well s preventing sirup formtion. n the cse of tin slip-top continers most of the chrcteristics of the crton re present except bsorption by the continer itself; there is therefore no prticulr gin from their use. The vcuumized tin, however, Figure 7. Absorption of fruit juices by Crton. hs given very good results in ll forms of sugr nd sirup pck. The fruit pcked in these continers kept well over long period fter defrosting. Molding ws prevented nd the flvor ws mintined perfectly. Cns defrosted nd kept t room temperture (68 to 7 F.) for ten dys hve been opened nd found in perfect condition s to color nd flvor (Figure 8), while fruit in crtons kept under the sme conditions hs shown mold growth within forty-eight hours (Figure 9). No dessiction, such s ws found in the crtons, cn develop in the vcuum-seled cn.

18 THE "FRozEN-pAc" METHOD OF PRESERVNG BERRES 19 Figure 8. Cn of frozen sirup-pck strwberries.

19 2 AGRCULTURAL EXPERMENT STATON BULLETN 278 Precooling effective in preserving fruit. Precooling before nd fter pcking ws found to be n effective mens of keeping the fruit. Subjecting fruit fresh from the field to hot storge pltforms reduced the turgidity nd chnged the color slightly nd ws lso found to provide conditions for further propgtion of the mny forms of molds which lter my grow nd spoil the ppernce of the pcked product. This precooling process to improve the pckged product cn redily be dopted by those plnts hving cold-storge fcilities. i L. - Figure 9. Mold growth on crton-pck bet-ries. Precooling the sirup is lso n effective wy of bringing bout quicker freezing nd improving the generl ppernce of the fruit. Severl lots of fruit were pcked to which pre-cooled sirup t 2 F. with density of 6 Blling ws dded. Freezing the fruit took plce in 7 hours, while similr lot with sirup dded t 6 F. did not freeze for 22 hours. During this time considerble interchnge hd tken plce. Compred with the precooled sirup lot, shrinkge of the fruit ws quite mrked. There re two definite improvement fctors obtined by immersing the fruit in cold sirup before pcking. The first benefit is the coting effect, which retrds oxidtion. The second is the preservtive effect, which is quite importnt. Here preservtion is brought bout by seling the fruit nd cooling it quickly to point where decomposition will not tke plce rpidly. Precooling pcked fruit before freezing. The experiments conducted on sirup- nd sugr-pcked fruits held in cold storge (3 F. to 31 F.) for

20 THE 'FROZEN-PACK" METHOD OF PRESERVNG BERRES 21 24, 48, 72, nd 96 hours indicte, however, tht decomposition is retrded, prcticlly complete equilibrium tking plce between the sirup nd the fruit juices (Figures 5 nd 6). Crton-pcked products subjected to these conditions, however, did not retin s fine flvor s the fruit in vcuumized tin, owing to the bsorption of the sirup nd juices by the fiber of the crton. Mold growth lso ppered to some extent. Undoubtedly this temperture is sufficiently low to preserve the fruit for long time t certin sugr concentrtions. Mgoon6 indictes tht the growth ctivity of microorgnisms prcticlly ceses s the freezing 7 '55 /22 Bemes -i'jo2. 1frop per C 4 3 7,9 gipo,e, 6 SP'-'? 4 \.4O.XUfl JO S!occ,ge Ti,,,e (//,9-j) Figure 1. Effect of storge time t 3 to 31 F. on sirup Cut-Out of sirup-pck Clrk Seedlmg strwberries. point (32 F. or C.) is reched. Price nd Hurd7 hve found tht crem with bcteril count of fifty thousnd orgnisms per c.c. decresed in number of orgnisms when held t 33 F. for 9 hours, while similr smples, kept t 35 F., incresed their count from thirty thousnd to fifty thousnd per c.c. during the sme period. The most desirble effect obtined by holding the fruit t 3 to 31 F. ws the equilibrium of fruit juices nd sirups, with the further stbiliztion of color, flvor, nd rom, ll of which were importnt in obtining n ttrctive, tsty product. A study of Figures 5, 6, nd 1 will show mrked shrinkge in weight of fruit nd in the density of sirups over the first 24-hour period. After tht, however, very slight chnges occur in either direction. Hence those chnges which normlly should occur with certin density sirups prove dvntgeous to the product if left to go to completion.

21 22 AGRCULTURAL EXPERMENT STATON BULLETN 278 An unbised exmintion of the cold-stored fruit by number of persons hs indicted distinct preference for the fruit which hs been stored under cold-storge conditions (3 to 31 F.) fr from 24 to 72 hours before freezing. Exmintion of fruits with initil-density sirups of 4 to 6 Blling were chosen s being cceptble. n no cse ws ny of the fruit chosen which hd been frozen immeditely. t ws contended tht such fruit lcked chrcter nd ws flt in comprison The fruit in the lower-density sirup (4 Blling) ws by fr the most plump (Figure 6), with fine light color similr to the fresh fruit. The 6 nd 7 Blling sirup incresed slightly the depth or drkness of color nd mde the product slightly sweeter in tste. Quick versus slow freezing. The freezing methods pplied were principlly the commonly used freezing-room methods (shrp room to -1 F.) except in two instnces. n order to duplicte quick-freezing methods s closely s possible, liquid ir ws used in few experiments, while cold circulting brine kept t F. ws lso pplied. n the shrp room the experimentl results previously mentioned were obtined by plcing the pcked fruit in cses in the previling mnner. Temprtures were usully held t F. to.1 F. nd freezing occurred s in commercil prctice. This method ws entirely stisfctory for the type of product, nd the results thereof re incorported in most of the tbles. The mjority of the berries pcked were run in this wy to obtin uniform nd comprble results. Even under these circumstnces it will be seen tht there is considerble vrition due principlly to mturity nd defrosting time. A comprison of the vrying rtes of freezing between non-circulted nd fn-circulted ir is shown by the following results: (1) it took 34 hours to reduce the temperture of the berries pcked in crtons nd csed to temperture of 271 F.; (2) with the fn the time ws decresed to 25 hours. Thus it is evident tht circultion fcilittes the cooling conditions nd is fctor where lrge quntities of products re hndled dily. Fiber-bord cses retrd the freezing ction. This is clerly shown in Figure 11 where comprison is mde in the rte of het loss between berries in crtons exposed directly to the freezing room nd crtons plced in the center of the fiber-bord cses. The crton exposed to the freezing room reches the freezing point (32 F.) in 4 hours, while it tkes 21 hours to rech the sme temperture under usul pcking methods. n this instnce the ir in the room ws kept circulting to obtin quick freezing. This indictes tht when quick freezing is desired in ordinry freezing rooms, it is essentil to keep the crtons or tins on try bords exposed to the direct ction of the freezing conditions within the storge room. Freezing with brine t F. to -1 F. gve comprble results with the foregoing methods so fr s it ws possible to observe. t seemed, however, from the results obtined, tht the pre-tretment given the fruit ws the most importnt fctor to be considered. After the proper pretretment ny good freezing method will prove stisfctory nd will give uniformly well colored nd flvored product. Freezing berries in cold sirup. The berries subjected to sirup t density of 6 Blling with temperture of 9 F. produced fine ppering product. The berries, while frozen, were like the originl fruit in ppernce nd the color ws protected by coting of sirup which

22 THE "FROZEN-PACK" METHOD OF PRESERVNG BERRES 23 prevented oxidtion. These berries hd no opportunity to chnge in chrcter before freezing took plce. The fruit ws first precooled, nd the cold sirup then dded. Where the berries were immersed directly into the cold sirup, freezing took plce in 3 minutes ::ih:.p.!eeee!. - - = : :::. : 45 25, :: FTJjj '5 56?69/O///2/ /O//At/ //i2 R,'7. 4 / Figure 11. Effect of fiber-bord box on freezing rte of strwberries in 6 sirup. Upon defrosting, however, the fruit ws very soft nd flbby in texture compred with fruit held t 3 to 31 F. for 24 to 72 hours before freezing. With the quickly frozen fruit there ws no opportunity to firm the berries by the interchnge of sirup nd fruit juices. This type of quick freezing could redily hve commercil ppliction if fruit product without bsorbed sugr is desired. The precooling cn be pplied in mnner similr to the present method of exhusting nd 6 Blling sirup t 1 F. pplied in the usul mnner. f the product, fter siruping, is tken to the freezing room on try bords freezing should tke plce within n hour. Cost of pcking one-pound fiber crtons. The cost of pcking vries somewht in different pcking plnts. One of these orgniztions, however, cooperted in this investigtion by supplying the figures on cse of 24 one-pound fiber crtons with 3:1 fruit-sugr rtio s follows: Lithogrphed crtons per cse 24/1 $684 Direct lbor, hndling, sorting, filling, cpping, etc..153 Receiving.9 Roylty (on grding equipment).4 5 Light nd power.6 Wter.5 $5. delivered to plnt.3 Freezing nd storge three months.22 24/1 cses corrugted mde up.967 Loding in crs -.1 Overhed -.18 Totl cost $15917

23 24 AGRCULTURAL EXPERMENT STATON BULLETN 278 To obtin the cost on frozen-pck fruit pcked in wood cses dd.243 to the cost heretofore indicted for corrugted cses. To the cost of the fruit must be dded the cost of lbor nd supplies. A cse of fruit usully weighs pproximtely 18.9 pounds. The ingoing weight is 12 ounces per crton but wste in hndling nd sorting will increse the weight by 3 percent to 5 percent. n figuring, therefore, it is best to dd pproximtely.9 pound per cse for the 24-crton cse nd.45 pound for the 12-crton cse. RECOMMENDATONS Hrvesting nd hndling. Fruit for freezing is best hrvested quickly nd preferbly in the cooler prt of the dy. Where lrge crops necessitte continuous picking, the fruit is best stored in shed wy from the het prior to removl to pcking plnts. All qulity chrcters re preserved by hving the fruit delivered quickly fter picking nd preferbly ll fruit delivered the sme dy it is picked. After delivery it is importnt to hve the fruit pcked nd stored within few hours. Simple cold storge will never be substitute for this system of pcking. Type of continers. Experimentl results indicte tht vcuum-closed continers give the best results. mproved types of other continers which will prevent bsorption nd ir interchnge my produce cceptble products. Efforts should be directed towrd the dvntges of vcuum tretment through development of the chepest stisfctory continer possible. Vrieties of berries. Strwberries dptble to freezing re the Mrshll, Clrk Seedling, or other vrieties with suitble color, firmness, nd good texture. n red rspberries, the Cuthbert is the outstnding berry. Lognberries nd Evergreen blckberries re stisfctory. When exceedingly ripe nd plump, the Evergreen blckberry mkes fine product, but requires considerble sorting. Sugr types. The type of sugr found to give the most uniform results is the fine grnulted mnufcturers' grde, with rtio of 3:1. Corser grined sugrs re not recommended t this time becuse they dissolve too slowly nd undissolved corse sugr detrcts from the ppernce of the product. Sirup densities. Sirup densities for strwberries should be 6 to 7 Blling; red rspberries 6 Blling; lognberries 6 to 7 Blling; blckberries 5 to 6 Blling. Generlly the higher-density sirups detrct from the flvor of the product by over-emphsizing the sweet tste. Precooling. Precooling is effective in retrding mold growth nd shrinkge. This precooling my tke plce by wshing with cold wter s is usully the cse in the more modern combintion systems of conveying the fruit to the grder by the sme wter used for wshing. Further precooling cn be crried on effectively by llowing filled cns to pss through box kept t very low temperture. Precooling by the ddition of sirup kept t very low tempertures is effective in reducing the het nd bringing bout more fvorble conditions for preservtion.

24 THE "FROZEN-PACK" METHOD OF PRESERVNG BERRES 25 The ddition of 6 Blling sirup t 1 F. is dvntgeous where quick freezing of sirup pcks is desired. The combintion of precooling the fruit nd the ddition of cold sirup will speed up freezing nd produce rozen berry of fine ppernce. Cold storge. Before freezing the fruit, the use of cold storge t tempertures of 3 to 31 F. is n effective wy to obtin sirup penetr. tion. Frozen fruit produced in this wy will hve fine color, flvor, nd rom nd will keep well fter defrosting. Quick freezing importnt. An importnt considertion in connection with the cold storge t 3 to 31 F. is the freezing of the product. t hs been shown by our experiments tht fruit treted by holding t low tempertures is relly improved when subjected to very low freezing tempertures to complete the process. Where such conditions re vilble it is good pln to freeze the fruit immeditely fter storge. The more quickly such fruit is frozen the better the texture. Usul freezing tempertures. Tempertures for freezing my vry from.1 F. to +1 F. where usul freezing-room methods re pplied. Freezing will tke plce quickly where brine is used t F. or below nd circulted round the cns which hve been precooled to temperture of 3 F. or below. Storge tempertures should then be provided t F. to.1 F. Lower tempertures thn this cn be used if fcilities re vilble nd will be effective in holding the fruit in better condition until redy for mrket. Extremely low tempertures for holding re not necessry. With berries pcked in crtons s well s in cns the fruit is decidedly improved by holding in storge t tempertures not bove +1 F. ACKNOWLEDGMENT The uthor cknowledges his pprecition to Professor W. S. Brown; J. J. Fisher; R. A. Rudnick; Roy E. nglls; B. D. Ezell; T. Onsdorff; Greshm Berry Growers, nc.; Hood River Apple Growers Cnning Compny; Americn Cn Compny; Continentl Cn Compny; nd vrious continer concerns for their vlued ssistnce in mking possible the mteril contined in this Bulletin. LTERATURE CTED Birdseye, Clrence Quick Freezing Pckging Perishbles. Modern Pcking Vol. 3, No. 11, pp Cruess, W. V.; Overholser, E. L.; Bjrnson, S. A. Storge of Perishble Fruits t Freezing Tempertures. Cliforni Agriculturl Exp. St. Bul McConkie, J. E. Report of Vcuum Pcked Frozen Berries. Given before the Annul Meeting Northwest Cnners Assocition. Portlnd, Oregon Cnning Age, My 1929, p. 413.

25 26 AGRCULTURAL EXPERMENT STATON BULLETN 278 4Diehl, H. C.; Mgness, J. R.; Gross, C. R.; nd Bonney, V. D. The Frozen Pck Method of Preserving Berries in the Pcific Northwest. U. S. Deprtment of Agri. Tech. Bul 'Josyln, M. A., nd Mrsh, G. L. Het Trnsfer in Foods during Freezing nd Subsequent Thwing. ndustril nd Engineering Chem. Vol. 22, No. 11, p November 193. GMgoon C. A. Spoilge in Frozen Pck Fruits. The Cnner, Mrch 15, 193, p. 27. Price, F. E., nd Hurd, C. J. Progress Report No. 18, June Oregon Committee on Reltion of Electricity to Agriculture.

26 o Z. ct,_j Appendix TABULATONS OF DATA TABLE. MARSHALL STRAWBERRES Pcked in Cylinders, Greshrn, 1929 Weight Before nd fter defrosting.. Sirup pck 2.. Blling.,, ',. C l>fl. 31 U) U) () L, f-, Degrees Degrees cc. Blling Lbs. Lbs. % Blling % 52 wter , L D lci D 1C 2c D C 3r, D C Totl verges , Situp pck 2 Blling D C C 1C D 1C D C C 1C D 1C C 1C D 1C , D C Totl verges.6255 Sirup pck Blling C lb D 1C C lb C 1C C 1C C 1C ,5 3 D 1C L lb ,666 24, C lc Totl verges Sirup pck 6 Blling A / 1A Sirup pck 6 Blling A 1A A A Totl verges._

27 AGRCULTURAL EXPERMENT STATON BULLETN 278 TABLE. MARSHALL STRAWBERRES Sttion Lbortory 1929, Mnufcturers' Grde Dry Sugr Pc d Z Sit 2 ' V Fruit before nd fter defrosting Weight o. St Volume of sirup - Si._ e ' o > to.. to to U ht Degrees Bll- Lbs. Lbs. % c.c. c.c. % ing l 1.66: : : Totl verges Pcked io tubs C C C 11) 1D 1D Pcked in tls lb 1.66: B D 2b 1.66: B D 3b 1.66: B 1D Totl verges Totl verges Pcked in cylinders (Greshm) 2 2: C 1D 4 2: B 1D 11 2: C 1D Totl verges Pcked in tubs 13& 3: A lb 14 3: A lb is 3: A 1B Totl verges Pcked in tils l5b 3: B 1D 16b 3: A lb Totl verges Pcked in cylinders (Greshm) 14 3 : A lb 16 3: A lb 21 3: A lb 22 3: A 1A 23 3: j_393 A lb Totl verges No. 12s (nmed Corvl is) pcked in tubs 12e 3: A A 12e 3: A 1A

28 1 TABLE ll-clark SEEDLNG STRAWBERRES PACKED HOOD RVER Sirup Pck in Vcuum Cns Before nd fter defrosting n Sirup density Weight Volume of sirup Z 9 55 o c) C. ' bc V tt o s.c Degrees Degrees inches inches Blling Blling % Ounces Ounces % cc. c.c. Bx 13 8 Wter D 1D Bx 13 8 Wter 9 i D D Bx 12 8 Wter D D Totl verges Bi D ld B D D Bi D D Totl verges B B 1C B B 1C B B D B 1C Totl verges B B lb B C C B C 1C B B 1C Totl ve;ges B A 1C B B lb B A C Totl verges [ B C 1D B C D B C lb B C lb 1otl verges P H N N NN z tt N - B N N N i/i N z N N N U) N.)

29 AGRCULTURAL EXPERMENT STATON BULLETN 278 TABLE V. CLARK SEEDLNG STRAWBERRES HOOD RVER, 193 Mnufcturers' Grde Dry Sugr Pck Vcuum Cns Weight Before rid fter defrosting Sirup cut-out 'C C or 21,jCS Cr Zr', '. '5 CC Degrees nches lnclie,i Ouncesl Ounces c.c. Blling. o so C SC C C U Cr No sugr Ax 13 Ax L D D in Totl verges Five-plus-one pck (5:1) Al Li D Al D D Totl verges Three-plus-one pck (3 :1) A A A A A A A B lb Totl verges._ r24.l Two-plus-one pck (2:1) A3 13 9, BiD A B A A ld A B LC Totl verges._

30 THE "FROZEN-PACK" METHOD OF PRESERVNG BERRES 31 J TABLE V. RED RASPBERRES STATON LABORATORY, 193 Mnufcturers' Grde Dry Sugr Pck - Vcuum Cns C-). C-) Weight Before nd fter defrosting 5). Sirup cut-out 5) 5- Degrees nches nches Os. 2. % Blling U S ',,, Seven-plus-one pck (7:1) Fl 11. ft C lb F! C 1C Ft B lb Fl 4.25 ft C lb Totl verges Five-plus-one pck (5:1) F t B 1D P C lb F2 4. ft C lb Totl verges i Three-plus-one pck (3:1) F A lb F A ic F B lb F A lb Totl verges Totl verges Wter pck P D PS 1 12 D Sirup pck, 4 Blling, cc. used G2 1. -i's C C G C 1C G B lb 7. -i's C C G2 8.5 s's C C Totl verges

31 32 AGRCULTURAL EXPERMENT STATON BULLETN 278 TABLE V. RED RASPBERRES GRESHAM, 193 Sirup pck in tubs Sirup density Weight Volume of sirup Beforend fter de- Before nd fter defrosting Befor: nd fter def rooting l > Degrees Degrees Blling Blling % Ounces Ounces % cc. c.c. % 1l l Totl verges ' 'rotl verges Totl verges Totl verge& S S S Totl verges Decrese.

32 7 THE "FROZEN-PACK" METHOD OF PRESERVNG BERRES 33 6 z 9 TABLE V. RED RASPBERRES GRESHAM, 193 Sirup Pck in Tubs Sirup density Weight Volume of sirup Before nd fter defrosting Before nd fter defrosting Before nd fter defrosttng -. '- - - _ t - o o Degrees Degrees -1 Blhng Blling 5 Ounces Ounces % cc. 12G G G G Totl verges G G G Totl verges G G G G Totl verges E G G G G Totl verges

33 34 AGRCULTURAL EXPERMENT STATON BULLETN 278 TABLE V. RED RASPBERRES GRESHAM, 193 Mnufcturers' Grde Dry Sugr Pck in Tub Weight Before nd fter defrosting Sirup cut-out. Ounces.2 o Degrees Ounces % cc. Biling 5-' 5- Seven-plus-one pck (7:1) HG C 1D -11G D 1D HG C 1D -11G C 1C Totl verges Five-plus-one pck (5:1) H2G C C H 2G C 1C H2G B lb H2G B lb Totl verges Three-plus-one pck (3:1) -13G A J 1A H3G A lb H3G B 1A H3G B 1A H3G A A Totl verges Two-plus-one pck (2:1) H4G B ld H4G B 1D Totl verges

34 117.8 THE "FROZEN-PACK" METHOD OF PRESERVNG BERRES 35 TABLE 1X. RED RASPBERRES GRESHAM, 193 Mnufcturers' Grde Dry Sugr Pck in Tubs Weight Before nd fter defrosting Sirup cut-out V V S :3 z.. ) :1: (.1 Degrees Ounces Ounces % cc 3&fing 5- Seven-plus-one pck (7:1) DG D 1D DG D 1D DG C 1D DG C 1D DG D 1D Totl verges._ Five-plus-one pck (5:1) D2G C lb D2G B 1C D2G C 1C D2G C lb Totl verges Three-plus-one pck (3:1) D3G A A D3G B lb D3G A A D3G A là D3G A A Totl verges Two-plus-one pck (2:1) D4G A D D4G B lb D4G B 1D D4G C 1D D4G B 1C Totl verges

35 AGRCULTURAL EXPERMENT STATON BULLETN 278 TABLE X. RED RASPBERRES GRESHAM. 193 Sirup Pck in Tubs Sirup density Weight Volume of sirup Before nd fter defrosting Before nd fter defrosting Before nd fter defrosting -o Z Dcgrees Dcgrees Bll- Blling ing % Os. Os. % cc. cc. % E2G B 1C E2G _ C C E2G B lb L Totl verges E3G B lb E3G C lb E3G B lb Totl verges E4G B C E4G A [B E4G B lb Totl verges E5G A lb E5G A A E5G A 1A Totl verges

36 f. "Dry pck: no liquid or sugr dded. TABLE X. LOGANBERRES STORAGE LABORATORY, 193 Sirup Pck in Vcuum Cns Sirup density Weight Volume of sirup Before nd fter defrosting Before nd fter defrosting Before nd fter defrosting d.-., Z....., Degrees Degrees ncises nches Bll ing Blling % Ounces Ounces % cc. cc % E B lc E ' C SC E C 1C E B lb E C 1C Totl verges_ E A A E A 1A E A lb E B 1A Totl verges ES B 11) ES B lc ES A 1C Totl verges E " D 1 E " " S D D E D C E D 1D E D ld lotl verges

37 AGRCULTURAL EXPERMENT STATON BULLETN 278 TABLE X. LOGANBERRES STATON LABORATORY, 193 Mnufcturers' Grde Dry Sugr Pck-Vcuum Cns Weight Before nd fter defrosting Sirup cut-out 4) 14) nches Ounces Ounces. % > c-c- C Degrees Bllinq U Cs Seven-plus-one pck (7:1) Dl C lc Dl 13? C D D B 1D Dl C C D C C Totl verges Five-plus-one pck (5:1) D B 'C D C ic D C lb D B lb D C 'C Totl verges Three-plus-one pck (3:1) D C la D A 1A D B lb D B lb D A 1A Totl s'eges Two-plus-one pck (2:1) D A D D 14 1, B 1C D' B C D B 'C D A C Totl verges Wter pck D D 1D D D D D ,2 C C D D 1D D D D Totl verges

38 12 THE FROZEN-PACK" METHOD OF PRESERVNG BERRES 39 TABLE X. LOGANBERRES GRESHAM, 193 Confectioners' Grde A Sugr, Dry Sugr Pck in Tubs (Frozen Quickly on Trys) Weight Situp cut-out Before nd fter defrosting -n 'SC" C CC C C 5-1", 1) Degrees Ounces Ounces % c. c. Blling Seven-plus-one pck (7:1) 11 G C D Ti G iC C 51 G C lc Totl verges Cs Five-pius-one pck (5 :1) J2G B 1C 52G C C J2G C lc Totl verges Three-plus-one pck (3:1) 41 J3 G " D ld J3G " D 1D J3G " C 1C Two-pius-one pck (2:1) 54 G2 1.69" 1 D ld 54G2 1.69" 1 C D 54 G2 1.69" C 1D "Sugr not completely dissolved. 7" Blling Sirup Pck Originl Volume Sirup Used 5 oz. GG B 1D GG B 1C G5G A C GG A C GG i A 1D Totl verges

39 Ounces ,7 4 AGRCULTURAL EXPERMENT STATON BULLETN 278 z Cs n. n. TABLE XV. BLACKBERRES STATON LABORATORY, 193 Confectioners' Gi-de A rid AA Dry Sugr Pck-Vcuum Cns Weight Sirup cut-out Before nd fter defrosting C, Ounces 91 cc. Two-plus-one pck Confectioners' A Degrees BlSng N7., , A 1C N , ,4 B 114 N B C Totl verges Three-plus-one pck Confectioners' A N A lb - N8 to ,7 2 B lb N A 1C Totl s erges Two-plus-one pck Confectioners' AA Nb 8.5 to A lb Nb B 1C Nb B lb Totl verges Three-plus-one pck Confectioners' AA Nt, it) A C N! 7. 1 t A lb Nh 8.S t B lb Totl verges Eighty-degree sirup (nvert) N12' A 1D Nt2 4 it A 1D N12 2 it B D N12i 2 it B 1D N12 2.i C OC N it C 1D Totl verges o -d Cl C) CCO3 >< 11) U C, C, FCo