ACIDIFICATION OF LYE PEELED TOMATOES AND SODIUM

Transcription

1 244 FLORDA STATE HORTCULTURAL SOCETY, 1970 BBLOGRAPHY 1. Pederson, C. S. Nturl, Acidified nd Fermented Vegetble Juices. Chpt. 30, pp Fruit nd Vege tble Juice Processing Technology. Tressler & Joslyn, Ed., Avi Publishing Compny Dennison, R. A Studies on the preprtion of processed celery products. Proc. Fl. Stte Hort. Soc. 65: Dennison, R. A. nd. W. Hoover Prepr tion of Celery-tomto juice blends from Florid-grown Celery. Proc. Fl. Stte Hort. Soc. 70: Wilson, C. W dentifiction nd quntit tive estimtion of lcohols in celery essentil oil. J. Food Sci. 34: Wilson, C. W. ll, C. J. Wgner, Jr., R. E. Berry nd. K. Veldhuis Reltionship of methods of recovering essentil oil from fresh celery on the chemicl composition nd flvor. Proc. Fl. Stte Hort. Soc. 82: Gould, W. A., W. B. Bsh, nd J. R. Geismn Hndbook for qulity evlution nd control of rw nd processed tomtoes. Ohio Agriculturl Expt. St. imeo Report. 7. Btes, R. P. nd J. W. Strobel Evlution of Florid-Grown Tomto Cultivrs nd Breeding Stocks for Therml Processing. Fl. Stte Hort. Soc. 82: Wilson, C. W Terpene nd sesequiterpene hydrocrbons in the essentil oil from fresh celery. J. Food Sci. 34: Snedecor, Sttisticl ethods, Fifth Ed. (ow Stte Univ. Press, Ames, ow, 1956), pp ACDFCATON OF LYE PEELED TOATOES AND SODU LEVEL OF THE CANNED TOATOES Richrd F. tthews Food Science Deprtment, FAS University of Florid Ginesville Abstrct Studies on the peeling of tomtoes (cultivr Homested) were conducted to determine the effects of cid tretment following lye peeling on the qulity of cnned tomtoes nd the effect of lye peeling on the sodium content of cnned to mtoes. The tretments were: (1) lye peel, (2) lye peel-cid dip, (3) lye peel-cid dded, (4) lye peel-cid tblet nd (5) stem peeled. Acid ddition did not ffect totl solids or color. Sodium content nd yield of the cnned tomtoes were higher for ll lye peel tretments thn for the stem peeled tomtoes. en per cent titrtble cidity vlues for the five tret ments were (1) 0.39, (2) 0.39, (3) 0.50, (4) 0.51 nd (5) ph vlues for tretments were (1) 4.41, (2) 4.41, (3) 4.24, (4) 4.14 nd (5) The ph of #303 x 406 cn of tomtoes ws reduced 0.17 units by the ddition of 0.46 g citric cid nd 0.27 units by the ddition of citric cid-clcium sulfte-sodium chloride tblets con tining 0.52 g effective citric cid. ntroduction Lye peeling of tomtoes is used in mny res of the United Sttes in the processing of tom- Florid Agriculturl Experiment Sttions Journl Series No toes for juice, puree nd whole-pck tomtoes. Considerble lbor svings hve been estimted for lye peeling over hnd peeling (3). Lye peel ing of Florid tomto cultivrs hs been evlu ted for its effect on percent titrtble cidity, ph, color nd totl solids of cnned whole tom toes (5). There were no negtive effects of lye peeling on these fctors, however, there ws n indiction of slightly higher ph vlues for the lye peeled tomtoes. As ph increses, microbio logicl spoilge problems increse nd bove ph 4.5 the sfety of foods processed t 212 F my be questionble. Acidifiction of lye peeled tom toes before het processing ws suggested s sfety mesure in processing. This work investi gted the cid dipping of tomtoes fter lye peeling nd the ddition of cid to the peeled tomtoes in the cn. Experimentl ethods Tomtoes, cultivr Homested, were obtined from commercil growers. All tomtoes were hnd hrvested when mture-ripe nd were pro cessed t Ginesville. Two seprte lots of to mtoes were obtined. Lot 1 ws pproching n over-ripe stge nd ws considerbly riper thn Lot 2. The tomtoes were dipped for 20 seconds into 21 percent lye solution mintined t 195 F. The tomtoes (20-lb lots) were lightly gitted during the immersion period; they were removed nd llowed to drin for 45 seconds nd were then immersed in rinse wter bth for 30 seconds. All lye peeled tomtoes received the sme tretment to this point.

2 ATTHEWS: LYE PEELED TOATOES 245 Tretments The lye peeled, rinsed tomtoes were put through peeling- reel to remove loose skins. After being cored nd hving the remin ing peel removed, the tomtoes were pcked into #303 cns. 2. Acid Dip The lye peeled, rinsed tomtoes were dipped 30 seconds in two percent citric cid solution nd llowed to drin. They were then put through peeling reel to remove loose skins. The tomtoes were cored, remining peel ws removed, nd the fruit ws pcked into #303 cns. -Acid Added The lye peeled, rinsed tomtoes were put through peeling reel to remove loose skins. The tomtoes were cored, remining peel ws removed nd the fruit ws pcked into #303 cns. Citric cid (0.5gC6H80_. H20) ws dded to the tomtoes in ech cn. ' 4. Lye Peel-Acid Tblet These were treted in the sme mnner s the Acid Added tretment except 50 grin tblet (Clcium-Acidulnt Type A-orton Slt Co.) ws dded to ech #303 x 406 cn. Tblet composition ws: Sodium Chloride (Culinox 999 slt) 60.9% Anhydrous Citric Acid 19.5% Clcium Sulfte (CS04 2H20) % Sodium Bicrbonte 3.5% Polyethylene Glycol 1.0% gnesium Sterte 0.1% Prt of the citric cid is neutrlized by the sodium bicrbonte, leving n effective citric cid content of 0.52 g. 5. Stem Peel The fresh tomtoes were put through tunnel which ws open to the tmos phere nd into which stem heted to 25 psi ws relesed. Temperture mesured in the tunnel ws 190 F. The tomtoes were in the stem portion of the tunnel for 90 seconds nd were then spryed for 45 seconds with cold wter. The tomtoes were cored, the remining peel removed nd the tomtoes pcked into #303 cns. All cns of tomtoes were finish filled with juice prepred from tomtoes of the respective tretment nd exhusted in wter bth to 100 F. They were then seled nd processed in 212 F still cook for 40 minutes nd wter cooled immeditely to pproximtely 100 F. All evlutions, except for percent yield, were mde on the cnned products within 30 to 60 dys fter cnning, determintions were mde by blending the entire contents of cn of tom toes nd exmining liquots of the blend for ph, totl titrtble cidity, totl solids nd color. Three cns from ech replicte tretment were nlyzed. Anlyticl Procedures Procedures used for the determintion of ph, titrtble cidity, totl solids, color nd percent yield were the sme s previously described (5). Ascorbic cid ws n lyzed s outlined in Section 20-8 of the Lbor tory nul for Food Cnners nd Processors (6). Sodium determintions were mde on n m monium oxlte extrct of blended tomtoes. Ten g of smple ws trnsferred to 100 ml volu metric flsk nd the flsk brought to volume with 0.24 N mmonium oxlte solution. The flsk ws shken t five min intervls for 30 min. The solution ws filtered until ml of filtrte ws collected. The filtrte ws nlyzed for sod ium by flme spectrophotometry. The experiment ws replicted three times, dt ws subjected to nlysis of vrince nd significnce ws determined t the 0.05 level. Results nd Discussion ph The stem peeled tomtoes hd men ph of 4.35, which ws significntly lower thn the ph of the lye peeled tomtoes nd of the lye peeled-cid dipped tomtoes (Tble 1). Acid dipping following lye peeling ws no more effec tive in reducing the ph of the tomtoes thn wter rinses nd sprys. The lye peeled-cid dded tomtoes hd ph of This ws reduction of 0.17 units per 0.46 g dded citric cid. Tble 1. ph OF LYE AND STEA PEELED TOATOES. TEEATENT 2. lye Peel 3- Lye Peel 4. Lye Peel +Acid Tblet 5- Stem Peel l 4.45 ^ l c l4 d 4.4l b ens followed by the sme letter re not different t the 0.05 level of significnce.

3 246 FLORDA STATE HORTCULTURAL SOCETY, 1970 The citric cid-clcium sulfte-sodium chloride tblets dded to the tomtoes reduced the ph to 4.14, reduction of 0.27 ph units for 0.52 g of dded effective citric cid (Fig. 1). This dded ph reduction by clcium-citric cid tblets over citric cid hs been ttributed by one worker (4) to the common ion effect of the dded clcium. The ddition of slt hs lso been demonstrted to reduce the ph of cidified tomtoes (8). Titrtble Acidity There ws no difference between the titrtble cidities of the stem peeled tomtoes (0.42 percent), the lye peeled tomtoes (0.39 percent), nd the lye peeled-cid dip tomtoes (0.39 percent) (Tble 2). The lye peeled-cid dded tomtoes nd the lye peeledcid tblet dded tomtoes were significntly higher in titrtble cidity thn the other tret ments. Their men vlues were 0.50 nd 0.51 percent titrtble cidity; this is n increse over the titrtble cidity of the stem peeled to mtoes of 0.08 percent for the lye peel-cid dded tomtoes nd of 0.09 percent for the lye peel-cid tblet (Fig. 2). Yield The yield of lye peeled tomtoes ws 76.3 percent nd the yield for the stem peeled tomtoes ws 67.9 percent. n previous work stem peeling produced the higher yields (5). The improved yields from lye peeling re no doubt ttributble to the shorter lye peeling immersion time (20 seconds vs. 30 seconds for previous work) used in this experiment. 4.5 PH. PH OF LYE AND STEA PEELED TOATOES Tble 2. PERCENT TTRATABLE ACDTY OF LYE 2. sye Peel h. Lye Peel +Acid A) STEA PEELED TOATOES. Tblet 5. Stem Peel b b.k2 b ens followed by the sme letter re not different t the 0.05 level of significnce. Peel Removl Two procedures were used in determining the degree of peel removl from to mtoes. With Lot 1 the peel remining on the tomtos fter lye or stem peeling ws removed by hnd nd weighed. The mount of peel re mining on lye peeled tomtoes ws 0.28 lbs per 20 lbs of tomtoes treted. After stem peeling the peel remining ws 1.26 lbs per 20 lbs of tomtoes treted. With Lot 2 ech tomto ws rted visully s to whether or not 95 percent of the peel hd been removed. t ws found tht 81.3 percent of the lye peeled tomtoes hd 95 percent peel re moved, but only 8.7 percent of the stem peeled tomtoes hd 95 percent peel removed. Lye TTRATABLE ACDTY OF LYE AND STEA PEELED TOATOES 4.4 TTRATABLE ACDTY C STEA LYE LYE + ACD DP LYE + ACD ADDED LYE + ACD TABLET.35 LYE LYE+ LYE+ LYE + ACD ACD ACD DP ADDED TABLET Figure. 1. Effect of cidifiction on the ph of lye peeled tomtoes. Figure 2. Effects of cidifiction on percent titrtble cidity of lye peeled tomtoes.

4 ATTHEWS: LYE PEELED TOATOES 247 Tble 3. SODU CONTENT OF PEELED TOATOES (ppm). Tble 5. TOTAL SOLDS OF LYE AND STEA PEELED TOATOES (percent)..: b k. Stem Peel b 115 +Acid Add d ens followed by the sme letter re not different t the 0.05 level of significnce. k. Lye Peel +Acid Tblet peeling is more efficient thn stem peeling s mesured by peel removl. Sodium Content The stem peeled tomtoes hd significntly lower sodium content (49 ppm) thn ny lye peeled tretment (Tble 3). The lye peeled tomtoes nd the lye peeled tomtoes with cid dded were highest in sodium content. The cid dipped tomtoes hd 90 ppm sodium nd the cid dipping ppered to id in the removl of sodium from the tomtoes. The in cresed sodium due to lye peeling would restrict the use of lye peeled tomtoes in low sodium diets. Ascorbic Acid en scorbic cid content rnged from high of 14.3 mg/100 g for stem peeled tomtoes to low of 11.7 mg/100 g for lye peel with cid dip (Tble 4). There ws no difference in scorbic cid content between the lye peeled nd the stem peeled tomtoes. All tretments following lye peeling resulted in lower scorbic cid levels. Totl Solids en totl solids for ll tret- Tble k. ASCORBC ACD CONTENT OF LYE AND STEA PEELED TOATOES (rng/loo g). 5. Stem Peel : 5.9 ens followed by the sme letter re not dif ferent t the 0.05 level of significnce. ments rnged from 5.8 to 6.0 percent nd there ws no effect of tretment on the totl solids (Tble 5). Color en color, s mesured by the Grd ner /b rtio, rnged from 1.24 to 1.30 nd there ws no tretment effect on the color of the cnned tomtoes (Tble 6). Conclusion Lye peeling incresed the ph nd the sodium content of cnned tomtoes to levels higher thn obtined by stem peeling. Wter rinses nd sprys were s effective in reducing the ph of lye peeled tomtoes s dipping in two percent citric solution followed by wter rinsing. The ddition of 0.46 g of citric cid to #303 x 406 cn of lye peeled tomtoes reduced the ph 0.17 units nd more thn offset the ph Tble 6. COLOR OF LYE AND STEA PEELED TOATOES (Grdner - /b rtio) b U 12. k c 1.U be 3. lye Peel l.ul 1.12 h. Lye Peel +Acid Tblet be k. Lye Peel +Acid Tblet Stem Peel U.3 5. Stem Peel l.kk ens followed by the sme letter re not dif ferent t the 0.05 level of significnce. ens followed by the sme letter re not dif ferent t the 0.05 level of significnce.

5 248 FLORDA STATE HORTCULTURAL SOCETY, 1970 increse of 0.06 units from lye peeling. The ddition of tblets contining citric cid-clcium sulfte-sodium chloride reduced the ph more thn citric cid lone. The yield of tomtoes obtined by lye peeling ws higher nd the peel removl from tomtoes ws more complete thn tht obtined by stem peeling. There ws no significnt tretment effect on the color or the totl solids of the cnned tomtoes. Acknowledgement Apprecition is expressed to Dr. H. L. Brelnd for the sodium nlyses nd to r. Richrd Johnson for product nlyses. LTERATURE CTED 1. Assoc. of Offic. Agr. Chemists Officil methods of nlysis, 10th ed. Wshington, D. C. 2. Goben, R. D Tomtoes swllow the cid pill. Cnner Pcker 137: Gould, W. A Evlution of lye peeling vs. stem peeling of tomtoes s to effects on cnned product qulity nd grde of cnned tomtoes. Reserch progress report No Ohio Agriculturl Reserch nd Develop ment Center. P Lopez, A., F. W. Cooler nd W. B. Wytt Acidifiction of cnned mid-atlntic tomtoes. Cnning Trde 90: tthews, R. F., nd Herbert H. Bryn Lye peeling of Florid tomtoes effects of time, temperture nd concentrtion. Fl. Stte Hort. Soc. Proc. 81: Ntionl Cnners Assocition Lbortory n ul for Food Cnners nd Processors, 3rd ed. Vol. 2, 444 p. Avi. 7. Powers, J. J Study flvor of cidified cnned tomtoes. Cnner Pcker 136: Pry, L. W. nd J. J. Powers Acidifiction of cnned tomtoes. Food Technology 20: U.S. Stndrds for grdes of cnned tomtoes Federl Register, June 23, (29 F.R. 7909). 10. Vn Blricom, L. D Custic lye peeling of tomtoes nd peches with sodium nd potssium hydroxide solution. Circulr 159. Clemson University, Clemson, S. C. DETACHENT CHARACTERSTCS OF SNAP BEAN PODS AND PEDCELS R. K. Showlter Deprtment of Vegetble Crops University of Florid Ginesville Abstrct Hrvester, Provider nd Astro vrieties of snp bens were evluted during one seson for pod detchment loction during mechnicl hrvesting. Pods were seprted from the plnt stems t four loctions: in the stem, between stem nd pedicel, between pod nd pedicel, nd in the pod. One-fifth of the Provider detch ments were in broken pods compred with one third of the Hrvester nd Astro detchments. Attched stems were found on 11 percent of the Hrvester pods nd 1 percent of the Providers. Significnt correltions were found between pod weight, pedicel dimeter, nd detchment force for five vrieties of snp bens hrvested t widely vrying mturities. As the pods nd pedicels incresed in size, detchment force lso incresed. Florid Agriculturl Experiment Sttions Journl Series No ntroduction ny pod nd plnt chrcteristics hve been considered in developing the vrieties of snp bens grown commercilly in Florid. n the pst, emphsis hs been plced on pod chrcter istics such s shpe, length, strightness, rough ness, color nd uniformity. However, rpid de velopment of mechnicl hrvesting hs creted new demnds for informtion on the seprtion of ben pods from their stems. chine-hrvested bens re inferior in qulity to those hrvested by hnd becuse of broken pods nd ttched stem sections. n consumer cceptnce test in South Crolin retil stores, 63 percent of the bens sold were hnd-hrvested nd only 37 per cent were mchine-hrvested (3). The loction of different fruit-stem seprtion points for ornges (6) nd lemons (1) hve been differentited becuse of their influence on the mrket potentil of the fruit. An bscission lyer normlly develops in tomto fruit pedicels t joint locted mid-wy between fruit nd stem. When these tomtoes re mechniclly hrvested, the sections of pedicels ttched to the fruit often puncture other fruit. Tomtoes with jointless pedicels hve n bscission lyer be-