Evaluation of six tomato (Lycopersicum esculentum) varieties for industrial tomato sauce preparation 1

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1 Evaluaton of sx tomato (Lycoperscum esculentum) varetes for ndustral tomato sauce preparaton 1 Horaco Ramrez,* Teresta Rodrguez* and Irvs Y. Pagan 4 ABSTRACT Ths study s concerned prmarly wth evaluatng sx processng tomato varetes grown n Santa Isabel by the Land Authorty of Puerto Rco: Zenth (Hyb.), Hybrd 337, Ventura (o.p.), Peto-98 (o.p.) and two Nema varetes (Nema-1, Nema-2). For each varety, the fruts were commnuted, pulped and concentrated. The tomato concentrate obtaned was used for sauce preparaton. The sx varetes were all found to be sutable for ndustral elaboraton of tomato sauce. Each of the sauces formulated had the requred characterstcs of a good commercal tomato sauce. RESUMEN Evaluaton de ses varedades de tomate {Lycoperscum esculentum) para la preparaton ndustral de salsa de tomate. Se evaluaron ses varedades de tomate para determnar s eran aptas para usarse en formulacones ndustrales de sasas de tomate. Las varedades fueron Zenth (hyb.), Hybrd 337, Ventura (o.p.), Peto-98 (o.p.) y dos varedades Nema (Nema-1, Nema 2). Se analzaron caracterstcas fjscas, qumcas y mcbrobologcas despues de dos semanas de elaboraton. Los resultados de estos anasts cumplen con el Grado A para sasas de tomate establecdo por el Departamento de Agrculture Federal. Basados en estos resultados, se puede conclur que todas las varedades evaluadas pueden usarse en formulacones ndustrales para la elaboracon de salsa de tomate de buena caldad. INTRODUCTION Tomato sauce s the concentrated product prepared from the lqud extracted from mature sound whole tomatoes, the sound resdue from preparng such tomatoes for cannng, the resdue from partal extracton of juce, or any combnaton of these ngredents, to whch salt, spces, one or more nutrtve sweeteners, a vnegar or vnegars, onons or other vegetable flavorng ngredents may be added (1, 3). Ths product s descrbed as an acd food (5), whch s defned as one havng an equlbrum ph of less than 4.6. 'Manuscrpt submtted to Edtoral Board 8 August Consultant engneer, Land Authorty of Puerto Rco. 3 Research Assocate, Laboratory of Food Technology 'Laboratory Techncan, Laboratory of food Technology. ry The authors thank Mr. Fred Fernandez for readng and offerng helpful suggestons for mprovng ths manuscrpt. 181

2 182 RAMIREZ ET AL./TOMATO In 1983, the Unted States led tomato growers worldwde (10). Statstcs from the Bureau of the Census ndcated that 77,364 cases of tomato sauce wth a value of $803.6 mllon were packed n the Unted States n 1982 (1), thus demonstratng the economc mportance of tomato producton and processng. Snce n Puerto Rcan cusne tomato sauce s an essental ngredent, t s produced locally by varous food processors. Tomato sauce s locally produced from tomato paste or puree whch are mported from dfferent countres. Ths paste or puree, n turn, s obtaned by concentratng tomato juce (6). Local farmers are tryng to establsh tomato varetes sutable for processng, thus addng a new dmenson to tomato producton n Puerto Rco. Ths study s concerned prmarly wth evaluatng sx processng tomato varetes grown n Santa Isabel by the Land Authorty of Puerto Rco: Zenth (hyb.), Hybrd 337, Ventura (o.p.), Peto-98 (o.p.) and two Nema varete: Nema-1 and Nema-2. These varetes were frst feldevaluated by the Land Authorty for characterstcs such as hgh Brx, hgh yeld and frut frmness. We proceeded to evaluate these sx varetes for good qualty tomato sauce. MATERIALS AND METHODS All sx tomato varetes were harvested by hand, packed n cardboard boxes, brought to the Food Technology Laboratory and stored for a maxmum of eght days at 45 F. After storage, fruts were weghed, washed and sorted by hand to remove broken, dseased, moldy or otherwse objectonable tomatoes. The selected fruts were washed agan and commnuted n a Ftzpatrck Model~D Commnutng Machne (Chcago, Illnos) 0 wth 1/4 nch dameter seve. The commnuted product was heated at a temperature of 180 F (82 C) for 15 seconds n a tubular pasteurzer (Votator, Lousvlle, Kentucky). The latter step nactvated pectnolytc enzymes nherent to the tomato that would otherwse cause the breakdown of the pectnous substances n the product wthn a very short tme (6, 7, 9). The skns and seeds were screened out wth a Langsenkap Model 1448 pulper (Indanapols, Indana) wth a nch dameter seve. The product was then passed through a fnsher (Langsenkap Model 1859, Indanapols, Indana) wth a nch dameter seve. Concentraton of the product was performed n a vacuum evaporator (Roto-Vak, Buflovak Equpment Dvson-Blaw-Knox Company, Buffalo, 'Trade names n ths publcaton are used only to provde specfc nformaton. Menton of a trade name does not consttute a warranty of equpment or materals by the Agrcultural Experment Staton of the Unversty of Puerto Rco, nor s ths menton a statement of preference over other equpment or materals.

3 J, Agrc. Unv. P.R. VOL. 74, NO. 2, APRIL, N.Y.) operated at a temperature of 120 F (49 C) under 20 ps vacuum. Samples were concentrated to 7.5 to 10.0 Brx dependng upon the varety. The tomato concentrate was then transferred to a 50-gal. stanless steel tank wth contnuous agtaton for formulaton purposes. The formula: Tomato concentrate 95.87% Modfed corn starch (COLFLO-67) 2.54% Salt 1.00% Onon 0.50% Garlc 0.05% Cayenne red pepper 0.04% The formulated batch was analyzed for percentage soluble solds ( Brx) by usng an Abbe refractometer (AO Mark II Dgtal Refractometer, Buffalo, N.Y.) accordng to Herschdoerfer (8). Determnaton of ph values was performed wth a Beckman phi 71 meter (Fullerton, Calforna). We commercally sterlzed the tomato sauce at a temperature of 200 F (93 C) for 1 mnute n a tubular pasteurzer (Votator, Lousvlle, Kentucky). Tn cans sze 211 x 300 were flled hot wth the product at a temperature of no less than 190 F (88 C) and sealed. The cans were then nverted and held thus for three mnutes to sterlze the lds. They were cooled to 100 F (38 C) n a spn cooler before beng cased and stored at room tempe-ature. After 2-week storage, 12 samples were taken for physcal (color and vscosty), chemcal ( Brx and ph) and mcrobologcal (total plate count) analyses. Color measurements were performed n a Lab Scan Spectocolormeter (Hunterlab, Reston, Vrgna), snce prevous works have shown that the L, a, b system s the most sutable for assessng color (2, 4). Vscosty of the tomato sauce was determned wth a Bostwck consstometer (Farfax, Vrgna) as the average dstance traveled by the sample n 30 seconds at room temperature. For mcrobologcal analyses, Plate Count Agar (PCA; Dfco Laboratores, Detrot, Mchgan) poured plates ncubated at 90 F (30 C) for 25 hours were used to quantfy bacteral populatons. Fgure 1 represents a flow dagram llustratng all processng steps n tomato sauce elaboraton. RESULTS AND DISCUSSION The followng tabulaton summarzes the percentage soluble solds ( Brx) and ph values of the sx tomato varetes. The hghest percentage of soluble solds s seen n Nema-2, whereas the lowest fgure s seen n Peto-98 (o.p.).

4 184 RAMIREZ ET AL./TOMATO Varety Brx ph Nema Nema Zenth (hyb.) Hybrd Ventura (o.p.) Peto-98(o.p.) Raw tomatoes Weghng Pre~washng I Inspecton gradng Washng I Commnutng I Preheatng Pulpng I Fnshng v Evaporatng Formulaton Inspecton Sterlzaton v Fllng ) V Sealng V Spn coolng Y Casng [Pasteurzaton) Storage FIG. 1: Flow dagram of tomato sauce processng.

5 J. Agrc. Unv. P.R. VOL. 74, NO. 2, APRIL, The mass balance per tomato varety appears n Table 1. In some varetes, the dscarded raw materal s hgh (Hybrd 337 and Ventura). As follows, ths was not due to varetes' defcences, but to a greater storage tme, snce the percentage of spoled fruts ncreases wth storage. Tomatoes should be processed wthn 24 hours after harvestng (2,9). Tme Varety Hours Days Nema-1 Nema -2 Zenth (hyb.) Hybrd 337 Ventura (o.p.) Peto 98 (o.p.) It s also mportant to pont out from table 1 that the yelds of fnshed tomato pulp ranges between 84.5% and 88.3%, whch can be consdered very good. The amount of tomato concentrate (.) obtaned from each varety s suffcent, although some equpment-related techncal problems produced losses n two of them (Hybrd 337 and Ventura). The soluble solds obtaned for each tomato concentrate were consdered good enough for formulatng purposes. The physcal and chemcal characterstcs of the formulated tomato sauce for each varety after two weeks' elaboraton are ndcated n Table 2. The numbers comply wth the Unted States standards for grades of tomato sauce under "U.S. Grade A" or U.S. Fancy" (1). Ths means that excellent tomato sauce can be produced n Puerto Rco wth the locally grown varetes tested. The followng tabulaton shows the mcrobologcal content of each varety of canned tomato sauce. Ths evaluaton was performed to verfy the thermal process gven to the formulated sauce before cannng, whch conssted of a one mnute retenton at 200 F (93 C) n a tubular heat exchanger. The mcrobologcal results ndcate that the varetes stored for a longer tme [(Hybrd 337 and Ventura (o.p.)] before processng exhbted hgher bacteral counts n the fnshed product. Ths was confrmed when the mcrobologcal analyses of Hybrd 337 and Ventura (o.p.) sauces showed consstently hgher bacteral counts than the ones of the other four sauces when assayed after a longer storage tme. Varety Hours Tme Days Nema -1 Nema - 2 Zenth (hyb.) Hybrd 337 Ventura (o.p.) Peto 98 (o.p.)

6 CO Varetes Noma-1 Nema - 2 Zenth (hyb.) Hybrd 337 Ventura (o.p.) Peto-98(o.p.) (A) Rawmateral 11M (B) Selected raw materal B/A % (C) Dscarded raw materal * Evaporator's losses, and 4.25, respectvely. C/A % U TABLE 1.Mass balance per tomato varety Crushed tomatoes Preheated crushed tomatoes Solds after pulper bs Resdue 8, (D) Solds after fnsher D/B Vc Resdue Tomato concentrate * 41.75* Soluble solds % 8, Evaporated water > H N -3 > O > O

7 s o Varety TABLE 2.Physcal and clemcal characterstcs of the formulated tomato sauce, for each varety, after 2 weeks of elaboraton Nema -1 Nema - 2 Zenth (hyb.) Hybrd 33V Ventura (o. p.) Peto98(o.p.) Weght (g)« Vacuum (n.hg)' "Brx 'Canned tomato sauce net weghts and vacuum measurements. -'Refractve ndex measured at 20 C (68 F). Total acdty ph % 4.0S Vscosty (cm) Refractve Index L Coor a b <s" r^ ro < o r -J z o > r o 00

8 188 RAMIREZ ET AL./TOMATO From the results obtaned we can conclude that each of the tomato varetes used for sauce formulaton s sutable for the purpose. It s worth mentonng that the soluble solds content n the fruts s an mportant parameter to consder, snce a hgh sold to water rato wll reduce elaboraton costs. A value of 4.5% falls wthn accepted ranges of ntal soluble sold content n fresh tomatoes for processng (2). LITERATURE CITED 1. Anonymous, "The Almanac of the Cannng, Freezng, Preservng Industres," Edward E. Judge and Sons, Inc., Westmnster, MD. 2. Bash, W. D., S. Z. Berry, and J. P. Dalmasso, Tomato cultvar evaluaton; raw, canned and juce. Food Processng and Technology No. 292, Department of Hortculture, Oho Agrcultural Research and Development Center. 3. Bnsted, R., J. D. Devey, and J. C. Dakn, "Pckle and Sauce Makng." 2nd ed. London Food Trade Press LTD. 4. Bontovts, L., Colour measurements n tomato cannng. Konserv-es Paprkapar No. 4, Abstract n FSTA Vol. 14 (1982) No F.D.A., "Code of Federal RegulatonsFood and Drugs 21, Parts " U.S. Government Prntng Offce, Washngton, D. C. 6. Flynn, G. and P. C. Crowther, Tomato paste or puree: an ndustral profle. Report, Tropcal Products Insttute G133, v + 8 pp. 7. Goose, G., Peter and Bnsted, Raymond, Tomato Paste, Puree, Juce and Powder. London Trade Press LTD. 8. Herschdoerfer, S. M., (Ed), "Qualty Control n the Food IndustryVol. 3." 2nd ed, Academc Press, London. 9. Lloyd, W. L. and W. A. Gould, Vscosty and lyophoress of commnuted tomato products. Food Processng and Technology No. 292, Department of Hortculture, Oho Agrcultural Research and Development Center. 10. Rodrgo, M., La nvestgacon actual en la ndustralzacon del tomate. Rev. Agroqtcmca TecnoL Alm. 24 (1): 1-14.