TOMATO PRODUCTS: PULP, KETCHUP, AND CHILI SAUCE TEXT

| 1.0630 | 15.27 1.0640 | 15.52 1.0650 | 15.77 1.0660 | 16.02 1.0670 | 16.27 | 1.0680 | 16.52 1.0690 | 16.77 1.0700 | 17.02 1.0710 | 17.27 1.0720 | 17.51 | 1.0730 | 17.76 1.0740 | 18.00 1.0750 | 18.25 1.0760 | 18.50 1.0770 | 18.75 | 1.0780 | 18.99 1.0790 | 19.24 1.0800 | 19.48 1.0810 | 19.72 1.0820 | 19.97 | 1.0830 | 20.22 1.0840 | 20.47 1.0850 | 20.72 1.0860 | 20.96 1.0870 | 21.21 | 1.0880 | 21.46 1.0890 | 21.70 1.0900 | 21.95 1.0910 | 22.20 1.0920 | 22.45 | 1.0930 | 22.70 1.0940 | 22.94 1.0950 | 23.18 1.0960 | 23.43 1.0970 | 23.68 | 1.0980 | 23.93 1.0990 | 24.18 1.1000 | 24.43 1.1010 | 24.67 1.1020 | 24.92 | 1.1030 | 25.18 1.1040 | 25.42 1.1050 | 25.67 1.1060 | 25.91 1.1070 | 26.16 ---------+---------- [20] This table gives the per cent of total solids contained by pulp of different specific gravities varying from unconcentrated pulp as it comes from the cyclone to the highly concentrated product. Illustration: Suppose that when the cyclone juice is all added to the tank the contents of which are vigorously boiling so that they are doubtless of uniform composition, the volume is found by the gauge stick to be 815 gallons. A sample of this partially evaporated pulp is withdrawn and filtered and the filtrate is found to have a Brix reading of 6.90. Let us suppose that the product is to be evaporated to a pulp having a specific gravity of 1.035 and the operator desires to know at what point to turn off the steam. By referring to Table 9 in the column headed by the figure 1.035, we find opposite the Brix reading 6.90 the factor .834. Multiplying the volume of the pulp (815 gallons) by this factor, we obtain 680 gallons. It follows, therefore, that the steam should be turned off when the evaporation has reached such a point that the gauge stick shows the volume of pulp to be 680 gallons. Table 9 may be used in the same way for calculating the volume of any pulp, hot or cold, of any specified specific gravity equivalent to a certain volume of pulp of any other stated specific gravity when held at the same temperature. For instance, the illustration given above serves equally well to illustrate how the relative value of two finished pulps of different specific gravities may be calculated. It also shows directly the relative value (based on tomato solids alone) of the same volume of two pulps of different gravity. Illustration: Suppose a shipment contains 1,000 cases of No. 10 cans of pulp thought to have a specific gravity of 1.040 but found on examination to have a specific gravity of 1.0365. What is the value of the pulp in comparison with pulp of specific gravity of 1.040? Turning in Table 9 to the figure 1.0365 in the left-hand column we follow the horizontal line containing that figure to the column headed by specific gravity 1.040. Here we find that .907 is the factor by which to multiply the volume of pulp of a specific gravity 1.0365 to obtain the equivalent volume of pulp of specific gravity 1.040. The answer to our question therefore is 1000 × .907 = 907. In other words pulp of a gravity of 1.0365 judged by the tomato solids it contains, has 90.7 per cent of the value of pulp of the gravity of 1.040. Table 9 is based on the results obtained from a series of samples of whole tomato pulp and cyclone juice varying in specific gravity from 1.02 to 1.05. The table was extended by calculation to give corresponding values for more dilute cyclone juices and more concentrated products. The lower portion of the table has been repeatedly confirmed by results obtained in the examination of cyclone juice and pulp, but the figures in the higher portion of the table are based on calculation from lower concentrations. This table is only applicable to pulp to which no other substance, such as salt, has been added. Salt if present to the extent of more than 0.25 per cent can be recognized by the taste. The amount of salt, when any has been added, may be determined by the method given on page 33 and the specific gravity corrected by subtracting from the apparent specific gravity 0.007 for each per cent of salt present. This gives the specific gravity of the salt-free pulp and the corresponding per cent of solids may be obtained from Table 9. TOMATO KETCHUP Ketchup is defined in the Federal food standards as the clean, sound product made from properly prepared pulp of clean, sound, fresh, ripe tomatoes, with spices, and with or without sugar and vinegar. The solid matter, or total solids, in ketchup varies from less than 12 per cent to over 37 per cent. This means that the product varies from a substance having barely sufficient tomato added to give color and taste, to a rich, heavy tomato ketchup. The variation of total solids in any one brand is, of course, less, but large differences are not unusual. Three bottles of one brand showed a solids content varying from 12 per cent to 16 per cent, and seven of another brand varied from 32 per cent to 37.2 per cent. The amount of solids in a non-preservative ketchup should be not materially less than 28 per cent. It is necessary to have a rather high solid content for ketchup of this kind, so that it may keep after being opened on the consumer’s table. The variation in the insoluble solids is comparable to that in the total solids. The values for a number of samples examined in this laboratory ranged from .9 per cent to 2.3 per cent. As the insoluble solids come from the tomato pulp the amount of insoluble solids is to that extent an indication of the amount of tomato pulp used in the manufacture of the ketchup from whole tomato pulp. The consistency of the ketchup is dependent chiefly on the amount of insoluble tomato solids present. The ash usually varies from 2 per cent to 4 per cent, owing to the different amounts of salt, which varies in general from 1½ to 3 per cent. The acidity ranges from .4 to 2.3 per cent. The acidity is one of the most important factors in preventing the growth of bacteria and yeasts in the ketchup after being opened. In order to secure the best results the ketchup should have an acidity of over 1 per cent (expressed as acetic acid) and an acidity of 1.25 per cent or higher adds to the keeping quality of the ketchup after the bottle is opened. An increase in acidity will necessarily require an increase in the amount of sugar in order to secure the proper flavor; or, vice versa, an increase in the sugar will necessitate an increase in acidity. In some ketchups about one-half of the acidity is due to the citric acid of the tomatoes and the remainder to the vinegar added in manufacture. With ketchups of exceptionally high acidity, the proportion of citric acid to total acid may be much less than this. There may be considerable difference in the acidity in ketchup of the same brand due to variations in manufacture. The sugar present in the ketchup is derived both from the pulp and from the added sugar. In ketchup ranging from 12 to 30 per cent total solids, from 9 to 22 per cent of the solids may consist of sugars. METHODS OF MANUFACTURE Ketchup may be prepared either from the fresh tomatoes, or from pulp. The most common practice is to prepare it from fresh tomatoes, although some manufacturers prefer to make ketchup during the winter, when they are not so busy with other products, and therefore use pulp. Presuming that the same quality of stock is used and the same care used in manufacture, there are some advantages in making ketchup from fresh tomatoes. The pulp loses some of its color by bleaching, and a ketchup made from pulp is naturally subjected to more heating than that made from fresh tomatoes. In the manufacture of ketchup the fresh tomatoes may be broken by steam or by the use of a mechanical breaker. Both methods have their advantages, some preferring the one method, some the other. In securing good quality in ketchup the same factors must be considered as in the making of pulp. These factors are care in manufacture and the use of a raw product of good color and quality. For discussion of these points in regard to pulp, see page 7. The constituents used in the manufacture of ketchup in addition to the tomatoes are sugar, vinegar, salt, onions and spices. The sugar generally used is granulated cane or beet sugar. Some of the lower grades of cane sugar may be used satisfactorily. The terms used to designate grades of sugar below granulated do not always give a correct idea of the purity of the sugar and in buying such grades it is best to have samples submitted and have analyses made for sugar content. The vinegar generally used is 100-grain distilled vinegar. The salt used is of the grade known as dairy salt. A variety of spices is used in the manufacture of ketchup. Among these are cinnamon, cassia, cloves, all-spice, pepper, cayenne pepper, ginger, mustard and paprika. Spices may be used either in the form of whole spices, ground spices or volatile spice oils. Whole spices are thought by some to produce a better flavor. Ground spices, when used, should be secured from a reputable manufacturer, as there is a possibility of adulteration or use of low-grade material in ground products. Volatile spice oils are used to some extent, especially of spices containing large amounts of tannin, where there is liability of discoloration due to the formation of iron tannate during the manufacture of the ketchup. Acetic acid extracts of spices are also used to a limited extent. The sugar may be added at any time during the making of the ketchup, but is preferably added during the latter part of the cooking. There is less danger of scorching if added at this time. It should be added gradually and scattered over the surface of the cooking ketchup so that it may go into solution more readily. Vinegar is always added a few minutes before finishing. The acetic acid of the vinegar is volatile, and a large portion of it will be driven off with steam if added at the beginning of the cooking. Salt may be added at any time during the cooking, but it is best to add it sufficiently soon so that it will be dissolved and thoroughly mixed with the product. The onions should be added chopped at the beginning of the cook. Spices, either whole or ground, are generally placed in a bag and added at the beginning of the cook. If the volatile oils are used, they should be added shortly before finishing the ketchup, as otherwise a large amount of them may be carried off with the steam. FACTORY CONTROL OF THE COMPOSITION OF KETCHUP Ketchup of uniform color, consistency and taste can be produced only by controlling the quality and quantity of its constituents. Therefore, any satisfactory method of control necessitates the determination of the solids in the batch of cyclone juice before sugar, salt, vinegar and spices are added. Control, based solely on uniform specific gravity of the finished product, assures only that the specific gravity is uniform; it does not assure uniformity in consistency, sweetness, acidity, or in any other characteristic of the product. Since, under any specific procedure in a factory, the distinctive tomato flavor and the consistency of the finished product depend entirely on the tomato solids, and since about half the final acidity and sugar content is derived from the same source, the control of the tomato solid content is especially important. Fortunately the solids in cyclone juice have a fairly uniform composition. The ratio of total solids to insoluble solids is fairly constant, likewise the ratio of sugar to acid. The sugar in cyclone juice varies from about 42 per cent to 54 per cent of the total solids, averaging about 50 per cent. As the consistency or body of ketchup is due chiefly to the tomato solids, the amount of evaporation necessary to secure ketchup of the desired consistency from a known volume of pulp measured at the boiling temperature and of known Brix or specific gravity can be determined from Table 9, page 56. For instance, if the volume of the boiling pulp is 800 gallons and the corrected Brix reading of the filtrate is 5.10, it is found from Table 9 that it will be necessary to evaporate to 423 gallons to secure a ketchup of approximately the consistency of 1.040 pulp, to 374 gallons for a consistency comparable to 1.045 pulp and to 334 gallons for a consistency comparable to 1.050 pulp. This evaporation is carried out, of course, with the addition of the necessary ingredients for the making of ketchup. The amount of these ingredients can be varied in order to secure ketchup of the desired flavor. After having once decided on the amount of ingredients to be used, the manufacture may be standardized. Supposing for instance on evaporating 800 gallons of partly concentrated pulp of Brix of filtrate (5.10) to approximately 334 gallons (calculated from the 1.050 column in Table 9) it has been found that the use of 301 pounds of sugar, 26.7 gallons of 100 grain vinegar, 66.8 pounds of salt and 50.2 pounds of onions together with spices gives ketchup of the flavor desired. Dividing the amount of each ingredient by 334, it is found that each gallon of finished ketchup contains .9 pound of added sugar, .2 pound of salt, .15 pound of onions, and about 10 ounces of vinegar. After having determined the amount of each ingredient per gallon of finished ketchup, it is easy to make a table giving the amount of ingredients necessary for a given volume of cyclone juice or concentrated pulp of any gravity. In Table 11 such calculations are made. This table is based on securing a ketchup having the consistency of 1.050 pulp and starting with 800 gallons of boiling pulp of specific gravity 1.0220 (Brix reading of filtrate 5.10). Some manufacturers may desire to base the amount of ingredients on 100 gallons or multiple of 100 gallons of finished ketchup. This may be done by first making out a table similar to 9 and then calculating the amount of pulp and other ingredients for 100 gallons of ketchup. This would, however, involve considerable work as unless the pulp used had a constant specific gravity, a calculation of the quantity of each ingredient would have to be made for the volume of pulp for each batch. TABLE 11.—_Manufacture of Ketchup. Quantity of Constituents to be Added to 800 Gallons of Boiling, Partly Concentrated Pulp_ =========+==================+=========+=============================== |Filtrate from pulp| | Added constituents Specific +-------+----------+Volume of+------+---------+-------+------ gravity |Degrees| Specific |finished | |100-grain| | of pulp |Brix at| gravity | ketchup |Sugar | vinegar | Salt |Onions at 68° F.|68° F. |at 68° F. | | | | | ---------+-------+----------+---------+------+---------+-------+------ | | | _Gals._ |_Lbs._| _Gals._ | _Lbs._|_Lbs._ 1.0154 | 3.50 | 1.0137 | 226.0 | 203 | 18.1 | 45.2 | 33.0 1.0158 | 3.60 | 1.0141 | 232.0 | 209 | 18.5 | 46.4 | 34.8 1.0162 | 3.70 | 1.0145 | 239.0 | 215 | 19.1 | 47.8 | 35.9 1.0166 | 3.80 | 1.0149 | 245.0 | 221 | 19.6 | 49.0 | 36.8 1.0170 | 3.90 | 1.0153 | 252.0 | 227 | 20.2 | 50.2 | 37.8 | | | | | | | 1.0174 | 4.00 | 1.0157 | 258.0 | 232 | 20.6 | 51.8 | 38.7 1.0178 | 4.10 | 1.0161 | 265.0 | 239 | 21.2 | 53.0 | 39.8 1.0182 | 4.20 | 1.0165 | 272.0 | 245 | 21.7 | 54.4 | 40.8 1.0186 | 4.30 | 1.0169 | 278.0 | 250 | 22.2 | 55.6 | 41.7 1.0190 | 4.40 | 1.0173 | 285.0 | 257 | 22.8 | 57.0 | 42.8 | | | | | | | 1.0194 | 4.50 | 1.0177 | 292.0 | 263 | 23.4 | 58.4 | 43.8 1.0199 | 4.60 | 1.0181 | 299.0 | 269 | 23.9 | 59.8 | 44.9 1.0202 | 4.70 | 1.0185 | 306.0 | 275 | 24.5 | 61.2 | 45.9 1.0206 | 4.80 | 1.0189 | 313.0 | 282 | 25.0 | 62.6 | 47.0 1.0211 | 4.90 | 1.0193 | 320.0 | 288 | 25.6 | 64.0 | 48.0 | | | | | | | 1.0216 | 5.00 | 1.0197 | 327.0 | 294 | 26.2 | 65.4 | 49.1 1.0220 | 5.10 | 1.0201 | 334.0 | 301 | 26.7 | 66.8 | 50.2 1.0224 | 5.20 | 1.0205 | 341.0 | 307 | 27.3 | 68.2 | 51.2 1.0228 | 5.30 | 1.0209 | 347.0 | 312 | 27.8 | 69.4 | 52.1 1.0232 | 5.40 | 1.0213 | 354.0 | 319 | 28.3 | 70.8 | 53.2 | | | | | | | 1.0236 | 5.50 | 1.0217 | 361.0 | 324 | 28.9 | 72.2 | 54.2 1.0240 | 5.60 | 1.0221 | 368.0 | 331 | 29.4 | 73.6 | 55.2 1.0244 | 5.70 | 1.0225 | 374.0 | 337 | 29.9 | 74.8 | 56.2 1.0249 | 5.80 | 1.0229 | 381.0 | 343 | 30.5 | 76.2 | 57.2 1.0253 | 5.90 | 1.0233 | 388.0 | 349 | 31.0 | 77.6 | 58.2 | | | | | | | 1.0257 | 6.00 | 1.0237 | 395.0 | 356 | 31.6 | 79.0 | 59.3 1.0261 | 6.10 | 1.0241 | 402.0 | 362 | 32.1 | 80.4 | 60.4 1.0266 | 6.20 | 1.0245 | 409.0 | 368 | 32.7 | 81.8 | 61.4 1.0271 | 6.30 | 1.0249 | 416.0 | 374 | 33.3 | 83.2 | 62.5 1.0275 | 6.40 | 1.0253 | 422.0 | 380 | 33.8 | 84.4 | 63.4 | | | | | | | 1.0279 | 6.50 | 1.0257 | 429.0 | 386 | 34.3 | 85.8 | 64.4 1.0283 | 6.60 | 1.0261 | 436.0 | 392 | 34.9 | 87.2 | 65.4 1.0287 | 6.70 | 1.0265 | 443.0 | 399 | 35.4 | 88.6 | 66.5 1.0291 | 6.80 | 1.0270 | 450.0 | 405 | 36.0 | 90.0 | 67.5 1.0295 | 6.90 | 1.0274 | 457.0 | 411 | 36.6 | 91.4 | 68.6 | | | | | | | 1.0299 | 7.00 | 1.0278 | 464.0 | 418 | 37.1 | 92.8 | 69.6 1.0304 | 7.10 | 1.0282 | 471.0 | 424 | 37.7 | 94.2 | 70.7 1.0309 | 7.20 | 1.0286 | 478.0 | 430 | 38.2 | 95.7 | 71.8 1.0313 | 7.30 | 1.0290 | 485.0 | 437 | 38.8 | 97.1 | 72.8 1.0318 | 7.40 | 1.0294 | 492.0 | 443 | 39.4 | 98.5 | 73.8 | | | | | | | 1.0322 | 7.50 | 1.0298 | 499.0 | 449 | 39.9 | 99.9 | 74.9 1.0326 | 7.60 | 1.0302 | 506.0 | 455 | 40.5 | 101.3 | 76.0 1.0330 | 7.70 | 1.0306 | 513.0 | 462 | 41.1 | 102.7 | 77.0 1.0335 | 7.80 | 1.0310 | 521.0 | 469 | 41.7 | 104.2 | 78.2 1.0339 | 7.90 | 1.0315 | 529.0 | 476 | 42.3 | 105.8 | 79.4 | | | | | | | 1.0343 | 8.00 | 1.0319 | 536.0 | 482 | 42.9 | 107.2 | 80.4 1.0347 | 8.10 | 1.0323 | 543.0 | 489 | 43.5 | 108.6 | 81.5 1.0352 | 8.20 | 1.0327 | 550.0 | 495 | 44.0 | 110.0 | 82.6 1.0356 | 8.30 | 1.0331 | 557.0 | 501 | 44.5 | 111.4 | 83.6 1.0361 | 8.40 | 1.0335 | 564.0 | 508 | 45.1 | 112.8 | 84.7 | | | | | | | 1.0365 | 8.50 | 1.0339 | 571.0 | 514 | 45.7 | 114.2 | 85.7 1.0369 | 8.60 | 1.0343 | 578.0 | 520 | 46.2 | 115.6 | 86.8 1.0374 | 8.70 | 1.0348 | 585.0 | 527 | 46.8 | 117.0 | 87.8 1.0379 | 8.80 | 1.0352 | 592.0 | 533 | 47.4 | 118.4 | 88.8