TOMATO PRODUCTS: PULP, KETCHUP, AND CHILI SAUCE TEXT

[8] This number refers to the section as given in the Methods of Analysis of the Association of Agricultural Chemists. [9] Comment by authors: The organisms counted as “yeasts and spores” are the yeast cell and yeast and mold spores, not bacteria spores. Bacteria.—Tentative Estimate the number of rod-shaped bacteria from the mounted sample used in 29[10] (yeasts and spores), but before examination allow the sample to stand not less than 15 minutes after mounting. Employ a magnification of about 500, which may be obtained by the use of an 8 mm. Zeiss apochromatic objective with X18 Zeiss compensating ocular with draw-tube not extended, or an 8 mm. Spencer apochromatic objective with X20 Spencer compensating ocular and a tube length of 190, or their equivalents.[11] Count and record the number of bacteria having a length greater than one and one-half times their width in an area consisting of five of the small size squares. Count five such areas, preferably one from near each corner of the ruled portion of the slide and one from near the center. Determine the total number of the rod-shaped bacteria per area in the five areas and multiply by 480,000. This gives the number of this type of bacteria per cc. If a dilution of 1 part of the sample with 8 parts of water instead of 1 part of the sample with 2 parts of water is used in making up the sample, then the total count obtained as above must be multiplied by 1,440,000. Omit the micrococcus type of bacteria in making the count. Thus far it has proved impracticable to count the micrococci present, as they are likely to be confused with other bodies frequently present in such products. [10] This number refers to the section as given in the Methods of Analysis of the Association of Official Agricultural Chemists. [11] The 4 mm. achromatic objective and the 10X ocular as given in the list of apparatus may also be used to secure this magnification. Determination of Total Solids 1. BY THE EXAMINATION OF THE PULP The total solids in tomato pulp may be determined by drying _in vacuo_ at 70° C.; by drying at atmospheric pressure at the temperature of boiling water; by calculation from the specific gravity of the pulp; or from the per cent of solids, specific gravity or index of refraction of the filtrate. The solids obtained by different methods on 31 samples of pulp are given in Table 4. (_a_) _By drying._—By drying either _in vacuo_ or at atmospheric pressure, it is our experience that after the sample has reached apparent dryness, four hours’ drying gives complete results. From 2 to 4 grams should be taken for the determination, and enough water added to distribute the sample uniformly over the bottom of a flat-bottomed dish at least 2.5 inches in diameter. The solids as determined by drying _in vacuo_ at 70° C. are about 108.5 per cent of the result obtained by drying at the temperature of boiling water at atmospheric pressure. This figure is the average of the results obtained by the examination of 20 samples of pulp, in all of which the per cent of solids obtained by drying _in vacuo_ agree quite closely with the per cent obtained by drying at atmospheric pressure multiplied by 1.085. In 15 of the 20 samples examined, the difference did not exceed 0.10 per cent, and in only one case did it exceed 0.20 per cent. The results obtained by the subsequent examination of a considerable number of other samples confirm this relation. (_b_) _By calculation from the specific gravity of the pulp._—There is a very exact relation between the specific gravity of pulp (determined by the method given above) and the per cent of total solids as determined by drying. The solids corresponding to pulps of various specific gravities are given in Table 5, or may be obtained from the following formula which is derived from the same table: Per cent Solids = 228 (sp. gr. of pulp - 1.000) + 19.1 (sp. gr. of pulp - 1.015). 2. BY THE EXAMINATION OF THE FILTRATE If a sample of pulp of considerable size be thrown on a folded filter, a filtrate is obtained whose composition has a definite relation to that of the whole pulp. (_a_) _By drying._—The per cent of solids in the filtrate may be determined by drying _in vacuo_ at 70° C, or under atmospheric pressure at the temperature of boiling water. As in the case of the drying of pulp, a constant relation is found to exist between the per cent of solids in the filtered liquor as determined by drying _in vacuo_ at 70° C., and the per cent of solids as determined by drying at atmospheric pressure at the temperature of boiling water. The per cent of solids in the filtrate obtained by drying at atmospheric pressure, multiplied by 1.125, gives the per cent of solids obtained by drying _in vacuo_. This relation is shown in detail in Table 5. TABLE 2.—_Composition of Whole Tomato Pulps_ ======================================= | Composition of pulps | +-------+---------------------+ |Sp. gr.| Total |Insoluble | Sample | at | solids(a)| solids | No. |20° C. | | | | | | | | | | | --------+-------+----------+----------+ | |_Per cent_|_Per cent_| 1290 | 1.0252| 5.94 | 0.66 | 1291 | 1.0273| 6.54 | 0.78 | 1292 | 1.0234| 5.50 | 0.80 | 1293 | 1.0293| 7.02 | 0.74 | 1294 | 1.0272| 6.48 | 0.69 | | | | | 1295 | 1.0361| 8.67 | 0.95 | 1296 | 1.0380| 9.00 | 1.06 | 1297 | 1.0465| 11.20 | 1.19 | 1299 | 1.0417| 10.07 | 1.23 | 1300 | 1.0322| 7.70 | 0.93 | | | | | 1301 | 1.0312| 7.36 | 0.91 | 1302 | 1.0310| 7.45 | 0.91 | 1303 | 1.0340| 8.17 | 0.91 | 1304 | 1.0292| 6.88 | 0.88 | 1305 | 1.0371| 9.03 | 1.19 | | | | | 1306 | 1.0370| 8.95 | 0.98 | 1307(b)| 1.0328| 7.86 | 1.01 | 1481 | 1.0449| 10.82 | | 1482 | 1.0444| 10.83 | | 1483 | 1.0464| 11.21 | | | | | | 1484 | 1.0423| 10.27 | | 1485 | 1.0347| 8.55 | | 1477(c)| 1.0610| 13.86 | | 1479 | 1.0411| 10.00 | 1.21 | 1486 | 1.0169| 4.34 | 0.62 | | | | | 1491 | 1.0198| 4.97 | 0.63 | 1496 | 1.0341| 8.27 | 1.15 | 1515 | 1.0352| 8.56 | 1.15 | 1529 | 1.0209| 5.11 | 0.89 | | | | | 1530 | 1.0252| 6.21 | 0.98 | 1531 | 1.0291| 7.17 | 1.08 | 1224(c)| 1.0486| 11.22 | 0.91 | 1325 | 1.0327| 7.86 | 0.93 | --------+-------+----------+----------+ ================================================================= | Filtrate from pulps | Sample +--------+----------+----------+----------+-------------+ No. |Sp. gr. | | Acid | Immersion | | at | | | as |refractometer| | 20° C. | Solids(a)| Sugar(d) | citric | 17.5° C. | --------+--------+----------+-------------------+---------------+ | |_Per cent_|_Per cent_|_Per cent_| | 1290 | 1.0233 | 5.24 | 2.41 | 0.58 | 36.24 | 1291 | 1.0252 | 5.71 | 3.10 | 0.53 | 37.80 | 1292 | 1.0211 | 4.88 | 2.48 | 0.49 | 34.51 | 1293 | 1.0276 | 6.28 | 3.35 | 0.61 | 40.04 | 1294 | 1.0256 | 5.82 | 3.20 | 0.55 | 38.27 | | | | | | | 1295 | 1.0340 | 7.69 | 4.36 | 0.67 | 46.03 | 1296 | | 8.05 | 4.47 | 0.66 | 46.86 | 1297 | 1.0446 | 10.27 | 5.61 | 0.89 | 56.70 | 1299 | 1.0394 | 9.09 | 4.96 | 0.81 | 51.75 | 1300 | 1.0304 | 6.88 | 3.55 | 0.67 | 42.84 | | | | | | | 1301 | | 6.68 | 3.27 | 0.69 | 41.56 | 1302 | 1.0293 | 6.61 | 3.43 | 0.64 | 41.76 | 1303 | 1.0323 | 7.29 | 3.77 | 0.71 | 44.65 | 1304 | 1.0274 | 6.20 | 3.03 | 0.64 | 39.74 | 1305 | | 7.98 | 4.14 | 0.82 | 47.30 | | | | | | | 1306 | | 8.01 | 4.71 | 0.69 | 47.60 | 1307(b)| 1.0308 | 6.97 | 3.79 | 0.66 | 43.15 | 1481 | 1.0421 | 9.64 | 5.15 | 0.99 | 54.20 | 1482 | 1.0422 | 9.86 | 5.62 | 0.94 | 54.75 | 1483 | 1.0441 | 10.19 | 5.67 | 0.98 | 56.45 | | | | | | | 1484 | 1.0396 | 9.23 | 5.42 | 0.81 | 52.10 | 1485 | 1.0332 | 7.73 | 4.35 | 0.72 | 45.85 | 1477(c)| 1.0579 | 12.75 | 6.55 | 0.97 | 67.15 | 1479 | 1.0386 | 8.96 | | | 51.57 | 1486 | 1.0158 | 3.76 | | | | | | | | | | 1491 | 1.0188 | 4.40 | | | 32.67 | 1496 | 1.0318 | 7.31 | | | 44.86 | 1515 | 1.0331 | 7.61 | | | 46.20 | 1529 | 1.0195 | 4.54 | | | 32.96 | | | | | | | 1530 | 1.0231 | 5.42 | | | 36.31 | 1531 | 1.0273 | 6.27 | | | 40.09 | 1224(c)| 1.0468 | 10.33 | | | 57.62 | 1325 | | 6.99 | | | 43.80 | --------+--------+----------+----------+----------+-------------+ ======================================================================== | | | Solids of filtrate | | | | +----------+------------------+-----------+ | Ratio |Insoluble | | | Ratio | Refractive| Sample | of pulp |solids in | | | sugar | constant | No. |solids to| total | Sugar(d) | Acid |to acid|of filtered| | filtrate| solids | | | | liquor(f)| | solids | | | | | | --------+---------+----------+----------+----------+-------+-----------+ | |_Per cent_|_Per cent_|_Per cent_| | | 1290 | 1.133 | 11.1 | 46.0 | 11.1 | 4.1 | 0.20556 | 1291 | 1.145 | 11.9 | 54.3 | 9.4 | 5.8 | 0.20550 | 1292 | 1.127 | 14.6 | 50.8 | 10.1 | 5.0 | 0.20564 | 1293 | 1.118 | 10.5 | 53.4 | 9.7 | 5.5 | 0.20548 | 1294 | 1.113 | 10.6 | 55.0 | 9.5 | 5.8 | 0.20525 | | | | | | | | 1295 | 1.127 | 11.0 | 56.8 | 8.7 | 6.5 | 0.20534 | 1296 | 1.117 | 11.8 | 55.5 | 8.2 | 6.8 | | 1297 | 1.091 | 10.6 | 54.6 | 8.9 | 6.3 | 0.20544 | 1299 | 1.108 | 12.2 | 54.6 | 8.9 | 6.1 | 0.20550 | 1300 | 1.119 | 12.1 | 51.6 | 9.7 | 5.3 | 0.20546 | | | | | | | | 1301 | 1.102 | 12.4 | 48.9 | 10.3 | 4.8 | | 1302 | 1.127 | 12.2 | 51.9 | 9.7 | 5.4 | 0.20551 | 1303 | 1.120 | 11.1 | 51.7 | 9.7 | 5.3 | 0.20549 | 1304 | 1.110 | 12.8 | 48.9 | 10.4 | 4.7 | 0.20546 | 1305 | 1.132 | 13.2 | 51.9 | 10.3 | 5.0 | | | | | | | | | 1306 | 1.117 | 11.0 | 58.8 | 8.7 | 6.8 | | 1307(b)| 1.126 | 12.9 | 54.4 | 9.5 | 5.7 | 0.20544 | 1481 | 1.123 | | 53.4 | 10.3 | 5.2 | 0.20545 | 1482 | 1.100 | | 57.0 | 9.6 | 6.0 | 0.20554 | 1483 | 1.100 | | 55.6 | 9.6 | 5.8 | 0.20550 | | | | | | | | 1484 | 1.114 | | 58.7 | 8.8 | 6.7 | 0.20544 | 1485 | 1.106 | | 56.3 | 9.3 | 6.0 | 0.20529 | 1477(c)| 1.111(e)| | 51.4 | 7.7 | 6.7 | | 1479 | 1.116 | 9.8 | | | | 0.20554 | 1486 | 1.154 | 14.3 | | | | | | | | | | | | 1491 | 1.128 | 12.7 | | | | 0.20565 | 1496 | 1.131 | 13.9 | | | | 0.20554 | 1515 | 1.125 | 13.5 | | | | 0.20556 | 1529 | 1.125 | 17.4 | | | | 0.20556 | | | | | | | | 1530 | 1.145 | 15.8 | | | | 0.20553 | 1531 | 1.143 | 15.1 | | | | 0.20547 | 1224(c)| 1.124(e)| 11.8 | | | | | 1325 | 1.123 | | | | | | --------+---------+----------+----------+----------+-------+-----------+ (a) Determined by drying _in vacuo_ at 70°C. (b) Composite of 1290 to 1306, inclusive. (c) This sample contained salt. (d) Expressed as invert. (e) Salt-free ratio. (f) Calculated by formula of Lorentz-Lorenz, (n^2 - 1)/(n^2 + 2)2. Note.—All specific gravities in this bulletin are on a 20°C/20°C basis. TABLE 3.—_Composition of Trimming Stock Pulps_ ============================================ | Composition of pulps | +---------+----------+----------+ Sample No.|Specific | Total |Insoluble | | gravity|solids(a) | solids | |at 20° C.| | | +----------+---------+----------+----------+ | |_Per cent_|_Per cent_| 1470 | 1.0373| 9.54 | | 1471 | 1.0385| 9.40 | | 1470-1 | 1.0349| 8.56 | | 1470-2 | 1.0316| 7.88 | | 1470-3 | 1.0284| 7.00 | | | | | | 1470-4 | 1.0258| 6.62 | | 1471-1 | 1.0334| 8.12 | | 1471-2 | 1.0258| 6.41 | | 1471-3 | 1.0229| 7.48 | | 1471-4 | 1.0191| 4.74 | | | | | | 1572 | 1.0424| 10.28 | | 1573 | 1.0392| 9.53 | 1.22 | 1574 | 1.0427| 10.29 | 1.17 | 1575 | 1.0386| 9.73 | 1.29 | 1662(b) | 1.0204| 4.85 | 0.18 | | | | | 1664(c) | 1.0577| 13.20 | 0.62 | 1665 | 1.0331| 7.74 | 1.10 | 701 | 1.0200| 4.89 | 0.72 | 703(d) | 1.0180| 4.24 | 0.10 | 705 | 1.0388| 9.85 | 1.83 | 706 | 1.0333| 8.35 | 0.98 | +----------+---------+----------+----------+ ===================================================================== | Composition of liquor obtained by filtering pulps | +---------+----------+----------+----------+-------------+ Sample No.|Specific | | | Acid | Immersion | | gravity | | | as |refractometer| |at 20° C.|Solids(a) | Sugar(e) | citric | at | | | | | | 17.5° C. | +----------+---------+----------+----------+----------+-------------+ | |_Per cent_|_Per cent_|_Per cent_| | 1470 | 1.0337| 7.68 | 4.11 | 0.58 | 45.90 | 1471 | 1.0334| 7.62 | 4.05 | 0.59 | 45.75 | 1470-1 | 1.0302| 7.11 | | | 42.87 | 1470-2 | 1.0279| 6.55 | | | 40.75 | 1470-3 | | 5.83 | | | 37.80 | | | | | | | 1470-4 | 1.0232| 5.53 | | | 36.40 | 1471-1 | 1.0288| 6.86 | | | 41.60 | 1471-2 | 1.0227| 5.41 | | | 36.10 | 1471-3 | 1.0275| 6.14 | | | 39.25 | 1471-4 | 1.0168| 3.94 | | | 30.35 | | | | | | | 1572 | 1.0400| 9.28 | | | 52.47 | 1573 | 1.0369| 8.53 | | | 49.33 | 1574 | 1.0401| 9.29 | | | 52.40 | 1575 | 1.0369| 8.28 | | | 49.37 | 1662(b) | 1.0201| 4.65 | | | 33.27 | | | | | | | 1664(c) | 1.0566| 12.70 | | | 66.92 | 1665 | 1.0304| 6.89 | | | 42.65 | 701 | 1.0184| 4.29 | 2.35 | 0.30 | 32.09 | 703(d) | 1.0178| 4.15 | 2.32 | 0.29 | 32.09 | 705 | 1.0359| 8.08 | 4.07 | 0.51 | 47.85 | 706 | | 7.29 | 3.51 | 0.46 | 44.69 | +----------+---------+----------+----------+----------+--------------+ ================================================================== Sample No.| Ratio of |Insoluble | Sugar | Acid in | Ratio | | pulp | solids | in | solids | of acid | |solids to | in total | solids | of | to | | filtrate | solids | of | liquor | sugar | | solids | | liquor | | | +----------+----------+----------+----------+----------+---------+ | |_Per cent_|_Per cent_|_Per cent_| | 1470 | 1.241 | | 53.5 | 7.6 | 7.0 | 1471 | 1.233 | | 53.2 | 7.7 | 6.9 | 1470-1 | 1.203 | | | | | 1470-2 | 1.203 | | | | | 1470-3 | 1.201 | | | | | | | | | | | 1470-4 | 1.197 | | | | | 1471-1 | 1.184 | | | | | 1471-2 | 1.184 | | | | | 1471-3 | 1.218 | | | | | 1471-4 | 1.203 | | | | | | | | | | | 1572 | 1.109 | | | | | 1573 | 1.117 | 12.8 | | | | 1574 | 1.109 | 11.4 | | | | 1575 | 1.175 | 13.3 | | | | 1662(b) | 1.042 | 3.7 | | | | | | | | | | 1664(c) | 1.040 | 4.7 | | | | 1665 | 1.123 | 14.3 | | | | 701 | 1.140 | 14.7 | 54.8 | 7.0 | 7.8 | 703(d) | 1.022 | 2.4 | 55.9 | 7.0 | 8.0 |