Table 1, Composition of pulp and of the liquor separated from it [9]
Table 2, Composition of whole tomato pulps [21]
Table 3, Composition of trimming stock pulps [22]
Table 4, Comparison of methods for the determination and calculation of solids in whole tomato pulp [23]
Table 5, Tomato pulp and filtered liquor [24]
Table 6, Corrections for specific gravity of hot pulp [43]
Table 7, Comparisons of methods for determining specific gravity [45]
Table 8, Corrections for specific gravity and Brix readings at different temperatures [55]
Table 9, Equivalent volumes of pulp of different degrees of concentration [ 56]
Table 10, Specific gravity and solids of tomato pulp [59]
Table 11, Manufacture of Ketchup. Quantity of constituents to be added to 800 gallons of boiling, partly concentrated pulp [65]
Table 12, Solids in Ketchup obtained by drying in vacuum at 70° C. and by Abbé refractometer from Geerlig’s table [68]
Table 13, Refractive index and per cent solids in Tomato Ketchup[ 69]
Table 14, Corrections for temperature to be used with Table 13 [ 70]

ILLUSTRATIONS

Fig. 1. Small specific gravity flask [36]
Fig. 2. Large specific gravity flask [36]
Fig. 3. Special head and flask receptacles for Babcock milk tester [37]
Fig. 4. Weight and specific gravity of tomato pulp [39]
Fig. 5. Specific gravity cup for hot pulp [44]

TOMATO PULP

INTRODUCTION

Tomato pulp is the fleshy portion of the tomato separated from skins, cores and seeds by means of a fine mesh screen and suitably concentrated by evaporation.

During recent years great improvements have been made in the manufacture of tomato pulp and in the quality and appearance of the product. The care exercised in the selection of the raw material and in all steps of the manufacture of tomato pulp has been greatly increased. This is equally true of pulp marketed in small cans to be used as soup stock in private homes and of the pulp sold in larger containers for the manufacture of soup and ketchup. The large buyers of pulp have determined the grade or quality which gives them the best results in the manufacture of other products and the degree of concentration which they can use most economically. It is now customary, therefore, for large sales of pulp to be made on specifications, and it is impracticable to comply with such specifications without carefully controlling the manufacture of the product. The raw material must be so selected and the manufacturing operations so controlled that the color and flavor of the finished product is conserved. This is discussed briefly on [page 7].

If he desires to sell under specification, the manufacturer must comply with his contract with respect to specific gravity, and he cannot greatly exceed the specific gravity specified without substantial sacrifice in cost of manufacture. It is therefore economical to determine the specific gravity of the product as accurately as practicable (see [p. 51]) and also to adopt methods of manufacture that will control as closely as possible the specific gravity of the finished product.

Beginning on [page 33], methods are given for the determination of specific gravity under various conditions of manufacture and sale, and on [page 50] is given the method for the determination of specific gravity of the cyclone juice or partly concentrated pulp which this laboratory has suggested as an aid to determining the volume to which the product should be evaporated to secure the desired specific gravity. This method has been used by a number of pulp manufacturers and found to be relatively convenient and practicable. It might be used to better advantage and to considerably greater profit if more help were employed—and some times more competent help—in determining specific gravity and controlling the point at which evaporation should stop.

The importance and economy of accuracy in the determination of specific gravity is not fully appreciated by all, though some of the larger manufacturers are now giving much attention to that subject. This matter is discussed on [page 50].