The Commercial Products of the Vegetable Kingdom by P. L. Simmonds

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[** The initial C. throughout these tables indicates that the plant
was grown in the colony; C.L., that the starch was prepared in the
colonial laboratory.]

That the extremes in this table should occur in the case of the
starches of commerce, was, perhaps, to be expected; nevertheless the
difference between the starch of the sweet potato and that of the
bitter cassava is nearly as great, and both these specimens were
prepared in the laboratory, by the same process, and subject to the
same temperature and exposure.

_Characters of the jellies formed by various
starches._--_Tenacity_.--I have met with no very precise results on
this subject, except the well-known fact that it takes a much larger
quantity of some starches, the arrowroot for instance, to form a jelly
of equal tenacity with that formed by others, such as the _Tous les
mois_; and hence in the West Indies the latter is universally
preferred to the cassava starches.

After trying various plans, the method which I found best fitted for
comparing the tenacity of different starch jellies, was the
following:--Of each of the kinds of starch, 24 grains were weighed out
and mixed with 400 grains of distilled water, in a porcelain capsule
of suitable size. The mixture was then heated and boiled briskly for
three minutes, with constant stirring, and was immediately poured into
a conical test-glass,[45] which the jelly nearly filled. The time at
which each glass was filled was noted, and exactly two hours were
allowed for the contents to cool in a current of air. The glass is
then set on a plate of glass, supported on a ring of a retort stand,
and the weight ascertained, which was necessary to force a metallic
disc, of ascertained size, through the jelly. The most convenient way
of doing this was by using a piece of apparatus of the form rudely
represented on the margin. The rectangular frame is of thin brass
wire, and the slightly cup-shaped disc, _d d_, is soldered to a wire,
attached to the upper short side of the rectangle. From the opposite
or lower side of the rectangle a small glass cup, _c._, is suspended,
into which weights are put as soon as the disc has been made to rest
on the surface of the jelly, _pp_ is the plate of glass on which the
test-glass is set. Whenever the disc tears the skin of the jelly and
begins to sink in it, no further addition, of weights is made, and
the weight of the disc, framework, and cup being known, we have an
estimate of the tenacity of the jelly. This process is but
approximative, and some practice is necessary before the operator
succeeds in getting uniform results from the same series of specimens.

+--------------------+
| | |
| | |
| | |
| d \_____/ d |
| |
| |
| |
| p--------------p |
| |
| |
+--------------------+
|
|
|
|
---------
c.

The following statement shows the results on such specimens as I could
procure. The disc was exactly 7/10ths of an inch in diameter.

TABLE NO. III.--TENACITY OF STARCH IN JELLIES.

No. Names of specimens. Weight in grains required
to break the jelly.
1. Tous les mois, C., C.L. 2,446*
2. Tous les mois, Grenada, Commercial 1,742
3. Maize, C., C.L. 955
4. Barbados yam, C., C.L. 895
5. Irish potato, from Belfast, C.L. 756
6. Tannia, C., C.L. 630
7. Bermuda arrowroot, finest Commercial 627
8. Common yam, C., C.L. 657
9. Guinea yam, C., C.L. 571
10. Plantain, C., C.L. 467
11. Potato starch, Commercial 467
12. Arrowroot, C., C.L. 393
13. Sweet potato, C., C.L. 368
14. Arrowroot, C., C.L. 340
15. Arrowroot, C. 301
16. Arrowroot, St. Vincent's, Commercial 289
17. Barbados arrowroot, Commercial 273
18. Wheat starch, Commercial 183
19. Buck yam, C., C.L. 151
20. Bitter cassava, C., C.L. 150
21. Sweet cassava, C., C.L. 78

[* In this instance the weight stated detached the jelly from the side
of the glass, but the skin of the jelly was not torn as in the other
cases.]

From this list it is obvious that, in respect of tenacity, there is a
very great difference between the jellies prepared from the different
starches--greater, indeed, than exists in regard to any other
character. At first I thought it probable that the tenacity of the
jelly would bear some relation to the size of the globules, and it is
true that we find the Grenada Tous les mois, the largest globule, next
the top, and the cassava among the smallest, at the bottom of the
scale. But, on the other hand, we have the Buck yam starch, a large
sized globule, very high; together with many other exceptions.

As an article of diet, the most tenacious varieties of starch are
preferred, on account of the economy of employing an article of which
a less quantity will suffice; and the same is true when applied to
starching linen, provided the jelly be not deficient in clearness.

_Clearness of jellies_.--When starch jelly is used for the purpose of
starching, or glazing linen, or cotton goods, those varieties that are
most transparent are understood to be preferred, provided, at the same
time, they possess the requisite tenacity. This and other matters
will be best determined by practical men in England; but having had
occasion many times to prepare specimens for trying the tenacity, the
opportunity was always taken of arranging the specimen of jellies in
the order of their clearness, or, to speak more accurately, of their
translucency. In this respect also they exhibit considerable
differences, varying, when prepared according to the formula described
under the head of tenacity, from very translucent approaching to
opaque. The order is shown in the annexed list, which begins with the
clearest.

TABLE NO. IV.--SHOWING THE ORDER OF CLEARNESS OR TRANSLUCENCY OF
UNIFORMLY PREPARED STARCH JELLIES.

Order. Names of specimens.
1. St. Vincent Arrowroot, Commercial
2. Arrowroot, C., C.L.
3. Sweet cassava, C., C.L.
4. Bitter cassava, C., C.L.
5. Bermuda arrowroot, Coml.
6. Arrowroot, C., C.L.
7. Irish potato, C.L.
8. Potato starch, Coml.
9. Buck yam, C., C.L.
10. Arrowroot, C.
11. Plantain, C., C.L.
12. Tannia, C., C.L.
13. Sweet potato, C., C.L.
14. Common yam, C., C.L.
15. Tous les mois, Grenada, Cml.
16. Barbados arrowroot, Coml.
17. Tous les mois, C., C.L.
18. Barbados yam, C., C.L.
19. Guinea yam, C., C.L.
20. Wheat starch, Coml.
21. Maize, C., C.L.

On comparing this list with the former one, and taking a general view
of the subject, it will be seen that the jellies that are most
tenacious are generally the least translucent, and that the order of
the two lists is more nearly the converse than occurs in regard to any
other properties.

_Percentage of starch yielded by different plants_.--On this point no
two writers do or can agree. The quantity of starch, even in the same
plants, the potato for instance, varies with the season, the soil,
climate, age, ripeness, length of time the roots have been out of the
ground, &c.

In the following table I have given the result of a series of trials
made in the Colonial Laboratory, Demerara. The roots were all fresh
dug, and, with two exceptions, noticed in the remarks, were fair
average specimens. The process was the common one. The grater or
rasping machine was of copper, to avoid injuring the color of some of
the starches, which an iron grater is liable to do:--

TABLE NO. V.--PERCENTAGE OF STARCH YIELDED BY DIFFERENT PLANTS.

No. Names of plants. Percentage of starch.

1. Sweet cassava 26.92
2. Bitter cassava 24.84
3. Another sample 20.26
4. A third 16.02
5. Common yam 24.47
6. Arrowroot (roots scarcely ripe) 21.43
7. Another sample 17.28
8. Barbados yam 18.75
9. Tannia 17.05
10. Another sample 15.35
11. Guinea yam 17.03
12. Plantain 16.99
13. Sweet potato 16.31
14. Buck yam 16.07
15. Another sample 15.63
16. A third, from a dark colored variety 14.83

From the foregoing list it appears that the sweet and bitter cassava
merit attention as starch-producing plants. They are occasionally
grown for this purpose in the colonies, and yield a large per centage
of starch; but there exists an opinion, whether well or ill founded,
that it is liable to rot linen, and the preference is given here to
the starch of arrowroot. It remains to be seen, however, what estimate
will be formed of this starch in England, for if it should prove an
esteemed variety, there can be no doubt of its proving a highly
profitable cultivation. Cassava grows readily in almost any soil, and
when the drainage is tolerable, two crops of the sweet variety can, it
is stated be grown in a year. I have seen it growing luxuriantly in
the light soils of the interior, as well as in the stiff clay soils of
the coasts. It is considered an excellent preparatory crop in new and
stiff land, on account of its tendency to loosen the soil. Were the
bitter variety fixed on, the preparation of _Casareep_ might be
combined with the preparation of starch; and as that substance is one
of the most esteemed bases for the preparation of various sauces, it
is probable that this might turn out the most profitable part of the
produce. At all events, bitter cassava would have this advantage over
all other starch-producing roots, that the juice of the roots could be
turned, to account as well as the starch.

Of all the plants mentioned in the list, starch is most readily
separated from the arrowroot, in consequence of the tissue being more
fibrous, and yielding little or no cellular tissue requiring to be run
off the starch. Time and water are thus saved in the process, and were
the fibrous residue pressed and dried, it could probably be turned to
good account in the manufacture of paper.

In respect of facility of preparation, the plantain starch, though of
excellent quality, ranks lowest, for the flesh-colored tissue in which
the starch is embedded is somewhat denser than the starch, and settles
down under it, and it is not a little difficult to arrange the process
so as completely to separate the finer parts of this matter from the
starch, and hence its color is never perfectly white.

_Yield of starch-producing plants per acre_.--On this subject, as
already remarked, I do not at present possess sufficiently accurate
data.

In England ten tons of potatoes are not unfrequently produced per
acre; now assuming 15 the per centage of starch, there would be a
yield of one-and-a-half tons per acre, which, at the-lowest quotation,
28s. a cwt., would give L42 per acre; and were the starch to rank with
that prepared from wheat, it would produce L40 per ton, or L60 per
acre. In the thorough drained land of Demerara, and under a good
system of cultivation, I have no doubt that ten tons of cassava could
easily be grown, and if it yielded 25 per cent. of starch, it would be
a return of 21/2 tons, or of L62 10s. per acre, reckoned at the price of
potato starch.

Of the yield of the plantain we possess much more accurate
information. A new plantain walk in this colony (British Guiana) will
yield 450 bunches, of 50 lbs. each, of which, as nearly as possible,
50 per cent. will be of core, containing 17 per cent. of starch, thus
producing 17 cwt. of starch per acre. But an old plantain walk, even
when free from disease, could not be reckoned to yield more than half
this quantity, namely, 81/2 cwt. per acre. Considering the value that is
set on the plantain as an article of food, and the difficulties
incident to the process of making starch from it, it is by no means
probable that it will ever be used as a source from which to obtain
starch.

Of the quantity of arrowroot that can be grown per acre, I have been
able (continues Dr. Shier) to procure no information; but from the
price it commands in the market, the facility with which it can be
grown, and the ease with which the process of separating the starch
can be carried on, it deserves a fair trial here. To cultivate it to
advantage it ought to be done on thorough-drained and well-tilled
land, planted at the proper season, and not dug till ripe and in dry
weather.

Of the Tous les mois, I have only been able to procure a single plant,
for which I am indebted to the kindness of the Hon. John Croal. As the
root was immature, it would be unfair to deduce from the quantity of
starch obtained, the per centage generally contained by the plant. Its
immaturity was also indicated by the globules being smaller than in
the specimen obtained from Grenada; in other respects, however, such
as the tenacity of its jelly, it stands highest. It is altogether one
of the most promising starch-producing plants, and obviously deserves
a careful trial. It is a plant that expends a good deal of matter in
maturing a considerable quantity of dense and bulky seeds, but as it
propagates both by root and seed, it is probable that, as a root-crop,
it would be highly advantageous to procure a variety that does not
flower.

Both the tannia and the sweet potato can be readily grown, and the
produce per acre is large; but from the foregoing tables it would
appear that there are other plants whose starch is likely to be held
in greater estimation.

_Difficulties attendant on the process of preparing starch_.--Were the
manufacture of superior starch to be carried out in this colony
(British Guiana) on a large scale and profitably, recourse would
require to be had to all the well-known means of economising labor. In
the cultivation as much as possible would require to be done by cattle
and implement labor, and this would be the easier to accomplish,
inasmuch as, to grow roots to great advantage, the land would require
to be thorough drained. When the produce was brought to the buildings,
machinery similar to what is already in use in Europe, for the
purpose of washing and rasping roots, and of separating and washing
starch, would suffice with comparatively little manual labor. An
ordinary amount of judgment being exercised in determining the proper
period of ripeness of the roots, and in selecting seasons when the
weather is usually most suitable for conducting the process of
manufacture, it does not appear that any unusual difficulty would have
to be encountered by growers or manufacturers, unless as regards the
obtaining of a sufficient supply of good water; for that is essential
to the production of good starch.

The creek water of the colony is generally too brown, and the trench
water too muddy, and contains often too much salt to produce starches
of the finest color, hence recourse would require to be had to rain
water, or Artesian water. The first is remarkably pure, and it
certainly does not appear that were sufficiently capacious reservoirs
built, or ponds dug, and protected from infiltration by the usual
well-known means, there would be great difficulty in getting a
sufficient supply of rain water. It is done in Bermuda, and why not
here? On the other hand, almost all the Artesian wells in the colony
contain a large quantity of oxide of iron held in solution by carbonic
acid, and which separates as an ochrey deposit on free exposure to the
air. Were this water used in the starch process, it would certainly
injure the color materially; but by a chemical process, exceedingly
simple, inexpensive, and easy of application, it is possible to purify
the Artesian water, and render it almost as fit as rain water for the
purpose of manufacturing starch.

In some of the other colonies a great deal of the best starch is
produced by the holders of small lots of land, and many parts of the
labor being light, and suited for women and children, it is one of the
most desirable cultivations for small holders, and would be very
beneficial for Demerara, where the lands of the peasantry too
generally lie in a state of utter neglect; yet small holders could not
be expected to be able to compete with those who should grow starch on
the large scale, and prepare it with the best machinery.

_Cassava meal, plantain meal, &c., as articles of export_.--It may
soon become an important question whether the plantain, or some of the
edible roots grown in the tropics, might not be sent to Europe in a
fresh state as a substitute for the potato. Many of them, the buck yam
and the cassava, for instance, ought to be used when fresh dug, for
every day they are out of the ground they deteriorate. This, however,
is not so much the case with some of the larger yams. It is worth
trying whether the finer sorts that deteriorate by keeping, might not,
after being sliced and dried in the sun, become articles of export,
either in that state or when ground to meal. For this purpose the
bitter cassava, the plantain, and the buck yam are the most promising.

Of the bitter cassava mention has already been made as a substance
from which the starch and _casareep_ might be prepared. In this case,
however, the woody and cellular tissue, with the small quantity of
starch left in it by the ordinary starch process, would form far too
poor an article of diet to constitute part of the food of man. But the
roots might be used as a medium from which to prepare cassava meal,
_casareep_, and the very small quantity of starch which is expressed
along with the juice, leaving all the rest of the starch to form part
of the meal. It is of such meal that the cassava cakes of the Indians
are prepared; and although by no means so nutritive as Indian corn
meal[46], there can be little doubt that in the Scotch and Irish
markets the cassava meal would obtain a preference; and were it
exported in quantity it would probably come into extensive use among
all classes.

The process would be as follows:--After washing in a revolving
apparatus, by which means the adherent earth would be got quit of, and
almost the whole of the thin dark colored cuticle become detached, the
roots could be reduced to pulp in a rasping-mill, without the use of
water; the pulp might be compressed in bags by hydraulic pressure,
whereby the juice, together with a small portion of the starch, would
be expressed. After allowing the starch to subside, the juice should
be concentrated to about the density of 1.4. The starch would be
washed, purified, and dried. The contents of the bags would then be
broken up and dried in the sun or in a current of air, after which the
meal would be sifted through a coarse sieve to separate the coarser
parts, which, if their amount was considerable, could be ground and
added to the rest. In this state of rough meal it is fit for making
the cassava cakes. If ground to flour it might be used to mix with
wheat, rye, or barley flour.

The process is usually conducted as follows:--The squeezed pulp is
broken up, sifted, and exposed to the sun on trays or mats till it is
fully more than half dry. An iron hoop of the size and thickness of
the cake to be made is then laid on a griddle or hot plate, and the
space within the hoop is filled evenly with the somewhat moist meal,
no previous kneading or rolling having been employed. As soon as the
coarse meal coheres, the ring is lifted and the cake is turned and
heated on the opposite side. The heat should not be sufficient to
brown the cake. The cakes are finally dried by exposure to the sun.
From the dry cassava meal cakes may be prepared by sprinkling it with
as much cold water as to moisten it to the proper point, and then
proceeding as above. Hot water cannot be employed, neither can
kneading, or any considerable degree of compression be used, otherwise
the water does not evaporate readily enough; the starch gets too much
altered by the heat, and the cake becomes tough.

If an acre of well-tilled thorough-drained land yield 10 tons of fresh
roots, and I have every reason to believe that such a return might be
obtained, I have ascertained that the produce would be 31/2 tons of
meal, 598 lbs. of _casareep_, and 2 cwt. of starch; and estimating the
meal at 1d. per lb., the _casareep_ at 1s. 5d. per lb., and the starch
at 40s. per cwt., the gross amount would be L78 13s. 4d. per acre. In
ascertaining these proportions, very simple machinery was employed,
and had the pulp been better pressed the quantity of _casareep_ would
have been considerably greater.

From the table given in a former note it will be seen that the cassava
meal prepared in this way contains but a very small proportion of
matter nutritive in the sense of contributing to the formation of
blood, and that the expressed juice carries off fully one-half of the
proteine compounds contained in the plant.

Lichenin is a variety of starch occurring in _Cetraria islandica_, or
Iceland moss.

_Indian corn starch_.--The advance of science has recently brought to
our knowledge the preparation and use of another article, not only
important as food, but also essential in the arts. I have had occasion
to mention the high value of the Indian corn, and I might with
advantage allude to many of its uses and properties; at present I must
confine my remarks to a product from this valuable grain, known as
corn starch, and yet another as the fecula of maize. In the close of
1849, Mr. Willard and his associates, of Auburn, established extensive
works at Oswego, for the preparation of these important products,
their establishment covering an area of 49,000 square feet. As the
proprietors have to some extent held unrevealed the process by which
they produce a starch more pure than the starch of commerce, we may
not indulge in speculative curiosity; yet I can hardly doubt their
great success is mainly attributable to perfect machinery, guided by
science and talent. The rapid and extended demand for these new
products presents sufficient evidence of their character, as we are
told that about three millions of pounds of this corn starch are
demanded annually by the trade, notwithstanding the usual supply of
wheat starch is undiminished. A remarkable feature of maize starch is
the absence of impurities; upon being subjected to analysis, it is
found that only 2 76-100 parts in 1000 are of other matter than pure
starch. According to Dr. Ure, wheat yields only 35 to 40 per cent, of
good starch, a material extensively used in arts and manufactures.

In addition to starch, the Oswego starch-factory produces from Indian
corn a fecula, peculiarly adapted to culinary purposes, presenting to
our domestic economy one of the most acceptable, pure, and nutritious
articles of food. Already has it become an indispensable household
article, and is consumed largely at home and abroad. The factory,
though in its infancy, consumes annually 150,000 bushels of corn,
equal to about nine millions of pounds in weight. Hitherto the
quantities of starch used for laundry purposes and in the
manufactories of America, have been produced from costly wheats,
though it may be found in many vegetable substances, such as potatoes,
the horse chesnut and other seeds. In England, where breadstuffs,
particularly wheat, have been raised in quantities inadequate to the
demand for food, attempts have been made to convert the viscid matter
of lichens into a gum, for the use of calico printers, paper-makers,
and ink makers; for the stiffening of silks, crapes, and the endless
variety of dry goods, which, by means of these gums or starch, are
made to appear of greater consistency. Most of these attempts had
partial success, yet the making of starch from wheat has not been
arrested.

The Oswego starch factory has happily introduced the use of Indian
corn, as a grain producing a larger proportion of pure amylaceous
properties than any other known vegetable substance, proffering to the
American manufacturer another economic advantage, sustaining, in a
most legitimate matter, sound rivalry and competition with all the
world. I am not aware whether the Oswego factory has converted its
starch into gum--a process easily accomplished by heat, and thus
rendered soluble in cold water, which cannot be done while in its
condition of starch. Here is another result of vast importance
derivable from Indian corn; and we can well conceive that, in a short
period of time, the advantages now derived from the production of corn
starch, may have grown into a national benefit.