T H E JOURLVAL O F I N D U S T R I A L - 4 S D EAVGIAVEERI*VGC H E M I S T R Y
310
ANALYSES SHOWING THE COMPOSITION OF THE DIFFERENT GRADES OF COMMERCIAL PACK PEAS B y JOHN C. DICGS Received November 19, 1913
T‘ol. 6 , NO. 4
I n undertaking this work, eleven samples of canned peas were obtained from a local packing concern, t e n of these representing three brands a n d several grades of each brand a n d t h e eleventh being a sample of so-called “soaked peas.”
Knowledge t h a t t h e maturity of t h e pea is a n important factor in its composition led t o a n investigation of t h e different grades of canned peas p u t o u t by a n Indiana packing concern. Work on peas has been conducted chiefly b y chemists who obtained their samples from t h e open market. The non-uniformity of methods used in grading a n d packing seriously interfered with a n y careful work in determining t h e exact effect of size a n d age upon the composition of t h e pea. D a t a at h a n d give information regarding t h e composition as t o t h e size of t h e canned pea: none, however, are available showing changes in composition t h a t m a y result with t h e maturing of t h e pea; A noticeable fact shown by t h e work of chemists is t h e u t t e r unreliability of t h e label as a guide t o t h e composition of t h e product. This work may, in a measure, assist in t h e establishment of standards of composition for each of t h e grades of canned peas. T h e work of McElroy a n d Bigelow of some twenty years ago gives us1 some analyses made of a large number of samples, of both American a n d foreign origin. No information is given as t o system of grading as t o maturity-if a n y system did exist. Dubois2 in 1910 made t h e analyses of more t h a n one hundred samples of canned peas. He draws conclusions regarding composition as t o size b u t has no d a t a for determining t h e effect of age upon composition. Street,3 t h e same year, published results of one hundred a n d eleven samples b u t , without t h e history of t h e samples a n d method used in grading a n d sizing, based all tabulations on label statements. Different systems of sizing a n d grading employed in various plants a n d t h e overlapping of one grade into t h e next t e n d t o reduce t h e results of different grades t o a n average rather t h a n differentiate between them. Since t h e samples were raised in different p a r t s of t h e country, t h e m a t t e r of soil, rainfall a n d climate would be interfering factors. Consequently, i t was thought t h a t if t h e common analytical factors were determined on t h e product p u t o u t b y a’single plant where uniform methods were used in sizing a n d grading, where t h e same variety of peas were packed, a n d one system used in packing a n d processing, there might prove t o be a definite relation between t h e composition a n d t h e grade of t h e pea. While i t has been shownZ t h a t t h e ratios existing between t h e organic plant constituents are differe n t for different sizes of peas, no literature has been published showing t h e relations existing among t h e various inorganic plant factors for these samples. I n view of this fact analyses were made showing t h e calcium, magnesium a n d phosphoric acid content of each grade of pea. A table has been calculated showing t o some degree t h e composition of t h e ash of each grade.
T h e peas used in this pack were grown in central Indiana within a radius of t e n miles of t h e packing plant. T h e soil in this section is uniform, consequently t h a t factor does not influence a n y particular grade. T h e season of packing usually extends from June 10th t o July I j t h . T h e peas are mowed, loaded on wagons a n d hauled t o t h e vining a n d thrashing machines. The hulled peas are passed through a squirrel cage washer into a grading t a n k of dilute brine (sp. gr. 1.07). T h e younger peas float in this solution a n d are removed b y a n elevator t o a bin for subsequent grading as t o size. This quality of pea is used for t h e Polk’s Best Brand. T h e peas which have sunk t o t h e bottom are carried by a n elevator into a stong brine grading t a n k (sp. gr. 1.11). This brings about another grading, some floating a n d some going t o t h e bottom. Those floating are made into t h e Greenwood Brand; those sinking, t h e harder a n d t h e more mature peas, into t h e M a y Day. E a c h of these three classes of peas is made up of large a n d small sizes. It is desirable t h a t t h e peas of a can be of uniform size. I n factory practice each class is separated into five sizes. Beginning with t h e largest a n d going t o t h e smallest, t h e names assigned t o these five sizes are Marrow F a t , Early June, Sifted June, E x t r a Sifted June a n d Petit Pois. These t r a d e names apply only t o t h e size of t h e pea a n d have nothing t o d o with t h e season of packing, T h e grading is accomplished b y means of perforated cylinders through which t h e peas pass. After proper sizing t h e peas are blanched. T h e blancher is a continuous washer in which t h e peas are held in hot water for a certain period. I n blanching t w o results are accomplished: ( I ) T h e outside mucous coat is removed from t h e pea a n d with i t some of t h e green coloring m a t t e r so t h a t t h e liquor of t h e can m a y be clear; ( 2 ) a n d t o force water into t h e pea so t h a t it m a y be tender, T h e time for blanching depends entirely upon t h e maturity of t h e pea. Blanching is not done “ b y rule of t h u m b ’ ’ b u t by competent workmen who very carefully determine when t h e peas have taken up t h e right amount of water, when the right amount of color has been removed, etc. I n general t h e time varies from two t o five minutes. F r o m t h e blanchers t h e peas go t o t h e filling machines. These p u t a certain weight of peas, varying according t o size a n d quality into t h e can a n d a d d t h e liquor, a salt sugar solution ( 2 4 pounds of salt a n d 24 pounds of sugar t o joo gallons water) sufficient t o fill t h e can. T h e lid is p u t on, sealed a n d t h e cans sent t o t h e retorts for processing where t h e y are heated a t 240’ Fahrenheit for 30 minutes.
U. S. Department of Agriculture, Bureau of Chemistry, Circ. 54. U. S. Department of Agriculture, Bureau of Chemistry, Bull. 13. a Conn. Agr. Exp. Station Report, 1910. U. S.Dept. of Agriculture, B u r . of Chemistry, Bull. 137.
T h e contents of each c a n were poured upon a sieve of l/g inch wire mesh a n d allowed t o drain for one min-
1
2
THE PACKING PROCESS
PHYSICAL E X A X I N A T I O N
T H E J O C R S I L O F I S D 1 7 S T R I A L An’D E N G I N E B R I S G C H E M I S T R Y
Apr., 1914
ute. T h e greatest total weight (Table I ) was 612 grams in t h e sample of “Soaked Peas.” T h e maximum t o t a l of t h e fresh peas was j g 8 grams a n d t h e minim u m 581 grams. T h e maximum weight of drained peas mas 4 2 1 grams. This sample, 7247 B, undoubtedly h a d a n excess of peas as would be indicated by t h e condition of t h e sample, “ P e a s all broken,” “Liquor very turbid.” T h e minimum of drained peas mas 3 2 2 grams. This can h a d a n excess of liquor. As a rule t h e small grades of peas TTere accompanied b y t h e larger per cent of liquor.
a number of samples might be run simultaneously. However, t h e samples assumed a dark color upon drying, especially those in which t h e starch content was low. T h e dried substance proved t o be hygroscopic a n d caused trouble in weighing. All of this would indicate t h a t when time permitted. i t would he advisable t o determine t h e liquors without drying n hich, of course, means t h a t t h e sample must t o a certain extent, be handled individually. I n many cases on account of t h e small amount of liquor obtained. it mas impossible t o make all of t h e desired determina-
TABLEI-PHYSICALEXAMIXATIOX OF CASNEDPEAS Peas and liquor
Label on can Sample 7246 B 7247 B 7248 B 7252 B 7253 B 7254 B 7249 B 7250 B 7251 B 7255 B 7256 B
Brand May Day May Day May Day Greenw.ood Greenwood Greenwood Polk’s Best Polk’s Best Polk’s Best Polk’s Best Everybody’s
Appearance of contents
Grade Marrow F a t Early June Sifted June Early June Sifted June Extra Sifted June Early June Sifted June E x t r a sifted June Petit-Pois Soaked Peas
Peas Peas all broken Peas all broken Slightly sprouted a n d broken Large and broken Small a n d slightly broken S e a r l y all slightly broken Slightly sprouted and broken Slightly sprouted and broken Small-not much broken Peas small-badly broken Large and all broken
T h e appearance of t h e drained peas a n d liquor was quite variable. We would have expected t h e smaller a n d better grades of peas t o have been less broken since t h e y required less blanching. This, however, was not always t h e case. T h e liquor of t h e more mature peas showed a greater tendency t o be turbid, d u e t o t h e longer time required for blanching a n d t h e greater tendency of these peas t o swell a n d burst. TABLE II-PERCENT.4GE Original basis
COJIPOSITION 7
Y; N
0
x
7
OF
CANNED P E A S Water-free basis
-
-
Liquor Liquor very turbid Liquor very turbid Turbid Somewhat turbid Somewhat turbid Slightly turbid Somewhat turbid Somewhat turbid Nearly clear Nearly clear Liquor muddy
d
c
x
z
-->--
R
___A___
Drained Total pea S 581 388. 5 594 42 1 590 322 598 370 596 386 598 379 598 39 1 5 86 370 595 360 594 35 1 61 408
----
Gravity
Drained 5% Liquor peas Liquor 192.5 6 6 . 9 33.1 70.9 29.1 173 268 54.6 45.4 228 61.9 38 I 210 64.8 35.2 219 63.3 36.7 207 65.4 34.6 63.0 37.0 216 235 60.5 39.5 243 59.1 40.9 204 66.i 33.3
Peas
Liquor I ,033
1 ,065 1.173
1.028
1.106 1.099 1 .O90 1.063 1.112 1.072
1.0135 1.025 I.02ii 1 ,0244 1.026 1.0178 1.0218 I ,0208 1 ,034
... 1.075 1.120
tions a n d t o check some inconsistent results. I n general, t h e methods of analysis used were those of Bull. 107, Bureau of Chemistry. I n order t o run a number of samples simultaneously, i t was necessary t o d r y a large quantity of t h e drained peas a n d pulverize t h e d r y sample until all would pass through a forty mesh sieve. F r o m this dried material t h e samples for subsequent determinations were weighed o u t . TABLE111-PERCENTAGE COMPOSITIONOF PEALIQUOR Original basis
Water-free basis 7
b
2
t.N 7
f
Contents in grams
Y)
0
f
-
N
e
X
z
2
d X
z
2 0
Y
s
d
; I C 7246B78.52 7247 B 8 0 . 7 7 7248B84.55 7252B82.29 7253 B 8 2 . 9 0 7254 B 85.92 7249 B 8 1 . 6 5 7250B86.32 7251B88.06 7255 B 89.61 7256B78.96
4 . 5 6 11.94 1 . 1 5 4 . 6 4 8.22 1 . 1 3 3.31 8.11 0.71 3.79 8.05 . . .. 6.50 . . 2 . 9 6 5.16 . . 4 . 5 5 9 . 1 8 1.97 3.09 6.09 1.46 2.85 3.30 . . 2.34 2.73 . . 3.95 9.87 1 . 3 2
0 . 4 0 0 . 1 6 7 21.23 5 5 . 8 5 . 3 5 1 . 8 6 0.777 0.60 0,145 24.1 42.6 5.87 3.12 0.754 0 . 4 0 0 . 1 0 6 2 1 . 4 5 2 . 5 4 . 5 9 2 . 5 9 0.686 . . . . . 27.8 51.0 . . . . . . . . . . . . . . . . 38.0 . . . . . . . . . . . . . 21 . O 3 6 . 6 . . . . P . . 0 . 5 3 0 . 1 3 1 2 4 . 8 5 0 . 0 1 0 . 6 8 2 . 3 4 0.713 0 . 3 4 0 . 1 1 8 2 2 . 7 41.5 1 0 . 6 6 2 . 4 8 0.862 . . . . . 2 3 . 9 27.6 . . . . . . . . . . . . . 2 2 . 5 26.2 . . . . . . . . 0 . 7 3 0 , 1 6 5 18.7 4 7 . 0 6 . 2 7 3 . 4 7 0 . 7 8 4
I n a general way t h e gravity of t h e drained peas was practically t h e same as t h a t of t h e fresh peas used in each brand. Samples 7 2 5 4 B a n d 7246 B were exceptions t o this rule. T h e gravity of t h e liquors was practically t h e same for all, t h e samples 7248 B a n d 7 2 j o B having t h e minimum gravity. T h e salt a n d sugar content of these samples help explain this discrepancy. PE R C E NTA G E C 0 DIP 0 S I T 1 0 S
T h e chemical analyses mere made on t h e liquor a n d drained peas independently. Considerable difficulty was encountered in working on t h e liquor. Owing t o t h e fact t h a t i t would quickly ferment, i t was necessary t o evaporate i t t o dryness in order t h a t
7246B92.9 7247 B 9 3 . 2 3 7248 B 9 6 . 5 4 7252B94.62 7253 B 93.87 7254B94.66 7249 B 9 3 . 6 1 7250B95.42 7251B95.22 7255B95.02 7 2 5 6 B 9 1 80
2.11 1.68 1.98 1.10 1.06 0.77 1.51 . .
. .
1.37 2.06 1.38 1.53 1.41 170
1.95 1.33 0.i6 0.46 . . 0.56 . . 0.16 3 . 1 1 1.85 1.52 0.58 . . 0.04 . . 0.11 1 7 185
7.8 0 . 5 5 0.086 29.78 23.7 2 7 . 5 0 . 7 9 0 . 0 8 0 29.21 16.33 1 9 . 5 8 1 . 6 1 0 . 5 4 0 . 0 4 8 30.65 2 2 . 2 7 21.89 5 . 6 8 . . . . . 25.83 . . . 7.89 . . . . . . . . . . . . . . 9.06 . . . . . . . . 25.59 . . . 3.00 . . . 0 . 7 8 0 . 0 7 3 3 2 . 2 2 48.66 2 8 . 9 3 2 . 1 7 0 . 5 4 0 . 0 7 1 30.07 3 3 . 1 5 12.72 1 . 7 1 . . . . . 32.38 . . . 0.93 . . . . . . . . 28.27 . . . 2.35 . . . 0 93 0 123 20 7 1 20 7 22 6 11 3
1.22 1.19 1.39
. . . .
. .
1.15 1.55
. . . . 151
Tables 111 a n d I Y X a n d B have been prepared showing t h e percentage composition of t h e drained peas a n d liquors on both t h e original a n d water-free basis. T h e composition on a water basis in a measure eliminates t h e abnormal figures t h a t m a y result from varying amounts of liquor added. Table I1 has been calculated on t h e basis of t h e peas a n d liquor as t h e y occur in t h e can. This table has also been reduced t o a water-free basis. T h e composition of t h e different samples varies quite as much as do t h e analyses made b y Street a n d Dubois. However, all determinations come within t h e limits found b y these authors. According t o t h e information given a t t h e factory
T H E JOCRYdL OF I-VDCSTRIAL A S D E Y G I S E E R I S G CHEMISTRY
312
plained b y Table I which shows all of these liquors t o be “ v e r y turbid.” T h e peas have been overblanched or over-processed a n d have burst, allowing t h e solids including starch a n d insoluble proteid t o become mixed with t h e liquor. It is also interesting t o note t h a t t h e gravities of these solutions have been increased t o t h e highest of t h e table. T h e other factors of these tables v a r y so greatly t h a t no fair conclusion can be drawn. Table V shows t h e average composition according t o t h e m a t u r i t y of t h e pea. T h e Polk’s Best Brand was made from t h e tender a n d more succulent peas -peas which have a gravity of less t h a n 1.07, t h e Greenwood was made from t h e fresh pea harder t h a n t h e Polk’s Best Brand a n d having a gravity between 1.07 a n d 1.11, a n d t h e M a y D a y from peas which sank in a 1.11 gravity brine. B y means of this table (dried peas, original basis) we see t h e water decreases
t h e salt sugar solution used in all grades was 2 4 pounds sugar a n d 2 4 pounds salt t o j o o gallons of 1%-ater. This would mean t h a t t h e liquor contained o . j i per cent each of salt a n d sugar. This figure is h a r d t o reconcile with t h e percentage of salt a n d sugar found in t h e pea liquor a n d canned peas. T h e maximum percentage of salt found in t h e liquor xyas 0.59 per cent in Sample 7247 B. T h e drained peas t a k e n from t h e same can showed 0.j z per cent of salt, a figure by no means t h e highest in this table. T h e samples of liquor having t h e minimum salt content were 7248 B a n d 7 2 j o B, each of which h a d 0 . j 3 per cent. T h e drained peas from these cans h a d 0.32 per cent a n d 0.23 per cent, respectively, these figures being t h e smallest in t h e table. This would indicate a difference in t h e strength of t h e salt solutions used. This assists in explaining t h e low gravity of t h e liquor of these samples. TABLEIva-PERCEXTAGE Sample 7246 B . . . . . . . . , 7247 B . .. . . , , . 7248 B . . . . . . . . . 7252 B.,. . . . . . , 7253 B . . . . . . . . . 7254 B . , . . . , . , 7249 B . . . . . . . . . 7250 B . . , . . . , . , 7251 B... . . . . . . 7255 B . ,, . . , . , , 7256 B . . . . . , . , .
.
.
Water 71.4 i5.81 74.57 i4,69 76.94 80.85 75.32 80.96 83.35 85.85 72.85
Ether extract 0.56 0.38 0.49 0.49 0.47 0.53 0.50 0.50. 0.39 0.42 0.55
Crude fiber 1.77 1.74 2.06 1.98 1.62 1.74 2.00 1.99 1.92 1.54 1.90
Proteid NX6.25 5.92 5.74 5.19 5.21 5.10 3,89 5.88 4.10 3.73 3.16 5.09
COMIPOSITI O N Sugar 0.89 1.14 0.66 1.22 1.39 1.31 1.33 1.44 1.62 1.85 1.11
T h e highest sugar content of t h e liquor was in Sample 7249 B, being 3.11 per cent. T h e corresponding sample of drained peas h a d 1-33 per cent sugar, one of t h e highest of this table. T h e minimum sugar content was in l i q u o r s a m p l e 7248 B where i t was 0 . 7 7 per cent. T h e corresponding drained peas sample h a d 0.66 per cent, t h e minimum of t h a t table. Sample 7 2 4 8 B especially seems t o be deficient i n these added constituents. We have n o explanation of this save t h a t t h e liquor is probably not made u p according t o formula. It has been suggested t h a t selective absorption m a y play a p a r t in determining t h e location of t h e salt a n d sugar added. This, however, is a field for further study. TABLE IV~P-WATER-FREE BASIS N Lo
7 2 4 6 B 1 . 9 6 6 . 1 8 20.7 3 . 1 59.2 7 2 4 7 B 1 . 5 9 7 . 1 8 23.71 4 . 7 45.65 7 2 4 8 B 1 . 9 4 8 . 0 9 20.41 2 . 6 1 55.87 7 2 5 2 B 1 . 9 3 7 . 8 4 20.58 4 . 8 1 48.16 7253 B 2 . 0 3 8 . 0 3 22.11 6 . 0 1 4 2 . 1 4 7 2 5 4 B 2 . 7 7 9 . 0 8 20.33 6 . 8 3 42.07 7 2 4 9 B 2 . 0 7 8 . 0 9 2 3 . 8 3 5 . 3 5 52.91 7 2 5 0 B 2 . 6 4 10.43 21.54 7 . 5 4 4 6 . 5 2 7 2 5 1 B 2 . 3 2 11.55 22.41 9 . 6 8 32.’53 7255 B 2 . 9 4 10.91 22.36 13.10 32.24 7 2 5 6 B 2 . 0 3 6.92 18.51 4 . 0 2 50.85
1.16 2.19 1.29 2.55 2.82 4.86 1.66 1.20 3.22 4.13 2.40
3.65 4.55 3.34 5.02 5.48 6.85 3.94 3.54 5.75 6.69 4.79
2.49 2.36 2.05 2.47 2.66 2.09 2.28 2.34 2.53 2.56 2.39
0.17 0.22 0.35 0.21 0.26 0.32 0.19 0.25 0.29 0.21 0.21
0.134 0.142 0.198 0.157 0.093 0.203 0,223 0.178 0.188 0.223 0,157
0.i30 0.714 0.639 0.716 0.675 0.640 0.667 0.738 0.T8.2 0.854 0.756
Liquors 7 2 4 6 , 47, 49 a n d 56 have very high starch content. These same liquors have t h e highest proteid content of t h e table. This is in a measure ex-
Vol. 6 , No. 4
OF
DRAIXEDPEAS,
Crude starch 16.93 11.04 14.21 12.74 9.i2 8.06 13.06 8.86 5.42 4.56 13.98
ORIGINAL
Total ash 1.04 1.10 0.85 1.27 1.26 1.33 0.97 0.67 0.96 0.95 0.32
Salt 0.34 0.52 0.32 0.64 0.65 0.92 0.41 0.23 0.43 0.58 0.66
BASIS Salt-free ash 0.70 0.58 0.53 0.63 0.61 0.41 0.56 0.44 0.53 0.47 0.66
CaO 0.047 0 053 0.0i8 0.053 0.060 0.061 0,047 0,047 0,049 0.031 0.057
XlgO 0.038 0.033 0.049 0.038 0.021 0.040 0.054 0.035 0.032 0.036 0,037
P206
0.208 0.172 0.158 0.179 0.165 0.128 0.166 0.147 0.131 0.142 0.185
from 81.37 per cent in t h e Polk’s Best t o 73.92 per cent in t h e S l a y D a y , t h e oldest peas. On account of t h e varying factor of water content n o conclusion regarding other constituents from this table can be drawn. According t o t h e water-free basis calculations of t h e drained peas, t h e crude fiber decreased with t h e age of t h e pea, changing from 1 0 . 2 j per cent in t h e youngest t o 7.1 j per cent in t h e mature peas. This fact is borne o u t b y Street, who says: “ T h e crude fiber of t h e immature pea, in which t h e meaty portion h a d just begun t o develop, is usually higher t h a n i n t h e more mature.’” Protein decreases slightly, 22.3 I per cent t o +21.j4 per cent, as t h e pea becomes older. T h e crude starch increases from 4 1 . 0 j per cent t o j 3 . j 7 per cent. T h e figures for t h e sugar content of these brands call for a n explanation. Bitting2 gives t h e average sugar content of fresh peas as follows: Grade
Original basis
.
First, corresponds t o Polk’s B e s t . . 0.88 Second, corresponds t o Greenwood. 0 . 7 1 Third, corresponds to M a y Day.. . . 0.55
Water-free basis 4.51 3.26 2.16
These figures indicate t h a t t h e sugar which forms in t h e pea during t h e early stage of growth does n o t keep pace with t h e other constituents as t h e pea matures. It has been suggested t h a t t h e variation of sugar content of t h e drained peas was due t o t h e sugar content of t h e liquor.. Lit.
1
LOG.
2
U. S.Dept. of Agriculture, Bureau of Chemistry, Bull. 126.
T H E J O U R N A L OF I N D U S T R I A L A N D E N G I N E E R I N G CHEMISTRY TABLE Va-PERCENTAGE
Water Brand M a y D a y ....... 73.92 77.49 Greenwood.. 81.37 Polk’s Best.
Ether extract 0.47 0.49 0.45
May Day.. . . . . . . . . Greenwood, . . . . . . . . Polk’s Best. . . . . . . . .
1.83 2.34 2.00
....
.....
Crude fiber 1.85 1.78 1.86
7.15 8.31 10.25
Proteid N X 6.25 5.61 4.73 4.22
21.74 21.01 22.31
313
DRAINED PEAS BASED ON B R A N D ORIGINAL BASIS
C O M P O S I n O N OF
Crude
starch
Salt
14.06 10.17 7.97
0.39 0.74 0.41
Total ash 0.99 1.28 0.89
WATER-QREBBASIS 53.57 1.55 3.54 44.12 2.55 41.05
3.85 5.78 4.98
Sugar 0.89 1.31 1.56
3.14 5.55 8.92
Salt-free ash 0.60 0.55 0.47
.
2.30 2.41 2.43
CaO 0.059 0.058 0.043
MgO 0.040 0.033 0.039
0.179 0.157 0.146
0.25 0.27 0.23
0.158 0.151 0.203
0.694 0.677 0.761
P20r
T A B LVbPERCENTAGE ~ CoMPosInos OF CANNEDPEASBASED ON BRAND Original basis
Water free basis
r
Brand May Day... . . . . . . . . . . . . Greenwood . . . . . . . . . . . . . . . Polk’s Best. . . . . . . . . . . . . . .
Water 81.28 83.70 83.91
Proteid N X 6.25 4.17 3.37 3.27
Crude starch 9.42 6.60 5.35
Sugar 1.00
Salt 0.47
PzOj 0.139
1.71
0.43
0.125
..
..
There are t w o points t h a t lead us t o believe this is not t h e case. F i r s t , t h e liquor of t h e sample 7249 B is abnormally high in sugar, b u t t h e drained peas of this can show only a normal a m o u n t of sugar. Secondly t h e Polk’s Best B r a n d would before processing have the highest water content a n d would absorb a smaller a m o u n t of liquor upon processing. Therefore, unless selective absorption comes into play, t h e conditions cannot be laid t o the composition of t h e liquor. T h e question is one open for study. T h e salt-free ash is slightly higher in t h e youngest pea. Upon comparing t h e analysis of t h e sample of “Soaked P e a s ” with t h e above averages, it is found t h a t it agrees quite closely with t h e M a y Day grade. T h e reason for this is quite a p p a r e n t for as far as m a t u r i t y is concerned these grades lie very close together. Table VI shows t h e maximum salt-free ash content of 2.66 per cent a n d t h e minimum of z . o j per cent with a n average of 2 . 3 8 per cent. T h e alkalinity of t h e ash varies from 2 . j t o 2.1 cc. N / r o HC1 per gram TABLE VI-ASH
OF THE DRAINEDPEAS
Percentage composition of ash Sample
Salt-free ash Water-free basis
7246 B . . . . . . . 7247 B . . . . . . . 7248 B . . . . . . . 7252 B . . . . . . . 7253 B . . . . . . . 7254 B . . . . . . . 7249 B... . . . . 7250 B . . . . . . . 7251 B . . . . . . . 7255 B . . . . . . . 7256 B.. . . . . . Maximum.. . . Minimum. . . . Average., . , , , (a)Cc. “10
2.49 2.36 2.05 2.47 2.66 2.09 2.28 2.34 2.53 2.56 2.39 2.66 2.05 2.38
Alk. of ash ( a ) 2.1 2.4 2.3 2.2 2.2 2.2 2.3 2.5 2.5
..
2.4 2.5 2.1 2.3
Pros 29.3 30.1 31.1 29.0 25.3 30.5 29.2 31.5 31.0 33.4 31.6 33.4 25.3 30.2
CaO
MgO
5.7 9.4 17.1 8.5 9.9 15.4 8.5 10.7 11.6 8.1 8.8 17.1 5.7 10.0
5.4 5.9 9.6 6.3 4.0 8.7 9.8 7.5 7.3 8.6 6.5 9.8 4.0 7.2
HC1 per gram water-free sample.
d r y sample. T h e phosphoric acid remains fairly constant averaging 2 5 . 3 per cent of t h e total ash. T h e CaO varies from j . 7 per cent t o three times t h a t a m o u n t . T h e MgO ranges from 4.0 per cent t o 9.8 per cent of t h e total ash. There seems t o be n o relation between t h e ash or a n y o€ its constituents a n d t h e m a t u r i t y of t h e pea.
...
Proteid N X 6.25 22.2 24.4 23.49
Crude starch 50.3 41.87 36.32
Sugar 5.27
Salt 2.52
...
..
10.67
2.41
PlOl 0.739 .
I
.
0.787
SUM M A R Y
T h e investigation has shown t h a t in a pack of peas p u t u p b y a single concern where t h e conditions are as nearly uniform as i t is possible t o make t h e m in factory work, great variations of results in individual samples are found. A large number of samples are desirable for conclusive results. There is considerable variation in t h e proportion of liquor a n d peas in t h e different grades of t h e product. T h e composition of t h e liquor of the canned pea is largely determined b y t h e blanching a n d processing, a n d a s t h e more m a t u r e peas require a longer period, we may expect t o find this grade with turbid liquors of high starch a n d proteid content. T h e young i m m a t u r e dried peas contain 18 per cent more water t h a n t h e oldest grade. T h e crude fiber decreases from 1 0 . 2 j per cent t o 7.1 j per cent on t h e drained peas, water-free basis. T h e per cent of sugar seems t o decrease with maturity. T h e reason is not a p p a r e n t a n d should be a field for further study. T h e p a r t played b y selective absorption in determining t h e location of added constituents is one requiring further study. T h e change in ash is very slight. T h e composition of t h e ash seems t o remain t h e same throughout t h e growth of t h e pea. (Credit is due t o C. F. Coffin, Jr., for much of t h e analytical work reported in this paper.) LABORATORIES I N D I A N A STATE BOARDOF HEALTH
INDIANAPOLIS
______ ON THE VALUATION OF LIME-SULFUR AS AN INSECTICIDE B y HERMANV. TARTAR Received January 10, 1914
A t t h e present time, t h e object of t h e examinations made of samples of commercial lime-sulfur solution in different chemical laboratories throughout t h e country, is t o ascertain d a t a regarding composition. I n m a n y cases, simply t h e total lime content, total sulfur content a n d specific gravity are ascertained. Oftentimes, however, quantitative determinations are also made of t h e different forms of sulfur in combina-
