ANALYTICAL EDITION
March 15, 1942
show no variation for the corn harvested in prime condition. It is evident, therefore, that restandardization is not necessary from year to year. Check tests indicate that the figures given here are applicable to all similar sweet corn varieties. Table I1 indicates that the specific gravities as determined by means of the xylene-carbon tetrachloride mixture are somewhat higher than those determined by means of the water containing enough sodium chloride to give a specific gravity of 1.000. This is possibly caused by the fact that water adhering to the vegetable is weighed when it is immersed in the xylene-carbon tetrachloride mixture because of its failure to dissolve in this mixture. When the vegetable is weighed in the aqueous mixture, only the vegetable itself is weighed. The final result would be a slight error in both methods, and a different set of standards would have to be prepared for each method. The brine method is somewhat the better of the two because of its low cost, because it is easier to prepare, and because it is less likely to change in use, although it should be tested with the hydrometer from time to time to be sure the specific gravity is 1.000.
TABLE11. 1940 SERIES Specifio Gravity of Thawed Corn In xylene-CClr In brine 1.042a 1.063 1.053 1.048" 1.051 1.050~ 1.062 1.053" 1.058" 1.065 1,0590 1.065 1.062" 1.059 1,066' 1.074 1.066' 1.081 1,070" 1.076 1.071* 1.078 1.073" 1.05s 1.074' 1.084 1.076a 1,052 1 os9 1.080 1.098 1,084 1.085 1.096 1.103 1.086 1.087 1,087 1.094 1.088 1.093 1.089 1.081 1.098 1,101 1.092 1.101 1.096 1.096 1.102 1.097 1.101 1.097 1.102 1.111 1.097 1,101 1,098 1.101 1.09s 1.106 1.098 1.09s 1.106 1.098 1.109 1.098 1.111 1.099 1.103 1,099 1.105 1,009 1.106 1.100 1.097 1.100 1.102 1,101 1.105 1.101 1 110 1.102 1.100 1.102 1.10.5 1.110 1.102 1,102 1.111 1.104 1.103 1.106 1.112 1.106 1.114 1.107 1.110 1.107 1.114 1,110 1.108 1.116 1.10s 1.109 1.111 1,109 1.112 1.116 1.109 1.110 1.120 1.112 1.116 1.113 1.110 1.113 1.115 1.113 1.117 1.118 1.117 1.121b 1.128 1.122b 1.122 1,130b 1.134 1.147 1 149b 1.154 1,150b 1,151b 1.155 a Immature. b Overmature.
Organoleptic, Based on 100 58 45 46
55 57 48 53 56 57 66
55 69 59 60 73 69 62
so
74 77 85 77 71 70 75 77 77 77 77 68 80 80 74 91 70 68 82 79 75 76 86 89 72 71 74 70 87 82 78 71 88 79 82 92 84 89 89 SO
80
SO
77 64 64 63 34 39 35
TABLE111.
241
COEFFICIENTS O F CORREL.4TION
FOR
SPECIFIC
GRAVITY OF THAWED COR?;
Correlation between: Xylene-carbon tetrachloride method a n d organoleptic tests (1939) Brine method and organoleptic testa (1940) Xylene-carbon tetrachloride method a n d organoleptic tests (1940)
Coe5cient
t0.8456
* 0.0221 * 0.0246
4-0.8408
0.0253
-0.8592
The following tentative standards are suggested, based upon the results using the brine solution for the determination of the specific gravity: Fancy Reject, immature Reject, overmature
1.080 to 1.118 1.079and lower 1,119and higher
These standards can be revised if and when other grades are generally packed.
Acknowledgment The authors wish to thank the Frosted Foods Sales Corporation, New York, N. y., for financial assistance, and the Snider Packing Corporation, Rochester, N. Y., for making available facilit'es a t one of its plants for this work. They also wish to thank the group of tasters connected with this corporation for running the organoleptic tests for the 1939 set of samples, and to thank L. S. Fenn of the Agricultural Marketing Service, United States Department of Agriculture, and his associates for running the organoleptic tests for the 1940 set of samples.
Literature Cited (1) Behrend, P., Maeroker, M., and Morgen, A., Landw. Vets.-Stat., 25, 107 (1880). (2) Boggs, Mildred, Western Canner and Packer, 32, No.2, 47 (1940). (3) Lee, F. A , , IND.ENG.CHEM.,ANAL.ED., 13, 38 (1941). (4) U.S. Dept. of Agr., Bur. Agr. Econoniics, Proposed Tentative U. S. Grades of Frozen Peas (February 25, 1939). APPROVED b y the director of the New York S t a t e Agricultural Experiment Station for publication a8 Journal Paper No. 472.
Determination of the Maturity of Frozen Peas New
F. A. LEE York State Agricultural Experiment Station, Geneva, N. Y.
A
REVISION of the method for determining the maturity of frozen peas (1) has been worked out, in which the mixture of xylene and carbon tetrachloride is replaced by water containing enough sodium chloride to give a liquid of specific gravity 1.000. This liquid is considerably less expensive than the former, is easier to prepare, and has the added advantage of undergoing less change in specific gravity in use. The following set of standards is suggested to replace those published before: Fancy Standard Substandard
1.072 and lower 1.073 t o 1.084 1.085 and higher
These standards can be revised if and when an extra standard grade is generally packed.
Literature Cited (1) Lee, F.A., IND.ENG.CHEM.,ANAL.ED., 13, 38-9 (1941). APPUOVBDb y t h e director of t h e New York S t a t e Agricultural Experiment Station for publication as Journal Paper No. 480.
