January, 1946
INDUSTRIAL AND ENGINEERING CHEMISTRY
(9) Grote, I. W., J . Biol. Chem., 93, 25 (1931). (10) Hachiya, T., and Nishimura, J., J . Pharm. SOC.J a p a n , 52, 756 (1932) (Eng. trans., pp. 89-91). (11) Horsfall, J. G., and Zentmeyer, G. A,, Phytopathology, 34, 1004 (1944). (12) Klein, G., and Farkass, E.,-Oesterr. Botan. Gaz., 79 (2), 107 (1930). (13) Mayer, R. L., Rev. mddicale, franc., 1941, 3-19. (14) Meckstroth, G. R., Citrus Znd., 25, 9 (1944). (15) Miller, E. V., Proc. Florida State Hort. Soc., 57, 144 (1944). (16) Ovcharov, K. E., Compt. rend. m a d . sci. U.R.S.S., 16, 461 (1937).
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(17) Powell, G. H., et al., U. S. Dept. Agr., Bur. Plant Ind., Bull. 123 (1908). (18) Ramsey, G. B., Smith, M. A., and Heiberg, B. C., Botan. Gaz., 106 ( l ) , 74 (1944). (19) Rigler, N. E., and Greathouse, G. A., IND. ENQ.CHEM.,33, 693 (1941). (20) Ilivier, H., and Borel, James, Helv. Chim. Acta, 11, 1219 (1928). (21) Tompkins, R. G., Rep. Food Inv. Bd. 1935, Dept. Sci. Indus, Res. London, p. 129 (1935). (22) Winston, J. R., U. S. Dept. Agr., Circ. 396 (1936). (23) Zentmeyer, G. A.,'Science, 100 (2596), 294 (1944). (24) Zentmeyer, G. A., and Horsfall, J . G., Phgtopathology, 33, 16 (1943).
Vitamin Retention in Processed Meat i EFFECT
. .
OFSTORAGE
J. F. FEASTER AND J. M. JACKSON American Can C o m p a n y , Maywood, Ill.
D. A. GREENWOOD AND H. R. KRAYBILL American Meat I n s t i t u t e , Universiey of Chicago, Ill. Determination of the B vitamin contents of samples of processed pork luncheon meat during storage for a year at 45", 70°, and 98" F. indicated no significant losses of riboflavin, niacin, or pantothenic acid. Thiamine retention during the year was excellent at 45' F. (89 to 100~o), fair at 70" (59 to 7601,), and relatively poor at 98" (12 to 20y0). The percentage of thiamine retained during storage was found to be independent of the initial thiamine content and independent of the heat processing schedule employed for the preservation of the product.
T
HE annual production of approximately two billion pounds
of canned meats, packed under federal inspection in 1942, 1943, and 1944, is more than double the prewar figure. I n view of the increased consumption by the armed forces and civilian populations, information regarding the influence of storage times and temperaturea on the nutritive values of canned pork luncheon meat is of timely interest. A previous paper in this series (9) presented the effects of heat processing on the B vitamins of pork luncheon meat, according to various time and temperature schedules. Certain lots of canned meat from that study were stored under controlled conditions, and the changes found in vitamin values during storage are reported in this paper. Published data demonstrating the effects of storage on the vitamin contents of canned meats are meager. The changes in vitamin contents of canned pork, dehydrated pork, and dehydrated beef during storage a t temperatures ranging from -20" t o 145" F. (-29" to 63" C.) were studied by Rice and Robinson (8). At the end of 10-month storage a t 38", 80' and 98" F. (3", 27", and 37' C.) the canned product retained 100, 56, and 29% of the thiamine present in the product immediately after canning. At higher temperatures there was almost complete destruction of thiamine after 10-month storage. During storage the thiamine of dehydrated pork and beef was less stable than the thiamine in canned pork. I n coqtrast with thiamine, the niacin, riboflavin, and pantothenic acid contents of these meat products stored for 10 months a t temperatures up to 99' F. (37" C.) were found to be essentially 100% of that contained in the meat after processing. Rice and co-workers (6) found that dehydrated mixtures of 67% pork and 33% cereals (wheat, barley, or soybean flour) or dehydrated milk yielded higher retentions of thiamine than dehydrated pork alone. Products rich in carbohydrate materials
stabilized the thiamine in dehydrated pork. Furthermore, the retention of thiamine in dehydrated pork was correlated with the moisture content of the samples between 0 and 6% moisture levels. Low moisture content was correlated with high thiamine retention during storage [e.g., 0, 2, 4, 6, and 9% moisture i n dehydrated pork gave 91,60,23,9, and 11%retention of thiamine during 7-day storage a t 120" F. (49' C.)]. Recent reports suggest that the type of product and time and temperature under which canned foods are stored may be important factors influencing the degree t o which the B vitamins are retained- Data presented by Knott (4) BUggeSt that 50% of the thiamine in evaporated milk may be lost during storage for one year. High-temperature storage appears to be unfavorable to retention of the vitamins in tomato juice, lima beans, and whole-kernel corn (3). The degree to which thiamine was re-, tained varied from product to product, with 20 t o 35% remaining after one year a t 110' F. (43" C.). Riboflavin, niacin, and pantothenic acid were retained to the extent of 75% or more in these vegetables stored for one year a t temperatures up t o 110' F. A d a m and Smith (1) summariaed the United States AgriculturaI Experiment Station research on the vitamin content of preserved foods. The extent of vitamin loss during storage depends upon the storage conditions and the vitamin. Ascorbic acid and thiamine are the vitamins more likely to be affected by processing and storage a t higher temperatures. Information has not been previously reported regarding the effects of variations in heat treatments, concentration of the vitamin in the product, or size of the can in which pork luncheon meat is packed on retention of the B vitamins during storage. The experiments described in this paper were designed t o study the effect of time and temperature of storage on the B vitamins in pork luncheon meat which had been packed in various sized cans and heat-processed according t o different time and temperature schedules. MATERIALS AND ANALYTICAL METHODS
The samples of canned pork luncheon meat were prepared from one of the lots of b e a t described previously (8). The heat processing e uipment, methods, and analytical procedures employed were %e same as those used before. The heat processin schedules are listed in Table I. The samples coded K, L, and were procesded according to a time-temperature schedule calculated t o simulate the heat treatments received by meat in different positions in a 21/~-pound (404 X 510) can (8) processed
id!
INDUSTRIAL AND ENGINEERING CHEMISTRY
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146 minutes a t 236' F. (113" C.). The heat treatments given codes K, L, and M were similar to those received by meat inch from the outside wall, I'/s inches from the outside wall, and at the center of the can, respectively. Two cans each of codes B and F, and six cans each of K, L, 31, N, and 0 were analyzed within 2 days after the samples were canned. The remaining cans of codes B, F, K, L, and h&were divided into Lhree lots, and one lot of each code was stored at 45" * 5", 70 1 2 O a n d 98" F. * 2 " (7", 21", and 37" C.) for the desired times. A11 samples of codes N and 0 were stored a t 7 0 " F. (21' C.). Duplicate cans of luncheon meat, codes B and F, were individually sampled at the end of the storage periods, with the exception that only one can of code B was sampled after 6 and 12 months a t 98 F. Six cans each of codes K, L, 31, N, and 0 were composited, and the sample for analysis was taken from the composite at each examination. O
TABLE I. HEATPROCESSING SCHEDULES Heat Treatment
CodO I< L SI S 0
I3
F
THIAMINE RETENTION
Can Size 14 g. (208 X 006) 14 g. (208 X 006) 14 E. (208 X 006) 14 g. (208 X 0 0 6 ) 14 g. (208 X 006) 12 o a . (300 X 308) 21/2 lb. (404 X 510)
Min.
F.
FO
.... ....
... , . . ...
2.24 0.63 0.23 2.78 2.78 0.08 0.26
....
72.4 2.87 59 146
225 260 235 233
O F THIAMINE IS HEAT-PROCESSED TABLE 11. RETENTION LUSCHEONMEATDURIKG STORAGE"
Code
The thiamine values reported in Table I1 are averages of duplicate determinations run in each of the two laboratories. Attention is called to the fact that, from data presented in Tables I1 and 111,percentage retentions of thiamine, riboflavin, niacin, and pantothenic acid can be calculated on the basis of the vitamin content of the meat as filled in the can and also on the basis of the vitamin content after heat processing and cooling the cans. The first of these two methods of calculating retention expresses the total change in vitamin values associated with heat processing and storage; the second method of calculation shows the specific effect of storage. The heat processes to which these samples of meat were subjected during canning permitted retentions of 52 to 95m0 of the thiamiqe of the unheated meat. Hence, the canned samples as placed in storage had thiamine values ranging from 0.30 to 0.54 mg. per 100 grams. The samples found to have the higher thiamine contents immediately after canning retained the greater amounts of thiamine after storage for one year. The changes in thiamine contents of canned samples B, F, K, L, and h l are presented graphically in Figure 1, which demon-
Vol. 38. No. I
Storage Temp., O F.
-Thiamine 0 mo.
PORK
Retention, lIg./lOO Grams3 ma. 6 mo. 12 mo.
I
