Nutritive Value of Canned Foods EFFECT OF COMMERCIAL CANNING OPERATIONS ON THE ASCORBIC ACID, THIAMINE, RIBOFLAVIN, AND NIACIN CONTENTS OF VEGETABLES J. R. X=IGSER, F. 81. STKOKG,
AND
C. A . ELVEHJEM
L’nicersity of Wisconsin, Madison, Wis.
In the preparation and canning of asparagus, peas, green ing operation. These types H E rapidly developing beans, and lima beans, the blanching operation has an of vegetatdes generally lose realization among food adterse effect on the yetention of w ater-soluble vitamins. 25--55y0 of their ascorbic acid industries of the importance After blanching in hot water these products retained 14at this stage and root vcgrof protecting the natural nu91, 36-99, and 59-103% of their raw-product ascorbic acid, tables only 10-20%. tritional values of their prodthiamine, and riboflavin contents, respectively. AnalaFarrell and Fellers (5) ucts has greatly stimulated gous figures for steam blanching were 39-93,32-88, and 63found that experimentally interest in research along 103qc. Green beans and lima beans retained 60-100% of canned green beans retained these lines. Consequently their original niacin after hot-water blanching and 5522-25% of their ascorbic there has bern a steady in100qc after steam blanching. Additional amounts of acid, 83% of their thiamine, crease in information regardthiamine were destroyed in the processing operation, and 9770 of their riboflavin. ing the effects of commrrcial whereas the three other vitamins were not seriously afThe low retention of ascorbic operations on the nutritional fected by processing. Values for over-all retentions of asacid may have been due quality of processed foods. corbic acid, thiamine, riboflavin, and niacin were 39-121, partially to the excessivr I n general, the canning in31-88, 63-103, and 77-100q& respectively. h.ead space indicated by the dustrv has kept abreast of . fill-in weights reported by this trend, but the data these workers. Similar rcavailable c o n c e r n i n g t h e tentions were found whether the beans were packed in tin or effects of commercial operation3 on canned vegetables are glass containers. Fellers, Esselen, Marlinn, and Dunker ( 7 ) restill quite limited. Harris et al. (9) studied the over-all ported that spinach retained 3 5 4 0 % of its ascorbic acid content effects of experimental canning on the retention of thiamine in canning and that asparagus, peas, lima beans, and spinach rein several vegetables and reported the following thiamine retentained 71, 66, 25, and 87% of their thiamine and 78, 100, 73, and tions: asparagus, 65-907,; lima beans, 32-60“; : cut green beans, 83m0; cut wax beans, 6OC;: peas (not blanched), 77-92Tc; sliced 38mG of their riboflavin, respectively. Fellers, Esselen, and Fitagerald (6) reported over-all retentions beets, 92%; spinach, 18-44?; diced carrots, 7 6 5 ; squash, 32of thiamine and riboflavin for some commerciallv canned vege3 9 7 ; tomatoes, 76-90?‘,. Experimentally and commercially tables. Aqparagus, peas, lima beans, and spinach wtainrd 72, 60, canned asparaguq from a single lot of raw product retained ap28, and 7 1 7 of thrir thiamine and 08, 100, 70, and Gr0of their proximatelv the same amounts of thiamine. King and Tressler ( 1 2 ) discussed the problem of vitamin C reriboflavin, respectively. tention in the canning of foods and pointed out that, although Finckr (8)compared the effects of various h i e s and temppratures of blanching on the thiamine content of peas and found neutral vegetables such as asparagus, peas, green beans, and kale that tlicre was an increasing loss of thiamine x i t h loiiger times frequently undergo losses of ascorbic acid in canning to the extent of 40-605, precautionary measures Kith regard to oxidation and and higher temperatures. Mayfield and Richardson ( 1 6 ) observed that home-cmncd cut solution )vi11 reduce such losses. For example, even such highly green beans rvtnined shout 60°C of their thiamine content when disintegrated products as neutral baby food. often retain 35-65? of the original antiscorbutic value. stored for 6 months and prrparcd for scrving. Under tlw samc Adanis ( I ) is of the opinion that some thiamine may be lost by conditions only 15 to 2 0 5 of the vitamin C remained. Langley, Richardaon, and Andes (14’) observed t h s l canned leaching, particularly during blanching, and that further loss due to destruction is to be expected from the sterilization process. I n carrots lost only a small amount of thiamine but a largc amount of vitamin C. reference t o ascorbic acid this author says,“Blanching accounts Clifcorn and Heberlein (4)published a n extensive report on the for heavier losser than any other canning operation, leaching beretention of thiamine in commercially canned vegetable-. They ing the chief cause: only a small proportion of the vitamin C is destroyed by oxidation.” For the control of ascorbic acid losses found that the most serious losses of thiamin(, occuried in the due to processing, he recommends thorough heat exhausting and blanching and processing operations. Reteni ions of thiamine during rommercial blanching of asparagus, green beans, lima keeping can head space at a minimum. Adam., Horner, and beans, and peas ranged from 64-lOOcl, and, during comnicrcial Stanworth ( 2 )observed that peas, green stringless beans, and leafv processing, from 58-79%. Over-all thiamine rrtentipns ranged vegetables which have a large surface area show the greatest losqes; from 31-8970 with a n average over-all retention of 57%. The most of the leaching occurs during the first2minutes of the blanch1 This IS t h e fourteenth of a series of papers dealing n l t h t h e general subthiamine content of canned vegetables was found to be signifiject “ N u t r i t i v e Value of Canned Foods.” Other articles have appeared i n cantly affected by grade and size of t h e raw products and by The Journal of Nutrition, Journal of the American Dietetic Association, Food of asparagus. the segment of the stalk canned in the Research, ANALYTICAL EDITION o f ISDUBTRIAL ISD ENQISEERINQ CHEWSTRY I n order to obtain more complete information on the subject, (August a n d November 1945), a n d ISDUSTRIAL AND EKGISEERITG CHEMISi t was decided to investigate further the retention of water-soluble T R Y (December 1945 a n d August 1946).
T
985
986
INDUSTRIAL AND ENGINEERING CHEMISTRY
TABLE I . RETESTIONOF VITAMINSIN Vitamin Content
hIe.,'100 G. D r v dan!ahne . IStation Cannery S o . 3,Alaska peas, No. 2 cans Ungraded, raw Y o.. X. sieve . ~. . Raw Blanched (3 niin. a t 190-200° F.) Blanched (3 rnin. a t 170O F.) Filled (no brine) Processed ( 2 5 min. a t 245O F.)
So. 4
sic\-e
Raw Blanched (3 min. a t 190-2OO1 F.) Filled Processed ( 2 5 m i n . a t 245O F.) Cannery S o . 4,.Uaska peas, S o . 10 cans Ungraded, raw No; 3 sieve Raw Blanched (5-6'/2 niin. a t 1902003 F,) Blanched (41,'-5 niin. a t 170-
175' F )
Filled Processed ( 5 5 m i n . a t 2403 F.) S o . 5 . sieve Raw Blanched (5-61/2 min. a t 190-200' F . ) Filled Processed (55 min. a t 240' F.) S o . 4 siei-e Raw Blanched (4I;z-5 min. a t 170175' F.) Filled Processed
(> O X l f E R C I A L L Y Retention. C:
n!t.
Ascurcurbic Thia- Ribo- bic acid niinea flai,in acid
136 7
1.10 0 . 4 7 100
100
88
79
1.06 0 . 4 5 100 0.98 0 33 7'3 76.8 0.88 0 30 E2 76 8 0.68 0.32 82
100
!i 1
..
148 0
1 08 0 60
141 0
1.16 0 66 100
, . .
0.95 0 . 5 2 .
1
93 7 106 0 0:$9 0 ' 4 3 107 0 0.51 0 50
. .,, ... ,.
114 3 i3.3 87 92
.
.
66 75 76
1.05 0.59 0 93 0.46 0 8 1 0 46 0 52
246' F.)
Quality gradedd, sinkers Sinkers, a t filler Sinkers, processed (-50 m i n . 245' F.)
at
3.3
92
83 64
100 73 67 71
24.60
29 20
2 5 50
26 10 28 10
2 4 00 15 29 (1 51>h
2 9 ' 10 15.29(1.51) 17.42(1 51)
2 8 90 29.40
30 60 33 7 0
li 28(1 62)
17 66 (1 6'2)
1 7 2 8 (1.62, 33 00
,.
23 60
24.10
100
' 3 70
20.50
82
78
77 44
65
100 88
100 78 78 83
i f
4'3
100
.
.. .. ..
64 76
..
76
..
24.60 2 5 10 1 3 i 9 $ 1 811
13 79 (1 81)
...
,.
21 10
35.00 32.40
79 60
73 ., 68 84
100
100
93 68 89
s9
93
93
*55
86 1Cl3
31 30 14 50 ( 2 90) 14 5 U l Z 90)
127.0 1.53 0.61 100 79.8 1.47 0.51 63 75 7 1.47 0 53 85 1.43 0 51 100
100
96
100 84
18.30 20 30
100
100
68
117
74
0.92 0 . 5 3
116'
26.SU 24.20 15 13 (1.81)
2 2 20
E8
92 1.03 0.60 106' 64.3 1.33 0.46 63 1.28 0.45 100
2 5 20
2s. 30 14.99(1.81) 14 99 (1.81)
100
, .
19'iIo 14 49 (1.81)
27.60 ,
60
0.93 0.31
Thiamine and rtbuHnvin barnpies
..
,.
..
i2 79
Ascorbic acid eairiples
101)
--
0 49
66.8 88 0.'93 0.'30 91 0.55 0.36
C a n n e r s Xo. 6 peas. sweets, S o . 2 cans Ungraded Raw Blanched (6 min. a t 200O F.) Quality gradedd, floaters Floaters, a t filler Floaters, procebsed (40 m i n . at
:6'
ter, C -__Dry 1 I a t__-__
100
, . .
Filled Processed ( 2 5 min. a t 245' F.)
Thia- Ribomine flavin
122.0 1.23 0 . 5 3 100 1.08 0.42 +i 7 65 9 7 . 5 O'Q4 0'38 80 9 7 . 5 0.68 0.42 80
Cannery S o . 5 , Alaska peas, S o . 2 cans Cneraded. raw 132.7 1.06 0.36 . . N o r 3 sieve Raw 142.0 1.04 0.44 100 Blanched (41/1-5 min. a t 190. . . 0.92 0 . 3 2 . 195' F.) Blanched (3 m i n . a t 200-205' F.) 90.6 64 Filled 121 0.s2 0'30 85 Processed (25 min. a t 245O-F.) 120 0.63 0 37 85 S o . 4 sieve Raw 9 8 . 4 1.00 0 3 5 100 Blanched (4'/2-5 min. a t 190-
195' F.) Blanched (3 niin. a t 200-205° F.)
c.I N S E D PE?S
36 90 24 10 12.10$ 2 . 9 0 ) 36 ii 11 10 (2.90) 16.52( 2 90; '
'
2 i 10
36 9(1 37.50
Vol. 39, No. 8 vitamins in commercially c a n n e d vegetables. Since ascorbic acid, thiamine, ritiuflavin, and niacin are the n-ater-soluble factors nm?t frequently found lackirig in human dietaries and of the greatest concern t o tlit: I'(Jl)d ~ of ~the d and S u t r i ~ i o nk
clusion of these factors in thc study. Furtherniorc,, it \vas felt that a simultancloub study of the effects of canriiiig o n beveral nutrients might give, a better picture of changcs undergone by the vcgctalilc* than n-oultl the study of ail!. one nutrient. Bccause of differences in stability to vaiious influences i t seemed that. in addition to thcir own nutritional significance, thesc compounds might give some indication as t o the relative r,xtoiit of changes due t o oxidation. extraction, heat, or light. AI! four of these vitamins urr n-ater-soluble. Each has a characteristic weakness, v-it h the exception of niacin, t o conditions encounterctl i n
37'bO 17 2U12.90)
20.50
11 30 (2.00)
100
100
11.30(2.00) 11 S I 2 00) 25 00 25 2 0 15 "0,2.00) 2 5 7 2
72'
115'
15 2 0 ( 2 00'1
14 1012 00) 24 37 24.7 0 24 7 0 25 i 0
tive to oxidation. thiarriinc t o high temperatures, and riboflavin to light. Corisequentl). it was hoped that R comparison of the retentions of tlic, four vitamins after each 01)eration might give sonic indication as to the rclativrh influence of each of t h r w conditions.
25.50 14.14( 2 . 0 0 ) Cannery S o , 8,peas, sweets, S o . 2 cans Kneraded. raw Q u i l i t y gradedd, f a n c y Quality graded, extra s t a n d a r d Quality graded, s t a n d a r d E x t r a s t a n d a r d , KO.4 sieve Raw Blanched ( 6 min. a t 190-200' F.) Filler Processed (35 m i n . a t 240' F.) E x t r a s t a n d a r d . S o . 5 sieve Raw Blanched (6 min. a t 190-200° F . ) Filler Processed (35 min. a t 240- F.) Cannery N o . 9, peas, sweets, S o . 2 c a n s j Ungraded, raw No. 4 sieve Raw Blanched (6-7 min. a t 190-20OC F.) Blanched (2 min. a t 185O F.) Filler Processed (25 m i n . a t 245O F.) S o . 5 sieve Raw Blanched (6-7 m i n . a t 190-200° F.) Blanched ( 2 min. a t 1SjC F.) Filler Processed (25 min. a t 245' F.) ~~
152.5 152.0 112.3 88.2
160
1.76 0 59
143.5 111.0 102.0 102.0
1.71 1.48 1.42 0.92
0.60 0 40
0.38 71 0 43 71
83 54
139.5 118 2 108 0 108.7
1.64 1.45 1 36 0.85
0.61 100 0.44 85 0.38 77 0.44 78
100 88 83
100 72 62
52
72
18.40 16.30 10.20(2.20) 10.20(2.20)
126 2
2.19 0.59
..
21.00
24 40
0.64 100 0.44 , . 74 0.41 82 0.53 82
100 79
100 69
18.60
22 00
80 59
64
131 0 2.12 0.59 100 1.75 0.37 . . iai:o , . 77 105 0 1.71 0:38 80 105.0 1.11 0 . 4 2 80
100 82 .. 81 52
100 63
0.55
1.83 0 . 5 9 1.68 0 55
156.0 2.33 1.84 ii$.'o 128 0 1.87 128.0 1.37
12-0
100
(i
67
..
17.50 16 E0 21 30
l i 00 29 70 27 00
22.90
29 70 26 70
100 67 63
26.70 28 30 16 76 ( 2 . 2 0 )
72
..
53
,.
64 71
2 6 40 29 10
28.30 16.95(2.20)
24 60 ls'io 15.60(4.50) 23 40 15.60(4.50) 16 47 (4 50) 20.20
12 O O ( 2 50) 20'20 12 0 0 ( 2 50)
24 60 27 30 26 40 15 5 2 ( 2 50)
'1 -111 thiamine 1-alues expressed as thiamine hydrochloride. b Figures in parentheses indic a t e amount o i solids introduced M-ith t h e brine, expressed as per cent of t h e original fresh weight of the sample. c N o t separated into sieve sizes; S o , 3 field grade on basis of tenderometer measurements. d 34-35O Salometer brine used for quality separation of peas a t cannery S o . 6 ; 45' Salometer of limaused beans for aquality t cannery separation S o . 16. brine
Concentration of brine used f o r separation of peas a t cannery S o . 8 is not known. e Per cent of filler-sample content retained after processing. f S o . 4 sieve peas, vacuumpacked.
August 1947
INDUSTRIAL AND ENGINEERING CHEMISTRY CAKNING PROCEDURES
.
1
This Tvork was conducted during the summers of 1943 and 1944 in canning plants located in Kisconsin, Illinois, and Michigan. Although the same general canning operations are n-idely used for any one product, there is considerable variation in the details of application. Differences in the number and kinds of cleaning operations, time, temperature, and type of blanch, the use or absence of quality grading, and time and temperature of the sterilization process are the most common variations. Such modifications may be necessitated by the condition of the raw product or the type of equipment used, or may be required in order to develop some particulw characteristics desired in the canned product. The personal experiences and opinions of each packer exert a further influence. Although many of these details probably merit further study, the amount of work involved has compelled the authors to limit the investigation to surveys of operations in tn-o plants packing green asparagus, four packing m e e t peas, and three each for green beans, Alaska peas, yellow n-hole kernel corn, and lima beans. hscorbic acid, thiamine, and riboflavin retentions Tr-ere investigated for all of these products. T h e studies on niacin retention viere rcstricted t o corn, green beans, and lima beans. h t each plant records were made of the sequence of operations, and a sampling schedule !vas prepared to include those t h a t seemed to be critical operations. Selected uniforni lots of raw product of known field and harvesting history were then passed through the canneries' regular operations. Such lots of r a x product were selected with regard to uniformity and total quantity so as to facilitate sampling and, at the same time, provide sufficient material so that operations could proceed a t their usual rate. Consequently the size of the lot selected varied with the capacity of the canning line under observation and with the number of grades and sizes into which the r a x product n-as separated for canning. For asparagus surveys 300- t o GOO-pound lots were canned. The lots of peas and lima beans neighed GOO t o 1200 pounds. For the xork on green beans lots of 400 to 800 pounds were used. Loads of the unhusked corn weighing 1 t o 2 tons were selected for work on that product. As each lot of product passed through the canning line, small samples were taken at intervals a t each of the predetermined sampling stations. All samples taken a t each station were combined and mixed. -4total of approximately 10 pounds was collected a t each station before the filling operation. At the filler six brined and closed, but unprocessed, cans were collected from each lot, with the exception of the asparagus samples and part of the pea samplcs, which were collected a t the filler without brine. Twelve cans were taken from the processed product. Six of the processed cans were used for vitamin analyses. The others were submitted t o t h e Continental C a n Company for food inspection a n d moisture analyses. Corrections for added sugar and salt, determined from the brine formulas and the weight of brine filled into the cans, were subsequently subtracted from the per cent dry weight of filler and processed samples. SAMPLE TESTISG
From each of the samples taken before the filling operation, 200 grams were wcighed into a S o . 2 can. One hundred grams of water were added, and the cans Tvere closed and processed. The can contents were subsequently analyzed for dry matter. Multiplication of these dry matter figures by 1.5 gave the dry matter content of the original material. Another 300-gram sample was tr-eighed out for ascorbic acid determination immediately after collection of the material and placed in the bowl of a Waring Blendor. An equal volume of stabilizing solution was added, and nitrogen was bubbled through the liquid for about 1 minute before the Blendor was started and through the resulting slurry throughout the blending period. Two to three minutes of blending resulted in satisfactory dijintegration of the material, except
987
in the case of green beans, which required approximately 5 minutes of blending for satisfactory results. Twenty- to thirtygram samples were weighed out from the resulting slurry, diluted to 250 ml. n-ith an aqueous stabilizing solution containing 37, metaphosphoric acid (sticks) and SSl, acetic acid, and filtered through paper. Duplicate aliquots of the filtrate were titrated x i t h 0.02'30 aqueous sodium 2,6-dichlorobenzenone-indophcnol dye solution buffered with sodium bicarbonate to p H 8.0 to 8.5. All titrations ivere completed within a n hour of the time that the sample was collected. With asparagus satisfactory results were obtained when the ascorbic acid slurry was prepared \vith an aqueous stabilizing solution containing 3c5, metaphosphoric acid and Sc', acetic acid. When this was tried with peas, serioue discrepancies were found in the ascorbic acid values bec:iuse of rapid osidation of the vitamin in the unblanched samplcs. Stern ( I 5j encountered similar difficulhs n-hich he overcam~1by increasing the metaphosphoric acid concentration to 6 5 , in the stabilizing solution. When our solution was modified accordingly, satisfactory results were obtained. A third portion weighing 200 grams was blended with an equal sulfuric acid and 2-3 ml. of chloroforni. The weight of 0.2 slurry was poured into a glass-topped pint jar and covered with 5 ml. of toluene. The acidified slurries w r e refrigerated, taken to the laboratory, and stored in cardboard boxes a t 4 " C. Subsequently they were used for the thiamine, riboflavin, and niacin analyses. Thiamine was determined by the thiochrome method of Hennessy (10) as modified by Ives, Wagner, Elvehjem, and Strong (If). Riboflavin was determined by the method of Snell and Strong ( I ? ) and niacin by the method of Snell and JT-right ( f 8 j , using the modified medium of Krehl, Strong, and Elvchjcm ( 1 3 ) . Duplicate assays 11-ere run for each of these vitamins. For vitamin analyses of the unprocessed cans collected a t the filling machine and of the processed samples, sis cans were opened in each instance. The total liquid and solid contents were measured; aliquots of each m r e recombined and blended with equal viveights of metaphosphoric acid-acetic acid solution or 0.2 S sulfuric acid for the determination of ascorbic acid and the mem, bers of the B comples studied. RESULTS A N D DISCUSSION OF ASSAYS
The results of the assays for the entire investigation are listed in Tables I and 11. All of the assay values were calculated to a dry weight basis. The per cent of dry matter in all samples is included in the tables to allow calculation of the values to the original basis. The values for filler and processed samples given in the tables xere corrected for added sugar and salt by subtraction of the brine solids. The brine corrections are based on the composition of the brines used and the amounts added t o the canned products. For calculation of the vitamin contents of filler and processed samples t,o original basis the corrected per cent dry weight should be used. Per cent retentions were calculated on the basis of the starting material wherever the sequence of canning operations made it practical. I n those instances where the starting sample was separated into a number of sizee and grades, per cent retentions for each size and grade investigated were calculated on the basis of the raJv material after separation rather than the ungraded lots. Canneries No. 6 and 16 are exceptions to this procedure; in those plants the product was quality-graded by brine separation after blanching. Therefore only the per cent retentions after blanching and the per cent of the filler-sample vitamin content retained after processing were calculated. Because of the difficulties encountered in 1943 with ascorbic acid determinations on peas, that part of the work was repeated in the summer of 1941. Therefore, the values reported for ascorbic acid retention in the canning of peas were determined on different lots of material than were the values for thiamine and riboflavin retention. I n some instances the blanching procedure used in 1944 differed from that used in 1943 and is listed accord-
988
ingly. The e s t r n t to which the commercial operations itudicd affected the ascorbic acid, thiamine, riboflavin, and niacin coutents varied considerably from one product t o another. Thcrc, is also some difference in the per cent retentions for a givcw product from onc cannery t o another. T h r variations apparently were the result of characteristics of each product --differences of size, maturity, and grade of individlots, and modifications of the canning operations. The percentage of original vitamin content of the raw foods rptainrii after blanching in hot-water hlanchers vias found to b ~ : ispar-
'
Vol. 39, No. 8
I N D U S T R I A L A.ND E N G I N E E R I N G C H E M I S T R Y
Vitamin
agus
Alaska Peas
4scorhic acid Thiamine Klboflarin Siacin
89-94 93-99 86-103
64-79 82-93 73-89
...
...
Smaller, more tender pea6 and lima beans retained l e s ~ of the vitamins than did more m a t u r e sizes a n d grades. I n general, blanching had a inore adverse effect on the ret,ention of nutrients than did any other operation. Since appreciable amounts of all four of these watersoluble vitamins are lost at this point,, it appears that clstraction is an important factor. Ascorbic acid tends t o be lost t o a greater extent than others, and it seems reasonable to conclude that o s i d a t i o n a l s o occurred. Lima. beans suffered thc greatest loss of thiamine, and g r e e n b e a n s s h o w e d the poorest, retention of aseorhir acid in this respect. Blanched peas, green beans, and lima heans retained approsimately the same proportions of their raw-product riboflavin contrnts. Some of these variations may be due t o the different range of time and temperature used for different vegetables. Asparagus Kas outstanding for its high retention of vitamins after blanching. Clifcorn a n d Heberlein' ( 4 ) observed that asparagus loses relatively Little thiamine in commercial blanching and felt that it was due t,o the low ratio of surface area to mass in this product, as compared t o peas, green beans, and lima beans; and to the comparatively mild blanching coniiit,ions used for asparagus. Distribution of the vitamins \Tithin the vegetables may also affect their ret,entions.
Sweet Peas 63-85 79-96 63-84
...
Green Beans 44-83 72-89 70-93
m-im
I.iiiij Beans 54-83 36-77 59-92 ~ 8 - w
Th(Irr2 n-as a tendency toward a slight decrease of all nf the> vitamins b e t w e n the blanching and filling operations, presumably because of the use of cold-witer rinses after blanching and from the drainage of fluids from'the blanched product. Oxidation [if ascorbic acid and light destruction of riboflavin may have also contributed to these losses. I t is difficult t o evaluate closely the effects OII peas and limb beans of quality separation by cold brine solutions, because the proportions of floaters and sinkers obtained from the ungraded products were not determined. However, it, appears that the operation has less rffect on raw products than on blanched prodUI'tF.
I-elluw whole lit~rrielcor11 retained 65-S20.c of its aicorbic acid, 6!)-113c; of ita rhiamirir~,70-93C: of its riboflavin. arid 74-CJlY0 of its
X-iraniin Content, 11g.1100 G . Dry W t . 4: cor bir Thia- Riho- Si?arid mines flavin cin
Sampling Station C!annery S o . 1, XU.2 Carib Raw, snapped, a n d washed Cut a n d sorted Blanched (6 min. a t 190° F.) and rineed Filled (no brine) Processed ( 2 5 min. a t 240° F.1 Cannery h-0. 2, Y o . 2 cans Cut, unwashed Washed Blanched (4 ,min. a t 150° F., Filled (no brine) Processed (15 niin. a t 248' F.) Blanched (11/2 min. at 167O F ) Procesed (15 min. a t 248' F . ? . hand filled ('annerv S o . 10. S o . 2 can; Snipped beans C u t , before blanch Blanched ( 4 1 / 2 min. a t 180' F I , washed Filled a n d brined Processed (28 min. a t 240' F i Cannery S o . 11, S o . 2 cans Rough-graded ?io. 3 sieve Raw Blanched (4-5 niin. a t lb0-1905 F . I Filled and brined Processed 120 min. a t 240' F.? S o 4 siere Snipped
