Journal of Food Science 1

8/14/2019 Journal of Food Science 1

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VITAMIN C CONTENT O F VEGETABLES. I. SPINACHD. K. TRESSI,ER, G. L. MACK, AND C. G. HIKG

N e w York State Agricultural E x p e r i m e n t S ta t ion , Geneva , N ew Pork, alzd theDepartment of Chemistry, University of P i t t sburgh , P i t t sbwgh , PennsyEva.nia

(Received for publication, October 23, 1935)Fresh spinach has long been known t o contain relatively largeamounts of vitamin C ; however, the amounts reported by the severalworkers differ greatIy. One difficulty in comparing the published

results lies jn the fact that there is littIe uniformity in the mode of re-porting the data obtained. Most analyses reported recently have in-dicated the amounts of ascorbic acid in milligrams per gram ofspinach. If one assumes, as suggested by Bessey and King (1933), that0.5 mg. of a.scorbic acid per d ay is required f o r protection of a guineapig f rom scurvy, the da ta in recent papers may be recalculated on auniform basis (Table I.).

TABLE 1Previous R e p o r t s OR the Asambi c Acid C o n t en t of Spinach

Investigator

Eddy, Kohman, and CarlssonHessler and C r a ig (1929)

(1925)Hessler, Johnson, and WalshVon liahn (1931)Wasson (1931)Kifer and Munsell (1932)Kifer an d Munsell (1932)Kifer and MunseU (1932)Bessey and King (1933)Bessey and King (1933)Tauber and Kleiner (1935)

(1931)

Source or rarietyof spinach

M a r ke t FreshBloomsdaleUnknownFresh Virginia SarogViroflayPrincess JuIiana r e sh Market resh

Ascorbic acidmg. p e r gm.

>O.G

0.07 to 0.100.17 t o 0.250.10


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4 D. K . TRESSLER, G . L. M A C K , AND C. G . KINGspinach is higher in ascorbic acid than market spinach. Wasson(1931) working in Brookings, South Dakota, states The spinachgrown in the college gardens does not seem t o have as high vitamin Cvalue as spinach that has been tested in some other laboratories.Moreover, she also finds that home grown spinach had greater anti-scorbutic potency than the spinach bought in the market. Kifer and Miinsell (1932) reported slight varietal difference invitamin C content among three varieties tested, Virginia Savoy, Viro-flay, and Princess Juliana, the last being lowest in potency.Ton Hahn an d Gorbing (1933) found that the vitamin C contentof spinach varies depending on the type of fertilizer used. Unbalancedfertilizers (i. e , those especially high in some one component) yieldedspinach relativeIy low in vitamin C, whereas soil treated with balancedfertilizers produced spinach high in this vitamin.The work reported in this paper was undertaken in order t o obtainsome data concerning the relative importance of variety, freshness,maturity, and soil on the ascorbic acid content of this vegetable.

METHODS USEDThe method of determining ascorbic acid described by Bessey and

King (1933) mas employed, but or purposes of comparison biologicalassays were also made on two samples. The procedure employed inmaking them is described below :Samples of the f resh ly p icked sp inach were carefuI ly packed , f rozen, andkep t in a conta iner w i th dry- ice . T h e cu ra t ive type of t e s t was used as a measureof ant iscorbut ic value . The guinea pigs were kep t on the standard Sherman and

Smith (1931) d ie t s upp lemen ted wi th a g e n e r o w allowance of f r e s h s p inach for tw oweeks t o assure thei r normal. g rowth r a t e , and t o permi t them t o reach approxi-ma te ly 325 gm. in weight. They were t hen given t h e basal d ie t only f o r 14 days,a t which t ime there w as evident an average s l igh t loss in weight. Test f eed ing masthen begun with weighed port.ions of food s upp l i ed s epa ra te ly t o each an imal ,The quan t i ty to be fed was ca lcu la ted f rom the indophenol t i t ra t ion value . Thef ood w a s consumed r ap id ly so t h a t t h e r e would no t have been a significant lossf rom oxidat ive des t ruct ion before it wa s eaten . Contro l group s mere g iven s t an -dard port ions of f r e s h ly prepared v h m i n so lu tio n, fed from graduated pipet tes .I t is evident f r o m the d a t a ( T a b l e 2 ) t h a t t h e a n im a l assays correspond closelywi th th e indophenol titratiou values.

EXPERIMENTALRelatz/ue Potency of Leaf a id f i t e r n

Appreciating the fact that leaves and leaf petioles often differmarkedly in chemical composition and therefore might contain verydifferent quantities of ascorbic acid, the ascorbic acid content ofleaves and s tems of freshly harvested spinach grown on Ontario clayloam soil was determined. The ascorbic acid content of the leaves and


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V I T A M I N C CONTENT O F VEGETABLES 5

Basal diet supplement

Prickly Winter SpinachHolitlndia SpinachAscorbic Acid Solutionllnsupplemented

stems of the Prickly Winter spinach was found to be 0.78 and 0.06mg. per gram respectively; that of the Ieaves and stems of the Hol-landia variety was 0.79 and 0.04 mg. per gram respectively. Thesedata indicate that whereas the leaves are high in ascorbic acid, thesterns are almost devoid of this vitamin. This shows that in euam-ining spinach, either the entire plants should be taken o r else the

TABLE PBiological Assay of Yitamin G in S@ncbeh LFfiWe8

No. of Vitamin C Initial Gain in weightanimals fed per day weight during 14daysw. gn i . gm .

4 0.5 320 384 1 .o 319 174 0.5 307 354 1.0 309 437 0.5 311 416 1.0 310 636 0.0 329 -113

Scu rr?scare atautopsy

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leaires and stems should be assayed separately; otherwise it would bedifficult t o obtain uniformly reliable data. Since in spinach the ascor-bic acid is principally in the leaves, the data presented in this paperrefer t o the composition of the leaves.

Ma tu r i t y and Ascorbic Acid ContentSpinach is a crop which grows and matures very rapidly in thespring. Often within one week f r om the time that the first leaves are

ready to harvest, the crop passes optimum maturity and begins tobolt (go t o seed). T o determine the influence of maturity of the cropupon it s ascorbic acid content, freshly cut spinach leaves from tw ovarieties mere analyzed before the spinach became large enough orharvesting, again four days later when it had nearIy attained f u l lgrowth, and again when it began t o bolt. On these dates t h e ascorbicacid content of the Pr ickly Winter varie ty mas 0.72, 0.75, and 0.78 mg.per gram respectively ; that of the Hollandia variety w as 0.78, 0.75,and 0.79 mg. per gram respectively. These figures indicate that theascorbic acid content of spring spinach leaves is nearly constant duringthe g r o w th period.

Influence of Varie ty and SoilTwelve varieties of spinach at optimum maturity were harvestedfrom upland soil (Ontario d a y loam at Geneva, N. Y . ) and the same

varieties harvested on the same day from muck soiI a t Holcomb, N. Y.O ne sample from each lo t was analyzed f o r ascorbic acid. While there


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6 D. K . TRESSLER, G.L. MACK, A N D C. G. R I N G

Eskimo ....................................................................Old Dominion..........................................................Nobel. ......................................................................

is a varietal difference, the soil on which the c rop is grown (Table 3 )apparent ly has a somewhat more important influence on th e ascorbicacid content of the leaves. It is noteworthy that on both soils th ePrincess Jul iana variety is th e lowest in ascorbic acid a n d that varietyis the one fo u n d by Ki fe r and Munsell (1932) t o possess the leas tantiscorbutic acid value of the three variet ies examined by them.

TABLE 3Ascorbic Acid Content of the Leaves of Smeral Variet ies of Spring S@m&

&own on Nw&and U pland Soil aad Harvested on the Same D a yAscorbic acid in leaves harvestedfromM u c k s o i l I UplandsoilVariety of spinachmg.p a r om. mg. per gm.

0.62 0.770.56 0.700.55 0.79

Vietor ia ...................................................................Viroflay...................................................................Broad FIanders......................................................Long StandingBloornsdale..................................Virginia 6;cvoy .......................................................Prickly Winter.......................................................Hollandia ................................................................King of Denmark....................................................Prineess Juliana.....................................................

Mean..................................................................

0.550.530.490.490.480.460.420.400.380.49

0.660.780.890.740.800.750.750.640.530.75

On the average the amount of ascorbic acid in the spinach leavesgrown on the upland soil was 50 per cent higher than t h a t o f thespinach f r om the muck soil. This point will be checked by examiningspinach grown on other muck and upland soils, t o see if this differenceis a general one.Loss of Ascorbic Acid During X tm a g e

Samples of spinach, cut as f o r marke t , were held at room tempera-ture f o r 17 days. Duplicate samples were kept a t 1 o 3" C. (33.8 to37.4' F.). Leaves from each of t.hesamples were analyzed fo r ascorbicacid (Table 4) a t t h e start of t h e experiment and at th e end of 3, 7,and 17 days. T he spinach on s tanding f o r th ree days at room tempera-ture lost approximately one half of its ascorbic acid ; but after threedays ' storage a t 1 o 3" C. (33.8 t o 37.4" F.) the spinach retainedpractically a ll of its ascorbic acid. This shows the importance ofrefr igerat ing spinach soon af te r it has been cut.

S U M M A R Y AND COKCLUSIONSThe ascorbic acid contents of twelve varieties of spinach gr ow n on

upland soil were compared with t h a t of the same varieties grown on


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VITAMIN C CONTENT OF VEGETABLES 7

Prickly WinterPrickly WinterHollandiaHollandia

muck soil, a l l samples being harvested an d anaIyzed on the same day.Those grown on the upland soil averaged 50 per cent higher in vitaminC than those f ro m the muck. While in both instances certain varietiesran somewhat higher t ha n the average i n ascorbic acid, yet the varietaldifferences are believed to be of secondary importance.

The vitamin C content of spinach as marketed is principally in theleaves, the stems being nearly devoid of this vitamin.Spinach stored a t 1 o 3' C. (33.8 to 37.4" F.) lost its ascorbic acid

very dowly, whereas tha t held at room temperature los t approximateIyone haLf of i t s ascorbic acid in three days, and practically a l l of it inseven days.

TABLE 4Loss of Ascorbic Acid from S p i ~ ~ huring Storage

mg. er gmI t 0 3 0.78

23 t o 26 0.78l t o 3 0.79

23 o 26 0.79

Ascorbic acid in l eaves after s torage fo r thenumber of days indicated below0 1 3 1 7 1 17

StorageVariety ofspinach i n degrees C.

mg.pergm.0.760.440.760.39

m g . g c r g m . mg. e r gm.0.72 0.390.05 Spoiled0.64 0.490.03 Spoiled

The percentage of ascorbic acid in growing spinach leaves did notchange materially during the harvest ing period of one week.

REFERENCESBESSEP,.A., AND EING,. G., 1933. The distribut ion o f vitamin C i n plant andanimal tissues, and i t s de te rmina tion. 5. Biol. Chem. 103, 687 698.EDDY,W. H., KOHblAN, E. F.,A U D CAELsSON, v., 1925. Vitamins in canned foods.

111. Canned spinach. Ind . Eng. Chem. 17 , 69-74.v. HLHN,F.v., A N D GORBING, J., 1933. Inflnence o f fertilizers on th e vitanijn ccontent of spinach. 2. Untersuch. Lebensm. 65, 601 16.V. HAEIN,.V., 931. Vitamin studies. IV. The vi t a mi n content of vegetables of

th e German retai l business. Z. Untersuch. Lebensm. 61, 545-610.HESSLER,. C., A N D CRAIG, . C., 1929. Vitamin C content of spinach and J o n a -than apples. Mo.Agr. Expt. Sta. Bull. 272, 67-8.HESSLER,M. C., JOEINSOH, D.,ANI, WrrZISH, R. B., 1931. The vitamin con ten t ofBloomsdale spinach. Mo. Agr. Expt . S ta . Bul l . 300,83 84.EIFER,ILDA.,A N D MUNSELL,1. E.,1932. Vitamin content of three varieties of

spinach. 3. Agr. Res. 44, 767-71.SIIERNAN,. C., AND SMITK, . L., 1931. The Vitamins. 2nd Ed. ReinhoId Com-

pany, New P o r k City.TAUBEE,H., A N D KLEINER, ., 1935. A method fo r th e qua n t i t a t i ve determinat ion

o f ascorbic acid (vi tamin C). J. Biol. Chem. 108, 563-70.WASSON,G. E., 1931. Vitamin C content of f r e sh and canned spinaeh, Swiss chard,asparagus and carrot s . 8.Dak. Agr. Expt . S ta . Bull . 261, 3-28.

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Journal of Food Science 1