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I l v D CSTRIAL A.VD ENGINEERING CHEMISTRY
Val. 20,
KO.
12
Relation of Chemistry to the Spice Industry John Glassford b l ~ c n n m ~A NxD COMPANY, BALIIWORE, Ma.
m H E fundamental food materials-fats, carbolrydrates, and protein--are, witti the exception of sugar, practically devoid of taste. If they did not naturally occur accompanied by flavoring substances or we could not flavor them artificially, we sliould choke trying to eat tlietn. Chief :imong tlie flavors thus used to render our foods more palatable are the spices. Spices, therefore, are not luxuries or unnecessary adjuncts t o tlie diet. They are necessities, and the instinct or craving for them is natural and healthy. Spices are more than flavors. Many of them are antiseptics :uid are used for t.he preservation of iood products heiore conwmption a i d as an aid in tho prevention of iernient.ation and consequent toxemia aft.er consumption. Just as the Eskimo craves lard and blubber without knowing that they are e f f cient heat producers, the inhabitant of the t,ropics craves spices without knoving that they save him from int,estinal troubles likely to occur in his hot climate. A third role that spices play iii the dict is as stimulants to the appetite and digestion. This they do by reason of their pungency or heat. Pepper holds its position as the most popular of all spices becanse it combines its delightful aroma wit,li sufficient bite to st,imulate the flow of t.he digesbive fluids tlirougfi the entire digest,ivc tract. Again, i t is a healt.liy, natural instinct for the Mexican to like his “carne con plenty of chili.” Chemistry is related to the spice industry niainly analytically. Spices 3re not synthesized. They grow. And all tlic chemist can do is to distingnisli good spices from bad ones. Even here lie is not absolutely necessary, for any person with :in educated nose and tongue can pick out good spices from had very ivell; indeed, sometimes better than tlie chemist, for the quality of spices, like t,hat of tea and coffee, cannot he determined entirely by analysis. Spices a r e d i s t i n guished f r o m o t h e r flavoring materials by their aromatic charact c r . For i n s t a o c c . vanilla, whiclr is a most popular flawr, is distinctly not a spice. A spice m u s t h a v e a eertain sharpness not found in flavoring ma; terials o t h e r t h a n spices. Often they are :,Is0 pungent in odor :md h o t o r a c r i d iii taste. Bearing these characteristics in mind, me might classify spices somewhat as follows: Fi$ure 1-Large Mills (1) aromatic, . . simnlv . ” :is allspice, anise, caraway, cardamon, celery seedl cinnamon, cloves, eoriwder, cumin, dill, fennel, mace, nutmeg, paprika, tumnieric; (2) aromatic in odor and pungent in taste, as capsicum, ginger, pepper, yellow or white mustard, and iii a class by itself, (3) hromi or tilack musbard, which is aromatic i n odor and pungent in both odor and tast,e.
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Composition of Spices
The principal constituents of spices arc their essential oils. Thereforethe chemistry of spices is largely included io the chemistry of essential oils. Rrsiii and nonvolatile crystalline principlcs, Iroumw, often contribute materially to the complete flavor. Essential oils are usually of highly complex composition and those of tlir spices are IIO except,ion to t,lierule. Mu& work remains to he done in their more complete analysis. Pepper, the principal spice of commerce, for instance, contains an essential oil consisting largely of phellandrcnc. Dipentene and a small quantity of a sesquiterpene, probably caryophyllene, are also present, but thcse are only diluerits or carriers, and the cliaract,cristic aroma of pepper cannot be reproduced with them, t,liough the pungent principle piperin, a crystalline alkaloid, i s well known. Ginger also owes its aroma t,o an essent,inl oil of suclr complex composition that it has hithcrto defied exact arid complete analysis. Neit,her is the exact, nature of its pungeiit principle, gingorol, known. This is described inerely as an odorless, viscid, strawcolored fluid. Of capsicum, about all UT know is that its extreme pungciicy is due t o a volatile crystalline principle known as capsaicin. Sot,biiig seemi; to b e known about it,s aromatic constituents, even those oS tbc highly aromatic arid nonpungent variety kiiovlm as paprika. Dill and caraway owe their aroma to essential oils which seem bo be almost identical in composition, bot,h consisting almost ent,irely of carvonc and limoneiie. Yet tlrey differ dist,inetly in odnr, and this difference must he due to ot,lier constituents, small in amount but contributing to the odor valne of the oils all out of proportion to the qusiitity present. Similarly, the essential 0011stituent of oil OS Ceylon cinnamon and China cassia is cinnamic xldchydc. The 11:tsor of the former, howcvcr, is far superior to that of the latter, diie entirely to minor little-known cnnstituents. Possibly the value of spices and their csseiit,ial nils is not. suHicieiitly great to offer the same incentive to t,heir analysis a n d syiithesis as is the case u.ith many high-priced perfume nils. Many perfume oils have been analvaed so nerfectlr that’ they can be riproduced syritlietieally wit.ii reinarkable fidelity. This is true of 110 fer Grinding Spices suicr oil. with the exckption kf t,hc volatile oil of black or hroivn mustard seed. The iionesseiitirtl constituents OS spices are of importancc only hecause t,liey are useful in t,he standardization of spices arid in the detection of adulteration. These are ash, total arid iiisoluhle in hydrochloric acid, crude fiber, which is mostly lignin, and, in a fen- instances, stR;rcli and qnercitannic acid.
I S D C S T R I S L A.VD ENCI NEEEING CHE.lfISTRY
December, 1928
Standardization of Spices
Coming as they do under t.he provisions of the Federal Food and Drugs Act, the U. H. Department of .4griculture has formulated definitions and standards for spices, as a guide in tile determination of adulterat,ioziand misljranding. For t.his purpose standards eannot he high standards, and spices which pass these stamlards :ire not, necessarily. high-grade spices, b u t a r c merely indicated to be uiiadulterated within the meaning of the Pure Food JAW. -4s thc principal adulterant or impurity in spices is dirt, i t is iiatiiral t h a t tlic ash coiitent should be tlic main criterion of purity, :rnd for 15 spices i t is t h e o n l y crit,criorr. Similarly, as an iirdiriition of e d u l t e r a t , i o n with inert nmxly vegetable tissue, the deterininat.ion of crude fiber, in addition to that of ash, is directed in inany cas(>s, Other I)oLicsWeighed, Packed, and Capped seiitial c o n s t i t u e n t s , "Brreigii mat,t,er," such as starch, qucrcitaimir acid, lime, but in only a fen. TO also deteriiiined in a number of c spices is the content. of any actual flaroriiig const,it,uerrtdetermincd. According to sucli stand;ards, spices of high flavoring value may be coodemned because of excessive ciint,eiit of ash ur crude fiber, whcreas spiecs which have long since lost thcir aroma through age or improper storage, but are free from actual adulteration, are declared to be legitimate articles of interstate commerce. Standa.rds emliodying esseiitial constit,uents are not more wed probably because of the diAiculty of determining these essential constituents. The coritent of essential oil, for illstance, is prescribed in only m e instalice, that of \Tolatile oil of mustarrd in brorru or black seed. I t so linppms that the volatile oil of mustard is capable of very aecuratc determination, xhiclr, no doubt, nccoimts for its imiversal use in the deterniiiiatiorr of the value of this spice. This one perfect case of the determination of a volatile oil is imfortrmately applicable oiilg to the browr or black must seed. The , not being essential oil of the yellow or white mustard suificiently n h t i l e , carmot be so deterniine(1. It is highly desirable that metliods for the determination of volatile oils in spices be further studied, to tbc eiid that, the det.ermination may be made with eaae and acciirwv niicl applied to the valuation of spices, primarily for t.he giiod of the spice t,rade and iircidentally for more perfcut 'legal stsndartlizatioii. It is true that the volatile ether extract, indicates approximately the volatile oil, but volatile ether ~ ' s t r tis~ riot t regitrdcd as :ill 3CcUr~teindication of volatiie oil content and is hardly worthy of more extensive use. Hortvelt' has ilouc some ?om1
J. Arincn. Ofiiinl
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mendable work on the estimation of volatile oil in cloves, but a.11accurate method of determining the vdat,ilc oil in the distillate after separation from the spice by distillation is desirahle. The solut,ion of this problem would be ideal if sucli determinations could be made in every case by volumetric methods sucli as have long been iii use in the estimation of the volatile oil of must,ard already mentioned, thus avoiding the separatioir of the oil from the distillate Related Industries
Closelyrelated totlic spice industry arc tlie industries using spices nncl otlier condimenti ns the essential ingrcdieiits of their products. These include manufact u r e r s of mayonnaise and otlier salad dressings, pickles, and condiniental sauces. The problems of the mnyomiaise manufact ure r chiefly concern t,he preservatioii of his product,, both mechanically and cheuiieally, Y in the form in wliicli in LithOBTsnhfd Tin Packages a i t l e a v e s his factory. I\iayomiaise is a ilcliciite product, sensitive to heat and cold, oxidatioii, aiid iiieclraiiical a,gitation. It is preserved witli salt, vinegsr, arid spices, aud recently lactic acid tias been recommemicd for tfiis purpose. The spices play only :I minor part as preservat.ivcs, for mayonnaise is very delicately flavored and ii!)t, niiich spice can be used, though upoil the taste used iil t,Iicir seiect,ion the popularity of tho product largely re&. Tire principal prob!enis are t o preserve tho oil :i@iist ranciclity arid the emulsion against separation. Ranciditg of oils is an old atid irnport,ant problem of the oil industry and iniicli has been Ieariied regarding it, among other things that potential rancidity of an oil can be detected beforr any actual rancidity has appeared. This Eact is applied by tlic m:mofaetiirer in the sc!ect,ion of oil Em iise in his maymimise. While great skill in making a stable product has bcen acquired by long practice in mayomiaise msnufaeture, the srientific principles of emulsification have not, t o my knonledge, been deliberately applied. The mmiufaeture of mayonnaise, as well as that of' pickles and sauces, is more of an artistic than a cliemical industry. The condiment manufact.urer, like a cook or a perfumer, is :t true artist. He blends flavors irist.ead of colors or odors. hut the success of his work is no less depeiident upoil his skill :and good tastc. The chemist assists him only in determining that his r m matcrittls are pure and of uniforiii quality, that. his products are properly sterilized or contain enmgll preservative ingredients t o keep tlicmfrom fermentation or putrefaction, and that t h y are so packed that they are sealed against thc cntraiicc of micro(irga&ms :mrl air wlrerercr t,liesc :LIT h:%rmfol.
Agr. C h c m . , 1. 151 ( i l l l i ) .
Committee Approves Institute of Health-Th? S n ~ a kGuninittfe on Commerce has approved the creation of a National Institute of Health as proposed in a bill introducrd by Senator Kansdell, of Louisiana, and now on the Senate calendar of business to be considered at the forthcoming session of Congress. In the rePoIt recommendin. the enactment of this bill. the committee pointed out that such legislation would provide an agency for pure scientific research on the cause and prevention
would set up ail \ r i ~ i ~rrlight I ~ X C ~ vllci ~ ~ administer gifts to promote such research, and would set up a system of fellowships to provide trained personnel for public health work. The bill seeks to promote the health of human bcinps, improw their earning capacity, reduce living eupenses, j,,,,,, their happiness, and prolong their lives, uf &cases;
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