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T H E J O C R N A L O F I N D C S T R I A L A N D ELVGIYEERILJTGC H E M I S T R Y
existence of xanthophyl t o a n appreciable extent in carrots and the ready solubility of xanthophyl in f a t makes it reasonably certain t h a t i-t was present in the f a t in t h e cases of artificial coloration with carotin. in which as complete oxidation of the pigments by t h e ferric chloride resulted as in the cases involving t h e natural pigment only. From the 1-iewpoint of the analyst it is unfortunate t h a t i t does not appear possible t o detect the presence of carotin added artificially t o butter f a t or oleomargarine. This conclusion may be a hasty one, however. Although it v d l probably never be possible t o difierentiate between natural and added carotin in fats, it may be possible, should the food laws ever require it: t o tell mThether carotin has becn added t o fat. While no a t t e m p t has been made t o u-ork out a n y tests in this connection it is suggested t h a t the possibilities of determining whether carotin has been added lie in t h e fact t h a t xanthophyl is naturally present in animal fats in very small proportion of t h e total pigment, while it is present in much greater proportion in all the vegetable matter containing carotin which might he used as a source of carotin for the artificial coloration of f a t ; furthermore. it would not be possible t o extract t h e carotin from these sources without, a t t h e same time, extracting the xanthophyl. Xccordingly! butter fat or oleomargarine containing added carotin would likewise contain a much greater proportion of xanthophyl t h a n is natural t o these fats. I t is doubtful if any simple test can be devised for determining the relative proportion of carotin and xanthophyl in fat. The solution of the problem would probably have t o involve a separation of the total pigment from the fat and a subsequent separation of the extracted pigment into its carotin and xanthophyl portions b y means of one of t h e relative solubility properties of these two classes of pigments. These properties are discussed fully in the studies on animal pigments previously published from this laboratory. As the question is not one of immediate moment t h e reader interested in t h e question is referred t o t h e publications mentioned. The strong reducing action of carotin on ferric chloride, which is the basis of the method for t h e detection of carotin, suggested t h a t other reducible ferric salts might be similarly affected and accordingly ‘serve equally well for the detection of carotin. This was found t o be the case. Ferric nitrate was found t o oxidize and decolorize carotin in butter fat but t h e test using this salt could not be simplified as in the case of ferric chloride, owing t o the insolubility of ferric nitrate in fat. I t was found necessary t o add some reagent which mould dissolre both t h e fat and t h e ferric nitrate, such as acetone. No green coloration accompanied the decolorization of t h e carotin in this test. b u t instead there was a suspension of a reddish brown iron oxide formed from t h e ferric nitrate. SUMMARY
I-It is pointed out t h a t t h e detection of carotin (the natural yellow pigment of animal fats) in oleo-
Yol. 8. No. 7
margarine is made necessary by t h e oleomargarine laws of many stares. 11-Cornelison’s test for carotin artificially added t o €at is shown t o be qu0te.d wrongly in Leach’s “ F o o d Inspection and Analysis.” 111-The relation between Martin’s test for artificial pigments in fats and Moore’s test for carotin added artificially t o f a t , as given in Leach’s “ F o o d Inspection and 9nalysis,” is shown t o be confused, and t h e true relation is pointed out. IV--It is shown t h a t bloore’s test for carotin in f a t or oleomargarine is not alone specific for carotin added artificially, b u t is equally specific for t h e carotin natural t o animal fats. T----It is shown t h a t the carotin is not dissolved out of the fat in Moore’s test, as stated b y Moore. b u t is merely decolorized b y t h e ferric chloride added. The reaction involved is shown t o be a reduction of t h e iron and t h e simultaneous oxidation of t h e carotin. VI-Modification and iniprovements in Moore’s tests are given. A method is also suggested for detecting both natural and artificial pigments (other t h a n carotin) in the same f a t . VII---The relation of Moore’s test t o t h e question of the natural state of carotin in fat, and t h e possibility of determining whether carotin has been added t o butter fat or oleomargarine are discussed. DAIRYCHEHISTRYLABORATORY USIVERSITY OF MISSOERI, COLUIIIBI.~
CULTIVATION AND CANNING OF MANGOES IN INDIA TARINI CHARAN
CII.4UDHERI’
Received May 3, 1916
The mango tree: Martgijera i i z d i c u , is a large evergreen and native of t h e south of Asia. I t grows in the Tropical Himalayas a t 1:ooo t o 3,000 ft. above sea leTTel, from Kumaun t o Bhutan, Bengal and Southern India. It has been known and cultivated all over India from very remote ages. I t is profusely connected with Sanskrit mythology and some religious rites of t h e Hindus and finds a place in t h e old Hindu tales and folklore. Mention is made of it by most of the foreign travelers in India. F. Jordanus notes t h e remarkable quality of the fruit about 1328 A . D . , and Baber, the founder of the l l o g h u l Empire in India, speaks of the excellence of t h e mango. Later on, Gracia de Orta, in the year 1563, states t h a t t h e fruit is so delightfully tasteful and highly refreshing t h a t : when in season,2 no other f r u i t can sell. There are numerous varieties3 of mangoes in India, the best and most widely grown being Fazlee, Langrah and Bombay. T h e plants can be grown from t h e seed or stone of t h e fruit; b u t it, is found t h a t on t h e same soil t h e seedlings rarely produce fruit equal in size, taste and flavor Government Research Scholar in Chemistry. T h e general flowering period of mango trees is from December t o February, and t h e principal ripening season for mangoes is from M a y t o the middle of August. W a t t , D. E. P., Vol. 5, 147. 3 Woodrow, “ T h e Mango, Cultivation and Varieties,” 11, 191 I : Firminger, Mango-Gard. I n d . , 1904, 256-61. 1
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July, 1916
T H E JOURNAL OF INDL'STRIAL A N D ENGINEERING CHEMISTRY
t o t h e parents. T h e usual method of cultivation and propagation is b y inarching. Maries states t h a t t h e best place for mango plantation is a raised, well-drained piece of land with a good depth of soil. The nature of the soil, however, does not appear t o interfere much with t h e growth of t h e tree. It is found t h a t in Bengal it succeeds equally well on a rich, deep, river deposit. on clayey or on sandy soil; while in Gwalior good trees are grown on Kankara-a soil with a large proportion of lime or stone nodules. For purposes of inarching, t h e stones of t h e fruit when t h e mango is ripe in season are usually sown, and when t h e plants have become one year old, they are potted out t o be grafted b y inarching with desirable trees. This is done during setting-in of t h e rain; in the second year of t h e growth of t h e seedling, t h e union being usually complete a t the growth of t h e rainy season. The essential principle in this method of grafting consists in bringing t h e cambium of t h e stock and t h e scion together before t h e graft is completely severed, t h e parts being fastened carefully so as t o exclude a.ir and water and t o keep the plant a n d the mother tree healthy during t h e short growing period. I t is t o be noted t h a t the scion and t h e stock should be of t h e same thickness. The best season for planting out t h e young grafts is in t h e early part of the rainy season. Firm states t h a t shade is necessary during the following six months, and t h e intervening land between the rows of grafts is cultivated with moderate irrigation and rich manuring and crops grown until the mango trees have attained t h e flowering size. Generally speaking, in five years t h e trees should bear a considerable quantity of fruit. The principal localities in India where good mangoes are said t o be produced are Mazagon in Bombay and Durbhanga; b u t t h e finest varieties of t h e fruit in extensive scale are grown a t Malda i n Bengal. I n Assam, on t h e other hand, t h e fruit ripens very badly and is extremely diseased, the mango weevil being very destructive t o the fruit.' Besides being eaten as a ripe fruit in India, numerous preparations are made of it. When green, it is peeled. cut into slices, and after removing t h e stone, it is p u t into curries or made into sauces, chutnies or pickles of various kinds. K h e n young and green it is boiled, strained, mixed with milk and sugar and t h u s prepared as the custard, known as mango-phul. When it is cut into pieces and dried, it is known as Indian amchoor; and when very young, small pieces are t a k e n in salad. So, also, ripe mango is used in curries and salads; and the mango juice, expressed and dried in thin cakes, is known as Indian amsath. I n recent years, pickles and chutnies are largely exported t o Europe, Africa and elsewhere. W a t t believed t h a t if mangoes, in fresh condition, could be conveyed cheaply into England, a trade as extensive as t h e fruits of the West Indies might be immediately anticipatedS2 T h e use of this fruit cannot be considered as a mere 1
M. Lefroy, Agu. J. India. I, 11, 164. W a t t , C. P. I., 1908, 765.
6 I9
luxury. I t is thought t o be a necessity b y medical authorities from medicinal and dietetic points of view. I n medicine, t h e ripe fruit is considered invigorating, fattening, laxative and diuretic. I t is a current view t h a t in many cases fresh ripe mangoes, eaten in large quantities, give rise t o troublesome boils, and on abstaining from taking mangoes, t h e eruptions heal u p . Gibson and Issabella, of the Medical College in the Philippine University,' conclude t h a t if a mother eats sufficient mangoes, the boils appear in her sucking infant? the cause being mainly attributed t o the richness of the gums in mango juice. The present writer has examined t h e Bengal mangoes both as regards their gum content and physiological influence. The juice of this fruit contains a small percentage of gums and is rich in sugar. I n 63 cases of men, women and children, who were overfed with mangoes (Fazlee and Langrah) for 7 days, not one case of eruption occurred. These two varieties of mangoes, especially preserred in pure sugar syrup, while possessing all t h e medicinal and dietetic value. is absolutely free from a n y such objection.2 The modern methods' of preserving fruit may be briefly classified under five heads: (I) heat or cold storage; ( 2 ) drying; (3) excluding air; (4) adding a third substance which acts as a preservative; ( j ) pickling in suitable liquors. Each of these methods, considered individually, is unsatisfactory for preserving mangoes. Sometimes t h e combination of ( 3 ) , (4) and ( j ) is applied. B u t the aim of scientific canning is not only t o preserve t h e fruit b u t t o retain all t h e delicacies of t h e fresh ripe fruit, viz., t h e natural color, taste and flavor. T o preserve t h e mango with all its delicacies requires a thorough familiarity of the character of t h e fruit and also t h e climatic condition of t h e country where t h e preserves have t o be stored, for. t h e selection of t h e proper process depends roughly on these factors. I t has been found t h a t no cut-and-dried process or combination of processes can preserve t h e mangoes in fresh condition. The writer announces t h a t with regard t o mangoes, which are sensitive fruits, he has been successful almost t o t h e ideal standard b y first sorting the ripe fruit suitable. for canning and estimating its degree of sweetness and t h e n determining t h e strength of t h e crystalline sugar syrup which has t o be so regulated t h a t it does not impart a n y additional artificial sweetness t o t h e fruit. A different temperature is also used for different varieties of mango, according to. t h e durability of t h e flavor and stiffness or softness of the slices. I n this process no preservative substance which may act prejudicially on t h e fruit, immediately or after a period of storage, is used.3 GH~RAMORA,':RAJ~H.~HI. IQDIA
The Philippine Jouvnal of Science, 1916. In Malda, the poor people, as a matter of moral right, live almost exclusively on mangoes of the garden owners. On inquiry the writer has almost no information of pimples, boils or cancers, excepting the usual stray cases. The Hindustan Fruit Preserving Co.. Malda, Bengal (India), are now working on these lines. 1
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