100 THE ANALYST. ON THE COXPOSITION AND ADULTERATION OF FRUIT JANS. BY M.A. ADAMS, F.C.S., F.R.C.S. A FEW months ago, when several samples of fruit jam were brought for examination, under the provisions of the I‘ Food and Drugs Act,” I was quite at a loss for any trust- worthy guide to assist me in the necessary examination, and so far as I know, this field of investigation has not been much worked. On this account, therefore, I trust to be excused for offering the following remarks and figures, relating to the nature and com- position of jams. I am painfully aware that a series of somewhat tedious proximate analyses have not brought to light much that is valuable, ye 1; in so far as no such analyses have hitherto been published, they may go for what they are worth, and perhaps save others, bent on similar investigation, some little trouble, or possibly even open out suggestions for the better means of attacking the question of jam adulteration than are at present in use.The following analyses relate to three classes of jam :--Zome ma&, which of course we know to have been made of nothing but the pure fruit and cane sugar. A oommemial jam of a most szyerior make, which we have every reason to believe is also absolutely pure, and lastly, a eommwciuljum of very inferior quality, which was found to consist, not wholly of the fruit which it was represented to be made of, but largely diluted with apple pulp. The analyses show the per-centage composition as regards glucose, cane sugar, other soluble matters, ash and moisture. The utmost range of difference in regard to moistwe lies between 37*5, and 23 per cent., and the average of good jam is about 30 per cent.The Ash in all cases is less than 1 per cent., and ranges from 0.22 per cent. to 0*95 per cent. The Skins alzd 886d8 (of courae this does not include the stones of plums, apricot or damsons) are less than I expected, and range from 1 #02 to 11.45 per cent. Other Soluble Xatter is a (( difference figure,” and, except in the case of ‘ I Steer’s Apricot,’’ in which it amounted to 14.07 ! !, averaged 3-83 per cent. As of course was to be anticipated, the bulk of the substance of jam is sugar, amounting to an average on the dried substance of 88.6 per cent., and ranging from 74.77 per cent. to 96-98 per cent., but, contrary to my expectation by far the larger partTHE ANALYST.101. -- of this sugar is inverted ; but in this particular comes Gut the most conspicuous of the differences between the several description8 of jam experimented upon, for while on an average only 6.71 per Cent. of uninverted sugar could be found in the horns made, in Beach’s there is 27-85 per cent., showing that at least in the ordinary domestic method of production the cane sugar is almost wholly inverted. This of course, absolutely negatives any attempt at determination of adulteration, if it may now be so considered, by the substitution and artificial glucose for cane sugar in the manufacture. I have nothing more at present to say on the chemical aspect of the analyses; from that point of view the matter is still pretty barren of indications which can assist in the demonstration of adulteration.So far as 1 know the only adulteration practised is the substitution of inferior fruit, or other vegetable pulp, for the more valuable fruit which it is ostensibly sold for, much in the same way as chicory is mixed with and sold as coffee for the purpose of extorting the price of coffee for the less valuable chicory. Among the many substances said to be used for this purpose in the manufacture of commercial jam, are mangel-wurzel, turnip, carrot, etc., and a common form of gelatine to fortify the pectose substances, but the principal ingredient of adulterated jam is more often apple pulp, the apples so used being refuse windfalls, whichare totttlly unserviceable for any other purpose.The detection of these foreign vegetable substances resolves itself into an investiga- tion by the microscope, and is not easy; for at the outset, the cellular and fibro-cellular structures, whioh enter into the formation of fruits, such as are usually made into jam, are naturally similar to the analagous structures in the adulterants, and to make the matter worse, the process of manufacture so breaks down and destroys the original natural features of the tissues that often, as a matter of practice, one has to deal with a mass of debris in which it is impossible to trace sufficiently the natural structural features to permit of anything like a safe conclusion as to admixture. It is true there are a certain few characteristic structures, like the cuticles of the raspberry and currant, which are very enduring, and such as none with adequate knowledge could fail to recognize, but the main bulk of the cellular tissue composing the parenchyma of the fruits is so soft and diffluent, and so similar that their slight special peculiarities are quickly and entirely lost in the mess to which they are reduced in the making of jam.Such, however, as remains to be observed are rendered more conspicuous by certain treat- ment ; for instance, by staining with Hoffmann’s Violet, the cells are pretty generally made to Bhow up well, and by tincture of iodine, the cells of apple, to the exclusion of all other cells are stained a most characteristic pinkish purple or greenish colour in such a manner that the presence of apple may be detected with the greatest certainty and utmost ease, and within certain limits a quantitative estimation may be arrived at.I n the raw apple, the development of this colour does not necessarily occur on the treat- ment by iodine, but always follows boiling in dilute acid, the natural acid of the fruit being usually of itself sufficient to determine the reaction. I beg to acknowledge the assistance of M i . L. Stansell in the conduct of these analyses. CONCLUSION OF THE PIZOOEEDINGS OF THE SOCIETY OF PUBLIC ANALYSTS.ANALYSES OF JANE4 MANLTACTURED IN 1888, SHOWING PERCENTAGE GOMPOSITION, a. ~ ~~~~ - DO. DO. CALCULATED UPON THE DRY SUBSTANCE. Ilboisfnre. 3.94 + 1.11 '6-39 0.98 2'94 3-82 4.19 1-75 3.45 0.40 . 5-00 3-09 -- -- -. -. *44 -34 -46 -30 -98 -40 -22 '53 -44 -34 .34 29-95 23.09 27-63 34.56 27'53 31-06 29.21 21-39 30-34 30.56 33-38 *37 -- -81 -48 -37 -66 *35 059 $9 -52 - -- -40 -80 *30 *46 -95 848 -66 -- 29-52 24-16 26.65 33-93 30.47 32-72 32.72 32-72 30.47 36.70 33'16 26'65 24.88 37'54 34.55 32*24 42-55 51-86 66-16 47-85 46-98 50.96 -- 58-81 14.17 8.86 0.94 12-22 6-22 5.28 7-95 Other Soluble matter.5-62 4.40 5-71 1.53 8-83 1.49 9-28 4.12 4.05 5.54 4.79 4-90 5.92 1-58 2.62 18.73 4.75 0.57 10-92 10.63 5-33 7-20 7-97 10.71 - Moisture 1 original Ubafaaoe. 29-95 24-76 36-70 23.09 27'63 34.56 26-66 33-26 27.53 31-06 33-93 26-66 29-21 30.47 33.38 24.88 27.39 30.34 32.72 54.55 37.54 30.56 32.06 32.72 - Cane sugar. 27*69 10.19 22.38 49-92 33.43 43.52 3-88 13-25 49*55 60.12 3.43 1-28 17.10 5-73 45-69 16.26 31.09 42-89 8-31 8-06 9.95 33.87 12.43 23*98 - skins and SCdS.5-19 11-21 4.04 3 *39 15-82 7.72 10.40 3*8! 3-36 4.77 4.58 4-56 3.37 4-81 2-13 1*35 3-34 1-80 3.83 2'71 7*9,7 3-45 4.13 3.80 - Skins and Seeds. 3-64 2.61 11.45 5-06 2.44 3-29 2.39 1-42 2-43 1-26 2.40 3.49 8'44 7-63 3-03 3.35 2.58 2-81 2.56 4.34 Glucose. Bsh. 0-62 1 *07 0.63 0'44 0.62 0.45 0.65 1.19 0-38 0.58 0.56 0'41 0.31 0.95 0.51 0-61 0.73 0.63 0.52 0.78 1-52 0.49 0.87 0.58 - EACH'S Black Currant Red Currant.. Blaokberry .. Raspberry .. Strawberry .. Gooseberry .. Apricot . . Plum .. ., Damson .. 9 t .. ,, .. .. 42.63 34.38 29-88 36-20 30.90 20.00 51-88 32.67 43-62 37-68 38-18 19 -40 38-40 24.20 28-48 35-91 4145 12-11 30-44 w 5 a 29.88 23'62 B h k Currant- Beach 9 , Home &e Y Y *Steer .. RedCnrrant Beach .. Blackberry- Beach .. Beach HomeMaG Strawberry- Beach .. Y Y Bemh 9 ) *Steer .. 97 Home Maii 9 9 *Steer .. Y 9 H~~~ ad& Gooseberry- Beach Apricot- Beech ,. Steer . . Plnm- B e d ,. 9 9 Reaoh Y, 'Steer .. *Sterr ., Dmson- Beach Y Y Eome Mad; Q&C%3- Qome Made 9 , 1) Home && Y Y 60.85 73-11 67-92 44-10 41*2S 46.78 75-77 77'59 42.64 29-01 86.62 88-83 73-28 86.89 49 *04 63.03 60.07 54-09 16-41 77-85 75.21 54.98 75.29 60.90 - 35.W Average .. Black Cnrrant Raspberrg .. Strawberry . + Gooseberry .. Plum .. .. Dam6on ,. Q u w e .. HOKE MADE !27*85 3.31 6-81 3-17 1-11 7.35 "21 4-84 t-94 55-01 65 *58 51.41 51.16 53-11 57.23 7.67 2-85 2-27 3.99 5-59 8.45 16.14 6.71 Average .. "Black Currant +Raspberry .. "Strawberry .. Apricot .. "Plum .. .. Average .. STEER'S Ib ,, .. .. 2-66 2-56 3-35 1.02 4.98 1.77 3.62 2.76 3.60 14-0 7 3.33 6.96 5.72 * All these were largely adulterated with apple. * All these were largely adulterated with apple.