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Deterioration of Foodstuffs
508
The Veter£nary Journal.
The procedure varies with the age of the subject and the condition of the cord. The whole cord may be placed within the grasp of the instrument, or the posterior portion may be severed with the kni fe, and the castrator applied only to the vascular cord, or the posterior and anterior portions may be crushed separately in the order indicated. The last procedure should be followed in the castration of grown horses, in which the small testicular artery may bleed after section without crushing of the posterior portion of tbe cord. The castrator in action is rapid, humane, and generally satisfactory, there being little bleeding, and it is equally serviceable for operation in th e standing and recumbent positions. Many thousands of horses, bulls, and other animals in England and the Colonies have been successfully castrated by broad crushing, which, in the standing operation, is becoming increasingly popular as a very convenient and expeditious method of effecting hcemostasis.
DETERIORATION OF FOODSTUFFS. co. T IP PERARY . IN the September issue of the VETERINARY JO URNAL, an account was given by the present writer of various organisms found affecting foodstuffs. In this section it is proposed to discuss some of the effec ts of micro-organisms and mould fungi upon foodstuffs. It was intended, had there been more time, to have carried out a series of experiments on the same lines as those of Konig, Spreckermann, and Bremer-; but unfortunately I had to return to my station, where there was neith er time nor the wherewithal to carry them out. A tran slation of the above writer's experiments was very l{indly lent to me by Mr. J. Hanley (Messrs. Bibby's, analytical chemist) at Liverpool, and from this translation th e following deductions were taken : Bacteria are a pathogenic species, and hence foodstuffs attacked by them are looked upon as pernicious and objectionable; but whether or not the objectionable character of decomposed material is brought about by mould fungi as well as bacteria has not yet been definitely determined. "The kinds of decomposition undergone by these materials, as well as their nature, under varying conditions of storage, &c., are but little understood, so there are strong 'reasons why an attempt should be made to answer these questions." Experiments were carried out by these three writers and others with the objects of determining in what manner the individual orga ns set up decomposition in the food stuffs under differin g conditions, and to find out whether the resulting altered materials are perni ciolls. \iVhen attacked by mould. fun g i, the proteid material undergoes no loss, only the pure protein loses, and correspondingly increases the protein combinations soluble irr"water. Alcohol and ammonia are not formed as a consequence of the moulding; the former results from yeast fermentation, and the latter is a decomposition product of protein and bacteria. R. Scherpe investigated rye and wheat in this connection, and found that the loss through weak moulding amounted to between 3"0 and 6'6 per cent., and through well-developed moulding the average in three varieties of rye was 45 per cent. In three varieties of wheat BY CAPTA I N GAMBLE, F.R.C.Y.S., C AHIR,
Deterioration
0/ Foodstuffs.
50 9
under equa l conditions the average loss was 32 per cent. Contrary to the result s obtain ed in the above·ment ioned in ves tigations, S cherpe found that the nitrogen of the protein had a share in this loss, the diminution in nitrogen amounting to be : in th e case of weak moulding, rye, 6 per cent. ; whea t, 3' 2 per cent. In the case of strong moulding, rye, TI7 per cent.; wheat, 2 t to 10 per cent. Scherpe observed in the case of strongly moulded corn a considerably hig her perce ntage of ammonia than in sound corn. The deg ree of acidity was considerably raised by weak mouldin g, whil st th e cellulose, under th e influence of th e mould ing, suffered an increase. K oni g, Speckermann, and Bremer repeatedly obse rved a consider· able loss of fat in foodstuffs rich in fat when kept und er ce rtain condition s. For example, in oil·cake, or oil ·cake mea ls, which had been kept for from six to twelve month s, the amount of fa t had diminish ed from 1 0 or 12 per cent. to a fe w percentages, Reitmayr found th a t in ea rthnut cakes which had been kept gettin g mouldy for two years th e fa t had sunk from 11 '9° per cent. to 0 '5 6 per cent, Ritthausen and Ba umann stored away two rape· seed ca kes for two years in closed g lass vessel s, and found in th e compl e tely mOllltied mass the foll o wing : !{ AP~: S E ED CAK I( (I) ,
\Vater
\'Vh en fre sh After two years .. ,
.. , 12 '45 per cent. .. , 21 '99
Fat
Fat in th e dry subs l:l.Il ce
10'45 per cent. 1 '98
12'02 pe r cent , 2'53
and in the second sa mple :- R APE SEED CAKE (2 ).
W ate r
Fa t
II
F at in the dry substance
- - - - - - - - - - - - --- - - - - -- - - - - -- -- - - - - - - -- - When fr e£h .. , Afte r tw o years .. ,
.. ,
' " 12 ' 31 per cent. 8'50 pe r cent. / , .. 23 '42 " 1'87 "
9 '69 per cent. 2'44"
The considerable decrease in the fa t of the rape-seed cakes was attributed to the life-work of the moulds, and there were recogni zed in the rape cakes whi ch had been kept for two years no less than fifteen di stinct species of micro·organisms ; but th ei r power of fat absorption was not gone into more closely, Similar observations upon the decrease of fat during the storage of the residues from the press ing of olives appear to have been made, sin ce Klein recom mended th a t, in order to avoid th e loss of fat in the olive pressings, th e latter should be dried ra pidly, or, bein g soaked with th e fruit water, they shou ld be strongly pre ssed or put th ro ug h rollers . He claim s that this treatmen t does not a llow of a ny extensive mould g rowth, but gives no explanation of th e decrease in fat. Sea rc hing in vestigations upon th e d ecomposition of fat with a na lyti ca l result s were published by Schmidt. Th ese go to show th at Aspergillus niger can obtain its total c8.rbon requirements from oil of a lm onds or free ol ei c acid. Out of 0' 294 g ra mm e of oil of almonds, 0'2 R5 g ramm e, or 96'93 per cent., wa s destroyed by Aspergillus ll ige y
The Veterinary J oU1'nal.
510
in forty-five days . After these observations it can no longer be doubt ed that fa t ca n be absorbed by micro ·organisms . In an experiment to determine the influence of different amounts of moisture upon mould growths und decomposition, Ko nig, Spreckermann, and Bremer took I kilogram me of cotton seed meal and mix ed it with different quantities of water, viz., So, 100, 200, 3 00,400, 500, and 600 c.c., and, in order that the normal conditions should be imitated as closely as possible, they were kept for seven ty-four days (from June 13 to S ep tember 25) in small linen b ags , and at the ordinary room temperature. The results obtained are given in the followin g table : OF ( I. ) Natural or ordinary cot ton seed mea l
EAC H ONE
( II .) 50
C.C.
KILOGRA ~I ~m
( 111. )
100 C.C..
OF
( IV.)
COTTON SEED
200 C.C.
lII E" L
AND WATER.
(V.) 300 c.c.
The mea l con· N o increase Bacteria n o t Bacteria no t in· Bacteria had de· tained only of the micro - incre as e d . creased. One veloped st r ong ly. Ve ry s tron g o f th e O 'i dium It was obse rved a fe w bac- organism s. de vel opme nt s pee i e s de- that two speci es teri a and of 2 Ojdium scribed under belong in g to the moul d spores a nd second- III . predom· pota t o-baci lli a r y se ri es I inated . group prerlominPenicillium I Less abu ndant ated, also the glallc",,, . I andin approxispecies ofOIc1 iulll mately equa l seen in Samp le n umbers were IV. was stro ug ly Peni c i I / i 11m represented . gla licul/I, ElIro- There were in t £UlIl ·,-epens, addition individ · and R Iligopus ual specim ens of
lIigr/rans.
(V !. )
4 00 C.C.
(V II .) ;00 c.c. and (V I". ) 1,000C.C.
S tron g development of th e p otatol b l cilli species Only Asper.
Excl u s i vely ba c t e ri a I growths. The moulds had only estabI /!illusjlavlts lish ed thenlwas present selv e ; at the ' o f the mould s ed ges, prob !bly 0 "ing to the gradual drying.
A spergillusjlavllS
This last experiment shows very clearly indeed what influence a different proportion of water has upon the growth of the microorganisms present in a particular sample. In the presence of a low water content (up to I I per cent.) absolutely no increase in their number took place; in the presence of a mean proportion of water (14 to 30 per cent.) mould and Oidium species predominated and increased, whilst the bacteria were the primary product in presence of 30 per cent. of water and above. In conclusion, it may be mentioned that in my experiments Aspergillus niger was not found, this mould being one of the ca uses of Pneumomycosis aspergillosis. In this connection an interesting sample of hay which was alleged to convey anthrax was examined at the Liverpool University, guinea-pigs being inoculated with an infusion from it. · Several of these animals died within twenty-four hours from putrid intoxication, and subcultures on glucose agar from their suu cutaneous tissues yielded in one case Aspergillus niger . Possibly the spores of the fun gus were introduced from the hay with the infusion, and remained unchan ged in the subcutaneous tissue of the g uinea-pig s until after death, a nd were then transferred to the more fa vourabl e culture medium (glucose agar), when the spores germinated, and a typical Aspergillus niger was produced, which I had the opportunity of examining under the microscope.
The Veter£nary Journal.
The procedure varies with the age of the subject and the condition of the cord. The whole cord may be placed within the grasp of the instrument, or the posterior portion may be severed with the kni fe, and the castrator applied only to the vascular cord, or the posterior and anterior portions may be crushed separately in the order indicated. The last procedure should be followed in the castration of grown horses, in which the small testicular artery may bleed after section without crushing of the posterior portion of tbe cord. The castrator in action is rapid, humane, and generally satisfactory, there being little bleeding, and it is equally serviceable for operation in th e standing and recumbent positions. Many thousands of horses, bulls, and other animals in England and the Colonies have been successfully castrated by broad crushing, which, in the standing operation, is becoming increasingly popular as a very convenient and expeditious method of effecting hcemostasis.
DETERIORATION OF FOODSTUFFS. co. T IP PERARY . IN the September issue of the VETERINARY JO URNAL, an account was given by the present writer of various organisms found affecting foodstuffs. In this section it is proposed to discuss some of the effec ts of micro-organisms and mould fungi upon foodstuffs. It was intended, had there been more time, to have carried out a series of experiments on the same lines as those of Konig, Spreckermann, and Bremer-; but unfortunately I had to return to my station, where there was neith er time nor the wherewithal to carry them out. A tran slation of the above writer's experiments was very l{indly lent to me by Mr. J. Hanley (Messrs. Bibby's, analytical chemist) at Liverpool, and from this translation th e following deductions were taken : Bacteria are a pathogenic species, and hence foodstuffs attacked by them are looked upon as pernicious and objectionable; but whether or not the objectionable character of decomposed material is brought about by mould fungi as well as bacteria has not yet been definitely determined. "The kinds of decomposition undergone by these materials, as well as their nature, under varying conditions of storage, &c., are but little understood, so there are strong 'reasons why an attempt should be made to answer these questions." Experiments were carried out by these three writers and others with the objects of determining in what manner the individual orga ns set up decomposition in the food stuffs under differin g conditions, and to find out whether the resulting altered materials are perni ciolls. \iVhen attacked by mould. fun g i, the proteid material undergoes no loss, only the pure protein loses, and correspondingly increases the protein combinations soluble irr"water. Alcohol and ammonia are not formed as a consequence of the moulding; the former results from yeast fermentation, and the latter is a decomposition product of protein and bacteria. R. Scherpe investigated rye and wheat in this connection, and found that the loss through weak moulding amounted to between 3"0 and 6'6 per cent., and through well-developed moulding the average in three varieties of rye was 45 per cent. In three varieties of wheat BY CAPTA I N GAMBLE, F.R.C.Y.S., C AHIR,
Deterioration
0/ Foodstuffs.
50 9
under equa l conditions the average loss was 32 per cent. Contrary to the result s obtain ed in the above·ment ioned in ves tigations, S cherpe found that the nitrogen of the protein had a share in this loss, the diminution in nitrogen amounting to be : in th e case of weak moulding, rye, 6 per cent. ; whea t, 3' 2 per cent. In the case of strong moulding, rye, TI7 per cent.; wheat, 2 t to 10 per cent. Scherpe observed in the case of strongly moulded corn a considerably hig her perce ntage of ammonia than in sound corn. The deg ree of acidity was considerably raised by weak mouldin g, whil st th e cellulose, under th e influence of th e mould ing, suffered an increase. K oni g, Speckermann, and Bremer repeatedly obse rved a consider· able loss of fat in foodstuffs rich in fat when kept und er ce rtain condition s. For example, in oil·cake, or oil ·cake mea ls, which had been kept for from six to twelve month s, the amount of fa t had diminish ed from 1 0 or 12 per cent. to a fe w percentages, Reitmayr found th a t in ea rthnut cakes which had been kept gettin g mouldy for two years th e fa t had sunk from 11 '9° per cent. to 0 '5 6 per cent, Ritthausen and Ba umann stored away two rape· seed ca kes for two years in closed g lass vessel s, and found in th e compl e tely mOllltied mass the foll o wing : !{ AP~: S E ED CAK I( (I) ,
\Vater
\'Vh en fre sh After two years .. ,
.. , 12 '45 per cent. .. , 21 '99
Fat
Fat in th e dry subs l:l.Il ce
10'45 per cent. 1 '98
12'02 pe r cent , 2'53
and in the second sa mple :- R APE SEED CAKE (2 ).
W ate r
Fa t
II
F at in the dry substance
- - - - - - - - - - - - --- - - - - -- - - - - -- -- - - - - - - -- - When fr e£h .. , Afte r tw o years .. ,
.. ,
' " 12 ' 31 per cent. 8'50 pe r cent. / , .. 23 '42 " 1'87 "
9 '69 per cent. 2'44"
The considerable decrease in the fa t of the rape-seed cakes was attributed to the life-work of the moulds, and there were recogni zed in the rape cakes whi ch had been kept for two years no less than fifteen di stinct species of micro·organisms ; but th ei r power of fat absorption was not gone into more closely, Similar observations upon the decrease of fat during the storage of the residues from the press ing of olives appear to have been made, sin ce Klein recom mended th a t, in order to avoid th e loss of fat in the olive pressings, th e latter should be dried ra pidly, or, bein g soaked with th e fruit water, they shou ld be strongly pre ssed or put th ro ug h rollers . He claim s that this treatmen t does not a llow of a ny extensive mould g rowth, but gives no explanation of th e decrease in fat. Sea rc hing in vestigations upon th e d ecomposition of fat with a na lyti ca l result s were published by Schmidt. Th ese go to show th at Aspergillus niger can obtain its total c8.rbon requirements from oil of a lm onds or free ol ei c acid. Out of 0' 294 g ra mm e of oil of almonds, 0'2 R5 g ramm e, or 96'93 per cent., wa s destroyed by Aspergillus ll ige y
The Veterinary J oU1'nal.
510
in forty-five days . After these observations it can no longer be doubt ed that fa t ca n be absorbed by micro ·organisms . In an experiment to determine the influence of different amounts of moisture upon mould growths und decomposition, Ko nig, Spreckermann, and Bremer took I kilogram me of cotton seed meal and mix ed it with different quantities of water, viz., So, 100, 200, 3 00,400, 500, and 600 c.c., and, in order that the normal conditions should be imitated as closely as possible, they were kept for seven ty-four days (from June 13 to S ep tember 25) in small linen b ags , and at the ordinary room temperature. The results obtained are given in the followin g table : OF ( I. ) Natural or ordinary cot ton seed mea l
EAC H ONE
( II .) 50
C.C.
KILOGRA ~I ~m
( 111. )
100 C.C..
OF
( IV.)
COTTON SEED
200 C.C.
lII E" L
AND WATER.
(V.) 300 c.c.
The mea l con· N o increase Bacteria n o t Bacteria no t in· Bacteria had de· tained only of the micro - incre as e d . creased. One veloped st r ong ly. Ve ry s tron g o f th e O 'i dium It was obse rved a fe w bac- organism s. de vel opme nt s pee i e s de- that two speci es teri a and of 2 Ojdium scribed under belong in g to the moul d spores a nd second- III . predom· pota t o-baci lli a r y se ri es I inated . group prerlominPenicillium I Less abu ndant ated, also the glallc",,, . I andin approxispecies ofOIc1 iulll mately equa l seen in Samp le n umbers were IV. was stro ug ly Peni c i I / i 11m represented . gla licul/I, ElIro- There were in t £UlIl ·,-epens, addition individ · and R Iligopus ual specim ens of
lIigr/rans.
(V !. )
4 00 C.C.
(V II .) ;00 c.c. and (V I". ) 1,000C.C.
S tron g development of th e p otatol b l cilli species Only Asper.
Excl u s i vely ba c t e ri a I growths. The moulds had only estabI /!illusjlavlts lish ed thenlwas present selv e ; at the ' o f the mould s ed ges, prob !bly 0 "ing to the gradual drying.
A spergillusjlavllS
This last experiment shows very clearly indeed what influence a different proportion of water has upon the growth of the microorganisms present in a particular sample. In the presence of a low water content (up to I I per cent.) absolutely no increase in their number took place; in the presence of a mean proportion of water (14 to 30 per cent.) mould and Oidium species predominated and increased, whilst the bacteria were the primary product in presence of 30 per cent. of water and above. In conclusion, it may be mentioned that in my experiments Aspergillus niger was not found, this mould being one of the ca uses of Pneumomycosis aspergillosis. In this connection an interesting sample of hay which was alleged to convey anthrax was examined at the Liverpool University, guinea-pigs being inoculated with an infusion from it. · Several of these animals died within twenty-four hours from putrid intoxication, and subcultures on glucose agar from their suu cutaneous tissues yielded in one case Aspergillus niger . Possibly the spores of the fun gus were introduced from the hay with the infusion, and remained unchan ged in the subcutaneous tissue of the g uinea-pig s until after death, a nd were then transferred to the more fa vourabl e culture medium (glucose agar), when the spores germinated, and a typical Aspergillus niger was produced, which I had the opportunity of examining under the microscope.