764 EXPERIMENT STATION RECORD. [Vol. 40 



acid was found in the juices in which the whole fruit had been fermented than 

 when the juice alone had been fermented. The authors suggest that this is 

 probably due to the fact that during fermentation small amounts of phos- 

 phorus-containing compounds in the pulp pass into solution. The percentage 

 composition of the ash of these same juices is also tabulated. 



An examination of apple juice in which the first, second, and third extrac- 

 tions are analyzed separately is recorded. The data show that the mineral 

 constituents and the alkalinity increase with succeeding extractions. 



Twenty-four samples of raspberry juice, which had been preserved by various 

 chemicals (for 1 liter of juice 2.5 gm. of formic acid, 1 gm. of salicylic acid, 

 1.5 gm. of benzoic acid, or 0.5 gm. of hydrofluoric acid), wire examined, 



It was found that salicylic acid was the most satisfactory, and that a tier 

 one year's standing the juice retained its color as well as its natural flavor 

 and aroma. Hydrofluoric acid ranked next in value, while formic acid was 

 found the least satisfactory. 



The bacteriology of canned foods, J. Weinzibl (Jour. Med. Research, 89 

 (1919), No. 3, pp. 849-418). — This is the report of an Investigation of the 

 organisms which may be present in canned foods. An historical survey is 

 given of the literature relative to the bacteriology of the canning industry, 

 in summarizing which the author points out that, although the results are 

 conflicting, all investigators are agreed that spoilage is due to the action of 

 microorganisms. Two types appear to be prominent, the colon group, which 

 causes swelling and decomposition with malodors, and the B. nitlitilis, or 

 spore-bearing group, which is difficult to kill in processing. 



In the present Investigation, a study was made of the organisms found in 

 spoiled canned foods, in experimental packs Subjected to different periods of 

 processing, and in ordinary commercial packs. Proper media -and conditions 

 of growth were selected to isolate molds and yeasts, aerobic and anaerobic 

 bacteria, and thermophiles. In connection with the bacteriological studies, 

 an examination of the cans was conducted to determine whether apparently 

 nonleaking cans were really tightly sealed and to determine the extent of 

 swelling in cans in which spoilage had occurred. 



Bacteriological examinations were made of 169 spoiled or suspected samples, 

 67 experimental or nnderprocessed samples, and 782 commercial or market 

 samples. The organisms isolated comprised 17 cultures of yeasts. 29 cultures of 

 molds representing 7 genera, and 392 cultures of bacteria representing 38 

 species. The most prevalent mold was Aspergillus nidulans. The most prev- 

 alent species of bacteria were /?. mesentericut, B. subtUis, is. thermoindifferemi, 

 B. rulgatus, and B. <■<■>< us. Members of the paratyphold-enteritidis group were 

 not found, nor was 1). botuliwus ever isolated. 



In spoiled and in underprocessed canned foods, both spore and nonspore- 

 forming bacteria were present, the spore-forming usually belonging to the 

 B. mesentericus group and the nonspore-forming to the lactic-acid-forming 

 group. In spoiled sardines, the colon group was the prevailing type, the 

 presence of which causes the swelling of the cans. The swelling of cans of 

 fruits and vegetables is thought to be due chiefly to the presence of anaerobic 

 bacteria such as B. welchii. 



In commercial canned goods giving no evidence of spoilage, microorganisms, 

 almost entirely spore-forming, were found In L':: per cent of the cases. As these 

 may develop in the presence of air. it Is pointed out that a vacuum is essentia] 

 to the preservation of canned foods under presold practice. 



Of the 700 cans tested for leakage, 64.1 per cent were found not to leak 

 The presence of viable spores in 19.2 per cent of the nonleaking cans is conse- 

 quently attributed to understerilization. 



