
TABLE 3.—Changes in acid and salt content and pH of sauerkraut during fermentation 





Acid ! pH Salt 
Fermentation period (days) 
Brine Solids Brine Solids Brine Solids 
Percent Percent Percent Percent 
Qe te SB pu Ea Se ee ee enero OU OZiAl ere ih A ears SUA avai munca nis OW Ne nana eo ER Gs 
(Bees Ep ES SES ae ee 2G) His | teers eee illo OPA SEI sian Lua PALS TIN lec eet hres Hs 
Wo poss SSR Ee oe ee i a ee 9 5a] eee en BS OP lee Pees eee erst i wy ane Re [eh cas eee 
Be Sea eS a a Nee ee 397 0. 88 3. 82 3. 89 Dee, 2.0 
Ts cop coed es ae el a Ae he alten ee Rr Peas tial aaa alg re ae || OAae e e  U 
2, () pe areratin amenreer eee yg ynibay sees mre tes . 91 1. 00 3. 85 SEL Loan the eget Boal Seka ae Cade es 
PO a ce TS Ss os a a A a 2) TE a | A yk pO | Ree | tO Pe 2. 0 1.9 
Deo aS SSeS US EI se eee a ee Pera 1. 00 93 3. 89 3. 91 Px il ee, 
BHD) as a cay I I a a le 1. 10 1. 00 3. 74 3. 88 2.0 114.7 
Bn eS SE ee ee a ee mae cae . 98 1. 07 Sy 7/8} PHA aul | eat te Sree anes | mince al 
BB cee S RO Ses eS a Ee ee a ee ot aN i em ALG Gat | eye Nee oe | Pa De Ce em (TRA der 2A ili abe eeeae 
BBE, case cb e e  e SOY hen Ess Ca CID Seg (eT ad oe apenas | epi i memeN|| ace Ha 
ED = 6 Sao ES SSE LS ee era ie eo are em 1. 41 1. 39 3. 63 3. 68 2.0 12) 
OD). 05 BBE SES aE ee 1. 43 1. 43 3. 63 EGO Oil ese pcan Meenas TE yx BV Seal eae 


1 Calculated as lactic acid. 
Heat Penetration and Lethality Values 
In table 4 are given lethality values for the 
processed pickled products. Total equivalent 
minutes at 160° F. were calculated according to 
the method of Esselen and others (8), assuming a 
Z value of 18, where Z is the slope of the thermal 
destruction time curve of the spoilage organism. 
Temperatures were recorded during both heating 
and cooling periods, and percentages of equivalent 
minutes at 160° F. during each of these periods 
were calculated. 
Etchells and Jones (9) have specified bringing 
the temperature of the product to 165° F. and 
holding at that temperature for 15 minutes before 
cooling quickly to 100° F. Esselen (6) has in- 
dicated that a holding time equivalent in lethality 
to 36 minutes at 160° F. in a pasteurization tank 
is necessary to provide a heat treatment adequate 
to prevent spoilage and objectionable enzyme 
activity. Pasteurization times for quart jars of 
whole fresh-pack pickles under these conditions 
were reported to be 40 minutes at 180° F., 35 
minutes at 185° F., and 30 minutes at 195° F. 
After processing, the products were allowed to 
return to room temperature without forced cool- 
ing. The temperatures during the cooling period 
were responsible for a large portion of the calcu- 
lated lethality values. 
The calculated lethality values for the total 
equivalent minutes at 160° F. for the various 
pickled products varied greatly. Sweet gherkins 
processed 5 minutes at 212° F. had a calculated 
value of 239. Dilled green beans and tomato- 
apple chutney, also processed 5 minutes at 212° 
F., had values of 2,127 and 2,002, respectively. 
Rate of heat penetration into the food was a 
factor in the differences in calculated lethality 
values. 
As would be expected, high lethality values 
were also obtained for corn relish processed 15 



minutes at 212° F., and for pickled pears processed 
20 minutes at 212° F. These values greatly ex- 
ceed those required for bacteriological safety. 
However, the heat treatment aids in the thermal 
destruction of various enzyme systems (7, 13)° 
that are responsible for loss of flavor and nutritive 
value of the pickled products. 
pH Values 
Determinations of pH were made on the pickle 
solids and brines before storage and after storage 
for periods up to 9 months (table 5). Townsend 
and others (19) have reported a pH of 4.6 to be the 
maximum permissible for products that relied on 
acidification for inhibition of the growth of Clos- 
tridium botulinum. Pickle products, when prop- 
erly prepared, have a pH too low for the production 
of toxin by Clostridium botulinum. However, it is 
possible for contaminating micro-organisms to 
grow and utilize the acid as a source of energy, 
thus lowering the initial acidity so that botulinum 
spores, if present, could produce toxin. Adequate 
water-bath processing would destroy these contam- 
inating micro-organisms, and would inactivate en- 
zymes responsible for changes in texture, flavor, 
and odor during storage. 
Binsted and others (4), however, have pointed 
out that the pH of a pickled product is influenced 
by acids other than acetic—such as lactic, citric, 
and malic—and that these acids may have little 
effect on the keeping quality of pickles. Binsted 
states also that since the dissociation constant of 
acetic acid is relatively small, there is often no 
difference between the pH of pickles with widely 
varying acetic acid content. 
5 Labbee, M. D. THE RELATIONSHIP OF PEROXIDASE 
AND CATALASE ACTIVITY TO THE DEVELOPMENT OF OFF- 
FLAVOR AND COLOR IN PROCESSED PICKLES. (Thesis, 
Ph. D., Univ. of Mass., Amherst) 1952. 
7 
