Pickled egg production: effect of brine acetic acid concentration and packing conditions on acidification rate.
U.S. federal regulations require that acidified foods must reach a pH of 4.6 or lower within 24 h of packaging or be kept refrigerated until then. Processes and formulations should be designed to satisfy this requirement, unless proper studies demonstrate the safety of other conditions. Our objective was to determine the effect of brine acetic acid concentration and packing conditions on the acidification rate of hard-boiled eggs. Eggs were acidified (60/40 egg-to-brine ratio) at various conditions of brine temperature, heat treatment to filled jars, and postpacking temperature: (i) 25 °C/none/25 °C (cold fill), (ii) 25 °C/none/2 °C (cold fill/refrigerated), (iii) 85 °C/none/25 °C (hot fill), and (iv) 25 °C/100 °C for 16 min/25 °C (water bath). Three brine concentrations were evaluated (7.5, 4.9, and 2.5% acetic acid) and egg pH values (whole, yolk, four points within egg) were measured from 4 to 144 h, with eggs equilibrating at pH 3.8, 4.0, and 4.3, respectively. Experiments were conducted in triplicate, and effects were considered significant when P < 0.05. Multiple linear regression analysis was conducted to evaluate the effect on pH values at the center of the yolk. Regression analysis showed that brine concentration of 2.5% decreased the acidification rate, while packing conditions of the hot fill trial increased it. Inverse prediction was used to determine the time for the center of the yolk and the total yolk to reach a pH value of 4.6. These results demonstrate the importance of conducting acidification studies with proper pH measurements to determine safe conditions to manufacture commercially stable pickled eggs.
Department of Food Science, New York State Agricultural Experiment Station, Cornell University, 630 West North Street, Geneva, New York 14456, USA.
Oscar
O
Acosta
Department of Food Science, New York State Agricultural Experiment Station, Cornell University, 630 West North Street, Geneva, New York 14456, USA.
Xiaofan
X
Gao
Department of Food Science, New York State Agricultural Experiment Station, Cornell University, 630 West North Street, Geneva, New York 14456, USA.
Elizabeth K
EK
Sullivan
Department of Food Science, New York State Agricultural Experiment Station, Cornell University, 630 West North Street, Geneva, New York 14456, USA oip1@cornell.edu.
Olga I
OI
Padilla-Zakour
D019342:Acetic Acid / Q000737:chemistry*; D004530:Egg Yolk / Q000737:chemistry; D004531:Eggs / Q000032:analysis*; D005511:Food Handling / Q000379:methods*; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D012492:Salts / Q000494:pharmacology*
D012492:Salts; C017082:brine; D019342:Acetic Acid