Baluts are fertile chicken or duck eggs that have been incubated and removed from the incubator prior to hatching for consumption. Chicken eggs are incubated for 11 to 14 days and duck eggs are incubated for 16 to 20 days. Baluts have an extremely specialized consumer market, with the majority of its consumers of Filipino decent. Current U.S. Department of Agriculture regulations for the storage of baluts prior to sale is 7.2ºC, the same as for infertile commercial table eggs. Consumer preference is to purchase live baluts for consumption. Since exposure to 7.2ºC causes embryo mortality within 8 hours of removal from the incubator, research was performed to assess mortality at various storage temperatures, which has not previously been established. Our study consisted of two identical trials to determine the livability of embryos when exposed to varying temperatures over predetermined storage times. Fertile Leghorn chicken eggs were incubated for 13.5 days and then removed from incubation, grouped, and placed in temperature-controlled environments corresponding to 15.6, 18.3, and 22.2ºC. At predetermined times, eggs were opened to determine embryo viability. Random swab samples of the internal egg environment were also taken aseptically to determine the presence of microorganisms. Results demonstrated that the livability of embryos was longer when exposed to storage temperatures closer to incubation temperatures (37.5ºC), and livability was shorter when storage temperatures neared refrigeration temperature (7.2ºC).
Jong, Joyce and Clark, F. Dustan
"Livability of Leghorn Balut Embryos Stored Under Varying Temperatures and Storage Times,"
Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences. University of Arkansas System Division of Agriculture. 1:35-39.
Available at: https://scholarworks.uark.edu/discoverymag/vol1/iss1/10