Thermal Food Processing

Thermal Processing of Poultry Products 209
7.2.3 CANNED AND RETORTED POULTRY MEAT
7.2.3.1 Current Research on Canned and Retorted
Poultry Meat
Thermally processed, commercially sterile meat and poultry products are commonly
referred to as canned products, although the containers can be flexible,
such as pouches, or semirigid, as in lunch bowls. 49 The incoming quality of raw
materials (refrigerated chicken legs and breasts) used for the manufacture of
canned chicken products and the outgoing quality of the finished products were
evaluated by Turek et al. 50 Analysis of the canned products showed complete
sterility and good physicochemical properties.
Lyon et al., 51 studied the texture profiles of canned, boned chicken meat from
birds treated under different processing regimes. They concluded that textural
fibrousness and cohesiveness of mass associated with shortening, aging chilling
times, and subsequent cooking of chicken meat may be an asset for products that
undergo further heat treatment, such as retorting.
Vacuum-canned, commercial, mechanically deboned chicken meat was initially
challenged by Thayer et al. 52 with either C. botulinum spores or Salmonella Enteritidis
irradiated at 0, 1.5, and 3.0 KGy, and then stored at 5°C for 0, 2, and 4 weeks.
None of the samples stored at 5°C developed botulinum toxin. However, when the
samples were temperature abused at 28°C, they became toxic within 18 h and
demonstrated obvious signs of spoilage, such as can swelling and putrid odors.
Studies were carried out by Rywotycki 53 to determine the effect of seasonal
variations in the temperature of the cooling water used, water consumption, and the
cooling time of pasteurized turkey meat cuts canned in containers of different sizes
and shapes, ranging from 0.455 to 1.365 kg. Season markedly influenced cooling
water temperature and hence the amount of water required for cooling; temperatures
were the highest in the summer and the lowest in the winter. Season also had a
marked effect on the shelf life of the canned product; bacterial counts were lower
in cans produced in winter months than those produced in the summer, with no
significant differences noted between products manufactured in the autumn or spring.
Sauvaget and Auffret 54 described the benefits of adding citric acid to canned
chicken, turkey, and rabbit for maintaining the integrity and firmness of muscles,
bones, and cartilage during the canning process. Zhang et al. 55 compared three different
types of thermocouples and receptacle designs with regard to their effect on
the observed heat penetration rate of a conduction-based heat treatment of chicken
gravy packaged in small-diameter containers (202 × 204 and 211 × 300 cans). Their
results indicated that stainless steel receptacles and needle-type thermocouples
inserted into 202 × 204 cans significantly increased the apparent heat penetration rates.
7.2.3.2 Regulations for Commercially Sterile Products
A canned meat/poultry product is defined by the USDA as a “product having a
water activity of 0.85 or higher and receives a thermal process either before or
after being packed in a hermetically sealed container.” The USDA further