Effect of E-beam treatment on expression of virulence and stress-response genes of Listeria monocytogenes in dry-cured ham.

Various adverse conditions can trigger defensive mechanisms in Listeria monocytogenes that can increase the virulence of surviving cells. The objective of this study was to evaluate the expression of one stress-response (sigB) and three virulence (plcA, hly, and iap) genes in L. monocytogenes exposed to a sub lethal dose of E-beam irradiation in dry-cured ham.

Effect of E-beam treatment on the chemistry and on the antioxidant activity of lycopene from dry tomato peel and tomato powder.

Tomato powder (TP) and dry tomato peel (DTP) have been previously used in our laboratory as a source of lycopene to manufacture meat products ready-to-eat (RTE) submitted to E-beam irradiation with good technological and sensory results. Present work describes the studies performed in order to investigate the effect of radiation on chemical changes and antioxidant properties of lycopene. DTP and TP were irradiated (4 kGy).

Irradiation is useful for manufacturing ready-to-eat cooked meat products enriched with folic acid.

Cooked sausages enriched with folic acid (0.6, 1.2 and 2.

Usefulness of calcium lactate, citrate and gluconate for calcium enrichment of dry fermented sausages.

Food manufacturers are interested in new ways to improve the nutritional value of their meat products. In this study, calcium lactate, gluconate and citrate have been added to dry fermented sausages in an attempt to determine whether they are useful for enriching these meat products with calcium. The sausages were manufactured with different amounts of pork backfat (6, 15, and 30%) and the salts were added in sufficient amounts to 100g of sausage to give 20% and 30% of the recommended daily allowance (RDA) of calcium established by the Institute of Medicine of the USA (1000mg/day).