Shelf-life extension and sanitation of fresh pork loin by E-beam treatment.

The usefulness of electron beam (E-beam) irradiation to increase the shelf life of whole fresh pork loin stored at 4°C has been studied. The shelf life was extended from 5 to 11 and 20 days after the application of 1 and 2 kGy, respectively. If a temperature abuse situation were to occur during product distribution (e.g., increase to 8°C), the shelf life would be extended from 3 to 8 and 15 days, respectively, after application of the same doses. When considering Listeria monocytogenes from a public health point of view, the irradiated whole fresh loin may be marketable for periods longer than 2 weeks, thus guaranteeing a practically Listeria-free product. Irradiation produced no important changes in the rheological characteristics of the meat. Although the sensory quality of irradiated meat was scored lower than the control immediately after irradiation, after 5 days in storage, irradiated meat scored higher than or not different from the control.

Reduced levels of serum FGF19 and impaired expression of receptors for endocrine FGFs in adipose tissue from HIV-infected patients.

BACKGROUND: To determine the role of fibroblast growth factor (FGF)-19 and FGF21 and the endocrine FGFs receptor system in the metabolic alterations that manifest in HIV-1-infected patients undergoing highly active antiretroviral treatment (HAART). METHODS: Serum FGF19 and FGF21 levels were determined in 4 groups of individuals as follows: (1) HIV-1-infected HAART patients with lipodystrophy (n = 38); or (2) without lipodystrophy (n = 34); (3) untreated (naive) HIV-1-infected patients (n = 34); and (4) healthy controls (n = 31). Serum FGF19 levels were correlated with anthropometric, metabolic, HIV-1 infection-related, and HAART-related parameters and with FGF21 levels. The gene expression of FGF receptor 1 and the coreceptor ß-Klotho was analyzed in adipose tissue from 10 individuals from each group. RESULTS: Serum FGF19 levels were significantly reduced in all groups of HIV-1-infected patients, whereas FGF21 levels were increased. FGF19 levels were negatively correlated with insulin resistance and insulin levels and positively correlated with high-density lipoprotein cholesterol. FGF19 was inversely correlated with cumulative exposure to nucleoside reverse transcriptase inhibitor and nonnucleoside reverse transcriptase inhibitor drugs. The expression of FGF receptor 1 and coreceptor ß-Klotho was reduced in adipose tissue from all groups of HIV-infected patients. CONCLUSIONS: FGF19 levels are reduced in HIV-1-infected patients, in contrast with FGF21 levels. Impaired expression of the corresponding receptor and coreceptor, which mediate the actions of endocrine FGFs in adipose tissue, suggests a resistance to the metabolic effects of FGF19 and FGF21 in HIV-1-infected patients. Considering the beneficial effects of endocrine FGFs on metabolism, the observed reduction in FGF19 levels and decreased sensitivity to endocrine FGFs in adipose tissue may contribute to metabolic alterations in HIV-1-infected patients.

Sanitation of selected ready-to-eat intermediate-moisture foods of animal origin by E-beam irradiation.

To optimize the sanitation treatment of ready-to-eat (RTE) intermediate-moisture foods (IMF), the behavior of Listeria monocytogenes Scott A (CIP 103575), L. innocua (NTC 11288), Salmonella enterica serovar Typhimurium (CECT 443), and Escherichia coli O157:H7 (CECT 4972) following treatment with electron-beam irradiation has been studied. As food matrixes, three RTE vacuum-packed products (Iberian dry-cured ham, dry beef [cecina], and smoked tuna) were used. Although an irradiation treatment is not necessary when the 10(2) colony-forming units/g microbiological criterion for L. monocytogenes is applied, a treatment of 1.5 kGy must be applied to IMFs to meet the food safety objective in the case of the "zero tolerance" criterion for the three strains. The IMF products presented negligible modifications of color (L*, a*, and b*), sensory (appearance, odor, and flavor), and rheology (hardness, springiness, adhesiveness, cohesiveness, gumminess, chewiness, and breaking strength) parameters at doses lower than 2 kGy. Therefore, the treatment of 1.5 kGy warrants safe IMF with sensory properties similar to those of the genuine products.

Effect of E-beam treatment on the safety and shelf life of mayonnaise potato salad.

The radioresistance of Listeria monocytogenes, Salmonella enterica serovar Enteritidis, and S. enterica serovar Typhimurium has been studied in a complex matrix like mayonnaise potato salad. D(10)-values of 0.56, 0.32-0.35, and 0.41-0.42 kGy were calculated for each organism, respectively. Keeping in mind these values, the microbiological criteria, the characteristics of the microorganisms, and a shelf life of the products of 20 days stored at 4°C, an irradiation treatment of 1 kGy was calculated to reach the food safety objectives. A duplication of the shelf life is also achieved with a dose of 1 kGy. Mayonnaise potato salad radiated with doses of up to 2 kGy showed negligible off-sensory characteristics.