Rheological behaviour of commercial cooked meat products evaluated by tensile test and texture profile analysis (TPA).

The breaking strength (BS) and energy to fracture (EF) of commercial cooked meat products (CMP) manufactured from different entire pieces were determined by tensile test. BS and EF were related to texture profile analysis (TPA) and physico-chemical data. Two textural profiles were characterized mainly by BS, springiness adhesiveness and fat content. Multivariate regression analysis confirms that TPA parameters could be used to construct models to predict BS and EF. Therefore, just one TPA analysis will allow to obtain both TPA and tensile parameters, providing valuable information about mechanical behaviour to improve product handling at industrial level especially in sliced CMP.

Inactivation of Salmonella enterica serovar Enteritidis on shell eggs by pulsed light technology.

This is a study on the efficacy of pulsed light (PL) technology for the inactivation of Salmonella enterica serovar Enteritidis on shell eggs. In preliminary studies on noble agar, a PL treatment of 0.7 J/cm(2) gave an inactivation of 6.7 log CFU/cm(2). Photoreactivation of Salmonella (0.5-0.7 log CFU/cm(2)) was observed. Different results were obtained in eggs according to the state of the cuticle. When unwashed eggs were pulsed, 24 to 80% of the samples showed the maximum decontamination (3.6 log CFU/egg), depending on the fluence applied. This maximum was not obtained on washed eggs, in which the highest reduction was 1.8 log CFU/egg with a fluence of 12 J/cm(2). PL can be a useful method for egg processing since the integrity of the cuticle is preserved, and requires that the treatment should be applied as soon as possible after laying and on unwashed eggs. As Salmonella has shown the capability of photoreactivation, it is advisable to keep eggs protected from light once they have been pulsed.

Pulsed light inactivation of Listeria monocytogenes through different plastic films.

The efficacy of decontamination by pulsed light technology through different plastic films has been assayed using Listeria monocytogenes Scott A as target microorganism. A 12-mum polyethylene film, a 48-mum polyamide/polyethylene/vinyl acetate-based copolymer, and a 60-mum polyamide/polyethylene copolymer were tested. Noble agar plates were surface inoculated and wrapped with different films. Unwrapped plates were also analyzed as control. Fluences of 0.175 and 0.35 J/cm(2) were applied. Pulsed light treatment achieved the same degree of inactivation (5-5.5 log cfu/cm(2)) in either wrapped or unwrapped samples. All the polymers showed the same behavior. These results indicate that pulsed light technology could be suitable for decontamination of packaged foods.

Fatty acid composition of salami from different countries and their nutritional implications.

'Milano-type' salami from 13 European and American countries were analysed to establish their nutritional value in relation to fat and fatty acid composition. The fat content, fatty acid profile, ratio of n-6/n-3 polyunsaturated fatty acids, ratio of hypocholesterolemic/hypercholesterolemic fatty acids (h/H) and the contribution to the daily intake recommended for the population were studied. Differences (P<0.05) in the dry matter, pH, water activity, fat content, and percentages of saturated, monounsaturated and polyunsaturated fatty acids were found. Principal component analysis permitted samples to be separated into three different groups: (1) salamis from Chile, Mexico and Brazil, with high n-6/n-3 ratios (14-16), medium iodine index (73-76) and high h/H ratios (2.6-2.7); (2) European salamis and salamis from Costa Rica and USA, with medium and high n-6/n-3 ratios (8-15), low iodine index (62-72) and low h/H ratios (2.1-2.6); and (3) products from Peru, with the lowest n-6/n-3 ratio (7.2), the highest iodine index (about 80) and medium h/H ratio (2.5).

Phenolic compounds and fatty acids from acorns (Quercus spp.), the main dietary constituent of free-ranged Iberian pigs.

The aim of the present work was to identify and quantify the phenolic compounds and fatty acids in acorns from Quercus ilex, Quercus rotundifolia, and Quercus suber. The concentration of oleic acid was >63% of total fatty acids in all cases, followed by palmitic and linoleic acids at similar concentrations (12-20%). The concentrations of alpha-tocopherol in Q. rotundifolia, Q. ilex, and Q. suber were 19, 31, and 38 mg/kg of dry matter (DM), respectively, whereas the concentrations of gamma-tocopherol were 113, 66, and 74 mg/kg of DM, respectively. Thirty-two different phenolic compounds were distinguished. All of them were gallic acid derivatives, in the form of either galloyl esters of glucose, combinations of galloyl and hexahydroxydiphenoyl esters of glucose, tergallic O- or C-glucosides, or ellagic acid derivatives. Several tergallic acid C-glucosides were also present in the extracts obtained from Q. suber. Acorns from Q. ilex and Q. rotundifolia showed similar polyphenol patterns mainly with gallic acid-like spectra. Chromatograms of Q. suber showed mainly polyphenols with ellagic acid-like spectra. Valoneic acid dilactone was especially abundant in Q. suber skin. The contribution of skin to the total phenolics of the acorn was relatively small in Q. rotundifolia and Q. ilex but relatively high in Q. suber. Skin extracts from Q. suber, Q. rotundifolia, and Q. ilex showed 1.3, 1.4, and 1.0 antioxidant efficiencies, respectively (compared to that of butylhydroxyanisole). Endosperm extracts showed lower capacity to prevent lipid peroxidation than skin extracts.

Changes in selected biochemical and sensory parameters as affected by the superficial inoculation of Penicillium camemberti on dry fermented sausages.

An atoxigenic strain of Penicillium camemberti was superficially inoculated on fermented sausages in an attempt to improve their sensory properties. The growth of this mould on the surface of the sausages resulted in an intense proteolysis and lipolysis, which caused an increase in the concentration of free amino acids, free fatty acids (FFA) and volatile compounds. Many of these were derived from amino acid catabolism and were responsible for the "ripened flavour", i.e. branched aldehydes and the corresponding alcohols, acids and esters. The development of the fungal mycelia on the surface of the sausages also protected lipids from oxidation, resulting in both lower 2-thiobarbituric acid (TBARS) values and lipid oxidation-derived compounds, such as aliphatic aldehydes and alcohols. The sensory analysis of superficially inoculated sausages showed clear improvements in odour and flavour and, as a consequence, in the overall quality of the sausages. Therefore, this strain is proposed as a potential starter culture for dry fermented sausage production.

Effects of feeding elevated concentrations of monounsaturated fatty acids and vitamin E to swine on characteristics of dry cured hams.

Thirty Large White×Great York gilts were fed six experimental diets containing three levels of poly and monounsaturated fatty acids. Within each dietary fat treatment, one group was fed a basal level of vitamin E (20 mg α-tocopheryl acetate/kg diet) and the other group received a supplemented level (200 mg α-tocopheryl acetate/kg diet). Concentration of α-tocopherol was significantly higher in hams from pigs fed supplemented dietary levels of vitamin E (P<0.0001), but no significant effect of dietary fat was observed. Dietary vitamin E supplementation reduced the concentration of thiobarbituric acid reactive substances after 9 days storage of sliced samples (P<0.0001), while dietary fat source showed no significant effect. Significantly lower oxidation was observed in ham homogenates from pigs fed higher concentrations of monounsaturated fatty acids after 120 min of incubation under pro-oxidant conditions (P=0.013). No effect of dietary treatment was observed in ham volatile aldehyde profile. No significant effect of dietary vitamin E was observed on surface redness during storage, but a significant effect was observed for luminosity after 7 days of storage (P=0.033). Hams from pigs fed diets enriched in monounsaturated fatty acid showed higher 'a' values (P=0.040) in stored sliced samples. Sensory evaluation revealed a significant effect of dietary vitamin E on redness of ham slices (P<0.001). Dietary supplementation with vitamin E also produced a significantly higher odour and flavour intensity (P=0.006 and P=0.01 respectively). Dry cured ham samples from pigs fed higher amounts of monounsaturated fatty acids showed a significantly higher consistency fat than those from pigs fed polyunsaturated fatty acids.