Effect of vaccination against gonadotropin-releasing hormone (GnRH) in heavy male pigs for Italian typical dry-cured ham production.

The aim of this study was to evaluate immunocastration (vaccination against GnRH using Improvac® vaccine), as an alternative to surgical castration in heavy male pigs (average live weight 165 ± 10 kg), used in the production of Italian typical dry-cured ham. A total of 60 Landrace × Large White male pigs were assigned to three groups of 20 units, including one group of surgically castrated (SC), and two of immunocastrated pigs, with two (IC2) or three (IC3) vaccine treatments, respectively. The groups were compared for green ham traits, processing weight losses, chemo-physical, and sensory properties of dry-cured hams. While IC3 were not different (P>0.05) from SC group, IC2 hams were found to differ (P<0.05) both from SC and IC3 groups in ham traits, final weight losses, texture and sensory boar taint in finished hams. Therefore, vaccination with three doses could be taken into account to control boar taint in the manufacturing of typical Italian dry-cured ham.

Extraction properties and absorption spectra of dry cured hams made with and without nitrate.

The spectral and extraction properties of nitrate-free dried hams (Parma hams) were studied as a function of maturing time and muscle type (semimembranosus and biceps femoris muscles). To understand the red colour of the processed meat, a three-step extraction using water, acetone and tetrahydrofuran (THF) as solvents was employed and the extracts from each step were submitted to spectrophotometric (visible) analysis while the corresponding residues underwent instrumental (CIE L* a* b*) colour evaluation. Results showed that the drier the meat the more the pigment is soluble in organic solvents, THF proving a major extractant in matured hams, regardless of muscle type. When Parma hams were compared with hams made using nitrate, the former displayed more intense (P<0.05) absorption in the red region in the aqueous solution, lower intensities in acetone and higher values in THF solution. Major differences in spectral characteristics were found between water and organic extracts of Parma hams, with both acetone and THF solutions exhibiting a doublet at 544-584 nm, and water extracts displaying two distorted peaks at 551 and 595 nm. It is concluded that dry curing of meat without nitrate yields a lipophylic stable red pigment whose hydrophobicity increases with ageing.

Lipid and cholesterol oxidation products in dry-cured ham.

An investigation was carried out on oxidative processes in dry-cured hams. Sixteen hams of various ageing times were divided into lean and fat parts, simulating typical consumer habits. All samples underwent analysis of peroxide value (PV), rancidity index (TBARs), 5 cholesterol oxidation products (COPs) and, in the lean samples, proximate composition. While the lean part was rather unaffected by oxidation, the external fat contained some of COPs, TBARs and PV. Comparison of hams at different ageing times revealed that lipid oxidation was substantially unaffected by the time of processing. It is concluded that good manufacturing practice will generally prevent oxidative damage in the edible part of dried hams, even if very long ageing times are used.

Evaluation of cathepsin B levels in fresh thighs selected for cured raw ham production.

Excessive meat tenderization in cured raw Parma ham has recently been correlated with abnormal levels of cathepsin B in freshly slaughtered thigh meat. We have developed a visual assay employing the substrate Z-Arg-Arg-NNapOMe for the quantitative detection of active cathepsin B levels in pork thigh muscle homogenates. The work was based on a kinetic characterization, in steady state condition, of pig muscle cathepsin B with several peptidyl chromophoric substrate analogs. This assay can easily and safely be performed by non-specialized personnel directly in the slaughterhouse or in the factory, for an early quality evaluation of thighs selected for Parma ham production. Our characterization has further indicated that the catalytic properties of porcine muscle cathepsin B and those of isoforms from other animal and plant species are practically identical. This is particularly evident in the commercially available bovine spleen isoform, which was employed as a model enzyme in most of the experiments.

Relationship between cathepsin B activity and compositional parameters in dry-cured hams of normal and defective texture.

Thirty-eight Italian dry-cured hams were analysed for cathepsin B activity, proximate composition and proteolysis index and results were related to lean tissue texture, as assessed by an expert panel, in order to search for relationships between excessive softness, a major problem in the raw ham industry, and chemical parameters. Softness was found to be related to protein breakdown which, in turn, was linked with higher residual cathepsin B activity and, to a lesser extent, to lower salt content. Results suggest that the use of raw ham of controlled enzyme activity would improve the texture quality of the end product.

Effects of temperature, aw and pH on the growth of Bacillus cells and spores: a response surface methodology study.

Effects of water activity (aw), pH and storage temperature on the growth of spores and vegetative cells of Bacillus spp. isolated from bakery products were studied in a model system and the growth was monitored spectrophotometrically in microtitre plates. Experiments, performed following a Central Composite Rotatable Design and aimed at development of response surfaces, resulted in two polynomials based mainly on first order coefficients. For both cells and spores, temperature, aw and pH acted additively and without any synergistic effect. This was also confirmed by isoresponse plots for the combinations temperature-aw, temperature-pH and pH-aw. Applications of the models to predict the shelf life of the actual food product are discussed.

[Pregnancy complication in homozygous (delta beta) zero-thalassemia. A clinical case]. / Gravidanza complicata in (delta beta) zero-talassemia omozigote. Caso clinico.

A case of a pregnant woman suffering from homozygous (delta beta) zero-thalassemia clinically running as thalassemia Intermedia is described. In this patient pregnancy could not follow its normal course and was interrupted in the 24th week, because of endouterine death of the foetus due to complications such as serious haemolytic anaemia following transfusional alloimmunisation and the presence of portal vein thrombosis. In this article the literature is reviewed and the need is shown for all thalassemic patients to be tested for the various blood antigenic systems, so that transfusional reactions can be avoided. Stress is laid on the importance of erythropoietin both in the pathogenesis of haematological and rheological modifications in thalassemic patients and also as a trigger in serious thrombotic complications.

Quality control in the meat industry by multivariate statistics. The case of raw ham.

Two multivariate statistical techniques were tested on sensory and instrumental data from raw ham technology. (1) Cluster analysis, applied to parameters ranging from the beginning of processing to the end of resting, originated three groups which provided an explanation of the observed trends in the occurrence of microbial defects. (2) Partial-least-squares (PLS) regression, used to relate three sensory descriptors to five instrumental variables, provided a fully instrumental method for the assessment of quality of aged ham. Application of both techniques for prediction and description purposes is discussed.

Induction of ovulation for gamete intrafallopian transfer (GIFT) using a gonadotropin-releasing hormone agonist and "pure" FSH: results obtained in 30 normally menstruating women.

About 30% of the ovulation induction cycles in GIFT and FIVET programmes are cancelled due to an inadequate response of patients to gonadotropins and/or clomiphene citrate. GnRH agonist-gonadotropins and/or "pure" FSH combination has been successful in inducing ovulation in patients with a previous history of cycle cancellation and/or alterations in the menstrual cycles. In order to reduce the number of cycle cancellations and obtain more homogeneous oocytes, GnRH agonist-gonadotropins and/or "pure" FSH combination in all candidates for GIFT and FIVET has been recently hypothesised. The Authors report results obtained from GnRH agonist-"pure" FSH combination in 30 normally menstruating patients of the GIFT programme: in 93% of cases the harvested oocytes were preovulatory, in 27.6% of cycles and in 28.6% of the GIFTs respectively an ongoing pregnancy was obtained. While the results obtained must be considered preliminary, they nevertheless suggest that the use of a combination of GnRH-agonist "pure" FSH in all patients in the GIFT programme may be of real clinical validity.

Aliphatic secondary amines in meat and fish products and their analysis by high pressure liquid chromatography.

A simple and reliable high pressure liquid chromatographic method for aliphatic secondary amines in foods has been developed. The method, which involves rapid extraction, derivatisation with dinitroflurobenzene and one-step liquid chromatographic analysis, allows dimethylamine to be determined without interference by the completing agent, whereas only a slight increase in the response of dimethylamine is caused by large amounts of trimethylamine. The presence of free secondary amines in a number of Italian meat and fish products and their formation as a consequence of some preservation techniques have been investigated. The results are discussed.