Polycyclic aromatic hydrocarbons (PAHs) in different types of smoked meat products from Serbia.

The contents of the16 EU priority PAHs in six different meat products from Serbia (beef ham, pork ham, bacon without skin, bacon with skin, cajna sausage and sremska sausage) were examined during the process of smoking. All these meat products from meat industry Zlatiborac, Mačkat, Serbia presented in this study, have not previously been analysed concerning to their contents of PAH compounds. Determination and quantification of PAHs in meat products were performed by a Fast GC/HRMS method.

Gas chromatography-mass spectrometry (GC-MS) method for the determination of 16 European priority polycyclic aromatic hydrocarbons in smoked meat products and edible oils.

A gas chromatography-mass spectrometry (GC-MS) method was developed for the analysis of 15 polycyclic aromatic hydrocarbons (PAHs) highlighted as carcinogenic by the Scientific Committee on Food (SCF) plus benzo[c]fluorine (recommended to be analysed by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) in fat-containing foods such as edible oils and smoked meat products. This method includes accelerated solvent extraction (ASE) and the highly automated clean-up steps gel permeation chromatography (GPC) and solid-phase extraction (SPE). Using a VF-17ms GC column, a good separation of benzo[b]fluoranthene, benzo[j]fluoranthene and benzo[k]fluoranthene was achieved.

Dioxin and polychlorinated biphenyl analysis: automation and improvement of clean-up established by example of spices.

To analyze polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDDs/PCDFs) and polychlorinated biphenyls (PCBs) in spices by gas chromatography-mass spectrometry, a new clean-up method had to be developed owing to the high content of essential oils in the samples. A solid-phase extraction (SPE) column with activated silica endowed with sulfuric acid and sodium hydroxide was used. Under these conditions, clean-up was achieved using at least 5-7 g of pepper and even higher amounts of other spices.

Traceability from a European perspective.

At pan-European level there is a need for traceability systems giving information on origin, processing, retailing and final destination of foodstuffs. Such systems shall enhance consumer confidence in food; enable the regulatory authorities to identify and to withdraw health hazardous and non-consumable foodstuffs from the market. Animal feeds are an element in this "food-to-farm" approach to public health.

Occurrence and biochemical characteristics of natural bioactive substances in bovine milk lipids.

Bovine milk lipids (BML) contain a number of bioactive substances with positive as well as negative properties, mainly in the class of fatty acids. Besides trans fatty acids (TFA), conjugated linoleic acids (CLA) are of particular interest. Apart from ruminant meat products the main source of CLA in food are BML.

Bioactive peptides encrypted in milk proteins: proteolytic activation and thropho-functional properties.

The bioactivities of peptides encrypted in major milk proteins are latent until released and activated by enzymatic proteolysis, e.g. during gastrointestinal digestion or food processing.

Evidence for peptide synthesis in the course of in vitro proteolysis.

The present paper reports on studies concerned with furnishing evidence for peptide synthesis in the course of in vitro proteolysis. To this end, the oxidized chain B from insulin (INS) (S = 5% in demineralized water) was subjected to tryptic proteolysis (E/S = 1/50; pH 5; 37 degrees C; 24 h). HPLC-as well as amino acid-and sequence analytical studies have shown that the heptapeptide INS 23-29 (Gly-Phe-Phe-Tyr-Thr-Pro-Lys) liberated by way of hydrolysis is linked by tryptic synthesis via transpeptidation or condensation to form a dimer which accounts for 15% of the amount of monomer.

Biochemical properties of regulatory peptides derived from milk proteins.

Biologically active peptides derived from milk proteins are inactive within the sequence of the precursor proteins but can be released by enzymatic proteolysis. Based on structure-activity studies, peptides with a defined bioactivity show common structural features. Moreover, many milk protein-derived peptides reveal multifunctional bioactivities.

Changes in histological structure and physiochemical properties of raw, cured, smoked pork loins resulting from freezing near cryoscopic temperature.

The aim of the study was to determine the effects of unintended freezing during cold storage (deep chilling conditions) and low freezing temperatures (-10 degrees C) of raw pork loins, cured and smoked, on their histological structure and some physicochemical characteristics. The experimental products after freezing at -10 degrees C, were stored at the same temperature for 0, 2, 4 and 6 days, thawed thereafter and immediately deep chilled at near cryoscopic temperature (-3 degrees C) for 0, 2, 4 or 6 days. These conditions were changing the histological structures of pork loin, the water holding capacity (WHC) was reduced by frozen storage but improved by deep chilling; the maximum shear force and energy were increased.

Trans fatty acids: implications for health, analytical methods, incidence in edible fats and intake (a review).

Trans fatty acids (TFA) are supposed to be related to a variety of physiological effects. Numerous studies in this field are gathered and compared, which mainly deal with the influences on lipoprotein levels in plasma and their effects with regard to coronary heart diseases. Furthermore, the analytical accessibility of trans fatty acids by different methods is presented.

Heat-induced changes in casein-derived phosphopeptides.

Phosphopeptides derived from casein may function as carriers for calcium and trace elements. In regard to such specific nutritive effects, the heat-induced changes in tryptic phosphopeptides liberated from bovine sodium caseinate as a model system were investigated. Both microwave and oven heating resulted in a marked loss of peptide-bound phosphorous (dephosphorylation) and a decrease of casein-phosphopeptides in the soluble part of the tryptic hydrolysate.

Ribonucleosides as minor milk constituents.

Ribonucleosides are minor milk constituents and show a typical pattern which is assumed to be species-specific. As well as the unmodified components adenosine, cytidine, guanosine, inosine, and uridine, modified compounds such as Nl-methyladenosine and N6-carbamoylthreonyladenosine--products of the transfer RNA catabolism--have been identified and quantified in individual and bulk herd (race: German black pied) milk samples throughout a whole lactation period. The results of our longitudinal study have shown that--with the exception of the colostral phase--the levels of these minor constituents vary only slightly throughout lactation.

Biologically active peptides in milk proteins.

Bioactive peptides have been identified as digestion products of several food proteins. All the bioactive sequences are hidden in an inactive state inside the polypeptide chain of the larger protein. Milk proteins are a rich source of biologically active peptides such as exorphins (casomorphins), phosphopeptides and immunopeptides.

Milk fat globules: fatty acid composition, size and in vivo regulation of fat liquidity.

Populations of large and small milk fat globules were isolated and analyzed to determine differences in fatty acid composition. Globule samples were obtained by centrifugation from milks of a herd and of individual animals produced under both pasture and barn feeding. Triacylglycerols of total globule lipids were prepared by thin layer chromatography and analyzed for fatty acid composition by gas chromatography.

Glycoprotein filament removal from human milk fat globules by heat treatment.

Freeze-etch electron microscopy was applied to milk fat globules to observe surface details. A remarkable array of filaments, approximately 0.5 micron in length, was seen on human, but not bovine, globules.

Sarcomere shortening of prerigor muscles and its influence on drip loss.

Detailed studies of muscle shortening post mortem at incubation temperatures between -2°C and +38°C revealed that the sarcomeres in unrestrained, excised red bovine muscle (M. sternomandibularis) shortened less than 10 % in the prerigor state between 6°C and 18°C. Below 6°C, sarcomeres contracted up to 70%.