The morphological detection of bone and cartilage particles in mechanically separated meat.

The calcium content of mechanically separated meat (MSM) is a common indicator of elevated bone contents due to the separation process, e.g. as applied in EU regulations. But a direct morphological proof of bone material is needed, especially to identify undeclared MSM additives to meat products. We present a new morphological method for the detection of both bone and cartilage particles, because elevated cartilage contents may be indicative of MSM additives also. The method is based on simultaneous staining with Alizarin Red and Alcian Blue. We investigated MSM, commercially produced from breast of veal, for elevated particle contents. In addition, we determined the rate of recovery for minced pork mixed with 0-5% bone or cartilage. The results show that staining with Alizarin Red and Alcian Blue is suited to the efficient and simultaneous detection of bone and cartilage material in meat mixtures. The morphological staining is simpler than previously applied methods. Preparations can be assessed macroscopically, and they can be quantified gravimetrically. Manual sorting and weighing of particles appears to underestimate MSM contents if particles are ground very finely.

Acceptability of lamb meat from different producing systems and ageing time to German, Spanish and British consumers.

In the present study German (DE), Spanish (ES) and British (UK) consumers' acceptance of lamb from their own country compared to lamb from Uruguay (UY) was evaluated. Two-hundred consumers in each country evaluated tenderness, flavour and overall acceptability of four types of lamb, two from UY (light and heavy lambs aged 20 d) and 2 local (with two ageing times, 7 and 20 d). In each country 1.5cm-thick slices of lamb were evaluated by previously selected consumers in controlled conditions. DE and UK consumers showed significantly (P<0.05) different acceptability scores between samples, the lamb from heavier animals and aged 20 d being the most appreciated. On the other hand the majority of the ES consumers significantly (P<0.05) preferred the meat from lighter lambs. Production systems, cultural aspects and consumption habits seem to affect the acceptability of the lamb to the consumers.

Eating quality of beef, from different production systems, assessed by German, Spanish and British consumers.

The acceptability of beef from Uruguay (UY), based on eating quality, was compared with beef produced in different European countries (Germany, DE, Spain, ES and United Kingdom, UK). Consumer tests were conducted in DE, ES and UK (each comprising 200 consumers) using 'Hall Tests'. In each country four samples were evaluated, two from Hereford steers from UY (finished at 2 and 3 years) and two from local meat (the same meat sample aged 7 or 20d). Consumers evaluated tenderness, flavour and overall acceptability using 8-point category scales. Hierarchical cluster analysis, highlighted the existence of different clusters of consumers. Two main clusters were identified in DE and UK. The main cluster identified in DE, was labelled as Prefer foreign-imported beef (n=128). These consumers preferred (P<0.05) the samples from UY_2y in terms of tenderness and overall acceptability. The other cluster was labelled as Prefer local beef in terms of flavour and overall acceptability (P<0.05) and comprised the majority of consumers from ES (n=176) and UK (n=153) and the cluster 2 from DE (n=69). UK, cluster 2 (n=33) that did not discriminate between origin and ageing time of beef. These results indicate that consumers did not prefer the same type of meat within the same country and it is possible that there are individual preferences that could lead to the concept of market segmentation being based on taste preferences. It would appear that Uruguayan beef would be very acceptable in Germany and to a lesser extent in Britain and Spain, although further studies are required that include labelling information.

[Consumer demands concerning meat between price and ethics]. / Verbraucheransprüche an Fleisch zwischen Preis und Ethik.

A review is given about consumer demands on meat. Mainly the problems of decreasing meat consumption, health aspects and special questions of ecological products are considered. The market gives evidence of a further drop in meat consumption and a more consistent differentiation of product lines. Eco-products, emphasising the animal welfare aspect, will have their place in that context but persist in the state of a minor market segment. Nevertheless it has to be expected, that also the conventional products will increasingly comply to modern consumer demands.

[Scanning electron and light microscopic studies of the surface epithelium of the rete testis and epididymis in the boar. II. Ductus epididymis]. / Rasterelektronen- und lichtmikroskopische Untersuchungen des Oberflächenepithels von Rete testis und Nebenhoden beim Eber. II. Ductus epididymidis.

The entire ductus epididymidis is characterized by pseudostratified columnar epithelium which contain principal and basal cells. Apical cells are found in the proximal segments. Long stereocilia projected from the apical surface of the principal cells. Signs of adjacent apocrine secretory activity are shown. The various segments of the ductus epididymidis present differences in the height of the epithelium, the development of the stereocilia, the appearance of granules in the cytoplasm, the luminal sperm concentration and the height of the peritubular layer.

[Scanning electron and light microscopic studies of the surface epithelium of the rete testis and epididymis of the boar. I. Rete testis and efferent ducts]. / Rasterelektronen- und lichtmikroskopische Untersuchungen des Oberflächenepithels von Rete testis und Nebenhoden beim Eber. I. Rete testis und Ductuli efferentes.

The use of the scanning electron microscope gave a three dimensional representation of the epithelial surface. Additionally, light microscopy revealed the representative structure of the epithelium. The rete testis showed a single layer of cubic epithelial cells. Short and dense microvilli were found on the surface. Sporadically a single, cilia-like structure was recognized. An extratesticular rete testis was identified. The flowing transition of the epithelium between the rete testis and the efferent ductuli occurred at different levels, so that both kinds of epithelial structures were recognized in the same area. The efferent ductuli were composed of a single columnar epithelium consisting of two cell types, principal cells and ciliated cells. The ciliated cells were recognized by their cilia protruding into the lumen. The principal cells showed microvilli on their surface and bleblike apical protrusions which erupt into the lumen.

Changes in porcine sperm lactate dehydrogenase isoenzymes during sperm maturation.

The changes in sperm lactate dehydrogenase (LDH-lactate: NAD oxidoreductase, EC 1.1.1.27) activity and the relative occurrence of LDH isoenzymes during sperm maturation were studied using pubertal German improved Landrace boars. The LDH of spermatozoa liberated from the testis, caput epididymis, proximal and distal corpus epididymidis and cauda epididymidis was spectrophotometrically quantified while the LDH isoenzymes were separated on fine cellulose acetate membrane strips with the Sartorius Sartophor system. The LDH content of sperm dropped drastically as they moved from the testis to the caput epididymidis. Thereafter, only little and insignificant changes were observed. Testicular sperm was composed more of the fastest anodically-migrating isoenzyme (LDH1) while with sperm maturation, the least or slowest migrating isoenzymes (LDH4 and 5) became progressively more dominant. This loss in LDH content in sperm and the shifts in the LDH isoenzyme patterns indicate that the development of sperm during maturation is dependent on a delicate balance between lactate and pyruvate, such that the cathodic isoenzymes involved in the anaerobic energy-supplying metabolic processes are sufficiently available for sperm activity and survival.