Meat ripening

Santos, C., Pena, M.J. and Rivas, J.C. (1986). Changes in tyramine during chorizo-sausage ripening. Meat Sci., 51, 518. 

Biogenic amines can be found in processed meat products as a consequence of microbial activity related to the fermentation involved in their processing, but amines can be also found in poor-quality raw materials as a consequence of microbial contamination. Therefore the BA content in cooked meat (not fermented) products might serve as a useful indicator of the hygienic quality of the meat employed for its elaboration. However, this relationship for ripened meat products is rather complex, since the ability to produce BAs of the fermentative microflora need to be well known before limits can be set. According to the few studies performed on BAs in meat products,... 

Hernandez-Jover et al. (72) derived an improved analytical method from the HPLC procedure setup they developed in 1995 (73) for the determination of BAs in fish. The method consists of the extensive extraction with HC104, ion-pair (with sodium octanesulfonate) RP-HPLC separation, postcolumn derivatization with PA/ME, and spectrofluorimetric detection. Determination limits were up to 1.5 mg/kg. In particular, His, Tyr, Phe, Ser (serotonine), Cre (creatinine), Try, Oct (octopamine), Dop (dopamine), Cad, Put, Agm (agmatine), Spm, and Spd were studied in pork and beef meat, fresh, cooked, or ripened. Tyramine, His, Put, Cad, and Try levels were... 

Catalases are mainly present in microorganisms such as Kocuria and Staphylococcus and are responsible for peroxide reduction. This reaction contributes to eolor and flavor stabilization. Nitrate reductase, also present in those microorganisms, is a very important enzyme for the reduction of nitrate to nitrite in slow ripened sausages where there is initial addition of nitrate. Recently, two strains of Lactobacillus fermentum have proved to be able to generate nitric oxide and give an acceptable color in sausages without nitrate/nitrite. This may be important in the case of cured meats with no addition of either nitrate or nitrite (Moller et al. 2003). 

Molly, K., Demeyer, D.I., Johansson, G., Raemaekers, M., Ghistelinck, M., and Geenen, I. (1997). The importanee of meat enzymes in ripening and flavor generation in dry fermented sausages. First results of a European project. Food Chem. 54, 539-545. 

In the case of salami, starter cultures can be cultivated on meat substrate and freeze-dried, where they remain active at a large rate. The storable culture substrate is added to the salami raw mixture to start the desired ripening process. Depending on process course, it can already contain flavour or flavour-precursors which contribute to accelerating the ripening process. 

Flavor is one of the most valuable characteristics of dry-cured ham (i, 2), a valuable non-cooked but ripened pork meat product from southwestern European countries, and dry-cured ham flavored products are also appreciated. The great interest of dry-cured ham flavor has lead to an extensive research on this topic. The first works on the compounds involved in dry-cured ham flavor were... 

Aldehydes are by far the most numerous compounds identified as dry-cured ham odorants, with different odors (green, rancid, toasted) and thresholds in air ranging from 0.09 to 480 ng/L (Table 1). Most of them were identified in the first works focused on dry-cured ham volatile compounds (7,2). Aldehydes are essential for meat flavor (70), but large quantities in meat and meat products have been related to lipid oxidation and deterioration (77). The effect of several quality factors has been researched and it was found that the rearing system of pigs (S) and ripening conditions (7) influence on the contribution to odor and the content of some aldehydes. 

The largest values for the 14-days group matched with the largest scores for the rancid note (it ). In fact, pentanal and hexanal (two usual indicators of lipid oxidation in meat, 11) were much more abundant in the 14-days group. It is known that during ripening of hams an increase of lipid oxidation volatile compounds takes place, and it is also followed by a important decrease (2). The decrease in some compounds could be related to the decrease of lipid oxidation caused by the depletion of the oxygen available in the tubes and to the lost of odorants by reactions with other components. 

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