Meat color

Meat color Meat curing Meat products... 

The principal packagiag use of PVC film is as a gas-permeable but water-vapor impermeable wrap for red meat, poultry, and produce. Sparkle and transparency, combined with the abiHty to transmit oxygen to maintain red-meat color, offer advantages in these appHcations. 

Cytochrome c is a heme containing protein which occurs in muscle at lower concentrations than does myoglobin. It was demonstrated some time ago (18) that oxidized cytochrome c reacts with gaseous nitrite oxide to produce a nltrosyl compound. Recent work (19, 20, 21) has examined the reactions of cytochrome c with nitrite and the contribution of the product formed to cured meat color in considerably more detail. The general conclusion is that even at the pH normally encountered in meat, the reaction can take place in the presence of ascorbic acid but probably does not affect meat color because of the unstable nature of the reaction product and the low concentration. 

The major health concern regarding use of curing salts is the possibility of nitrosamine formation in the cured products. Nitrite ion appears to be the precursor compound required for nitrosamine formation, rather than NO. Inclusion of reductants such as ascorbate, now required in bacon, lowers nitrite level in the product and increases the level of NO available for cured meat color formation and stability. 

In contrast to fresh muscle, meat has low levels of NAD (Madhavi and Carpenter, 1993). Thus, NAD-dependent enzymatic pathways for NOMb formation ate relatively unimportant in meat curing. In commercial practice, nitrite is reduced to NO by nonenzymatic means, including use of reductants such as ascorbate and erythorbate. Although meat has sufficient reducing ability to obtain a slow conversion of nitrite to NO, ascorbate or its isomer, erythorbate, is commonly added to curing brines or sausage emulsions to obtain faster NO production and thus a more rapid development of cured meat color. Care must be taken... 

Colorants and pigments, in meats Color density, see also Colorimetry Colorimetry, see also Color analysis amylose, 689-692... 

In general, replicate samples are essential when analyzing ground meat color. An efficient practice may involve the preparation of patties ( 25 g) so that an entire sample is used during analysis. A small petri dish ( 5 cm in diameter) serves as an excellent mold for patty formation while maintaining geometric shape, surface area, and compaction. 

An average of two to three readings per sample surface will more accurately reflect meat color. 

AMSA (American Meat Science Association). 1991. Guidelines for Meat Color Evaluation. Recip. Meat Conf. Proceed. 44. Am. Meat Sci. Assoc., Kansas City, Mo. 

An overview of instrumental analyses used to measure meat color and their relation to human visual appraisal. 

Solberg, M. 1968. Factors affecting fresh meat color. Proc. Meat Ind. Research Conference, Chicago. March 21, 22. 

L-Ascorbic acid is also added to food in essentially a non-nutrient capacity such as a preservative or oxygen acceptor, as an acidulant, as a stabilizer of cured meat color, or as a flour improver. Because of the ene-diol group, it has a marked inhibitory influence on the oxidation-reduction reactions responsible for undesirable color, flavor, and odor development. Its mechanism of action is dependent upon the characteristics of the food or food ingredient, the associated environments, the processing technology, and the storage expectancy of the product. 

Advantages cited in more recent reports with the ascorbate treatment include reduced curing time (480,483,485,487,488) better, more stable, and more uniform color (480,482,483,485,489-495), less nitrite required or lower nitrite levels (480,482,496-500), better flavor, and less rancidity. To emphasize the importance of the ascorbic acid application in lowering the residual nitrite levels in cured meat, the data of Brown et al. (497) may be examined (Table XVII). Other additives to accompany the ascorbic acid treatment of meat have been suggested. Boren-stein and Smith (501, 502) reported the use of ethylenediaminetetraacetic acid (EDTA) or its salt (preferably Fe) in combination with ascorbate and with nitrite or nitric oxide to accelerate the formation of cured meat color. Other additives (503-506) cited with ascorbic acid were cysteine (505), glutamate (504), histidine (500), niacin, niacinamide (504,505, 506), phosphates (503), and succinate (504). 

The central iron atom has six coordination bonds, each representing an electron pair accepted by the iron from five nitrogen atoms four from the porphyrin ring and one from a histidyl residue of the globin. The sixth bond is available for binding with any atom that has an electron pair to donate, e.g., 02 or NO. The oxidation state of the iron atom and physical state of globin play an important role in meat color formation. 

An undesirable reaction of sulfite in food is the cleavage of thiamin by means of an attack at the pyrimidin moiety (Zoltewicz et al., 1984). This was one of the reasons for a ban, in many countries, on the use of sulfite in meat. Another reason is the preserving effect on the meat color, which makes stale meat look as if it were fresh. Sulfite, however, is unable to reduce metmyoglobin back to myoglobin (Wedzicha and Mountfort, 1991). 

AMSA (1991). American Meat Science Association Committee. Guidelines for meat color evaluation. Chicago National Live Stock and Meat Board. 

GOUTENFONGEA, R., RAMPON, V., NICOLAS, N. and DUMONT, J. P. (1995). Meat color changes under high pressure treatment. 41st Annual International Congress of Meat Science and Technology. San Antonio, Texas, USA, pp. 384-385. 

Since N2 has a low solubility in water and in fat, there is little reaction with meats (which are 70%-75% water). Therefore, it is useful for displacing O2 in packagings (Church, 1994 Sebranek and Houser, 2006). With little or no O2 present, meat color is the brown of MMb and aerobic bacteria do not thrive. 

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