Stabilization of meat lipids with nitrite-free curing mixtures

Several nitrite-free meat-curing mixtures have been formulated. The mixtures included salt, sugar, ascorbates, an antioxidant and/or a chelator, an antimicrobial agent and dinitrosyl ferrochemochrome (DNFH). They imparted to meat a similar oxidative stability as that of sodium nitrite. Butylated hydroxyanisole and t-butylhydroquinone were the best anti-oxidants and polyphosphates, ethylenediaminetetraacetic acid and diethylenetriaminepentaacetic acid were the superior chelators. The antimicrobial agents used were potassium sorbate, propryl paraben, fumarate esters and sodium hypophosphite. In the above mixtures, the added effect of (DNFH) on oxidative stability of the cooked meats was similar to the added effect of 150 ppm sodium nitrite.     

Color Formation in Nitrite-Free Dried Hams as Related to Zn-Protoporphyrin IX and Zn-Chelatase Activity

ABSTRACT:  The development of red pigment Zn-protoporphyrin IX (ZPP) in nitrite-free Parma hams was investigated in 5 leg muscles at several stages of processing and the activity of muscle Zn-chelatase was concurrently assayed for its potential role in ZPP formation. A steady increase of the pigment was observed throughout the manufacturing stages at mild temperatures while no development was observed during the prior cold resting phase. The enzyme was partly inactivated according to a muscle-dependent pattern, resulting in similar ZPP contents, hence color, in finished hams. It is concluded that enzyme-dependent synthesis of ZPP in nitrite-free dried hams contributes to color development, enabling muscles in dried hams to become more similar in redness than in green thighs. Therefore, checking raw meat for the enzyme content may be a means to control color formation in nitrite-free dry-cured meat derivatives.     

巴马火腿红色色素的研究进展

综述了巴马火腿红色色素研究的最新进展。巴马火腿在腌制时不添加硝酸盐或亚硝酸盐 ,经过长期的加工过程 ,巴马火腿肉具有稳定的红色。巴马火腿的红色色素与添加硝酸盐或亚硝酸盐腌制的普通火腿的红色色素具有不同的吸收光谱、颜色稳定性和抗氧化性。根据巴马火腿红色色素的吸收光谱、荧光光谱、高压液相色谱和高分辨率电喷雾电离质谱 ,证实了巴马火腿的红色色素是锌 原卟啉IX。     

Color and Oxidative Stability of Nitrite-Free Cured Meat after Gamma Irradiation

The effects of 5 and 10 kGy irradiation on the color and oxidative stability of meats treated with nitrite or a nitrite-free curing system were investigated. The nitrite-free curing system consisted of the preformed cooked cured-meat pigment, sodium ascorbate and sodium tripolyphosphate with or without sodium acid pyrophosphate. Irradiation had no detrimental effects on the color or flavor of either cured samples. Polyphosphates had a beneficial effect on oxidative stability but had a slight detrimental effect on color stability of irradiated samples.     

Thermal and photochemical degradation of myoglobin pigments in relation to colour stability of sliced dry-cured Parma ham and sliced dry-cured ham produced with nitrite salt

Lipophilic and hydrophilic extracts of the red pigments from Parma ham and nitrosylated pigment of dry-cured ham produced with nitrite salt were prepared with acetone/water (75/25 v/v %) solution and aqueous phosphate buffer, respectively. The spectral characteristics differed for both the lipophilic and the hydrophilic Parma ham pigment compared with the dry-cured ham produced with nitrite salt. The red lipophilic pigment(s) extractable from Parma ham was(were) found to be very stable towards thermal degradation in acetone/water (75/25 v/v %) solution for temperatures up to 70 °C in contrast to the lipophilic pigment(s) extractable from dry-cured ham produced with nitrite salt, which was(were) found to have an energy of activation of 99 kJ/mol for thermal degradation. In contrast, quantum yields for photodegradation of the lipophilic ham pigments exposed to 366 nm (420 nm) monochromatic light were larger for Parma ham than for nitrite-cured ham [1.6×10^–5 (6.9×10^–6) versus 1.6×10^–6 (2×10^–6) mol einstein^–1] as determined for acetone/water (75/25 v/v %) solution. In agreement with these findings for the extracted lipophilic pigments, sliced Parma ham showed better colour stability than sliced dry-cured ham produced with nitrite salt, when stored in the dark at low oxygen concentration, in contrast to a faster initial discolouration for Parma ham when exposed to light, as shown for chilled storage for 35 days under retail conditions for the two products each packed at two oxygen levels (0.4 and 21%).     

KINETICS OF PIGMENT DEGRADATION IN SLICED COOKED HAM

Sliced cooked ham was vacuum packaged and held in the dark at −15C. 10C, and 30C, and at 10C in the light, for up to 96 h. At 24 h intervals, samples were analyzed for pigment concentration by spectrophotometry. A decrease in pigment concentration was observed over time under all conditions. Pigment degradation increased at higher temperatures and with light exposure. Kinetic parameters were determined, indicating that pigment degradation follows first order kinetics and the temperature dependence of these reactions indicated an Arrhenius relationship. The activation energy was 3.3 kcal/mol. The visible spectra for the extracted pigments in cooked ham showed the typical pattern of nitrosylmyoglobin. Pigments extracted from ham displayed in the light had spectra with similar absorption maxima to those from those stored in the dark.     

驴肉火腿的试制与质量控制

本文主要论述了在驴肉火腿的试制过程中,添加猪脂肪、β-环状糊精可以改善和提高制品的风味和质地,添加红曲米色素、淀粉和亚硝盐可以改善制品的色泽,结果都比较令人满意.     

Spectral characterisation of red pigment in Italian-type dry-cured ham. Increasing lipophilicity during processing and maturation

Spectroscopic studies of Parma ham during processing revealed a gradual transformation of muscle myoglobin, initiated by salting and continuing during ageing. Electron spin resonance spectra did, however, conclusively show that the pigment in dry-cured Parma ham at no stage is a nitrosyl complex of ferrous myoglobin as found in brine-cured ham and Spanish Serrano hams. Both near-infra red reflectance spectra of sliced ham and UV/visible absorption spectra of extract of hams, obtained with aqueous buffer or acetone, showed the presence of different red pigments at varying processing stages for both solvents. Especially, the pigment extracted with aqueous buffer exhibited unique spectral features different from those of well-known myoglobin derivatives. At the end of processing, the pigment(s) becomes less water extractable, while the fraction of red pigment(s) extractable with acetone/water (75%/25%) increases throughout the processing time up to full maturation at 18 months. The chemical identity of the 6th ligand of myoglobin could not be conclusively established, but possible candidates are discussed. The partition of the pigment(s) between pentane and acetone/water showed a strong preference for pentane, suggesting that only the heme moiety is present in the acetone/water extract, and that Parma ham pigment is gradually transformed from a myoglobin derivative into a non-protein heme complex, which was found to be thermally stable in acetone/water solution     

Studies on the antioxidative activity of red pigments in Italian-type dry-cured ham

Aqueous phosphate buffer extracts and acetone/water extracts of pigments from Parma ham were assessed as antioxidants by (1) electron spin resonance spectroscopy using a spin probing technique to evaluate their efficiencies as scavengers of free radicals, and (2) by electrochemical measurement of oxygen depletion rate in an aqueous methyl linoleate emulsion to evaluate their efficiencies as chain-breaking antioxidant, and using both methods, compared with the effect of apomyoglobin and nitrosylmyoglobin. Aqueous phosphate extracts and acetone/water extracts of Parma ham pigment both scavenged a semi-stable nitroxide radical (Fremy's salt), and both extracts reduced the rate of oxygen consumption for lipid peroxidation (initiated by metmyoglobin) very efficiently. For apomyoglobin no antioxidative capacity was observed, and the heme moiety of the pigment(s) of Parma ham were concluded to have antioxidative properties. The more lipophilic pigment, as extracted by acetone/water, had the most significant effect, and its ability to inhibit lipid oxidation was further tested in a model food system based on cooked pork. The lipid oxidation was increasingly inhibited by increasing additions from 0.12 ppm to 0.24 ppm Parma ham pigment, and the pigment protected -tocopherol against degradation in a concentration dependent manner.     

Red Pigment of Parma Ham and Bacterial Influence on its Formation

The red pigment of Parma ham was compared with the myoglobin derivatives present in meat and meat products. Spectral patterns of 75% acetone extracts and electron spin resonance spectra from Parma ham differed from those of the myoglobin derivatives. Staphylococci isolated from Parma ham generated red myoglobin derivative from metmyoglobin. Model fermented sausage prepared by inoculation with the isolates developed a more desirable red color without nitrite or nitrate treatment. The red pigment of Parma ham and the model sausage appeared to be the same myoglobin derivative. The reddening of Parma ham is probably caused by the action of bacteria.