The color of fresh meat is an extremely important characteristic influencing the consumer's purchase decision. The stability of pigments in meat is highly variable and is governed by a variety of factors. The effects of exogenous factors (i.e., storage and display conditions) have been well researched. The control of these variables currently offers the best means for maximizing meat color stability. Biochemical factors which are inherent to the meat itself have received far less research attention and an understanding of these presents the greatest potential for prolonging color stability in fresh meat.

The biochemical basis for discoloration in fresh meat: a review

References.- 1 Solubility of Proteins.- 1.1 Introduction.- 1.1.1 Factors Affecting Solubility of Proteins.- 1.2 Solubility of Meat and Fish Proteins.- 1.2.1 Solubility of Muscle Proteins.- 1.2.2 Solubility of Stroma Proteins.- 1.2.3 Protein Solubility in Processed Meats.- 1.2.4 Solubility of Blood Proteins.- 1.2.5 The Effect of Heating on Solubility of Proteins.- 1.2.6 The Effect of Freezing and Storage When Frozen on Protein Solubility.- 1.2.7 The Effect of Protein Modification and Irradiation Treatment.- 1.3 Solubility of Milk Proteins.- 1.4 Solubility of Egg Proteins.- 1.5 Solubility of Plant Proteins.- 1.5.1 Soybean Proteins.- 1.5.2 Peanut Proteins.- 1.5.3 Pea and Bean Proteins.- 1.5.4 Sunflower Proteins.- 1.5.5 Corn Proteins.- 1.5.6 Miscellaneous Plant Proteins.- References.- 2 Water Holding Capacity of Proteins.- 2.1 Introduction.- 2.2 The Mechanism of Protein-Water Interaction.- 2.2.1 Factors Influencing Water Binding of Proteins.- 2.3 Water Holding Capacity of Proteins in Meat and Meat Products.- 2.3.1 Water Binding Capacity of Muscle Proteins.- 2.3.2 Factors Influencing Water Binding of Muscle Proteins.- 2.3.3 Water Binding in Comminuted Meat Products.- 2.3.4 Milk Proteins in Comminuted Meats.- 2.3.5 Soy Proteins in Comminuted Meats.- 2.3.6 Corn Germ Protein in Comminuted Meats.- 2.4 Water Holding Capacity of Milk Proteins.- 2.5 Water Holding Capacity of Egg Proteins.- 2.6 Water Holding Capacity of Plant Proteins.- 2.6.1 Soybean Proteins.- 2.6.2 Pea and Bean Proteins.- 2.6.3 Sunflower Proteins.- 2.6.4 Corn Proteins.- 2.6.5 Wheat Proteins.- 2.6.6 Miscellaneous Proteins.- References.- 3 Emulsifying Properties of Proteins.- 3.1 Introduction.- 3.2 Hydrophobic and Hydrophilic Properties of Proteins.- 3.3 Interfacial Film Formation and Properties.- 3.4 Factors Affecting the Emulsifying Properties of Proteins.- 3.4.1 Protein Concentration.- 3.4.2 pH of Medium.- 3.4.3 Ionic Strength.- 3.4.4 Heat Treatment and Other Factors.- 3.5 Emulsion Stability.- 3.6 Measuring Emulsifying Properties.- 3.7 Emulsifying Properties of Meat Proteins and Proteins Utilized as Extenders in Meat Products.- 3.7.1 Protein Functionality in Comminuted Meats.- 3.7.2 Emulsifying Properties of Various Muscular Proteins.- 3.7.3 Emulsifying Properties of Blood Proteins.- 3.8 Functionality of Nonmeat Proteins in Comminuted Meats.- 3.8.1 Milk Proteins.- 3.8.2 Soy Proteins.- 3.8.3 Corn and Wheat Germ Proteins.- 3.9 Milk Proteins as Emulsifiers in Food Systems.- 3.9.1 Emulsifying Properties of Caseins and Caseinates.- 3.9.2 Emulsifying Properties of Whey Proteins.- 3.10 Emulsifying Properties of Egg Proteins.- 3.11 Emulsifying Properties of Plant Proteins.- 3.11.1 Soybean Proteins.- 3.11.2 Pea and Bean Proteins.- 3.11.3 Corn Proteins.- 3.11.4 Miscellaneous Proteins.- References.- 4 Oil and Fat Binding Properties Of Proteins.- 4.1 Introduction.- 4.2 Fat Binding Properties of Proteins of Animal Origin.- 4.2.1 Muscle Proteins.- 4.2.2 Soy Proteins in Comminuted Meats.- 4.2.3 The Effect of Corn Germ Protein Flour on Fat Binding in Ground Beef Patties.- 4.2.4 Milk and Egg Proteins.- 4.3 Fat Binding Properties of Proteins of Plant Origin.- 4.3.1 Soy Proteins.- 4.3.2 Pea, Bean and Guar Proteins.- 4.3.3 Corn Germ Proteins.- 4.3.4 Wheat Proteins.- 4.3.5 Cottonseed Proteins.- 4.3.6 Miscellaneous Proteins.- References.- 5 Foaming Properties of Proteins.- 5.1 Introduction.- 5.2 The Mechanism of Foam Formation.- 5.2.1 Factors Affecting Foam Formation.- 5.2.2 Foam Stability.- 5.3 Milk Proteins.- 5.3.1 Factors Affecting the Foaming Properties of Milk Proteins.- 5.4 Egg Proteins.- 5.4.1 The Effect of Processing on Foaming Properties of Egg Proteins.- 5.5 Blood Proteins and Gelatin.- 5.6 The Foaming Properties of Plant Proteins.- References.- 6 Gelling Properties of Proteins.- 6.1 Introduction.- 6.2 The Mechanism of Protein Gel Formation.- 6.2.1 Heat-Induced Gelation.- 6.2.2 Protein-Water Interaction in Gels.- 6.2.3 Factors Affecting the Properties of Gels.- 6.3 Gelling Properties of Meat Proteins.- 6.3.1 Myofibrillar Proteins.- 6.3.2 Sarcoplasmic Proteins.- 6.3.3 Gelation of Red and White Muscle Proteins.- 6.3.4 Factors Affecting the Gelling Properties of Meat Proteins.- 6.3.5 Myosin Blends with Other Proteins and Lipids.- 6.3.6 Fish Proteins.- 6.3.7 Collagen Gelation.- 6.3.8 Blood Proteins.- 6.4 Gelling Properties of Milk Proteins.- 6.4.1 Gelling Properties of Whey Protein Concentrate, Isolate, and Individual hey Proteins.- 6.4.2 The Effect of Heating and Protein Concentration.- 6.4.3 Gelation of Casein.- 6.4.4 Factors Affecting the Gelling Properties of Milk Proteins.- 6.5 Gelling Properties of Egg Proteins.- 6.5.1 Gelation of Egg White.- 6.5.2 Gelation of Yolk.- 6.6 Gelling Properties of Soy Proteins.- References.

Functionality of Proteins in Food

Functional Properties of the Myofibrillar System and Their Measurements

High-dose Irradiation: Wholesomeness of Food Irradiated with Doses above 10 kGy.

An overview of myoglobin-initiated lipid oxidation in simple model systems, muscle, and muscle-based foods is presented. The potential role of myoglobin spin and redox states in initiating lipid oxidation is reviewed. Proposed mechanisms for myoglobin-initiated lipid oxidation in muscle tissue (pH 7.4) and meat (pH 5.5) are evaluated with the purpose of putting forward general mechanisms explaining present observations regarding the catalytic events.

Myoglobin-induced lipid oxidation. A review.

Frankfurter quality was monitored to evaluate effects of frozen storage on meat components. After fresh meat controls were tested, beef, pork, and pork fat were frozen and stored at −17.8°C for 1–37 wk. At 6-wk intervals, functional and quality tests were performed on thawed and control meat samples and on frankfurters made from the samples. Frozen storage significantly affected beef and pork lean (drip loss, % solids and N in drip, extractable protein, water binding, emulsifying capacity) and fat (beef-thiobarbituric acid and pork-peroxide values); frankfurters produced from these ingredients were also affected (cooking tests, penetration force, sensory panel scores).

Effects of frozen storage on functionality of meat for processing

A multiple wavelength analysis of the reaction between hydrogen peroxide and metmyoglobin.

A study was made of the effect of low-dose gamma irradiation on the content of thiamine (B1), riboflavin (B2), niacin, pyridoxine (B6) and cobalamin (B12) in pork chops, and thiamine, riboflavin and niacin in chicken breasts. Gamma irradiation from a caesium-137 source was used to irradiate the samples in a range of 0.49 to 6.65 kGy from -20 to +20 degrees C. Over the range of dose and temperature studied it was possible to derive a mathematical expression for predicting the losses. A calculation was made of the effect of the loss of thiamine, riboflavin and niacin due to irradiation on the overall loss of these vitamins in the American diet. The losses of riboflavin and niacin were of the order of a fraction of a per cent. Pork is an important source of thiamine, but the calculated loss at 1.0 kGy of this vitamin in cooked pork was only 1.5 per cent. There were initial increases with radiation doses up to 2-4 kGy in the measured concentrations of riboflavin and niacin in both pork and chicken. The increases were highly significant, and are of concern both to the study of radiation effects and the chemical method of the determination of these two vitamins.

Effect of gamma irradiation on the B vitamins of pork chops and chicken breasts.

The effects of ionizing irradiation and frying on the thiamine and riboflavin content of bacon were determined. Significant destruction of thiamine but not riboflavin occurred during both the irradiation and frying. The destruction of thiamine was found to be directly related to the dose of ionizing radiation or the degree of cooking. Frying before irradiation, reduction of water content by lyophilization, and irradiation at - 40°C rather than 2°C produced significantly greater retention of thiamine. Frying the bacon following irradiation produced radiation dose-related, nonadditive, increased destruction of thiamine. The protective effect of frying before irradiation was not directly linked with the reduction of moisture by frying.

S.A. Ackerman

Papers

Effects of frozen storage on functionality of meat for processing

A multiple wavelength analysis of the reaction between hydrogen peroxide and metmyoglobin.

Effect of gamma irradiation on the B vitamins of pork chops and chicken breasts.

Effect of gamma ray irradiation and frying on the thiamine content of bacon

Fluorometric Determination of Thiamine Vitamers in Chicken