Liquid Egg Products

The whippability of egg white can be enhanced by various additives, such as glycerol, starch syrup and triethyl citrate. Typical compositional data for frozen egg products are provided in Table 11.15. 

Eggs are pretreated as described earlier (cf. 11.4.3 and Fig. 11.5). Despite sanitary conditions at plants, eggs cannot be entirely protected from microorganisms. Pasteurization is difficult due to 

Most of the egg white proteins are relatively stable at pH 7, so normal pasteurization conditions do not negatively affect processing properties such as whippability. An exception is conalbu-min, but addition of metal ions (e. g. Al-lactate) can stabihze even this protein. Addition of Na-hexametaphosphate can also improve the stabihty of conalbumin. 

Pasteurized hquid egg products are generally also preserved by chemical means, e. g., addition of sorbic or benzoic acid. 

Powrie, W.D., Fennema, O. Effect of heat treatment on viscosity of yolk. J. Food Sci. 35, 864 (1970) 

---

Table 6. Minimum Pasteurization Requirements for Liquid Egg Products ...

Liquid egg products must be of exceUent microbiological quaHty with very low total bacteria counts. Pasteurization conditions are more severe than conventional methods for pasteurizing egg products, and aseptic packaging is usually necessary for the success of these products. 

Jung, Y.S. and Beuchat, L.R. 2000. Sensitivity of multidrug-resistant Salmonella typhimurium DTI 04 to organic acids and thermal inactivation in liquid egg products. Food Microbiology 17 63-71. 

FIGURE 6.1 Major components of a pulsed electric field system. (From Amiali, M., Inactivation of Escherichia coli 0157 H7 and Salmonella enteritidis in liquid egg products using pulsed electric field, PhD dissertation, McGill University, Montreal, Quebec, Canada, 2005.)... 

Amiali et al. (2005, 2006b, 2007) observed a synergistic effect of PEF and temperature when pasteurizing liquid egg products (egg white, egg yolk, and whole egg). More inactivation of E. coli 0157 117 and S. enteritidis were noticed when the EF intensity and treatment increased along with an increase in the treatment temperature. Up to 5-log reduction was reported at a field intensity of 30kV cm, treatment temperatures of 30°C or 40°C (depending on the egg product) and treatment time of 210 ps. 

The PEF treatment of liquid egg products, including whole egg, egg white, and egg yolk, inoculated with S. enteritidis and/or E. coli 0157 H7 was reported by Amiali et al. (2004, 2005, 2006b, 2007). Amiali et al. (2004) dialyzed liqnid egg products in order to obtain high EF intensity. The maximum inactivation rates of E. coli 0157 H7 were 1-, 2.9-, and 3.5-log reduction for egg white, egg yolk, and whole egg, respectively. The energy density required to treat egg white was 5.210kJ L", whereas 3.080kJ was required for egg yolk and whole egg products. The results... 

Amiali, M., Ngadi, M.O., Raghavan, V.G.S., and Nguyen, D.H. 2006a. Electrical conductivities of liquid egg products and fruits juices exposed to high pulsed electric fields. International Journal of Food Properties 9 533-540. 

Liquid Egg Products. Grade B eggs or other eggs not needed for the shell egg market go to an eggbreaking plant. After breaking, the liquid products obtained include whole egg, egg white, and egg yolk. These products are destined for the food industry and are unlikely to he found in retail stores. 

Table 11.15. Composition of frozen and liquid egg products (values in %)...

Rose, E.L. and Holub, B.F., Effects of a liquid egg product containing fish oil on selected cardiovascular disease risk factors A randomized crossover trial. Food Res. Int., 39, 910-916, 2006. 

Butyric acid is a carboxylic acid also classified as a fatty acid. It exists in two isomeric forms as shown previously, but this entry focuses on n-butyric acid or butanoic acid. It is a colorless, viscous, rancid-smelling liquid that is present as esters in animal fats and plant oils. Butyric acid exists as a glyceride in butter, with a concentration of about 4% dairy and egg products are a primary source of butyric acid. When butter or other food products go rancid, free butyric acid is liberated by hydrolysis, producing the rancid smell. It also occurs in animal fat and plant oils. Butyric acid gets its name from the Latin butyrum, or butter. It was discovered by Adolf Lieben (1836—1914) and Antonio Rossi in 1869. 

Cholesterol can be removed from eggs, dairy products and animal fats. Milk and egg yolk can be mixed with (3-cyclodextrin to complex the cholesterol, forming a precipitate that can be removed by centrifugation or filtration. Using cholesterol as a process aid, 80% of the cholesterol has been removed from cheeses84,85 and liquid eggs.86 Similar results have been obtained by treating lard and tallow.79... 

Catalase (Aspergillus niger var.) Produced as an off white to tan, amorphous powder or as a liquid by controlled fermentation using Aspergillus niger var. Soluble in water (the solution is usually tan to brown), but practically insoluble in alcohol, in chloroform, and in ether. Major active principle catalase. Typical applications used in the manufacture of cheese, egg products, and soft drinks. 

The eggs and egg products, thanks to their texture-improving properties, emulsifying effect, and foaming ability, are multifunctional components used in food technology in liquid or dried form. 

Bakers may use egg products in liquid, dried, or frozen forms. Liquid eggs, which have been churned, filtered, and pasteurized by the egg producer, are available in refrigerated tank cars to the large wholesale bakeries. The quality of dried egg products have been immensely improved in recent years, and many types of dried eggs are widely used by U.S. bakers in their production of bakery foods. Frozen egg products have lost ground to dried eggs because the former require careful thawing, a tedious, labor-intensive, and sometimes uncertain process. 

The control of the supply of the air to drying belts to prevent saturation from the liquid egg is an important factor.in preventing multiplication of bacteria in the product during the process of desiccation. 

Egg products, in liquid, frozen or dried forms, are made from whole eggs, white or yolk. They are utilized further as semi-end products in the manufacturing of baked goods, noodles, confectionery, pastry products, mayonnaise and other salad dressings, soup powders, margarine, meat products, ice creams and egg liqueurs. Figure 11.5 gives an overview of the main... 

Special Dietetic Foods. Many types of special dietary products are now available for people who must limit their consumption of substances present in ordinary foods. For example, there are artificially sweetened jams, jellies, salad dressings, sauces, and soft drinks. The term dietetic does not always mean that the product contains an artificial sweetener. Rather, it may mean that considerably less than the normal amounts of natural sweetener were used in the recipe. It may also be used to designate lowfat varieties of items such as salad dressings. Also, both dry and liquid forms of low-cholesterol egg products are sold in most supermarkets. However, it is best for anyone who has been placed on a modified diet to consult his or her doctor or dietitian before using any special dietetic foods because use of the new product may result in a significant alteration in the nutritional value of the prescribed diet. 

---