Liquid Egg White Research Articles

Technological evaluation of dried egg white prepared by different techniques

AbstractEgg white was spray dried, using Egyptian fresh eggs, with and without glucose removal. Glucose depletion in egg white was carried out using bacteria yeast and enzyme.Foam capacity and stability of liquid egg white was also decreased by dehydration, except for egg white in which enzyme was used for glucose removal. Foam was more stable in samples desugared by yeast and least stable in enzyme treated egg white. Both pan drying and spray drying methods had the same effect on foam capacity and stability of egg white.The pH value of liquid egg white was found to decrease by removing glucose and to increase by dehydration.The specific volume data and organoleptic evaluation of angel food cakes in which dehydrated egg white, imported dried egg white and fresh egg white were used, showed that the best method to prepare dehydrated egg white is by using enzymatic treatment for glucose removal before dehydration.

Factors affecting the growth of Pseudomonas fluorescens in liquid egg white.

Pseudomonas fluorescens grew rapidly in fresh egg albumen diluted with water. Growth of the bacteria in egg albumen was stimulated by the addition of carbohydrate and ovomucoid-rich egg exudate. Polyacrylamide-gel electrophoresis for residual egg albumen revealed extensive proteolysis of albumen inoculated with the organism. A fluorescent compound with absorption maximum at 408 nm was isolated from a defined salt medium inoculated with P. fluorescens. It shortened the lag phase and increased the final cell yield of the organism when added to the salt medium (100 mug/ml).

Factors Affecting the Growth of Pseudomonas fluorescens in Liquid Egg White

Pseudomonas fluorescens grew rapidly in fresh egg albumen diluted with water. Growth of the bacteria in egg albumen was stimulated by the addition of carbohydrate and ovomucoid-rich egg exudate. Polyacrylamide-gel electrophoresis for residual egg albumen revealed extensive proteolysis of albumen inoculated with the organism. A fluorescent compound with absorption maximum at 408 nm was isolated from a defined salt medium inoculated with P. fluorescens. It shortened the lag phase and increased the final cell yield of the organism when added to the salt medium (100 mug/ml).

Isolation of Psychrophilic Bacteriophage-Host Systems from Refrigerated Food Products

Thirty-eight bacteriophage-host systems were isolated from 22 of 45 refrigerated food products examined under psychrophilic conditions. Isolates were obtained from ground beef, pork sausage, chicken, raw skim milk, and oysters, whereas no isolations were made from liquid egg whites and processed meat products. Thirty of the 38 psychrophilic bacterial hosts were gram-negative rods, and 27 of these were classified within the genus Pseudomonas ; three were members of the family Enterobacteriaceae. The remaining eight were gram-positive cocci, which were tentatively classified as Leuconostoc. Plate counts of psychrophilic bacteria were greater than 2.2 × 10 5 /ml (g) in all but one sample which contained phage, whereas phage titers ranged from less than 100 to 6.3 × 10 6 plaque-forming units/ml (g). Phage isolates showed limited host ranges usually attacking only those hosts upon which they were isolated. Of eight phages tested against 13 cultures of known identity, one showed lytic action, and this was against strains of P. fragi.

Isolation of Psychrophilic Bacteriophage-Host Systems from Refrigerated Food Products 1

Thirty-eight bacteriophage-host systems were isolated from 22 of 45 refrigerated food products examined under psychrophilic conditions. Isolates were obtained from ground beef, pork sausage, chicken, raw skim milk, and oysters, whereas no isolations were made from liquid egg whites and processed meat products. Thirty of the 38 psychrophilic bacterial hosts were gram-negative rods, and 27 of these were classified within the genus Pseudomonas; three were members of the family Enterobacteriaceae. The remaining eight were gram-positive cocci, which were tentatively classified as Leuconostoc. Plate counts of psychrophilic bacteria were greater than 2.2 x 10(5)/ml (g) in all but one sample which contained phage, whereas phage titers ranged from less than 100 to 6.3 x 10(6) plaque-forming units/ml (g). Phage isolates showed limited host ranges usually attacking only those hosts upon which they were isolated. Of eight phages tested against 13 cultures of known identity, one showed lytic action, and this was against strains of P. fragi.

Physical and Functional Properties of Gamma Irradiated Liquid Egg White

INTRODUCTIONPOSSIBILITIES of preserving foods by applications of ionizing radiations have prompted numerous investigations during the past decade. Most of these studies have been primarily concerned with the micro-biological and organoleptic properties of irradiated foods. The possibility of control and elimination of Salmonella in egg products has received considerable attention. Results obtained in these studies indicate that ionizing radiation as a means of pasteurizing egg products has excellent potential (Ketchum et al., 1965).The ability of radiation pasteurization to control Salmonella in egg products has been amply demonstrated. Comer et al. (1963) reported that 0.54 Mrad. of gamma radiation would be sufficient to destroy or control eighteen species of Salmonella in frozen whole egg. Other workers using different egg products, other sources of ionizing radiation, and various species of Salmonella have reported similar results (Proctor et al., 1953; Nickerson et al., 1957; Brooks et al., 1959; and Mossel, 1960). The .

Equivalent Pasteurization Temperatures to Kill Salmonellae in Liquid Egg White at Various pH Levels

THE pH of the medium has a major influence on the susceptibility of bacteria to heat. Hansen and Riemann (1963), in a review of factors affecting the heat resistance of nonsporing organisms, indicated that maximum resistance usually occurs near neutrality. Most pasteurization studies either have not considered or have given little attention to pH as a variable in altering the time and/or temperature required to kill bacteria in liquid egg white (EW).A review of the literature revealed the following information on the pH of EW during pasteurization. Ayres and Slosberg (1949) readjusted the pH of fermented EW to 9.0 before flash pasteurization at 59.4°C. A patent by van Olphen (1953) claimed that pathogenic bacteria in EW could be destroyed by increasing the pH to 9–12, then pasteurizing at 40–55°C. Elleman (1955) referred to a similar process which called for adjusting the pH of EW to 10.5 with NH4OH, holding .

Effect of Sodium Chloride and Storage Temperature on the Growth of Salmonella oranienburg in Egg Yolk

METHODS for controlling salmonellae in foods are of concern to processors and public health officials. From April 1962 to March 1963, 32 outbreaks of salmonellosis were investigated. Sources of 22 were definitely established and 64% were due to poultry and poultry products (U. S. Public Health Service, 1963). Methods to control salmonellae in dried egg products have been reported by Ayres and Slosberg (1949), Banwart and Ayres (1956) and Wilson (1948). Pasteurization was reported by Winter et al. (1946) and Goresline et al. (1951) to be effective in controlling salmonellae in liquid whole egg. Altering of pH to reduce salmonellae in liquid egg white was reported by Banwart and Ayres (1957). The effects of salt in egg products on salmonellae apparently have not been studied. The USDA grading regulations (1963) state that egg products must be cooled to 45°F. within1½ hours after draw off from the holding vat. Products containing…

Effect of Centrifuging Yolk-Contaminated Liquid Egg White on Functional Performance

INTRODUCTIONWHEN egg white becomes contaminated with yolk, it suffers a loss of certain desirable functional characteristics. This effect was noticed by St. John and Flor (1931) who reported that one drop of yolk in 30 ml. of egg white was sufficient to reduce the egg white foam volume from an original 135 ml. to 40 ml. Smith (1959) reported that as little as 0.01 percent of yolk would impair the functional performance of egg white. He also noted that greater dispersion of the yolk throughout the albumen increased the harmful effects.Several methods have been devised for estimating the amount of yolk in egg white (Cook and Mehlenbacher, 1946; Bergquist and Wells, 1956; Colburn, 1960; Cotterill, 1961) but information in the literature on the physical properties of yolk contaminated liquid egg white is limited. Likewise, several suggestions have been forwarded for alleviating the harmful effects of yolk (Murray and…

Effect of Chemical Additives on Yolk-Contaminated Liquid Egg White

THE origin of the concept that chemical additives will improve the functional performance of yolk-contaminated egg white is vague. Koudele and Heinsohn (1960) credited Kothe (1953) with the discovery of a chemical additive to partially overcome the adverse effects of yolk contamination in egg white. The patent by Kothe (1953) concerned the use of a variety of ester-type organic chemicals, of which triethyl citrate was mentioned. It is conceivable that when an earlier patent, authored by Mink (1939) concerning the use of various anionic surface active compounds to improve the performance of egg white, was granted, chemical additives may have been used to improve yolk-contaminated egg white. However, specific effects on yolk-contaminated egg white were not mentioned in either of these patients or in other patents which concerned the use of chemical additives in egg whites (Littlefield, 1939; Werbin, 1952; Finucane and Mitchell, 1954; Jensen and Hale, 1954; Schaffer, 1956;…

A Simple Procedure for the Estimation of Total Lipids in Liquid Egg White

Abstract THE estimation of small amounts of lipids in egg white has become an important quality control test in the egg processing industry. Bergquist and Wells (1956) adapted, to egg white, a micromethod described by Heinemann and Rohr (1950) for the determination of fat in skimmilk and non-fat dry milk solids. This method entails an ethyl alcohol, ethyl ether, petroleum ether extraction in an ammoniacal system. The amount of lipid in this extract is determined by observing the area of a monomolecular surface film. Colburn (1960) evaluated several factors affecting the accuracy of this test and devised an alternate method to measure the surface area of the lipid. His method gave comparable accuracy in less time and partially corrects for film pressure variations. Smith (1960) reported that while increasing amounts of natural whole egg yolk results in increasing linear increments of film area, the individual lipid components do not result in…