Application Notes

Monitoring pH and Salt During AN #: 07_020_11_001 Market: Food & Dairy Powdered Egg Processing Subcategory: Eggs and Egg Products Product: HI902C, HI4115

Description: Powdered eggs, also known as dried eggs, are fully dehydrated eggs, and are one of the most common products from the poultry industry. The realized value of powdered eggs versus fresh eggs is extensive. Dried eggs are more cost- effective, occupy less storage space, have a reduced weight per volume, and eliminate the need for refrigeration. When stored properly, powdered eggs exhibit a shelf-life of 5 to 10 years; certain products such as freeze-dried eggs exhibit a shelf-life of up to 25 years. There is a wide range of dried egg products, including whole egg powder with and without sugar, egg yolk powder, and egg white powder.

The process to manufacture egg powder is performed in specialized processing plants. The typical process starts with the breaking of eggs, followed by the separation of albumen (egg white), yolk, and eggshell. The albumen may be processed independently for the production of egg white powder, in which the albumen liquid undergoes filtration, chilling at approximately 4°C, fermentation to remove glucose, and spray drying before packaging. Fermentation of albumen liquid is necessary as glucose may react with amino acids during the spray drying process, in which a brown color may be produced. Whole egg powder and egg yolk powder are processed by chilling the liquid at approximately 4°C, dry pasteuriz- ing at temperatures around 64 to 70°C for short periods of time to remove bacteria, and subsequently spray drying prior to final packaging.

Several chemical factors can alter the quality of the finished egg powder product, including pH and sodium. If the pH levels of the raw egg are too high, the protein structures may unfold. To inhibit proteins from breaking down, the pH can be measured at different stages in the production process. The range of pH levels for final products of whole egg powder, egg yolk powder, and egg white powder are pH 7.5 to 9.5, pH 6.0 to 6.6, and pH 6.5 to 8.5, respectively.

Sodium chloride is one of the key in- gredients in egg powder, in that many food-processing companies that use dried eggs including fish, mayonnaise, and salad dressing, prefer salted egg powder. The addition of salt reduces gelation, or solidification, by preventing the aggregation of lipoproteins during freezing. High content of sodium chloride can also result in decreased foaming of the products; specifically for egg white powder, foaming is a desirable quality in baking. Thus, testing the finished egg powder before packaging helps to predetermine the quality and www.hannainst.com shelf life of the products. Application Notes

Monitoring pH and Salt AN #: 07_020_11_001 Market: Food & Dairy During Powdered Egg Subcategory: Eggs and Egg Products Product: HI902C, HI4115 Processing Cont. Application: A customer from an egg powder manufacturing company contacted Hanna about measuring the amount of sodium in their egg powder products. The company wanted to determine sodium chloride through argentometric titration using silver nitrate as the titrant. In this type of titration, the chloride content in the egg powder re- acts with silver nitrate to form silver chloride precipitate; the amount of sodium is determined indirectly through the amount of chloride that was reacted. In the past, the customer had been performing a manual titration, but now required a more time-efficient alternative that would yield higher accuracy. Hanna recommended the HI902C Automatic Potentiometric Titrator with the HI4115 Silver/Sulfide Combination Ion Selective Electrode. The HI902C Automatic Titrator would not only analyze the sodium chloride content of their products through the use of the ISE, but would also measure parameters such as pH and temperature. The HI902C is available with either one or two analog boards, where each board consists of a BNC connection, a temperature port, a reference electrode port, and a stirrer assembly. By supplying the customer with a titrator equipped with two analog boards, the customer was able to switch between channels to either perform a pH measurement or a titration. For the titration procedure, the HI902C was integrated with the customer’s analytical balance, where the weight of their samples can be automatically transferred into the method calculation, saving time and reducing potential error. The customer also appreciated the support they received from Hanna in how to prepare, condition, and store the Silver/Sulfide ISE; the assistance permitted a smooth transition from a manual titration with an indicator dye to an automatic potentiometric titration. Overall, the HI902C provided a fast and accurate solution to the customer’s egg powder testing needs.