WINTER BONUS MAGAZINE 2025

The quality of a product determines its acceptability to potential consumers. Egg quality is determined by the internal quality of the egg, weight and the condition and appearance of the eggshell. Grading eggs by quality is critical for consistency in food safety and to facilitate uniformity, packing, and pricing. Grading affects the profit margin for commercial egg producers. During the grading process, eggs are transferred from one point in the egg grading machine to another. This article investigates the influence of impacts caused by these transfer points on the quality of eggs. 1. Transfer points in egg grading machines The introduction of mechanical, electronic and automated egg grading and packing machines has made vast improvements in the consistency and quality of eggs supplied to the market by commercial egg producers. Modern egg grading systems have numerous transition points where eggs are transferred from one point in the sorting system or carousel to another. Typical egg transfer points make use of suction cups in a suspended cup-conveyor system (see Figure 1) to move eggs from one point (see Figure 2) to another or grading points in the system. Bucket elevators, lift systems, and rod and curve conveyors are also used during grading, and each of these present a potential impact point. It is essential that all transferring of eggs occur with the utmost care to ensure smooth egg conveying and, thus, minimal damage to the delicate eggshell. The force of an impact on an egg can be measured in Newtons. Using a set of ten Vencomatic electronic eggs, the impact force on the eggs can be measured at every transfer point in a grading system. Should the impact in Newton measured by the electronic eggs be higher than the force in Newton required to crack the egg (typically >40 N), there is a strong likelihood that hairline cracks may occur at the point of impact. The impact on eggs by the egg transportation system can be measured across several impact points to identify the specific points where the impacts were higher. 2. Measuring the impact force of transitions on eggs Retha Gericke – Technical Advisor: Poultry Figures 1 and 2: Transfer of eggs using suction cups (left) and carousel (right). The green Vencomatic electronic eggs measure the impact force, as recorded on the Gregg mobile application. Commercial egg grading: The importance of transfer point impacts on egg quality www.agribonus.co.za Winter 2025 BONUS 53