Yolk and eggshell colour: are these the parameters that influence egg purchasing? A systematic review

SUMMARY Factors such as price, egg availability, lifestyle and origin influence egg purchases. The eggshell and yolk colour can also influence consumer decisions at the time of purchase. Therefore, the objective of the study is to identify whether the physical characteristics of eggs, such as the colour of the yolk and shell, influence the purchase decision through a systematic review using the PRISMA guidelines. After the selection, 17 studies (from 1963 to 2021) were compiled. The United States presented the largest number of studies on the topic among the countries. The number of article observations ranged from 197 to 7845 respondents, and it was possible to verify that most of the respondents were women. Most respondents showed preference for brown eggs and the medium yellow colour was the most cited answer as preferred by consumers. Although eggs are one of the most consumed foods of animal origin in the world, there is still a lack of knowledge on the part of consumers about the factors that influence the characteristics of eggs, demonstrating that inaccurate information can affect preferences and consumption habits.