Just Egg claims superior sustainability for its mung-bean based egg product compared to conventional eggs.  The company claims a 77 percent reduction in water usage and a 40 percent lower carbon footprint.  In a recent evaluation conducted in France, Stephane Bergeron and Maurice Doyon refute these claims that are based on an incomplete life-cycle analysis. 

The authors of the article point to the fact that the processing component of mung-beans is not taken into account.  Extraction of protein from the vegetable source requires grinding and extraction followed by spray-drying using both water and energy.  Packaging and transportation are not taken into account in determining the carbon footprint of Just Egg.  The product is manufactured and packed at a plant in Minnesota, requiring distribution to retail points of sale in the U.S. increasing the transport component.  In comparison, eggs are essentially local in their production requiring shorter distances between packing plants and retail outlets.  The comparison did not take into account the energy associated with the plastic containers for Just Egg compared to the predominantly fiber packing for eggs that can be recycled.

An important consideration relates to the relative protein content of Just Egg and conventional eggs.  Taking into account digestibility for eggs and mung-beans and applying data prepared by the Food and Agriculture Organization a kilogram of Just Egg contains 63 grams of available protein compared to 147 grams per kg for real egg.  Based on the adjustments to the life-cycle analysis and applying nutritional value, real eggs have a carbon footprint 25 percent lower than that of Just Egg.  The analysis considered crude protein. If the amino acid composition of mung-bean protein and the balanced composition of real eggs are compared, the Just Egg product is even less nutritious and sustainable than real eggs consumed in shell form or as processed products.