Potato Protein

Starch plants separate potatoes into starch, pulp and a liquid that still contains protein. Recovering and drying that protein creates another saleable ingredient from the same crop.^4,5

1. 01 // Source Potatoes Potatoes enter a starch plant, which separates the starch from the liquid carrying potato protein.
2. 02 // Process Protein recovered The protein is concentrated from potato juice by a method such as coagulation or filtration.
3. 03 // Process Concentrate dried The recovered protein is spray dried into a powder for storage and transport.
4. 04 // Output Potato protein The dry concentrate reaches the kibble plant as an ingredient that contributes mostly protein.

1. 01

   Raises recipe protein

   A concentrate with about 80% crude protein makes a substantial contribution to the finished food's protein figure without increasing its meat content.^4,5

2. 02

   Supplies amino acids

   Potato protein's essential amino acids tested as readily digestible in a rooster assay. Formulators still have to balance the amino acids across the complete recipe.⁴

3. 03

   Sells a starch byproduct

   Starch production leaves potato juice containing protein. Recovering it gives the processor another ingredient to sell from potatoes already being processed.^4,5

4. 04

   Offers another protein source

   A dog diet for chronic intestinal disease paired potato protein with fish meal and other ingredients. That shows a formulation use, not a proven benefit of potato protein alone.³

How much A study of 8 dogs fed mixed plant-based diets containing 3.7 to 11.2% potato protein; a typical commercial amount is unpublished.¹

1. Critics say

   Potato protein raises protein without adding meat

   Evidence

   1. Strong
   2. Some
   3. Thin
   4. None

   Crude protein includes plant protein. Potato protein measured about 80% protein on a dry basis in a starch-plant survey, so adding it raises a food's protein figure without raising its meat content.^4,5

2. Brands say

   Dogs digest potato protein exceptionally well

   Outruns the evidence

   Evidence

   1. Strong
   2. Some
   3. Thin
   4. None

   Its essential amino acids tested as highly digestible in an assay using 4 roosters per treatment. An 8-dog study fed mixed diets containing potato protein, so neither study proves exceptional digestibility of this ingredient in finished dog food.^1,4

3. Brands say

   Potato protein soothes sensitive guts

   Outruns the evidence

   Evidence

   1. Strong
   2. Some
   3. Thin
   4. None

   A study reported improvement in 14 dogs with food-responsive diarrhea and 7 with inflammatory bowel disease. The diet also contained fish meal and added omega-3 fats, and some dogs received drugs. It did not isolate potato protein.³

4. Owners say

   Potato protein causes heart disease in dogs

   Outruns the evidence

   Evidence

   1. Strong
   2. Some
   3. Thin
   4. None

   FDA reports included foods with potato ingredients but cannot identify a cause. In a 60-dog, 18-month trial, a diet containing potato protein did not produce clinical DCM. That trial compared whole recipes, not potato protein alone.^2,7

5. Critics say

   Potato protein is just filler

   Outruns the evidence

   Evidence

   1. Strong
   2. Some
   3. Thin
   4. None

   A starch-plant survey measured about 80% crude protein in the concentrate, and a rooster assay measured digestible amino acids. It has a nutritional job. The fair label concern is how much of the food's protein comes from plants.^4,5