Dried White Potatoes

Dried potatoes come from the same food lines that make instant mashed potatoes. A raw tuber is about four-fifths water, so cooking and drum drying turn it into a light, shelf-stable starch.^1,2,7

1. 01 // Source White potatoes Raw tubers average about 20.6% dry matter, so most of what goes in is water.
2. 02 // Process Washed, peeled, sliced Food lines wash, peel and slice the tubers. The peel holds 3 to 10 times the glycoalkaloids of the flesh.
3. 03 // Process Precooked and steamed Slices sit in water at about 71 to 74 C for 15 to 20 minutes, then steam at 88 to 100 C.
4. 04 // Process Mashed and drum dried The cooked potato is riced into a mash and dried on a heated drum to a sheet of 6 to 8% moisture.
5. 05 // Output Flakes or granules A dry, cooked product about 75% gelatinized, highly digestible starch, broken into flakes or granules.

1. 01

   Makes kibble expand

   Cooked starch puffs in the extruder and binds the kibble. In one trial the 30% potato starch diet gave the largest expansion, more pores, harder kibbles and lower density.⁴

2. 02

   Starch without grain

   Potato lets a recipe drop corn, wheat and rice. Potatoes or sweet potatoes were in 42% of foods named in FDA's DCM reports, a report set that was over 90% grain-free.⁶

3. 03

   Precooked, digestible energy

   Food-grade flakes arrive already cooked, about 75% highly digestible starch. In an ileal dog study, starch from potato flour was over 99% digested, like five grain flours.^2,3

How much One dog trial replaced corn with potato starch at 10, 20 and 30% of the diet, and dry matter and energy digestibility rose.⁴

1. Critics say

   Potatoes spike a dog's blood sugar

   Evidence

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

   In a 14-beagle trial of 7 starch sources, corn and potato diets gave the highest glucose peaks; sweet potato and pulses gave smaller ones. The trial used potato starch, not whole dried potato, and measured short-term glucose, not disease.⁵

2. Brands say

   Potatoes are gentle and easy to digest

   Outruns the evidence

   Evidence

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

   The starch digests almost fully, over 99% in an ileal study. That same study gave potato flour the lowest ileal protein digestibility of 6 flours, 64%. Nothing shows potato suits sensitive stomachs better than other starches.^3,4

3. Vets say

   Grain-free potato foods cause heart disease

   Outruns the evidence

   Evidence

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

   FDA found potatoes or sweet potatoes in 42% of foods named in DCM reports, against 93% for peas or lentils. FDA says the reports do not supply enough data to show cause.⁶

4. Owners say

   Potatoes are toxic to dogs

   Outruns the evidence

   Evidence

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

   Solanine and chaconine build up in green, sprouted or damaged peel, at 3 to 10 times flesh levels. The warnings concern raw peel and green tubers, not peeled, cooked flakes at kibble amounts.^1,2