What are POTATOES, Introduction , Impact of Sugar, Defects

Here we will be discussing what are potatoes, their basic introduction and how to deal with the potatoes before processing.

The potato is not a root but an underground stem. As such, it contains most of the elements of an above ground stem, including:

• Bark (cork)
• Vascular system
• Pith
• Buds (eye)

As long as the potato is intact, it is still a living organism requiring a good supply of air for breathing. The food supply is furnished by the tuber itself. The starch that is stored during the growing season is used to support life in the tuber until after sprouting, when the young sprout is capable of manufacturing its own food supply.

The potatoes takes in oxygen from the air and releases carbon dioxide. The transportation of oxygen in the potato tissue, is by diffusion. One of the causes of potato breakdown and disease can be traced to the diffusion process.

Diffusion is usually slow. If the potato is heated too much so that the oxygen demand is increased, or if the potato is too large in size so that insufficient air is available, this can result in breakdown, black heart, rot etc. Potatoes put into storage are usually in sound condition, with reasonably low sugar content.  Excessive build-up of sugar may be caused by an adverse environment.

Factors Affecting the Quality of Raw Potatoes:

• High Temperature
• Low Temperature
• Shock from excessive movement
• Any environmental conditions that are not normally experienced by the tuber
• Naxious Gases

How Sugar is created in the Potatoes:

Sugar is created by decomposition of starch.  It is actually the first stage in the use of starch for food.  By breaking down starch into sugar, the potato can accumulate and excess quantity of sugar;  this enables it to meet emergencies created by the adverse environmental factors.

If this is carried too far, the potato will attempt to reproduce itself in the form of aerial tubers, spurting, etc. Needless to say, the excess sugar build-up causes poor quality in the form of dark colour when we try to fry the potato. Wounding of the potato may result in bacterial infection and subsequent rot.

This, of course, results in poor quality or complete raw material loss. A portion of these losses can be prevented by providing a storage atmosphere for proper suberization. Suberization is the healing of any bruised, skinned or cut portion of the tuber, also the thickening of the periderm (skin) on all uninjured surfaces. This reduces moisture and weight losses from shriveling and the and the danger of rot by preventing the entry of storage rot organisms.

How to improve Raw Potatoes Quality before Processing in the industry:

A great impact on the quality of potatoes arriving at the factory can be achieved by following a few simple guidelines.

• In general, potato quality begins to deteriorate as soon as potatoes are loaded on trucks.
• Reducing the transit time from field/market to processing industry
• Potatoes exposed to temperatures above or below 12 – 25ºC should be protected from the elements.  Outside of this range, deterioration may begin.

Above we have explained the basic definition of potatoes, factor affecting the quality of raw potato before processing in the industry, how sugar is the enemy of potatoes and its impact on the potatoes. Also we discussed how we can improved and avoid potato deterioration before processing.