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DOWN TO EARTH:  Preventing food wastage

The Agrodoc

DOWN TO EARTH:  Preventing food wastage

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IN BARBADOS, considerable food wastage occurs on-farm, in supermarkets and in households.
On farm, it may be because of poor harvest intervals which result in over maturity of crops like okras, cucumbers and beans which require harvest at frequent intervals to prevent them becoming unmarketable.
In addition, lack of training of labour may result in rejection of produce which is actually marketable.
Of course when a glut of a crop occurs, that crop may remain unharvested, because it is not feasible to pay high wages to harvest a crop for which there is no sale or for which the price is too low. The lack of markets for various grades of a crop also results in a high percentage of crop remaining in the field. In this regard, there is a dire need for the expansion of the agro-processing industry to facilitate the use of all grades.
In supermarkets, some of the wastage which occurs may be as a result of poor on-farm, post-harvest handling and  transportation practices causing crop damage which only shows up after the product reaches the supermarket.
Further spoilage may result from poor handling and storage practices at the supermarket itself. For instance, crushing of vegetables when bags or boxes are stacked too high, if storage temperatures are incorrect or if incompatible fruits and vegetables are stored together.
Fruits and vegetables emit ethylene during maturity. This ethylene can  cause damage or unpleasant flavours   in susceptible fruits and vegetables and therefore care must be taken to separate these two categories of produce.
Rough handling by supermarket staff as well as customers is also responsible  for spoilage of fresh produce.
Proper packaging can alleviate this to some extent.
Another way supermarkets can reduce their wastage is for staff to be vigilant and remove from their counters product which is sound except for surface blemishes so that this can be offered as a “partially prepared” product: e.g cole slaw mix, sliced carrots, fruit salad, soup and stew mixes and vegetable slices for dipping.
Householders can assist nationally in the reduction of food wastage and thus contribute to food security by buying produce when it is plentiful and attractively priced and preserving it so that it can be used in times of scarcity. It makes good sense to preserve foods.
Once food has been harvested, it begins to deteriorate until eventually it becomes unfit for consumption.
Physical Deterioration
After harvest, fruits and vegetables lose moisture. This results in limp, wrinkled vegetables with a poor texture.
Chemical Deterioration
 Enzymes are present in all foods. These speed up decay by breaking down the tissues of the food through oxidation, browning and ripening. This is very evident when apples or yams are peeled and quickly become brown due to the activity of enzymes in the presence of air. This activity of enzymes is affected by temperature.
At our ambient temperatures and even at the lower temperatures of a freezer, enzymes will remain active. However, their activity stops when they are heated above 70°C. This is why blanching (treatment with boiling water) is recommended before freezing fruits and vegetables.
Microbial deterioration
The organisms which cause deterioration of foods are fungi, bacteria and yeasts.
These multiply very rapidly in favourable moisture, and temperature conditions, so these conditions must be avoided if food spoilage is to be reduced.
These grow from spores in the air which multiply on foods causing them to become “mouldy”. Fungi grow best in moist conditions, at temperatures between 20°C and 40°C. but are destroyed by temperatures above 70°C.
Yeasts are microscopic organisms found in the air and soil, and on fruit surfaces. They can cause spoilage in many foods such as syrups, fruits, fruit juices and jam. Yeasts grow best between 25°C and 30°C and most are destroyed at temperatures above 60°C.
Bacteria are minute organisms which, under ideal conditions, divide rapidly   in contaminated food. They are more dangerous than fungi and yeasts and many cause illness. Although normal bacteria are destroyed during heat treatment by boiling, some spores survive boiling for hours and resume normal activity when conditions become more favourable. Bacteria are controlled by using an acid or dry medium or by adding large quantities of sugar and salt.  
Preservation processes prevent the spoilage of food products by these organisms and thus extend their shelf life.
• The Agrodoc has over 40 years experience in agriculture in Barbados, operating at different levels of the sector. Send any questions or comments to: The Agrodoc, C/o Nation Publishing Co. Ltd, Fontabelle, St Michael.