The effort against global hunger and food security especially in world’s poorest countries are often encumbered by crop losses.
Crop losses are an indication of wastage of agricultural resources e.g. land, water, labour and capital and other input that brought about the agricultural produce.
It has been reported that about one-third of food produced by and for human consumption is often lost globally which amounts to approximately 1.3 billion tons per year. As a result of this, post-harvest loss has been a determinant of food problem in developing countries.
Post harvest losses (PHL) can be explained as losses that occur along food supply chain, from the stage in the farm until it gets to the table of the final consumer.
Losses to farm produce along the chain are encountered in storage, handling, transportation and processing which in-turn results in a decline in farm produce quality, quantity and market value of the commodities.
The main causes include mechanical damage, physiological deterioration and biological causes. It could also be attributed to socioeconomic and institutional factors such as inadequacy in marketing information and support systems, inappropriate transportation facilities, unfavorable government policies, lack of technical know-how and poor maintenance of existing infrastructure.
Tomato is a widely cultivated vegetable, which has a high yield and is economically attractive.
In Nigeria, tomato accounts for 18% of average daily vegetable consumption, which makes it an important crop. About 1,701,000 tons of tomato was produced in Nigeria as of 2008, making Nigeria 13th largest producer of tomato.
It is mostly cultivated in South-western part under rain-fed conditions and also in North under irrigation system.
As a result of its high perishable nature, a lot of problems is being encountered in their production chain such as disease, nematode etc. causing a decrease in quantity and quality.
Although poor post handling of tomato products can be accounted for as a result of negligence on the part, in situations where rotten tomato fruits are mixed with healthy and this can have the multiplying effect of rot on healthy tomato.
However, one of the country agricultural policies is for farmers in the country to be encouraged to employ simple but effective on-farm cold storage facilities and agro-processing technology in order to add value to tomato produced in farm and to increase their shelf-life.
To birth this into reality, high-energy sources like refrigeration is required which is not available and affordable to local farmers.
The aim of this technique is to increase the shelf-life of the crops and to make them stay longer before they are sold in the market.
The implication of this is that local farmers will have to sell their produce at a reduced price since they cannot store them for long period of time which in turn means a decrease in the income of the farmers and their welfare.
If more attention and resources are not only diverted to the planting and harvesting process only but also to the post-harvest production process, it could guarantee an increase in food availability across the nation, thereby reducing the need for food importation and also impact positively to the welfare of farmers.
The difficulty experienced in the storage of tomato for a long period of time is as a result of very high moisture content in them.
Storage extends the length of the processing season and enables continuity of product supply throughout the season.
Although they can be stored at ambient condition for a short period of time if there is enough ventilation to reduce the accumulation of heat from respiration.
Ripe tomatoes can be stored for a longer time at a temperature of about 10-15Oc and 85-95% relative humidity because this temperature reduces both ripening and chilling injuries to minimal level thereby allowing the tomatoes to stay longer.
The unavailability of these conditions in Nigeria results in losses of appreciable quantities of harvested tomatoes.
Very low storage temperature can also be detrimental to the shelf-life and quality of fruit products because a very low temperature can decrease its flavour, quality and pH of the fruit.
Therefore, to maintain an appropriate storage system, an understanding of the correct temperature is needed to ensure the extension of shelf life and also marinating the quality of tomatoes.
Refrigeration storage is one of the effective methods of preserving the quality of tomatoes. At a low temperature, the texture, nutrition, aroma and flavour of many fruits can be preserved. Although the storage of tomatoes at a very low temperature of 100C, can prone them to chilling injury.
This indicates that refrigeration may not be an effective way of storing tomato for a long time. However, in a situation where the farmer can afford refrigeration storage and temperature regulation of around 10-150C and humidity of 85-95%, can prevent tomatoes from chilling injury thereby allowing them to be stored for a long time.
The major challenges faced by farmer is the huge cost associated with this kind of storage system as they cannot be afforded by local farmers.
Although the huge refrigerating storage is important, so is the control storage temperature and humidity during the storage process as these factors are responsible for damages caused to tomato production chain.