PRACTICES DURING HARVEST AND COOLING LEADING TO CONTAMINATION OF FARM PRODUCE

Contamination of fresh produce by Microbes can occur easily during harvesting.

Contamination is commonly caused by field workers or by the physical environment of the produce.

Environmental sources of contaminants include soil, water, air, hands, containers, etc.

Preventing contamination of produce with pathogens is critical, since their presence increases the risk of illness for consumers and lowers food safety.

Contamination of agricultural produce during harvest

Some products like grapes and strawberries; are manually harvested, never cooled nor washed at harvest and packed in the field immediately after harvest.

Packing in the field generates a condition where contamination can occur easily from soil, other solid contaminants and disease causing microbes from the hands of the packer.

Since manual harvesting (the use of hands during harvest) is involved, there is a great deal of handling and contamination of the product is likely.

Some farmers use water taken directly from rivers or holding ponds for washing produce whose safety is doubtful.

When fruits and vegetables are immersed in such water containing pathogens, they can become contaminated.

Others do not clean machines for use in harvesting and handling produce before and after use, a practice that allows residues from the previous harvest to contaminate the new harvest.

Others handle containers and packing materials carelessly, allowing them to be full of dirt and other contaminants.

How produce is contaminated during cooling

Cooling methods using water and ice as the cooling media have the greatest potential for contamination of fruits and vegetables.

It is crucial that ice used in cooling is produced from chlorinated, potable water and stored in a hygienic manner.

Water and ice used for cooling systems should be free of bacterial contamination.

Practices that minimize contamination of agricultural produce

Add an approved disinfectant  to keep  water free from micro-organisms.

These include disinfectants such as sodium hypochlorite, calcium hypochlorite or liquid chlorine.

Good hygienic practices should be followed in handling containers and packing materials to prevent product contamination.

It is important to place a water settling and filtration device in the cooling-water treatment system to remove organic material.

Cooling water should be replaced regularly (at least once a day, depending on the amount used and condition of the produce).

Sick people should not be allowed to work in the farm especially during harvest as some diseases like typhoid among others are spread though contact.

Handling agricultural produce correctly will make you have an edge in agribusiness

If you visit Wakulima, Korokocho or any other market in Kenya, you will see Lorries loaded with hundreds if not, thousands of fruits or vegetables.

If not, hardworking women-trying to eke a living will be seated in the hot sun; their produce placed on gunny-bags lined on the ground, just next to them is slurry from yesterdays’ rain.

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As the fruits or vegetables are piled on each other in the Lorries cabins, they bruise each other, those at the bottom squashed.

To crown it all, two or more brokers are sitting on them as they haggle with customers.

By the end of a single day, 10% of the produce will go bad. If it takes 3 days to sell all the produce, over 30% of the produce is destroyed.

Let’s get back to the women. If some of the produce they were selling remained at the end of the day, can’t be sold the following day as the sun will have wilted it.

It has been observed; over 40% of agricultural produce is destroyed at the post harvest stage.

This loss would have led to higher incomes and changed the fortunes of farmers and those product supply chain.

At times a total loss can occur if the produce is highly perishable; for example vegetables and fruits.

We must understand that seeds, vegetable or fruits are living commodities that continue to respire long after they have been detached from the mother plant.

Seeds respire slowly therefore can handle rough treatment and still be viable years later.

This is not the case for vegetables and fruits for they respire and deteriorate very fast after suffering wounds from rough treatment.

Who is the loser at the end of the day? – The farmer. The broker would have made their cut, the city council theirs- the farmer crying all the way to his wife!

When Kenyans are selling produce to the international markets, it is well packaged, handled and inspected by our best graduates who work for KEPHIS [Kenya plant health inspectorate service]

What happens when we want to sell produce locally? Nobody cares! - The produce is loaded and ferried in a dirty pickup that probably ferried a corpse the other day.

When the produce gets to the market who handles it? Your guess is right- it is that ‘fella’ who is water phobic.

The last time he had a shower was when he was rained on as he was caring a 100 kilo sack of potatoes.

The logic behind this article is- you can earn more if you mind how you handle produce as you will reduce wastes due to rotting.

Have a careful day! Will you?

LiveJournal Tags: Conditions in Horticultural markets in Kenya

Cooling of agricultural produce.

LiveJournal Tags: Cooling of agricultural produce,Effect of storage temperature on agricultural produce,Post harvest technology

During harvest time, the temperature of harvested produce is almost the same as ambient temperature.
Sometimes it can be high as 40⁰ degrees depending on the surrounding environment.
If temperatures are high, the respiration rate of the produce increases consequently increasing the evolution of ethylene, a gas responsible for ripening and senescence.
The objective cooling of produce is to slow down the rate of respiration thus prolong its shelf life.
PRE-COOLING
Pre-cooling is the rapid lowering of the field heat from freshly harvested produce before a comprehensive cooling regime is undertaken so as to maintain its quality.
Methods of pre-cooling vary from plant produce to produce. For example when cut flowers like roses are harvested, they are dipped in a bucket containing water mixed with a fungicide before being taken to a cold room.
Conversely tea is kept under a shed or in a cool place after harvest as the application of water to it, will reduce its storage life and encourage rotting.
Other produce like grapes should not be immersed in water as this will remove the natural wax layer on the fruit.
The natural wax is important in enhancing long storage life; furthermore it is a quality requirement of the market.
For most crops, storing them where cool air is circulating, under a shed, is sufficient to remove field heat.
Precautions to consider during cooling agricultural produce
Inappropriate cooling temperatures or methods may subject produce to abnormal ripening or chilling injury.
Abnormal ripening is mostly observed in fruits. They either ripen very fast or fail to do so when exposed to room temperature.
During cooling, a high relative humidity is maintained to prevent an excessive loss of water.
Such loss may result to wilting, shriveling, flaccidness or loss of nutritional value of produce.
Ethylene is an important gas produced naturally in fruits and vegetables as it promotes ripening.
However, during storage it should be absent or present in minute amounts; ripening is desired after the produce has reached the customer.
To prevent its production during storage, cooling must be done rapidly.
High ethylene producing commodities like fruits should not be stored together with low ethylene producing commodities like vegetables.
The produce must also be cooled at temperature which is above freezing point for temperate commodities or chilling point for tropical and subtropical commodities.
Chilling or freezing of produce affects the flavor of fruits its quality in terms of or will result to chilling injuries.
Unfortunately, these methods are not used by small scale farmers because they are at times at far flung areas away from power lines and the cost involved.
The quicker the temperature of the produce is lowered after harvest, the longer the storage life.

POST HARVEST HANDLING AND CARE OF CUT FLOWERS IN KENYA

Floriculture is a very rewarding occupation worldwide. It contributes about 40-50% of the revenue earned in horticultural sector, despite the fact that the acreage of floriculture is the smallest in horticulture sector; it is the largest in earnings. It covers about 25% of the volume of horticultural exports. It can be concluded that this industry largely depends on cut flowers for revenue; with quality of cut flowers being of greatest importance.

The floriculture sector is dominated by a myriad of large industry players who have an advanced production and post harvest technologies. Small scale farmers are now venturing into floriculture thanks to poverty reduction efforts by nongovernmental organizations.

The small scale farmers face numerous challenges; on handling cut flowers, the correct stage of harvesting, use of agro-chemicals and market quality requirements. This article seeks to explain the concepts behind post harvest management of flowers so that these farmers may be able at least to cut down post harvest losses by 50%.

It is a known fact that flowers are more delicate than other agricultural commodities. This is based on the premise that; a cut flower is a more complex organ than a seed, a fruit and a vegetable, which are single morphological units this calls for specialized care of the cut flowers as discussed in the below popular topics.