Smart farms

: 07 April 2016; Hits: 16089

Zero energy cooling chamber extends fruits and vegetables shelf-life

Small-scale farmers can increase shelf-life of fruits and vegetables for up to nine days by storing their produce in simple non-energy reliant cooling chambers.

A zero energy cool chamber does not demand any form of power to run, making it appropriate for off-the grid farmers.

The structure, which is build by locally available material, relies on the principle of evaporative cooling.

Materials required include bricks, river-bed sand, bamboo and water. Two parallel brick walls are constructed in form of a rectangle above the ground. Sand is filled into the cavity between the two walls.

A standard small-scale unit can be constructed with measurements of 165 cm by 115 cm floor. Erect a cavity of 67.5 cm high-leaving an inter-space of 7.5cm. Drench the river-bed-sand- filled cavity with water.

Make a cover lid of bamboo with straws of grass.

How it works

Evaporative cooling occurs when air, which is not saturated with water, passes over a wet place. This cools the sand-bed of the cooling chamber.

As water evaporates from the bed, it causes a cooling effect. Faster rates of evaporation lead to greater cooling.

Cooling in the produce happens because water consumes energy to change to gaseous state. This means energy that could have facilitated metabolism in the fruits or vegetables is used up.

Cooling chambers can reduce temperature to between 10 degree Celsius and 15 degrees Celsius. And humidity would be kept well above 90 per cent.

Low humidity air sucks a lot of water from the system. Increased humidity causes drop in temperatures due to low metabolism in the foods because of inactivity of enzymes.

Active enzymes cause more ripening and deterioration of the skin of fruits.

Tests have confirmed that freshly harvested fruits can remains strong-skinned for six days while ripe ones would be marketable for three more days.

Morning and evening watering of the structure is important to keep the moisture content constant. It works like a refrigerator.

A few farmers in Eastern regions are using this method to maintain freshness and firmness of mangoes.

Storing

Fruits ad vegetables have to be kept in perforated polythene bags. Further information is available on the On-Farm Storage Technology manual by the Amity University Uttar Pradesh.

Food and Agricultural Orgnisation says more than 40 per cent of farm fresh produce goes bad for being perishable.

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: 07 April 2016; Hits: 16170

Why broiler-indigenous hybrid is more profitable

A farmer who opted to cross indigenous and exotic broiler chickens is making more profit from the sale of hybrid dorep poultry, which have improved characteristics.

Jeremiah Kamadi of Busia County says the secret lies in the boosting the attributes of the two breeds, a boiler and any indigenous chicken to obtain a hybrid.

Broilers are exotic birds reared for meat production. They grow rapidly and reach maturity faster than indigenous chicken.

They mainly feed on commercial feeds while indigenous birds obtain their nourishment from multiple, since most of them are reared on free-range. Adding green diet does not considerably boost the taste of the vigorously growing broilers.

“Broilers are excellent meat producers. But their meat is less attractive in the market-especially in rural areas. Crossing a broiler with an indigenous chicken drastically improves the quality of the meat,” he says.

Given that the traditional chicken yield smaller quantity meat, the crossing improves its weight for a higher fetch-the dorep chicken would have fairly good weight and improved taste.

A cock can weigh from three kilogrammes onward while a hen would yield from two kilogrammes, with both depending on feeding and other management practices.

Dorep is easy to raise since it can feed on broilers mash and ordinary food remains and grains besides scavenging for insects, grass and other green matter around the homestead.

Besides, the agripreneur said, the maturity time of the breed is higher than traditional chicken, because of the characteristic inherited from the broiler.

“In two to three months, a farmer would start earning from the eggs. The weight of the chicken would also be reasonably good for sale. Dorep farming means quick maturity and higher earnings.” he said.

A mature cock can fetch between Sh1,500 and Sh2,000 while a hen can earn one between Sh500 and sh1,000 depending on the demand.

The eggs are sold like kienyeji ones earning between Sh20 and Sh25 per piece. Kamandi, who started with 50 hens saw the potential in the hybrid, therefore, increased the brood to 200.

Kamadi, however, warns that rushing into poultry farming before identifying the market, would be disastrous.

“The longer the time you take to sell your chicken after attaining maturity, the more loss you welcome in sustaining them. You must first know if you will be supplying the chicken to urban residents or some business enterprise,” he said.

Thieves frequently visiting his farm have, however, discouraged him from his Funyula enterprise and he is looking for a safer place to relocate to.

One can buy chicks from hatcheries or incubate dorep-laid fertilised eggs.

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: 07 April 2016; Hits: 8615

Proper hygiene safest way of increasing milk shelf-life

Farmers must stick to proper milking practices to reduce contamination, which significantly reduces the shelf-life of this highly perishable product before it reaches far-flung markets.

According to the Food and Agricultural Organisation (FAO), contamination occurs in the milking and post-handling processes, increasing microbes that quicken deterioration.

Danger

Milk suppliers from Rift Valley and other regions have resorted to adding hydrogen peroxide to prolong the shelf-life of raw milk.

The Kenya Dairy Board says more than 70 per cent of between 100,000 litres and 200,000 litres of raw milk transported to Nairobi daily is locally ‘treated’ with this chemical for preservation.

The board warns that unregulated use of the chemical can enhance development of throat cancer.

Good use is safe

Delia Grace, a food safety expert at Nairobi’s International Livestock Research Institute (ILRI), says hydrogen peroxide is not entirely harmful when used in small amounts. In fact, it is industrially used in preserving the milk and production toothpaste because of its disinfection and bleaching properties respectively.

“There are minor concerns over known negative health effects of consumption of moderate amounts of hydrogen peroxide, but these are much higher than would be present in milk."

"The main concern is that it might be used to stabilise deteriorating milk which is not of good quality, allowing for marketing and sale of sub-standard produce,” said Grace, who leads ILRI’s Food Safety and Zoonoses program

Hygiene is key

FAO says the journey of lengthening the lifespan of milk starts way before the actual process of milking.

Cleaning the udder with lukewarm water and dirt-free individual drying towels would ensure moulds, fungi, bacteria and other germs are greatly reduced.

The stockman must also observe high standards of personal hygiene.

The global agency says milking equipment must be clean and most preferably smooth and rivet-less. Rough and riveted surfaces are most likely to host microbes, which cannot be eliminated while cleaning the equipment.

Increased contamination and normal environmental temperatures accelerate microbial activity, therefore, the milk goes bad before it reaches the market.

Sterilisation

Inasmuch as the micro-organisms may not be eliminated completely, hygiene can keep them at about 50,000 per milliliter, which is not risky, FAO says.

Regular tests for mastitis and other cow ailments and routine hygiene procedures would help reduce the level of microbes in milk.

Disinfectants like sodium hypochlorite at 300 ppm can be added water used for cleaning the udder.

Regular sterilization of milking equipment, including drying them in the sun, would reduce instances of microbial infestation in the milking containers.

Containers

A recent sting operation conducted jointly by the Kenya Dairy Board and police found the suppliers packing milk in plastic 20-litre jerrycans.

“Non food grade plastic can contain heavy metals or chemicals above levels considered safe. It can also be unsuitable for storing food because it is thin or weak and prone to rupture or breach by pests or because it can be easily scratched, and the scratches are difficult to clean,” she said.

Aluminum gallon containers are preferred for transporting milk and glass containers for home storage.

With the low temperatures of below 4 degrees Celcius being the most preferred to arrest microbial activity ILRI says cooling remains the best approach of preserving raw milk before processing. At home, fresh milk can be placed in a cold water bath.

Steve Staal from the institute says FAO has worked with other agencies in developing lacto-proxidase treatment, but approval status of the enzyme is unclear.

For that reason, it is not in use in Kenya.

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