Post harvest storage, use of beans

Nari, Normal

The National, Tuesday November 3rd, 2015

 Droughts in PNG present opportunities for Papua New Guineans to develop strategies in post harvest storage and use of food crops already cultivated here such as cassava, corn and beans. 

The country would then save a lot of money by reducing importation of food such as rice, flour and noodles.

This article follows last week’s by presenting ways of processing legumes like beans, peas and peanuts and storage tips. 

These food crops are already being cultivated in PNG and prepared in simple forms such as boiling, roasting and mumu.


Preparation and use of beans

Phaseolus bean, or common bean, is the world’s most important food legume. 

Farmers eat common beans in two forms, as dry beans and as snap beans (the green pods are consumed as a vegetable). 

Beans are an attractive crop for farmers because of their adaptability to different cropping systems and short growing cycle. 

They are however susceptible to many diseases and climatic stresses.

Beans are nutritionally rich in protein and iron, in addition to being a good source of dietary fibre and carbohydrates. 

They make an important contribution to human nutrition, especially for poor consumers. 

Apart from common beans, there are other pulses common to PNG. 

These include soya beans, lima beans, snake beans, winged beans or as bin, broad beans and peas.



Smallholders usually harvest beans by uprooting whole plants. 

The uprooted plants may be dried in the field or taken to the homestead where they are dried on bare earth, mats, sacks, tarpaulins or iron sheets. 

The drying period may take up to a week depending on the weather and amount of drying in the field before harvesting. 

The dry beans are beaten with sticks either directly or after putting them into sacks. 

The haulms and pods are later removed by hand and winnowed.

Normal practice in PNG is the removal of dried beans from the field, followed by sun-drying and removal of seeds from pods, or vice versa, where seeds are removed before drying. 

Most of these seeds are kept as planting material.



Green bean leaves are eaten as vegetables. Pods harvested before they dry may be cooked whole (as in a mumu) or opened so that the seed is cooked and eaten either alone or mixed with vegetables, potatoes or bananas.

Dry beans can be boiled alone or with corn seeds until both become soft. 

They can be eaten alone or with green vegetables. 

Alternatively, potatoes, bananas and green vegetables can be added towards the end of the boiling period with the mixture pounded into a paste.

Dried bean seeds, removed from pods, can be also boiled alone and then ground into a paste. 

This paste may be eaten immediately or fried. In both cases the paste is usually eaten with other foods as stew.

Pigeon peas and soybeans should also be well dried in the sun for storage. 

Peanuts and soybean are also rich sources of cooking oil. 

Dried pigeon pea should be soaked in water overnight then boiled and eaten with other food.


Cooking dried beans

To prepare dried beans, one measure of dry beans with four measures of water can be boiled for two minutes. 

They are soaked for an hour and then boiled until softened. 

Alternatively dried beans can be soaked in cold water overnight before boiling and softening. 

Adding salt and flavourings give good tastes.



Storage losses may be due to a number of factors. The main losses are caused by insects and rodent damage, fungus growth and rotting. 

It is therefore imperative that grain foods are properly dried and stored in both air and water-tight containers. 

Cereals are safely stored at 12-14 per cent moisture content while beans and other pulses are stored between 13  per cent and 15 per cent moisture content.

Storage containers vary from earthen pots to baskets, to big metal or cement silos. 

The storage containers chosen de depending on financial capabilities, materials availability and prevailing climatic conditions. 

However, whatever container is used, it must keep the product dry and cool and protect it against insects, fungi, rodents, domestic animals and thieves.

Mixing grain with wood ash, burned cow-dung, fine sand and lime can save seeds from damage. 

The material used should fill the spaces between the grains, thereby restricting insect movement and emergence. 

Earthen pots sealed with mud can store grains for about one year. 

Baskets smeared with mud, clay or cow-dung on the outside can protect grains for a period of 6-9 months. 

Protect your seeds from weevils by using tins, jars or earthen pots.



Drying of the grains and pulses is absolutely crucial for safe storage. 

It is very harmful for a product to become wet during drying.

The product should be dried in thin layers to allow air to circulate freely.  Where drying in open air is not adequate, drying above the fireplace may be appropriate.


NARI’s research and development efforts in beans and other legumes have resulted in several recommendations to support families with nutritional, soil improvement, and food security requirements. – NARI