Sweet potato as food security

Focus
Communities in Papua New Guinea have traditional ways of coping with shortages of fresh food(taim hangere) based on local seasonal calendars. However, extreme climatic pattern changes and events such as the 2015-2016 droughts have shown that food processing and preservation is an area that needs to be improved to enhance food security and livelihoods of rural communities writes MIRRAM SIMIN.

To build the resilience of these communities, the National Agricultural Institute (Nari) has been delivering climate-smart agricultural trainings under the European Union funded Climate Change Resilience (EUCCR) project.
Part of this programme focuses on up-skilling vulnerable communities with food processing methods to improve the length of time for storing and using important staple food crops.
One of these methods looks at how flour can be made out of tuber crops like sweet potato.
Communities located along the Madang-Morobe boarders have benefited from these trainings.
One of these places is Teptep.
Teptep is situated some 2,100 metres above sea level in the Naiyudo local level government (LLG) in Raikos and shares a common border with the Yus LLG in Kabwum, Morobe.
Teptep was placed under Category 4 of disaster impact during the 2015-2016 droughts.
Sweet potato flour processing skill was introduced to farmers in Teptep in trainers of trainer’s workshops between October and December, last year.

Display of dried sweet potato slices and flour.

In total, over 150 farmers representing 10 parishes from both Naiyudo and Yus LLGs were trained.
Sweet potato was introduced here over 300 years ago but has now become one of the most commonly cultivated staple food crops in the Highlands, parts of the Mamose and New Guinea Islands.
Teptep is no different.
It’s cool, highlands like climate makes it ideal for sweet potato farming.
In fact, the area was once known for supplying fresh produce into Madang town and Lae city, by air.
Apart from its socio-cultural significances, sweet potato also has great economic potential for the livelihoods of rural farmers.
Annually, about 520,000 metric tonnes of sweet potato are produced around the country.
However, sweet potato tubers are best consumed fresh within two to three weeks.
They are highly perishable because they contain large amounts of carbohydrate and moisture.
But as flour, sweet potato can be stored and used for six to 12 months since about 87 per cent of moisture is removed.
Sweet potato flour offers many other useful benefits besides extended shelf life and use, over long periods.
Sweet potato flour can be used best when mixed with conventional wheat based flours.
In this way, sweet potato flour can be made into bread and muffins, for household consumption.
This can diversify the range of food and diet of rural families.
On the other hand, mixing sweet potato flour and wheat flour can also boost the nutritional value of bakery products.
It has been established that sweet potato, especially the orange fleshed varieties are rich in nutrients like beta-carotene and vitamins A, C and E.
So bakery products made by mixing sweet potato flours would offer higher content of vitamins that have many health benefits.
For example, sweet potatoes contain essential fibers and magnesium that can help to prevent or manage many health conditions such as diabetes, depression, heart diseases, arthritis and cancers.
Vitamins in sweet potato can also help improve hair, skin, vision and digestion. There is also opportunity for rural farmers to process and sell sweet potato flour as well as home baked buns and scones made with it.

Chapati made from sweet potato flour made during farmer training at Teptep in Raikos, Madang.

Income earned from these could help families to purchase store foods like rice to sustain them during times of stress such as the current Covid-19 pandemic lockdown.
Sweet potato is made into flour using cleaned tubers that have been peeled and stripped into very thin pieces using knives, peelers or graters.
The thin slices of sweet potato are soaked in a solution of lemon and water for five minutes before they are strained and dried in the sun on a safe raised bed, protected by a fine meshed screen net.
To prevent browning of the sweet potato, lemon juice extracted from ripe lemons is mixed with one liter of water.
The solution is used to soak the slices for a minimum of five minutes and strained before drying.
The slices would take approximately 8 hours to be completely dried.
This depends on the weather and the amount of the sunlight.
The final step is where a pestle and mortar or a hand mill is used to ground the dried pieces of sweet potato into flour.
The flour is then packed into containers and stored away for up to a year in cool dry places using used bags of flour, rice or pots and dishes to prevent contamination by water, pests and insects.
EUCCR project trainings promote active participation of young people.
This can be seen in success of Yangen Etara, a youth from Kaweng parish.
He started training farmers in his own area and a local school has expressed interest in engaging his services.
Women are also engaged prominently.
Yamoi Mussa, a mother from Teptep, said such trainings help to complement women programmes initiated by the local church to generate income their families need to afford basic goods and services, like education and health.
Nari has been undertaken sweet potato flour making training with inclusive farmer groups under different projects over the last few years.
We believe this would help to increase the resilience of rural farming communities now and long into the future.

  • Mirram Simin, a research associate specialised in post-harvest and processing. She is based at Nari’s Mamose research in Lae.