1

Household Food Preservation for

Food Security in a Changing Climate

CAPro PROJECT

2

1.1 INTRODUCTION

Climate change and variability characterized by widespread droughts, changes in rainfall patterns and floods, is now a major cause of

food insecurity. This is shown by temporary or chronic fluctuations of food production and supply, especially in semi- arid and arid areas due to unreliable rainfall and rising temperatures. Livestock production has also been affected, as seen from death of many livestock from prolonged drought. Maintaining the continuity of food supply when production is seasonal and unpredictable is therefore challenging. An additional problem is that a substantial amount of the food produced in a favorable season is lost to pests and natural elements due to high perishability. Kenya loses 30 to 40 % of food harvested due to poor post harvest handling, spoilage and pest infestation. This is partly due to lack of knowledge on how to preserve this food. This worsens the problem of food availability in some seasons and consequently high food prices, which make resource poor households suffer from hunger and malnutrition. Fruits, vegetables and meat are the most perishable foods, yet very important for our health and easy to preserve when in they are plenty, and utilize them in times of food scarcity.

Preservation of fruits, vegetables and meat

Fruits, vegetables and meat have high water content which makes them spoil easily. The easiest and cheapest way of preserving these foods at home is by sun drying /dehydrating. Drying reduces the amount of water in these foods to a level at which food spoilage microorganisms cannot survive in them.

To save food for tomorrow

What do you need today? Preservation

3

Advantages of Sun Drying

Preserving food by sun drying requires no energy except the heat of the sun.

Dried food also requires no energy to maintain it while stored, unlike freezing that requires expensive freezers and electricity to maintain.

Little storage space is required for dried foods.

Drying food is easy to do and doesn’t require any special skills or equipment

1.2 DRYING OF FRUITS AND VEGETABLES

Which Fruits Can Be Dried?

Fruits that can be dried include pumpkin, pears, Mangoes, bananas, apples pineapples pawpaw.

Which Vegetables can be Dried?

Outside the traditional dried foods such as cereals and pulses, the following can be dried when in plenty to avoid wastage: Green

leafy vegetables such as kale, cowpea leaves, spider plant, amaranths, spinach, black night shade, pumpkin leaves, herbs, cabbage, onions, snap beans cauliflower, peppers and many others that are available in different localities. Root Vegetables such as beetroot, carrots, sweet potatoes, cocoyam and cassava can also be sun dried.

What Equipment and Materials do we need for Sun drying?

A wooden chopping board or granite surface, stainless steel sharp knife, drying trays or mats (not metallic), sufurias, perforated

stainless steel or wooden spoons, plastic basins or buckets, netting or loosely woven fabric, cotton dish clothes and food storage containers.

What is the Procedure for Drying?

Drying takes place in several phases: pre-treating, drying, packaging and storing the product.

4

Pre-drying treatments of Fruits and Vegetables

Selection

• Use only ripe, good-quality fruit and vegetables.

• Select fruit and vegetables individually.

• Throw away rotten, damaged or diseased fruit and vegetables.

• Remember, processing cannot improve fruit or vegetables of poor quality.

Washing

• Wash your hands and clean all working surfaces before handling fruit or vegetables.

• Use clean water to clean the fruits and vegetables.

• Wash individually, selected fruit and vegetables in clean water.

• Take care to avoid breaking the skin of the fruit during cleaning and thereby contaminating the flesh.

• Place the washed fruit and vegetables into a clean basket, rack or bucket and take to the peeling or blanching area.

Peeling, Cutting and Slicing

• Always use clean, sharp stainless steel knives to avoid discoloration of the food

• from rusty knives.

• Carefully peel the food, keeping removal of the flesh to a minimum to prevent unnecessary wastage of food.

• Dispose peelings and seeds of fruits as soon as possible because they attract flies and other insects.

5

• Peelings can be used as animal feed or as mulch, or be buried if there is no other use.

• Thicker and larger slices will dry at a slower rate than thinner/smaller pieces.

• Thickness of fruit or size of vegetable pieces depends on the type of fruit being dried.

• Very thin or very small pieces tend to stick to the drying trays and will be difficult to remove.

• Thicker and very large pieces may not dry fully and may subsequently deteriorate after packing. The person cutting and slicing the food should therefore use judgment, to decide on the appropriate thickness. Table 1 gives some guidelines on suitable thickness of selected vegetables and fruits.

Blanching

Blanching refers to scalding of food in hot water or steam especially vegetables and fruits. Blanching for fruits and vegetables reduces discoloration, eliminates intercellular gases responsible for oxidation reactions and deactivates enzymes which disintegrate tissues and maintains the natural color of the fruit or vegetable. Blanching in water is easier than in steam and gives better results.

Prepare blanching water and blanch the vegetables as follows:

Add 5 grams (Approx. 1 teaspoon) of common salt to l liter of clean

Avoid Unnecessary Waste of Food when peeling Fruits and Vegetables

6

boiling water or 3 grams of citric acid in one liter of water. However, salt is better than citric acid because the acid destroys the nutrients in the process of blanching. Steam blanching is recommended for fruits while vegetables can be subjected to either of the two

1. Put the vegetables into the boiling water for the time specified in Table 1.

2. Remove and cool the vegetables immediately after water blanching or steaming in order to avoid excessive softening of the tissues or further cooking. Cooling is achieved by immersing the hot vegetables in cold water so that the vegetables can reach a temperature value under 37° C as soon as possible. Prolonged cooling time results in losses in valuable water soluble nutrients. To avoid this, the temperature of the cooling water should be as low as possible and better still, put under running water in a colander (perforated stainless steel basin).

Table 1: Slicing of Fruits and Vegetables, and Blanching Parameters

Vegetable/Fruit Slices sizes Recommend-ed Blanching Temperature, °C

Time (mins.)

Green Peas Whole seeds 85-90 2-7Snap beans Remove the fi-

brous ends and cut into 5cm or other desired length

90-95 2-3

Cauliflower Remove the stalks and sep-arate the small segments

Boiling 2

Carrots 2 mm thickness or shred

90 3-5

7

Peppers 2-3 mm 90 3 Leafy green vegetables (Su-kuma/cowpea leaves/Black night shade Amaranths)

Slicing not recommended to reduce loss of water soluble vitamins

85 3-5

Cabbages Long thin strands

90 5-8

Herbs Not recom-mended, to prevent escape of aromatic oils that give herbs their flavor

- Not recom-mended

Sweet potatoes 3-5mm thick-ness

Boiling 30-40 Blanch before slicing

Cassava 3-5mm Boiling 30-40: Blanch before slicing

Bananas 5mm thickness Boiling 5 (in steam)Mangoes 2-3mm thick-

nessBoiling 5 (in steam)

Pears 2 -3mm thick-ness

Boiling 5 (in steam)

Apples 2-3mm thick-ness

Boiling 5 (in steam)

Vegetable/Fruit Slices sizes Recommended Blanching Tem-perature, °C

Time (mins.)

Pumpkin 2-3mm or shred Boiling 3-5 in steamPineapple 2-3mm thick-

ness Boiling 5 (in steam)

8

Drying

• Spread fruit or vegetable on clean dry trays or mats. Spread evenly in one layer thickness to prevent sticking to one another and for faster drying.

• Cover with loosely woven clean ‘cloth, mosquito netting, or wire screen, to keep insects and dust from getting onto the food. Fasten cloth so it will not be blown off by the wind.

• Place trays of fruit or vegetables in direct sunlight or use a solar dryer if it is available to dry. This may mean placing the tray flat or it may require putting tray on blocks or stones where air can circulate freely over and under food.

• Keep away off the ground, from dust, away from animals and people. Protect from storms and dew and take in when in danger of rain.

• Turn the food 2 to 3 times a day to speed up drying, and continue drying for several days

• Test for dryness by squeezing a handful of the dried food. If there is no moisture left on the hand and the fruit or vegetable springs away when hand is opened, the food is properly dried.

• Vegetables should be dried until they are brittle or crisp. Some vegetables actually shatter if hit with a hammer or any heavy object. At this stage, they contain about 10 percent moisture (See Table 2 on testing for dryness).

• Remove from the sun and cool completely before packing.

9

Table 2: Test for Dryness for Selected Fruits and Vegetables, and Period of Storage after Drying.

Type of Vege-table/fruit

Testing for dryness How Long Can Dried Fruits and Vegetables be stored after Drying?

Green Peas Hard and rattles 6-12 monthsSnap beans Tough ribs, thin edges

crumble6-12 months

Carrots Slices tough and shreds are brittle

6-12 months

Peppers Brittle 6-12 months Leafy green vegetables (Su-kuma/cowpea leaves/Black night shade Amaranths)

Crumble readily 6- 12 months

Cabbages Extremely tough 6-12 monthsHerbs Crumble easily 6-12 monthsSweet potatoes Extremely leathery,

shreds are brittle6-12 months

Cassava Tough 6-12 monthsBananas Leathery and brittle 1-2 monthsMangoes Pliable without stick-

ing together6-12 months

Apples and pears

Leathery with no moisture when squeezed

6-12 months

Pumpkin Brittle 6-12 monthsPineapple Pliable without stick-

ing together 6-12 months

10

What are the Benefits of Drying Fruits and Vegetable?

Apart from addressing the issue of food security by minimizing food loss from perishing.

• Drying ensures food supply all year round

• Dried fruits and vegetable are tasty, nutritious, lightweight, easy-to-prepare

• Dried fruits and vegetable are easy-to-store and use, and the storage space is minimal compared with that needed for fresh foods

• Dried fruits and vegetable are high in fiber and carbohydrates and low in fat, making them healthy food choices.

1.4 Packaging and storing of dried vegetables, fruits, and meat

Dried foods are susceptible to insect contamination and moisture re-absorption and must therefore, be properly packaged and stored immediately.

• First, cool completely, because warm food causes sweating which could provide enough moisture for mould to grow.

• Pack as soon as dried products have cooled down to avoid contamination by dust and germs and as tightly as possible without crushing.

• Containers in which dried food is stored need to be moisture proof, keep-insects out and keep dirt away. Common packaging materials include: Stone jars, jar or pots made of clay or metal, dry gourds, paper bags, cloth bags, glass jars, plastic bags and containers and tin boxes with tight fitting lids .

• Pack foods in amounts that all can be used at once. Each time a package is re-opened, the food is exposed to air and moisture that can lower the quality of the food and result in spoilage.

• Seal containers of food to make then air tight. For containers with

11

loosely fitting lids: Place the lid on container, then dip a strip of cloth (about 1 to 2 “ centimeters wide) in melted paraffin or beeswax. Wrap, while warm, around container at joining of lid. Be sure all space between containers and lid is covered by strip of cloth.

• If the food has been put in bags, place the small bags in a large container like a clay pot or plastic container. Plastic bags can be sealed by passing a burning candle over and close to the sealing line.

• Label the food indicating the name/type, date packaged and amount.

• Store the Dried foods in cool, dry, dark areas. Recommended storage period for dried foods range from 4 months to 1 year.

The storage life of dried foods is affected by four factors :

Temperature: Temperature determines how long dry foods can stored. The cooler the storage is, the longer the storage life of the products. On the other hand, rise in temperature reduces the storage life, even with the very best packaging methods. Therefore, store in a cool, dry place, where the temperature remains constant because frequent temperature changes shorten storage life.

Food moisture content: Most well dried foods have a moisture content of about 10%. Although it is very difficult and unnecessary to remove all moisture from dry foods, it is important that any food be stored when it is as dry as possible. Foods with excess moisture can spoil right inside their containers.

Oxygen content: Foods packed in air don’t store as well as in air free containers. This is because air contains oxygen which oxidizes many of the compounds in food. Hence, when packing dried foods, exclude as much air as possible to prolong storage life.

The container the product is stored in:

To get the best storage life out of your dried product, it must have an air

12

tight seal. Containers that are suitable for storing dried food include:

• Sealable plastic food storage buckets

• Sealable food quality metal or plastic cans

• Sealable polythene paper

• Glass containers are excellent for storage

Whatever container you use, be sure it is suitable for storing food because your product can be tainted with whatever the container is made from. Thin Plastic bags are not good air tight containers, for even if they are sealed, the relatively thin plastic ‘breathes,’ allowing air to pass through.

Care of Dried Food during Storage

• Foods that are packaged seemingly “bone dry” can spoil if moisture is reabsorbed during storage. Check dried foods frequently during storage to see if they are still dry. Glass containers are excellent for storage because any moisture that collects on the inside can be seen easily.

• Use immediately, foods affected by moisture, but not spoiled or re-dry and repackage.

• Moldy foods should be discarded.

COOKING AND CONSUMING OF DRIED VEGETABLES,AND FRUITS Water removed during drying must be replaced either by soaking, cooking or a combination of both.

Soak root, stem and seed vegetables in sufficient cold water (enough only to cover) until nearly restored to their original texture. Half –an- hour to two hours gives an acceptable result while 2 to 6 hours gives a product that is soggy..

Add water constantly to ensure that the food is not in contact with air.

13

Vegetables

Never supply more water than they can take up and always cook in the water they have been soaked in.

Greens, cabbage and tomatoes do not need to be soaked. Add only sufficient water to keep covered, and then simmer until tender.

Cook in the soaking water because it contains the minerals which are essential to our health. More water must be added constantly during cooking. Cook the vegetable until tender

Seasoning of Dried Vegetables and fruits

During soaking, vegetables lose a lot of their flavor. They can be seasoned with garlic, onion and various herbs when cooking, depending on the taste of the user.

Dried fruit can be eaten in the dried state or cooked. If they are to be cooked, it is better to soak them first in ¼ cup of sugar per cup of fruit. However, add the sugar only at the end of cooking time, so as not to stop the fruit from reabsorbing water.

A pinch of salt added to the fruit brings out the fruit’s flavor.

Lemon, orange or grapefruit juice can be added for its flavor and vitamin C content.

Summary

Drying fruits, and vegetables remains to be the best option for many households because the process requires low cost and simple technology and it is applicable to a wide range of vegetables and fruits grown in Kenya, and other developing countries.

14

References

1. Brett, A, Cox, D.R.S., Simmons, R. & Anstee, G. (1996). Producing Solar Dried Fruit and

Vegetables for micro and small-scale Rural Enterprise Development: Handbook 3: Practical Aspects of Processing. Chatham, UK: Natural Resources Institute.

2.Bruin, S. (1988). Preconditions and drying of food materials. Oxford-New York: Elsevier

3. CGIAR (2011). Research program on climate change: Agriculture and food security.

Copenhagen, Denmark. Accessed on 14th May 2013 from www.ccafs.cgiar.org/commission

4. F.A.O (n.d). Food losses prevention in perishable crops. In FAO document Repository:

Agriculture and consumer protection. Accessed from www,fao.org/docrep/5860e/58620E06.htm on 14th may 2013.

5. Roiziz, J. F. (1997). Drying food stuffs: techniques, processes, equipment Technical guide book . Netherlands: Backhuys Publishers

15

Acknowledgement

The author is grateful to Rockefeller Foundation for funding the production of this booklet, through the Climate Adaptation Project (CAPro) of Egerton and Laikipia Universities.

Susan M. Kamuru Email: kamu3sus@gmail.com

Egerton University

Department of Applied Community Development Studies

P.O Box 536,

Egerton-Kenya

16