This manual was created by a graduate student as part of a Trellis Fund project, led by Teso Women Development Enterprise, Ltd.

Introduction

This training manual was prepared in 2018 by Claire Adkison and Okalo Paul for the Trellis Fund project, "Promoting mango and orange value addition." It was prepared for use by Teso Women Development Enterprise Ltd. for use in training smallholder fruit farmers in the Teso region of eastern Uganda.

The purpose of this training manual is to provide information on good postharvest practices and value addition of fruit. Improving postharvest handling of fruits will enhance fruit quality and decrease losses. Value addition of fruit creates the opportunity for turning perishable fruit into a product that can store for longer periods of time. Increased knowledge in these subjects can result in increased income for farmers, availability of nutritious fruit for a longer part of the year, and less fruit wasted.

Why postharvest?

Postharvest practices include everything after a crop is harvested to when it gets to the final market or consumer. This includes harvesting, packing, storing, transporting, processing, and marketing of produce. Good postharvest practices will increase the quality and the worth of the product while decreasing the amount that deteriorates. By understanding the optimal conditions for your product, you can decrease losses.

Why value addition?

Value addition refers to the transformation of a product from its original state to one of enhanced worth. For produce this includes the creation of jams, jellies, juice, pulp, nectar, and dried product that can be sold to businesses, restaurants, and consumers for an increased profit.

Section 2: Harvest and postharvest of oranges and mangoes

Section 2 describes the harvest and postharvest practices that are important to optimize quality of fruit.

Postharvest basics in the field

Good fruit quality begins with harvesting and immediately after harvest. Fruit are living – they breathe, respond to temperature changes, and can get injured. See page 4 for a list of general good postharvest practices.

Harvesting oranges

Oranges do not continue to ripen after being harvested, so they must be left on the tree until fully mature. Oranges might remain green even if fully ripe. If you are not sure an orange is ready to be harvested, remove it from the tree and cut it in half with a knife. If juice from the orange drips down and the flavor and color of the pulp are sufficient, the oranges are ready to harvest.

When harvesting oranges, cut them off the tree with a bit of stem remaining so the point of attachment from the stem to the fruit does not leave a wound. Any type of wound on the fruit will cause rapid deterioration as moisture will move out of the fruit and pathogens will move in.

Postharvest handling of oranges

Fruit should be handled gently and with care. They are living tissues that can be bruised, can get too wet, too dry, too hot, too much sun, or too crowded.

Harvesting mangoes

Mango maturity differs due to varieties. Mangoes will often continue to ripen after harvest. As mangoes grow in trees, it is often difficult to harvest due to the height. Harvesters must take precaution to not injure the fruit when harvesting or lowering fruit to the ground. Using a net with a sharp blade attached can allow for harvest without having to pull the fruit off of the tree. Latex staining can occur in some varieties of mango and precaution should be taken to avoid, see the section in the manual on latex staining.

Postharvest handling of mangoes

Fruit should be handled gently and with care. They are living tissues that can be bruised, can get too wet, too dry, too hot, too much sun, or too crowded.

Mangoes are sensitive to temperatures that are too cold and the fruit will be damaged if stored at less than 10°C. Mangoes do not have a protective layer around them that aids in protection from damage and therefore will bruise very easily. Extra care should be taken to be gentle with mangoes and to avoid over packing of containers.

Packaging should not include more than 2-3 layers of fruit. If it is available, a liner should be placed in between each layer to decrease bruising. Mangoes are sensitive to the sun and should be placed in the shade after harvest. The sun will harm the skin of the mangoes, especially in varieties that are sensitive to latex staining. It will darken the stain and cause an unsightly fruit.

Section 3: Preparation for processing

Fruit selection for processing

After harvest, fruit can be sorted to select for which will be processed. If you are not planning on processing all of your harvest, the highest quality fruit can be taken for fresh market while the next best will be utilized for processing. Fruit that are defected or unevenly ripe can be processed, but pieces of the fruit that are damaged, rotting, or immature must be cut off and not included.

Fruit used for processing must be mature and healthy. Using diseased or contaminated fruit will lead to a final product that is of poor quality or not safe to consume.

Food safety

Extra precaution must be taken to ensure that value added products are of high quality due to food safety. Many harmful microorganisms can live in environments that are high in sugar or moisture. To protect from creating a poor quality product or one that could make people sick, it is important to take great care to maintain good practices. These include personal hygiene, equipment cleaning, creating an acidic environment, and pasteurization.

Preparing for processing

• Those making value added products should be sure to have clean hands.
• Fruit should be washed prior to processing.
• Equipment and supplies that will be utilized should also be cleaned. Bottles or jars that will be utilized should be sterilized (if glass) in boiling water. Plastic containers are not as safe to use, as high temperatures can melt the plastic.
• All materials should be on-hand and ready to be used, as the processing can often occur rapidly and it is better to be prepared.
• Page 9 includes a list of materials needed for processing.

Section 4: Value addition

Contains protocol for creating various value added products, including:

• Mango juice
• Orange juice
• Mango jam
• Orange or mango preserves