The fruit Mango (Magnifera indica L.) originates from south Asia and is cultivated in tropic and subtropical areas in over 90 countries (Crane et al. 2009). Mango is called “the king of fruits” because of its flavour, delicacy and nutritional contents and in the tropical horticulture production it is considered as the second most important fruit crop (Singh et al., 2013). Mango fruit contains a fair source of phosphorus and potassium, and a good source of vitamins A, C, B-6, and E (pers. com., Chaka, 1, 2014). Furthermore, Mango fruit is an important part of people’s diet in several developing countries (Crane et al., 2009). Mangoes just like any other horticultural produce are perishable. This means that they are susceptible to changes in loss of water, or due to chemical reactions involving enzymatic activities respiration, or attack by microbes or insects hence postharvest losses occur in these fresh fruits.
Postharvest period begins when the commodity item is separated/removed from its medium of growth or its parent plant and it ends when the commodity goes into the process of preparation for final consumption. Postharvest losses are losses in quality and quantity in harvested produce that occur between time the produce has been harvest and its final consumption. This is usually a serious problem in Africa where storage and handling practices to minimize these losses are actually not followed due to poor processing and storage of both perishable and non-perishable crops. Postharvest losses of fruits and vegetables are estimated at 5-20% in developed countries and 20-50% in developing countries. Postharvest losses are in two different forms namely: Handling losses (these are mainly due to transportation, loading and offloading and also packaging) and storage losses (mainly due to storage environment which usually have variations in temperature, humidity and air circulation).
1.1 PROBLEM STATEMENT AND JUSTIFICATION
Malawi loses a lot of produce due to post harvest losses. Farmers put a lot of emphasis in production of various agricultural fruits but a greater part of the produce is lost through post-harvest losses due to handling and storage, but these losses are most of the times ignored but they have a great impact on agricultural sustainability. In order to achieve food security in Malawi, there is need to address this issue of post-harvest losses. For Malawi, to solve these problem there is need for information and knowledge of post-harvest losses and how to reduce them, hence there is need of research and information of post-harvest losses for mangoes in order to reduce such losses in Mango production.
• to assess the postharvest losses in mangoes due to storage technologies
• To determine and identify the postharvest losses in mangoes.
• To measure the postharvest losses in mangoes.
• To identify and determine the postharvest handling practices leading to postharvest losses.
• To identify appropriate storage technologies that would minimize the postharvest losses.
3.0 LITERATURE REVIEW
Postharvest losses are a major concern in a lot of countries all over the globe including in Africa and these losses are often ignored but they have a great Impact on the growth of the agriculture sector especially in the developing countries. Losses can appear in any stage of the product value chain during activities such as harvesting, transportation, packaging, storage and even at the market places (Hodges et al.,2011). Major causes for food waste are insufficient operational activities within supply chains, such as handling, storage and transportation (Murthy et al., 2009). Understanding the many factors that contribute to post harvest losses of fruits and vegetables is very critical, these factors include environmental conditions such as heat, drought, mechanical damage during harvesting and handling, improper post-harvest sanitation, unsuitable packaging materials, poor cooling and storage practices (Wyszynski, 1997)
Post-harvest losses in fruits can be measured by both quality and quantity losses. The qualitative losses are foremost due to biological deterioration including water stress, mechanical injuries, respiration rate, compositional changes and many more. (Kader., 2004). These losses are often the effect of environmental factors such as temperature, humidity, sanitary factors and the concentration of ethylene (the chemical responsible for ripening of fruits), carbon dioxide and oxygen. The environmental and natural conditions such as: temperature and humidity speed up the rate of normal metabolic processes that are responsible for keeping the mangoes alive. Mango just like any other fruits are living things even after harvesting them, this means that they continue to respire even after being harvested. Some factors include: long storage durations, mechanical injuries, and handling practices are also responsible for speeding up metabolic processes that eventually lead to rapid or accelerated losses in fruits. In Malawi, the key players in the post-harvest handling of mangoes are farmers, local (intermediate) traders and vendors. Mangoes are mostly harvested mature green. After harvesting the mango, farmers then sell to intermediate traders who then sell to the vendors.
Practices that may alter metabolic processes of mangoes are: careless handling of picked produce, loading and offloading of the produce, shaking of the vehicle transporting the produce, unnecessary packing of produce in transportation medium, poor storage conditions of storage facilities of the produce, and packing the produce in a pattern that restricts the movement of air in the storage facility. The qualitative losses are more complex to measure, but the quantitative losses are of greater importance to measure especially in developing countries such as Malawi.
4.0 METHODS AND MATERIALS
4.1 Study Area.
The study will be conducted in Lilongwe, at Bunda college campus and at mitundu market.
4.2 Assessment of the effect of storage on post-harvest losses of mango
A sample of green and ripened mangoes will be exposed to different storage conditions. Some among the sample will be exposed to sun, some will be stored in a shady place and some will be put in refrigerators. The subjects will be exposed to such conditions because these conditions are the ones mostly used by local farmers, traders and even retail stores. Then loss of quality in form of physical appearance, firmness, mass, pH, Vitamins A due to different storage conditions will be measured and recorded.
4.3 assessment of effect of various post-harvest handling processes.
the impact of post-harvest handling practices on postharvest losses in mango will be assessed using questionnaires. These will be used to collect relevant data from farmers, local traders and retail stores. The questionnaires will be targeting specific handling practices depend on the individual (farmer, local trader and retail stores) from which data will be collected. The post-harvest handling practice being targeted most is the Transportation of the produce.