Design and development of a fruit and vegetable storage chamber for increased shelf life

Author

Danga, Chido, R.

Title

Design and development of a fruit and vegetable storage chamber for increased shelf life

Abstract

The supply of food can be induced either by an increase in production or a reduction in loss. Post-harvest losses of tomatoes are high for the smallholder farmers in Zimbabwe mainly due to an increase in ripening that leads to deterioration and senescence. Ripening of tomatoes is further increased by lack of appropriate post-harvest infrastructure, technology to increase shelf life, high field temperatures on tomatoes before and after harvesting, pest and disease attack. One of the methods that can be used to increase the shelf life of tomatoes is the use of a storage chamber for increased shelf life by reducing production of ethylene, a gaseous plant hormone that accelerates ripening and senescence during storage. The study aimed to help in enhancing the quality and increase the shelf life of tomatoes through the use of storage chamber for increased shelf life that is economical, easily operated, and socially friendly in terms of operation. The study objectives were to design and develop a chamber for increase shelf life of vegetables and fruits, to evaluate the performance/ effectiveness of storage chamber by removing air and to maintain the quality and increase shelf life of tomatoes stored in the storage chamber by removing air. The storage chamber is more effective due to the availability of pores that absorb and store water, in-turn reducing the temperature and ethylene inside that makes the tomatoes deteriorate. Experimental chambers 1 was equipped with a ball valve and pressure gauge, with the purpose of allowing air passage and measuring internal pressure, respectively. Chambers 2 solely featured the ball valve and was constructed from readily available and inexpensive polypropylene plastic. On the first day of testing, air was withdrawn from the chambers to specific pressure levels - 0.6 psi for chambers 1, while the pressure for chambers 2 remained unknown as it lacked a pressure gauge, and no pressure was removed from the control chambers where tomatoes were placed in an open space. The process of air extraction from the chambers was repeated in each experiment to maintain tomato quality and titratable acids were analyzed.
In maintaining the quality of tomatoes titratable acids experiments were carried out. In experiment 1, (day 1) the tomatoes were all at the breaker stage in both the chamber and the control and the acid content was 1.037g/l. In experiment 2, (day 4) the TA had no significant difference between the chamber and the control (p>0.05). In experiment 3, (day 8) the chamber had a significantly (p<0.05) higher value of titratable acids than in the control due to reduced air. In experiment 4, (day 12) tomatoes ripening in the chamber had significantly (p<0.05) higher TA values than those ripening in the control. In experiment 5, the chamber had significantly (p<0.05) high TA values due to reduced production of ethylene and low pressure registered by the chamber. In experiment 6 day 20, tomatoes that were ripening in the chamber had significantly (p<0.05) high TA values than in the control. Low TA in the control results in accelerated ripening and senescence-related alterations. Tomatoes with low TA values may have used their acids in the metabolism of living tissues, which depletes organic acids.
The researchers recommend that smallholder farmers in Zimbabwe, particularly communal farmers, should utilize these types of storage chambers to enhance the shelf life and quality of their tomato harvests before going to market. Durable materials like glass or stainless steel are advised to withstand the chamber pressures. Tomatoes used in the study should also be grown by the researchers to ensure accurate pre-harvest data.In summary, the low-cost storage chamber technology shows promise as an intervention to reduce post-harvest losses and improve the marketing window for tomatoes cultivated by resource-constrained smallholder farmers in Zimbabwe.

Date

June 2024

Publisher

BUSE

Keywords

Post-harvest losses

Tomato storage

Shelf life extension

Ethylene reduction

Supervisor

Engineer Zingwari, O.