Coolbot Coldroom technology enhance postharvest quality and shelf-life of tomato (<i>Solanum lycopersicum</i> L.) fruits

Abstract

Fruit and vegetable value chain actors in developing countries experience postharvest losses of 20 – 50% depending on the crop and management practices. One of the reasons for such loss is mentioned to be lack of affordable technologies to enhance produce storability during handling after harvest. Temperature management serves as the number one practice for extending shelf life of fresh produce. CoolBot is a device coupled to room air conditioner capable of dropping the room temperature to as low as 2oC. Storage rooms installed with the technology seem suitable for handling fresh fruits and vegetables over an extended period. Despite the awareness creation upon the value chain actors, they are yet skeptical of these technologies’ performance and cost-effectiveness during utilization. Therefore, this study was designed to evaluate the performance and cost-effectiveness of two CoolBot Cold-rooms (CB-CR) independently, one set at temperature of 13±1oC and the other at 16±1oC, respectively. Tomato fruits of the variety Assila harvested at three maturity stages were used during the evaluation. A 2x3 factorial experiment arranged in a Completely Randomized Design (CRD) with two factors; storage condition (CB-CR at 13±1oC and CB-CR at 16±1oC) and Maturity stage (mature-green, breaker and light red) were used. Following 42 days of storage at pre-defined storage conditions, results indicated no significant interaction of maturity stage and storage condition among variables. However, external fruit colour change in terms of Lightness (L*), Chroma (C*), and Hue (H*), marketable fruits (%), soluble solid content (% Brix), titratable acidity (MeqL-1), weight loss (%) and firmness-compression (kg/mm) varied with maturity stages. External fruit colour change from yellow yellow-green colour (L*C*h* = 57, 31.7, 110) to yellow yellow-red (L*h*C*= 39.7, 42.3, 43.0) was delayed more on mature green (MG) compared to other stages at both CB-CR (13±1oC and 16±1oC). Percentage marketable fruits was much higher on mature green fruits (84.83%), followed by Breakers (60.91%) and light red (48.58%). Based on electricity consumption, storage of tomato at CB-CR 16±1oC (160.2 KWh) was more beneficial than at CB-CR 13oC (272.7 KWh) due to less power consumption. It is therefore imperative to conclude that, more benefit can be realized when CB-CR storage is combined with the proper harvest maturity stage. Similarly, mapping of crop price change over season is required for proper storage timing using the technology throughout the year.