Farmer's Mini Cold Storage: An Innovative CoolBot Technology for Enhancing Shelf Life of Green Chilli under Bangladesh Condition
Abstract
The study evaluated the effectiveness of a low-cost cold storage condition (CoolBot) in extending the shelf life of Green Chilli under different storage treatments. Six parameters viz., color retention, texture, bruising, rotting, weight loss and total remaining weight were studied across storage condition up to 27 days. Results revealed that the control treatment (T0) at room temperature exhibited rapid deterioration with complete loss of marketable quality within 9 DAS (days after storage). In contrast, all CoolBot treatments significantly delayed quality loss. Among them, Green Chilli stored under polythene covering (T4) showed superior color and texture retention up to 18 DAS (scores >4.0). It showed lowest bruising (1.33%) at 12 DAS and 20.67% at 21 DAS. Less rotting percentage (15%) at 18 DAS and (43.67%) at 21 DAS was also noticed in the same treatment. Weight loss was lowest under polythene coverings (T4) (6.37 kg loss at 27 DAS). The highest remaining Green Chilli weight at 21 DAS was observed in polythene covering (8.25 kg) and the second highest remaining weight was in newspaper coverings (7.73 kg). The findings demonstrate that CoolBot storage substantially prolongs Green Chilli shelf life compared to room temperature storage, with polythene covering (T4) providing the best short-term quality retention, maximum remaining weight and minimum loss during the study period. This suggests that CoolBot cold storage combined with appropriate packaging can serve as a cost-effective solution for reducing postharvest losses and improving Green Chilli marketability under Bangladesh condition.
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Introduction
Green Chilli (Capsicum annuum L.)is one of the most important spice and vegetable crops in Bangladesh, consumed both in green and dry forms. It holds significant economic value, contributing to farmers' income, national spice demand and export potential. However, despite its importance, Green Chilli production faces serious challenges in postharvest handling, resulting insubstantial quantitative and qualitative losses. Green Chilli suffers considerable deterioration due to its perishable nature and lack of proper storage facilities (Mandal & Hoq, 2018). In Bangladesh, postharvest losses of fruits and vegetables range between 20–30%. Under ambient conditions in Bangladesh, where high temperature (27–35°C) and low relative humidity prevail, the shelf life of Green Chilli rarely exceeds 3–4 days, making it difficult for farmers to store and market their product efficiently. Texture softening and water loss are intensified at higher temperatures, while bruising accelerates microbial infection, leading to increased rotting percentage. As a result, growers are often forced into distress sales, limiting profitability and weakening the supply chain. Website: www.ijoear.com Journal DOI: 10.25125/agriculture-journal The absence of accessible cold storage facilities is one of the major constraints in preserving Green Chilli quality after harvest. Bangladesh lacks adequate cold chain facilities at the rural and farm-gate level. Consequently, the lack of affordable storage forces farmers to sell immediately after harvest, leading to oversupply in peak seasons, reduced farm-gate prices, and substantial postharvest losses. This situation results in economic losses due to distress sales and contributes to national food and nutritional insecurity. To address these constraints, there is a need for affordable and accessible cold storage technologies that can reduce postharvest losses, extend shelf life, and maintain the quality of Green Chilli.
CoolBot technology is a new innovative technique where temperature and humidity can be controlled at desirable conditions. The device allows a standard air conditioner to function as a refrigeration unit capable of cooling a well-insulated room down to 5–10°C at a fraction of the cost of conventional cold storage (Store It Cold, 2024). This technology is low-cost, energy-efficient, and simple to operate, making it suitable for farmer cooperatives, small traders, and rural entrepreneurs. Previous studies demonstrated that CoolBot-based mini cold rooms can significantly extend the shelf life of vegetables such as tomato, leafy greens,and collards by reducing weight loss, delaying colour change, maintaining texture, and minimizing microbial spoilage (Kathambi et al., 2022; UC Davis Horticulture Innovation Lab, 2022).
In addition to temperature regulation, relative humidity (RH) control is crucial in postharvest storage. High RH (85–95%) helps reduce transpiration, thereby minimizing weight loss and shriveling of Green Chilli (Kitinoja, 2018). For Green Chilli, maintaining cool and humid conditions slows respiration, reduces transpiration-related weight loss, minimizes bruising effects, and lowers rotten percentage, thereby preserving higher marketable yield overextended storage periods (Cheng et al., 2023; Mi et al., 2023). The adoption of CoolBot mini cold storage in Bangladesh can significantly reduce postharvest losses of Green Chilli, thereby improving marketable yield, enhancing farmer profitability, and strengthening the rural economy. By maintaining quality parameters such as colour, texture, and firmness, while reducing bruising, rotten percentage, and weight loss, CoolBot technology provides a viable solution for postharvest loss management in Green Chilli. 'Affordable Cold Storage Technology Extension for Mitigating Climate Change Risk and Increasing Farmers Income' is a Project funded by Environment, Forest and Climate Change Ministry, Government of the People's Republic of Bangladesh. The project was implemented by the Department of Agricultural Extension (DAE), Khamarbari, Dhaka, Bangladesh under the Project Director of Talha Zubair Masror. CoolBot Technology was first time initiated in Bangladesh under this project. This technology can also empower smallholders to delay sales, take advantage of better market prices, and expand into high-value markets such as exports and processing industries.
The overall objective of this study is to evaluate the effectiveness of low-cost mini cold storage using CoolBot technology in reducing postharvest losses of Green Chilli. The specific objectives are: To assess the effect of CoolBot storage on key postharvest quality parameters of Green Chilli. To compare the performance of CoolBot storage with ambient storage conditions in terms of postharvest loss reduction. To provide recommendations for optimizing CoolBot storage conditions (temperature and RH) for Green Chilli in the context of Bangladesh.
Conclusion
The present study demonstrated that the use of a low-cost CoolBot cold room significantly reduces postharvest losses and preserves the quality of Green Chilli in Bangladesh. Storage under ambient conditions resulted in rapid deterioration of colour, texture, and firmness, with severe bruising, rotting, and weight loss within 9 days. In contrast, the CoolBot system effectively delayed these deteriorative changes by maintaining low temperature and high relative humidity, extending shelf life up to 27 days depending on the type of covering used.
Polythene wrapping (T4) showed superior performance in terms of weight loss and minimum rotting percentage of Green Chilli. Among the CoolBot treatments, protective coverings played a critical role in further enhancing storage quality. Polythene wrapping (T4) was most effective in maintaining colour, texture, and minimizing bruising during the early and mid-storage period. Overall, the combined use of low-cost CoolBot storage and appropriate protective coverings significantly reduced postharvest losses, maintained marketable quality, and improved potential yield and economic return for Green Chilli farmers in Bangladesh.
The findings highlight that CoolBot technology offers a practical, low-cost, and effective solution for smallholder farmers to extend the shelf life of perishable horticultural crops, ensuring better marketability and reduced economic loss CONFLICT OF INTEREST The authors declare no conflict of interest.