Postharvest losses of fruits and vegetables in Sub-Saharan Africa (SSA) represent a significant challenge to food security, with losses estimated to range from 30% to 50% before consumption. These losses have far-reaching implications, not only for the region’s food supply but also for economic stability and the livelihoods of smallholder farmers. The causes of postharvest losses are multifaceted, involving a combination of biological, technical and infrastructural factors. Biological factors, such as perishability and susceptibility to diseases and pests, exacerbate the situation, especially when combined with inadequate harvesting, handling and storage practices. Furthermore, technical and infrastructural challenges, such as the lack of cold chain infrastructure, limited access to efficient packaging and unreliable transportation systems, significantly contribute to the high rates of spoilage. These issues are compounded by socioeconomic factors, such as limited access to technology and market constraints, which affect smallholder farmers’ ability to mitigate losses
(Makule et al., 2022; Etefa et al., 2022).
A particularly promising solution to reducing postharvest losses in SSA is the use of biodegradable and edible coatings for fruits and vegetables. These coatings offer a low-energy, cost-effective and scalable alternative to traditional plastic-based packaging. The benefits of coatings extend beyond preservation, as they can extend the shelf life of perishable produce, reduce spoilage and enhance food safety without relying on harmful synthetic materials. Given the growing environmental concerns associated with plastic waste, the shift towards biodegradable coatings represents a critical opportunity for both environmental sustainability and economic resilience in SSA. Notably, biodegradable coatings can be derived from natural, renewable sources, such as starch, chitosan and proteins, which are abundant in the region’s agricultural sector. This makes their adoption particularly relevant to the unique agricultural and economic context of SSA
(Jahangiri et al., 2024; Pirzada et al., 2020).
This review aims to critically analyse the development and application of biodegradable and edible coatings in SSA, focusing on their potential to address the pressing issue of postharvest losses. The article will examine the latest advances in coating technologies, explore novel directions for future research and highlight existing gaps in knowledge and practice. By investigating the interplay between coating materials, the regional agricultural context and technological innovations, this review seeks to provide a comprehensive overview of the potential for biodegradable coatings to transform postharvest management in SSA. The ultimate goal is to chart a path forward for integrating these innovative technologies into practical, scalable solutions for the region’s agricultural challenges.
Postharvest challenges specific to SSA
Limited cold storage and unreliable electricity
Among the most pressing post-harvest challenges in SSA is the lack of cold storage infrastructure together with the unavailability of electricity. The use of cold storage infrastructure is vital in retaining the quality of perishable fruits and vegetables; yet in many areas across SSA, this issue persists. For example, in rural areas where most small farm owners are based, the absence of cold storage infrastructure causes food deterioration and losses of 30%-50% of harvested food products
(Makule et al., 2022). The lack of sufficient cooling infrastructure further exacerbates the sensitivity of food products to deterioration, especially tropical fruits like mangoes and bananas that are best stored in cooled and infrastructurally enabled surroundings in order to extend the life span of the products. Further absence of electricity in many areas of SSA makes food preservation through retaining the cold chain difficult for farmers in attempting to protect food products or access cooling infrastructure or technologies (
Rutta, 2022).
Various solutions have been proposed over the years because of the gaps in the current infrastructure; however, most of these solutions are yet to be utilized due to the prevailing high costs and lack of awareness regarding the products being promoted in preference over those requiring refrigeration (
Sibanda and Workneh, 2020). Despite the challenges in investing in cold chains or other forms of renewable solutions, there are opportunities in meeting this challenge (
Mayanja and Oluk, 2023) (Fig 1).
Crop diversity and postharvest losses
The diversity of products in SSA’s agriculture sector also remains quite high and includes tropical fruits like mangoes, papayas, avocados and bananas, in addition to indigenous veggies like amaranth, African nightshade and spider plant. The post-harvest factors these products encounter is quite different from others due to the perishable nature of the products and unavailability of proper storage and processing infrastructure. For tropical fruits, diseases like fungal infections, Colletotrichum and Fusarium have been significant factors in the loss of post-harvest yield of fruits in SSA due to unfavorable climatic factors
(Kouadia et al., 2019). Damage from bruises due to mechanical damage, inappropriate handling and storage in addition to the warmer climate have also resulted in increased disposal of spoilt fruits
(Sharma et al., 2024).
The local veggies also have challenges of their own such as a low market demand and poor post-harvest handling. Despite the nutritional and local significance of the veggies, they often suffer from poor post-harvest handling and hence incur high losses
(Strecker et al., 2022). The varieties of the veggies, each handled in different ways based on distinct features of the veggies, highlight the need for different approaches in post-harvest handling.
Smallholder-dominated, informal markets and weak logistics
The post-harvest losses in SSA are further hampered by the nature of markets in agriculture that are mostly smallholder-dominated and involve informal markets. The smallholder farmers do not have access to advanced post-harvest technologies and infrastructure and the involvement in informal markets hinders the standardization of post-harvest management approaches
(Kansanga et al., 2023). The informal markets are characterized by poor logistics infrastructure, no access to cold storage infrastructure and inefficient transport networks.
All this further hampers the reduction of post-harvest losses in SSA. It has also been observed that in most cases, the vegetables and fruits are distributed over long distances through unideal approaches, further leading to the wastage of products owing to their deterioration (
Gelaye, 2024). Absence of synchronization among farmers, suppliers and consumers further hampers this process through lack of standard approaches in post-harvest management.
Low awareness of coatings and limited food safety frameworks
The consumer landscape in SSA also poses challenges for the adoption of innovative postharvest solutions, such as biodegradable coatings for fruits and vegetables. Consumer awareness of the potential benefits of coatings remains low and there is limited understanding of their role in enhancing shelf life and improving food safety (
Ahlawat and Kumari, 2025). Notably, there is a lack of regulatory frameworks to standardise the use of such technologies, which hinders their widespread adoption (
Picot-Allain et al., 2022). The absence of robust food safety frameworks further exacerbates the situation, as consumers are often unaware of the risks associated with improperly stored or handled produce. Without adequate regulation and consumer education, the potential for widespread adoption of innovative postharvest technologies like edible coatings remains limited.
The socio-economic barriers, such as income levels and education, can influence consumer behaviour, with those in higher income brackets more likely to accept biofortified or coated foods (
Etumnu, 2016) (Table 1). Addressing gaps in consumer awareness and regulatory frameworks is essential for promoting the acceptance and scalability of new postharvest technologies. Enhancing consumer education on the benefits of coatings and improving food safety standards would support reducing postharvest losses and improving food security in SSA.
Principles and current practices of biodegradable and edible coatings
Barriers to moisture, gases and microbes
The effectiveness of edible coatings is rooted in their ability to act as barriers against moisture, gases and microbial contamination. Polysaccharides and lipids form hydrophilic and hydrophobic matrices, respectively, which reduce water loss and maintain firmness in perishable produce (
Buţu et al., 2024;
Matche and Singh, 2023). In addition, coatings regulate the exchange of gases such as oxygen and carbon dioxide, thereby slowing respiration and delaying ripening, a mechanism that mimics modified atmosphere storage (
Tapia-Blácido et al., 2018;
Dhall, 2013). Beyond passive barriers, coatings can be enriched with antimicrobial and antioxidant compounds such as essential oils, phenolics, or herbal extracts, providing active defence against microbial growth and oxidative degradation
(Rajial et al., 2024; Zaritzky, 2010). Collectively, these mechanisms protect perishable produce from both physical and biochemical deterioration, making coatings a critical tool for reducing losses in perishable supply chains.
Conventional biopolymers for edible coatings
The most widely studied edible coatings rely on biopolymers derived from renewable resources such as starch, alginate, chitosan and gums. Starch is abundant, inexpensive and valued for its film-forming capacity, though its poor water resistance necessitates chemical or physical modification
(Rostamabadi et al., 2024; Veiga-Santos and dos Ouros, 2024). Alginate, extracted from brown seaweed, offers strong gel-forming properties in the presence of calcium ions and can be combined with other polymers to improve mechanical stability
(Wardejn et al., 2024). Chitosan, derived from chitin, is notable for its inherent antimicrobial and antifungal properties, which have been exploited in composite coatings enriched with essential oils
(Elgadir et al., 2024; Díaz-Montes and Castro-Muñoz, 2021) (Fig 2). Gums such as gum Arabic and xanthan gum serve as hydrocolloids that enhance texture and barrier properties, especially when blended with starch or alginate
(Marasinghe et al., 2024; Ravindran et al., 2024). While these biopolymers are promising, limitations in mechanical strength, transparency and water vapour resistance remain critical challenges, requiring further innovation and adaptation for SSA’s climatic conditions.
Feasible low-tech application methods
The practical deployment of edible coatings depends heavily on the method of application, with dipping, brushing and spraying being the most common. Dipping ensures uniform coverage but can lead to excess use of coating material, making it inefficient for large-scale operations. Brushing allows for precise, targeted application but is labour-intensive and best suited for small-scale or artisanal production (
Xiao, 2021). Spraying, by contrast, provides consistent coverage and is scalable, making it the most efficient option for industrial applications, though it requires initial investment in atomising equipment
(Andrade et al., 2012). From a sustainability perspective, spraying also minimises material waste and energy inputs compared to dipping and brushing (
Buţu et al., 2024;
Jurić et al., 2024;
Avramescu et al., 2020) (Table 2). For SSA, where low-cost, adaptable solutions are critical, dipping and brushing remain feasible for smallholder farmers, while spraying holds promise for cooperative packhouses and larger-scale value chains.
Emerging directions in biodegradable coating research for SSA
The development of biodegradable coatings tailored for Sub-Saharan Africa (SSA) is moving beyond conventional biopolymers toward advanced, multifunctional materials. These innovations draw on locally available resources, frontier material science and nutrition-sensitive agriculture frameworks (Fig 3).
Waste-derived biopolymers
Agro-waste valorisation presents a sustainable pathway for generating biopolymers such as cellulose, starch and chitosan from materials like cassava peels, banana pseudo-stems and mango kernels. These raw materials are abundant in SSA and offer dual benefits: reducing agro-waste while producing low-cost, biodegradable packaging alternatives (
Nath, 2024;
García-Mahecha et al., 2023). Their biodegradability and biocompatibility make them suitable for edible coatings, with demonstrated applications in packaging, mulching films and fruit surface treatments
(Garg et al., 2024; Ashitha et al., 2020) (Table 3). Importantly, local production of these coatings aligns with circular economy principles, promoting value addition within rural communities and reducing dependence on imported synthetic polymers
(Valle et al., 2024; Ni and Friedman, 2024). Despite this potential, challenges persist around standardisation, scalability and cost competitiveness compared to plastics, highlighting the need for region-specific techno-economic evaluations.
Smart and responsive coatings
Smart coatings represent a next-generation approach, integrating materials that respond to ethylene accumulation, microbial activity, or pH fluctuations. Ethylene scavenging coatings incorporating agents like potassium carbonate can delay fruit ripening, while antimicrobial polymer films with embedded nanoparticles inhibit microbial growth
(Gaikwad et al., 2025; El Guerraf et al., 2024). Similarly, pH-responsive films provide visual indicators of spoilage, enabling real-time quality monitoring
(Zhang et al., 2025; Pawar and Rana, 2019). Globally, such technologies remain in the early adoption phase due to high production costs and concerns over the overuse of active agents
(Bhattacharya et al., 2023). For SSA, the relevance of these coatings lies in their potential integration once basic biodegradable coating use is established. Their application could bridge postharvest technology gaps by reducing losses in long, informal supply chains while supporting consumer trust through visible freshness indicators
(Singh et al., 2025; Yogita et al., 2024).
Nanostructured biopolymers
Nanocellulose derived from agro-residues such as pineapple leaves and sisal fibres offer superior mechanical strength, barrier performance and antimicrobial potential for coating formulations
(Vanaraj et al., 2024). Incorporating nanostructures enhances gas and moisture barrier properties, crucial for tropical environments with high humidity
(Zhao et al., 2025). Nanocomposite films also exhibit antioxidant activity, further extending fruit shelf life (
Türker, 2024). The nanostructures used in these formulations have unique properties that make them useful for food packaging. For example, nanocellulose reinforcement features rod-like cellulose nanocrystals (5-20 nm diameter, 100-500 nm length) embedded in a polymer matrix, showcasing its crystalline structure and hydrogen bonding networks. Chitosan nanoparticles (50-200 nm diameter) have a positively charged shell that encapsulates antimicrobial cargo, demonstrating a membrane disruption mechanism against bacterial cells.
Notably, nanoemulsion structures feature lipophilic droplets (50-200 nm) dispersed in a hydrophilic continuous phase, stabilized by a surfactant layer. Nanoencapsulation systems include unilamellar and multilamellar liposomes (100-500 nm) with bilayer phospholipid membranes that compartmentalize hydrophobic and hydrophilic bioactive compounds (Fig 4). However, debates persist around nanoparticle migration, food safety and regulatory oversight, particularly in SSA, where regulatory frameworks for nanomaterials are underdeveloped
(Mishra et al., 2024; Ghanbarzadeh et al., 2015). Addressing these concerns requires collaborative policy development and consumer education to balance performance benefits with health and safety assurance.
Microbiome-aware coating design
In SSA, spoilage is often driven by polymicrobial consortia thriving under hot and humid conditions. Conventional coatings with broad-spectrum antimicrobials may be insufficient in these contexts. A novel direction involves metagenomics-guided coating design, which tailor antimicrobial activity against dominant spoilage organisms while minimising disruption of beneficial microbiota
(Anupama et al., 2025). Such precision approaches could extend shelf life more effectively than generic formulations and reduce the risk of fostering antimicrobial resistance (
Mäki et al., 2023;
Schmidt et al., 2017, 2018). However, the integration of genomics into coating design is still experimental, requiring interdisciplinary collaboration between microbiologists, material scientists and agronomists.
Commodity-specific case studies in SSA
The perishable crop commodity groups in SSA include high-value export fruits like mangoes, papayas and avocados, as well as staple crops like bananas, plantains, tomatoes and leafy vegetables
(Mohanapriya et al., 2024). These crops are crucial for food security and export earnings. However, they face substantial postharvest losses due to factors like inadequate infrastructure, poor handling and lack of cold storage.
Mangoes, papayas and avocados are valuable export products, but face losses due to premature harvesting, fungal diseases and high temperatures
(Geremu et al., 2022; Rimpika et al., 2021). Inexpensive materials can help reduce respiration rates and disease incidence, opening up export opportunities. Bananas and plantains are widely consumed in SSA, but suffer significant losses due to poor handling, high moisture and warm climates
(Kikulwe et al., 2018). Social factors, like resource constraints in female-headed households, exacerbate these losses. The lack of cold storage infrastructure and poor logistics networks further worsen this aspect of food preservation
(Mensah et al., 2025).
Tomatoes and leafy vegetables are essential in SSA’s daily diet, but face substantial losses due to inadequate packaging, lack of pre-cooling and poor storage capacity
(Amissah et al., 2025). The particular category of veggies referred to includes amaranth and nightshade veggies that are more fragile compared to other veggies like tomatoes
(Tschirley et al., 2010). Antimicrobial or antioxidant coatings could be a cost-effective preservation solution, but research is still in its early stages. Lab research shows promise, but field studies involving SSA value chains are needed to develop applicable solutions.
Physiological and microbiological outcomes
Edible coatings contribute to postharvest quality by delaying physiological ripening processes and suppressing microbial growth. By modulating gas exchange and reducing respiration rates, coatings extend the shelf life of perishable produce such as mangoes, tomatoes and leafy greens
(Zdulski et al., 2024). Antimicrobial agents incorporated into coatings such as essential oils, phenolics and chitosan effectively inhibit microbial colonisation and decay during storage (
Muñoz-Tebar et al., 2023;
Aguilar‐Veloz et al., 2020). Studies also demonstrate that coatings can lower ethylene production and delay enzymatic browning, further preserving quality under tropical conditions. These physiological and microbiological benefits make coatings a valuable tool for mitigating losses in SSA’s hot and humid environments, where pathogens thrive and supply chains are prolonged.
Environmental and economic perspectives in SSA
Plastic alternatives and recycling limitations
Plastic remains the dominant packaging material in SSA, yet the region faces acute challenges in managing plastic waste due to weak recycling infrastructure. Urban centres generate increasing volumes of single-use plastics, but less than 10% is recycled, with most ending up in landfills, waterways, or open dumps
(Ziani et al., 2023). Biodegradable coatings offer a compelling alternative by eliminating the need for synthetic plastic films while maintaining protective functions for perishable produce. Their biodegradability and renewable origin reduce environmental pollution and align with global sustainability goals. For SSA, where waste management systems are underdeveloped, coatings present an attractive option for reducing reliance on plastics while simultaneously addressing postharvest losses.
Cost considerations and local sourcing
Affordability is critical in SSA, where smallholder farmers and informal traders dominate the fresh produce sector. For coatings to be viable, they must be produced at low cost and preferably from locally available raw materials such as cassava peels, mango kernels, or banana pseudo-stems
(Gupta et al., 2022). Locally sourced production not only reduces dependency on imports but also stimulates rural bioeconomies and creates employment opportunities (
Sørensen et al., 2022). However, cost constraints remain a significant challenge: commercial biopolymers like alginate or chitosan are often expensive and inaccessible in SSA markets. Developing low-cost extraction and processing methods tailored to regional agro-wastes is therefore essential to ensure competitiveness with both plastics and traditional packaging.
Competing with traditional packaging
A critical debate concerns whether biodegradable coatings can realistically outcompete traditional, low-cost packaging methods such as banana leaves, jute sacks and woven baskets. These materials are widely used in informal markets and are deeply embedded in local food systems
(Samanta et al., 2015). While coatings offer superior preservation by delaying ripening and suppressing microbial growth, traditional packaging has cultural acceptance, availability and near-zero cost on its side
(Jahangiri et al., 2024). Thus, coatings may be most viable as complementary technologies, enhancing the performance of traditional packaging rather than replacing it outright. For example, applying coatings to tomatoes transported in woven baskets could reduce spoilage while maintaining existing distribution practices. The environmental and economic dimensions of edible coatings in SSA underscore both opportunities and constraints. Coatings provide a promising plastic alternative, particularly in regions with poor recycling infrastructure and offer potential economic benefits through local production from agro-wastes
(Soni et al., 2023). However, cost competitiveness and the need for SSA-specific LCA evidence remain unresolved challenges. Moreover, the cultural entrenchment of traditional packaging suggests that coatings may succeed best when positioned as complementary innovations rather than direct substitutes.
Integration into SSA food systems
Smallholder adoption barriers
Adoption of coatings by smallholder farmers, the backbone of SSA’s food production, faces several challenges, including limited awareness, lack of technical training and high input costs. Education levels and access to extension services directly influence farmers’ capacity to understand and implement new technologies
(Mabe et al., 2021). Where extension systems are weak, farmers rely on informal knowledge networks, which may not disseminate accurate information about coating benefits. Financial barriers are equally critical: most smallholders operate with minimal access to credit and are hesitant to invest in untested technologies
(Kamau et al., 2022) (Fig 5). The absence of cooperative financing models and local processing units for coating materials further limits accessibility. To promote adoption, initiatives should emphasize farmer training, demonstration plots and inclusive financing schemes that lower entry costs and build confidence in coating technologies.
Synergies with other interventions
Integrating coatings with complementary technologies such as evaporative cooling and improved packaging offers a powerful pathway to strengthen SSA’s postharvest systems. Evaporative cooling using simple, locally available materials such as charcoal, clay, or sand provides an affordable, low-energy method to maintain humidity and reduce temperature during storage
(Palumbo et al., 2022). When combined with coatings, this method can double shelf life by reducing both physiological and microbial spoilage. Likewise, advanced biodegradable packaging enhanced with nanoparticles or antimicrobial compounds (
e.g., silver, zinc oxide) can reinforce the protective function of coatings
(Lei et al., 2024). Together, these interventions offer synergistic benefits: coatings act as primary preservation barriers, while evaporative cooling and packaging maintain the external microenvironment. However, widespread adoption depends on developing context-specific combinations suited to local climate and market dynamics, supported by training and supply chain integration.
Policy and regulatory harmonization
The absence of harmonised regional food safety regulations remains a key barrier to scaling coatings in SSA. Fragmented national frameworks, outdated legislation and limited regulatory capacity restrict the commercial rollout of novel postharvest technologies
(Morse et al., 2018). In countries like Malawi and Ethiopia, inconsistent food safety enforcement limits market confidence, particularly for export commodities. Regional harmonisation through organisations such as the African Continental Free Trade Area (AfCFTA) and the East African Community (EAC) could streamline standards, enhance traceability and facilitate trade
(Union et al., 2014). International collaboration guided by WHO and FAO frameworks can further ensure that coatings meet global benchmarks for food contact materials
(Das et al., 2024). Strengthening capacity in testing laboratories, certification systems and risk communication is therefore essential to ensure safe and equitable implementation.
Linking coatings with ICT and sensor-based shelf-life prediction
The integration of ICT and sensor-based systems represents a novel frontier for optimizing the application and distribution of coated produce in SSA. IoT-enabled sensors and wireless monitoring platforms such as FreshSense allow for real-time tracking of temperature, humidity and ethylene levels throughout the supply chain (
Kumar and Sharma, 2024). Machine learning algorithms can analyse this data to predict remaining shelf life, enabling dynamic routing of produce to markets before spoilage occurs. Intelligent packaging with visual indicators such as pH-sensitive films can also inform traders and consumers about freshness status
(Kansal et al., 2024; Qiao et al., 2024).
Integrating coatings with these digital systems would not only reduce waste but also enhance market efficiency and traceability. However, technological disparities, high setup costs and limited digital literacy among farmers pose challenges. Addressing these gaps through public-private partnerships and digital extension platforms could accelerate adoption while ensuring inclusivity. Integrating biodegradable coatings into SSA’s food systems requires an ecosystem approach that bridges technology, policy and socio-economics. Overcoming smallholder adoption barriers, aligning coatings with other low-cost preservation strategies and harmonising regulatory frameworks are immediate priorities. The emerging convergence between coatings and ICT-driven shelf-life monitoring offers a transformative opportunity to modernise SSA’s postharvest chains. If effectively implemented, these integrated systems could reduce food waste, enhance trade competitiveness and foster resilient, sustainable food systems across the region.
