Chitin as a Sustainable Cooling Solution: Field Evaluation of Passive Thermal Liners for Heat Management in Small-Scale Southern Strawberry Product

Commodities

Practices

Strawberries deteriorate faster than nearly any other commercial fruit from the moment of harvest. In the Southern region, peak-harvest ambient temperatures routinely exceed 25 °C, and cooling delays of just 2 to 8 hours cut marketability by 20 to 70%. Yet the field-to-cooler transit window remains a critical gap in the strawberry cold chain: commercial insulated containers and active refrigeration are designed for industrial supply chains and remain cost-prohibitive for the small-scale, direct-market growers who define Southern strawberry production. No affordable cooling option currently exists for this producer segment, where active refrigeration is precluded by its electrical infrastructure requirements. This project addresses that gap by field-validating chitin nanofiber (ChNF) passive thermal liners as a low-cost, sustainable and drop-in solution for standard harvest containers. Chitin is a renewable biopolymer with thermal conductivity comparable to expanded polystyrene, and we have developed a laboratory-scale fabrication method that produces deployable liners. Building on this foundation, we will fabricate liners for two consecutive seasons, run field trials at Southern Piedmont Agricultural Research and Extension Center, and quantify the effect on pulp temperature gain, precooling time, 24-h postharvest loss, and 12-day cold-storage shelf life. Liner durability across reuse cycles will be tracked, and a techno-economic analysis will deliver producer-actionable adoption metrics: per-liner fabrication cost, cost per harvest utilization, and break-even loss-recovery threshold. Outcomes will be disseminated through an on-farm field day, Virginia Cooperative Extension publications, and peer-reviewed manuscripts, providing Southern strawberry producers and extension agents with the first field-validated evidence base for ChNF liner adoption.

This project aims to develop and field-validate ChNF passive thermal liners as a low-cost postharvest heat management option for small-scale Southern strawberry producers, generating the performance and economic feasibility evidence needed to support practical adoption. Central hypothesis: ChNF passive thermal liners will reduce pulp temperature gain during the field-to-cooler transit window, thereby decreasing 24-h postharvest loss and extending cold-storage marketable shelf life, with the cost competitive with conventional insulated containers.

The specific objectives are to:

1. Fabricate ChNF passive thermal liners using our laboratory-validated production method and prepare sufficient quantities for two seasons of field evaluation.
2. Quantify the effect of ChNF liners on pulp temperature gain, precooling time, and 24-h postharvest loss during field-to-cooler transit, and assess performance consistency across repeated reuse cycles, using paired lined and unlined containers at Southern Piedmont Agricultural Research and Extension Center (Blackstone, VA) across two harvest seasons.
3. Determine whether transit-phase heat mitigation translates into extended cold-storage marketable shelf life through standard postharvest quality assays.
4. Evaluate the economic feasibility of ChNF liner adoption through techno-economic analysis, comparing fabrication and use costs to the monetized value of prevented postharvest losses and to conventional insulated container benchmarks.