Assessment of Physico-chemical Changes in Stored Coconuts (Cocos nucifera L.) and Their Impact on Seed Germinability

Abstract

Coconut (Cocos nucifera L.) seednuts are recalcitrant and may lose viability during storage as their physico-chemical characteristics change. This study assessed changes in mature coconuts stored under ambient laboratory conditions (25–30°C; 60–70% relative humidity) for six months and examined their relationship with seed germinability. Approximately 120 healthy nuts were collected at full physiological maturity, and samples were evaluated at monthly intervals. Moisture content, oil content, coconut-water pH, total soluble solids, and respiration rate were measured, while germination was assessed over a 60-day period. During storage, moisture content declined from 49.2 ± 0.5% at harvest to 35.0 ± 0.5% after six months, while oil content decreased from 63.5 ± 0.4% to 51.1 ± 0.5%. Coconut-water pH declined from 6.1 ± 0.1 to 5.3 ± 0.2, whereas total soluble solids increased from 4.2 ± 0.2 to 7.0 ± 0.4 °Brix and respiration rate increased from 3.8± 0.3 to 6.0 ± 0.3 mg CO₂ kg⁻¹ hr⁻¹. Germination decreased progressively from 96.0 ± 1.2% to 20.5 ± 2.5%. Moisture content and oil content were positively associated with germination, with reported correlation coefficients of r = 0.87 and r = 0.81, respectively. These findings indicate that prolonged ambient storage was accompanied by progressive physico-chemical deterioration and reduced seed germinability, highlighting the importance of storage duration and conditions in maintaining coconut seednut viability.