(P20-25-26) Post-harvest Stress Alters Phytochemical Quality in Selected Indigenous Crops

Objectives: Postharvest stress can remodel plant bioactives that contribute to functional food quality. We evaluated how handling and storage influence phytochemical profiles of indigenous Ghanaian crops, focusing on phenolics, flavonoids, tannins, and selected tomato phenolic compounds.

Methods: Tomato and cassava were sampled across postharvest stages, and Bambara groundnut was evaluated under different preservation conditions. Total phenolics, flavonoids, and tannins were assessed using standard assays, and selected tomato phenolics were quantified by reverse-phase HPLC. Values are reported on the study’s assay basis and compared within-crop across stages. Differences across stages and storage conditions were evaluated at p≤0.05.

Results: In cassava, total phenolics and tannins increased from farm to later postharvest stages, while flavonoids peaked at the market stage in Techiman samples before declining. In Bambara groundnut stored with ash, total phenolics increased from approximately 360 to 430 (month 1) and declined to about 400 by month 2, whereas naphthalene-treated samples declined to about 320 by month 2. In deteriorated tomatoes, phenolic compounds increased sharply after sorting; gentisic acid reached 5,153.50 μg/g in wooden-box samples and 8,113.50 μg/g in plastic-basin samples on day 1, with concurrent increases in catechin and gallic acid. Patterns were consistent with stage-dependent biochemical remodeling during storage and deterioration.

Conclusions: Postharvest handling and storage induce substantial phytochemical remodeling in indigenous crops, with implications for functional quality and interpretation of food composition data. Optimizing handling and storage could help retain desirable bioactives without promoting deterioration-related shifts. Future work should assess how these changes translate to sensory quality.

Funding Sources: N/A