Metabolic and electrical responses to potassium deficiency stress in strawberries

The effects of potassium concentration on the metabolomic and electrical responses of strawberry fruits were investigated. The potassium concentration of fruit harvested in January, March, and April were determined. Quality differences were observed in April, with lower potassium levels resulting in lower Brix values and acidity. Intracellular resistance and cell membrane capacity, as determined by impedance analysis, were correlated with acidity and sugar content, respectively. In addition, metabolomic analysis by gas chromatography-tandem mass spectrometry (GC-MS / MS) indicated that stress markers, such as putrescine, were detected before quality differences appeared. While impedance analysis is useful for evaluating the tissue condition of strawberries, metabolomic analysis can be used to predict quality changes.