Effect of Maturity Stage and Short-Term Storage on the Biological Quality of Sweet Pepper Fruits

Sweet pepper plants of Spartacus cultivar were grown in plastic tunnel on rockwool using the fertigation technique. The three year experiment was carried out in 2006-2008. Fruits were harvested every year in three maturity stages: green, turning and red. The contents of ascorbic acid, phenols, soluble sugars, nitrate and ammonium ions, total nitrogen, free amino acids and dry matter were determined in freshly harvested fruits as well as after short-term (two weeks) storage.

Red pepper fruits accumulated significantly more ascorbic acid, soluble sugars and phenols in comparison with the green and turning ones. The level of nitrate ions was highest in the green fruits and decreased during their ripening while the ammonium ion concentration increased. The lowest content of amino acids was observed in green fruits.

Two week storage at 5-8°C, followed by two days at room temperature caused the reduction of nitrate ions in green and red fruits. Ammonium ion content as well as phenol and soluble sugar level increased in stored fruits, irrespectively of their maturity stage. Ascorbic acid content increased in the stored turning and red pepper fruits as related to its initial concentration. Dry matter content did not change after storage. Biological quality of harvested pepper fruits depended of their maturity stage, however, their response to short-term storage was similar.