Influence of Ca²⁺, K⁺ and NO₃⁻ fertilisation on nutritional quality of pepper

A study was conducted in order to assess the effect of different fertilisation levels of Ca 2+ , K + and NO 3 − on the bioactive nutrient content in red pepper ( Capsicum annuum L) fruits. The experiment was carried out in a greenhouse, under hydroponic culture. Lycopene, β‐carotene, vitamin C, total phenolic compound, sugar, nitrate and potassium contents and antioxidant activity were determined. Increasing Ca 2+ and NO 3 − concentrations in the root medium increased the lycopene and β‐carotene contents in pepper. Antioxidant activity was determined in the hydrophilic (HAA) and lipophilic (LAA) fractions. HAA was increased by intermediate and high Ca 2+ concentrations in the culture medium. However, LAA was raised only by NO 3 − treatments. Vitamin C, sugar and total phenolic acid contents were not affected by Ca 2+ or NO 3 − treatments. K + treatments had no effect on nutritional quality of pepper. An increased supply of Ca 2+ and NO 3 − in the culture medium could constitute a useful practice for improving the nutritional attributes of pepper as well as its commercial quality.