EFFECT OF DIFFERENT FERTILIZATION TREATMENTS ON THE TOTAL PHENOLIC CONTENT OF PEPPER FRUITS

Abstract

Pepper (Capsicum annuum L.) is a very important agricultural crop in Serbia, and has great economic importance. Pepper fruits are used in the food industry like fresh or processed products and are characterized by excellent culinary and nutritional properties. They are an exceptional source of bioactive substances (carotenoids, ascorbic acid, phenolics, capsaicin) which are considered strong antioxidants, so in addition to application in the food industry, peppers is also used in the pharmaceutical and cosmetic industries. Due to the increased tendency of the use of pepper fruits in human nutrition, researchers aspire to find cultivation technology that will provide both high yield and nutritious fruit with good quality. In this paper six different starter fertilizer (Super Star, Elixir Zorka, Šabac) doses (0, 15, 20, 25, 30, 35 kg/ha) were examined in combination with four treatments of biostimulator (Kelpak, Kelp Products Ltd.) application (without, once, twice and three times) at different stages of plant development on pepper variety Slonovo uvo (Superior, Velika Plana) in open field conditions. Extracts of fresh fruits were prepared with 80% methanol. Total phenolic content (TPC) was determined using the standard spectrophotometric Folin-Ciocalteu method. The obtained results are expressed as mg of ferulic acid equivalents (FAE) per g of fresh weight. TPC was in range from 0.51 to 2.31 mg/g FAE. The obtained preliminary results do not show a clear influence of used fertilizers on the increase of total phenolic content in peper fruits, so it is necessary to continue research in order to find an appropriate model of fertilizers use to improve the pepper fruits quality.