Emine Kucuker

Changes of Bioactive Compounds and Ethylene Production of Japanese Plums Treated with Pre-Harvest Aminoethoxyvinylglycine

The effects of pre-harvest aminoethoxyvinylglycine treatments on bioactive compounds, fruit ripening, and quality of plum fruits (Prunus salicina Lindell cvs. “Black Beauty,” “Black Amber,” and “Friar”) were investigated in this research. Whole trees were sprayed once with an aqueous solution containing aminoethoxyvinylglycine (0, 100, and 200 mg L–1) two weeks before the anticipated commercial harvest for each cultivar separately. In all plum cultivars, the results showed that aminoethoxyvinylglycine treatments were effective in reducing ethylene production and respiration rate. The red color development was delayed by aminoethoxyvinylglycine treatments during the ripening. The fruit mass and geometric mean diameter significantly decreased, while loss of flesh firmness was decelerated with aminoethoxyvinylglycine concentrations. Aminoethoxyvinylglycine treatments decelerated loss of flesh firmness. Soluble solid content was reduced, whereas titratable acidity and ripening index increased with aminoethoxyvinylglycine treatments. Aminoethoxyvinylglycine-treated fruits exhibited lower levels of total phenolics, total antioxidant activity, and individual phenolics. This study revealed that pre-harvest aminoethoxyvinylglycine treatments were more effective in delaying plum fruit softening. The main advantage is to maintain the firmness of late-harvested fruit by retaining bioactive compounds of plum fruit.

Effect of Aminoethoxyvinylglycine and Methyl Jasmonate on Individual Phenolics and Post-harvest Fruit Quality of Three Different Japanese Plums (Prunus salicina Lindell)

Abstract In this research, effects of aminoethoxyvinylglycine (AVG) and methyl jasmonate (MeJA) applied 2 weeks ahead of estimated harvest date on fruit color, firmness and individual phenolic compounds of three plum varieties wereinvestigated during the cold storage. Fruits of “BlackAmber”, “Black Beauty” and “Fortune” were kept at 0 ± 0.5°C temperature and 90 ± 5% relative humidity for 4 weeks. During the storage, decreases in L*, chroma and hue angle values were observed. AVG treatments differed significantly (p < 0.05) by control and MeJA treatment. In all plum varieties, AVG treatment resulted in significant increases in flesh firmness at the end of storage. MeJA increased significantly the firmness of “Black Beauty” and “Fortune” fruit at the end of storage. Chlorogenic acid was detected as major phenolic compound in plum varieties. AVG treatment to “Black Amber” fruit increased the contents of chlorogenic and p-coumaric acid during storage, whereas it reduced chlorogenic and p-coumaric acid content in “Fortune” fruit. MeJA treatment led to not only increase the contents of rutin, ferulic acid and naringenin in the fruits of “Black Beauty” and “Fortune” varieties during the storage but also significantly increase the kaempferol content in “Black Amber” and “Black Beauty” fruits. While AVG treatment compared to control significantly decreased the contents of chlorogenic acid, quercetin and naringenin in “Black Amber” fruits at the end of cold storage, it increased content of p-coumaric acid. At the end of storage, AVG and MeJA treatments reduced significantly the content of ferulic acid in “Black Beauty” fruits. In addition, MeJA treatment significantly increased chlorogenic acid, ferulic acid and kaempferol contents in “Fortune” fruits.

YAPRAKTAN ÜRE UYGULAMASININ FARKLI ARMUT (PYRUS COMMUNIS L.) ÇEŞİTLERİNDE VERİM, MEYVE KALİTESİ VE BİOAKTİF BİLEŞİKLER ÜZERİNE ETKİSİ

The effects of foliar urea treatment on yield, fruit quality and bioactive compounds of three different pear cultivars (Akca, Santa Maria and Deveci) were investigated in this study. Whole trees were sprayed twice with an aqueous solution containing urea (0% and 0.1% CH 4 N 2 O) 30 and 60 days after the full bloom for each cultivar separately. The per tree yield, fruit weight and geometric mean diameter were significantly increased with urea treatment according to control. The color characteristics, soluble solids content, pH and titratable acidity didn’t change with the urea treatment. The urea treatment significantly reduced fruit flesh firmness. Urea treatment significantly reduced total phenolic content of Santa Maria. Total antioxidant activity of all varieties significantly reduced with the urea treatment. Urea treatment significantly increased naringenin content of Akca and Santa Maria, and rutin content of Deveci pear. The nitrogen content of the pear varieties was significantly increased with urea treatment. Additionally, urea treatment significantly increased zinc content of Deveci, and potassium, calcium and magnesium content of Santa Maria pear. Keywords: Pear, urea, phenolic, mineral nutrient, yield