Investigation of chemical properties of apple pekmez produced with different methods

In this study, pekmez were produced by two different methods (applying open pan method (AYP) and under vacuum concentration (VYP) ), using Red Delicious Starking Apple which are grown in Isparta. Total dry matters (TKM), soluble solids (SÇKM), pH, titratable acidity (TA), invert sugar, total sugar, protein and hydroxymethyl furfural (HMF), phenolic compounds, mineral matters, aroma compounds and organic acid compositions were determined in fresh apple and both AYP and VYP pekmez samples. Sensorial evaluations of pekmez samples were also determined. In additional to, the pekmez samples were stored at 20±2°C during 4 month and chemical changes were evaluated as statistically.According to results of produced apple pekmez, TKM, SÇKM, pH, ash, TA, invert sugar, total sugar, protein, HMF were found as 71.51 %, 70.76 %, 5.54, 2.41 %, 0.41 %, 53.25 (dry matter; DM), 65.07 % (DM), 3.11 % (DM), 5.48 mg/kg, respectively in AYP and 72.23 %, 71.37 %, 5.65, 2.49 %, 0.42 %, 51.27 % (DM), 77.46 % (DM), 4.06 % (DM), 0 mg/kg, respectively in VYP.In this study, chlorogenic acid, catechine, epicatechine and caffeic acid.were analysed as phenolic compounds. Chlorogenic acid concentration was found as dominant according to other phenolic compounds in AYP and VYP samples. Chlorogenic acid concentration were 257.42 mg/kg (KM) and 302.7 mg/kg (KM), respectively, in AYP and VYP samples. After 4 month storage at room temperature, chlorogenic acid concentration decreased as 5.05 % and 6.62 %, respectively, in AYP and VYP samples.Potassium (K) was found as the dominant mineral matter in AYP and VYP samples. The amount of K were determined as 7913.93 mg/kg (DM) and 7844 mg/kg (DM), respectively, in AYP and VYP samples.2-methyl butanal and 2-propanon were found as the dominant aroma compounds in VYP and AYP, respectively. However, hexanal was dominant in fresh apple. The results shown that aroma compounds in AYP was richer than VYP Oxalic acid was found in apple, however not existed in AYP and VYP. Malic acid was the most dominant acid as compared to other organic acids. This acid were found as 26559.95 mg/kg (KM) and 28047.12 mg/kg (KM) in AYP and VYP, respectively. And these organic acids in AYP and VYP decreased during storage.