Research on the evaluation of myrtle fruit (Myrtus communis L.)

Myrtle, Myrtus communis L., as a member of Myrtaceae family, is a perennial plant with black and white fruits, and grown intensely at the Mediterranean region of Turkey. In this study; in order to evaluate black myrtle fruits, the suitability of fruits on concentrate and marmalades production was researched and suitable processing parameters were determined. Fruits were mixed with water at different ratios and the mashes were heated at various temperature and times. Extract which were used to concentrate production and pulp which were used to marmalade production were obtained after mash heating. Considering the yield and soluble solids; additional to 1:1 fruit:water mixing ratio, 75°C for 45 minutes and 85°C for 15 minutes mash heating parameters were selected for extract and pulp production respectively. Concentrate with 68-70°Bx and marmalades with 58-60°Bx were produced by evaporating extract and pulp:sugar mix both under vacuum and normal atmospheric conditions. The highest changes on physical and chemical properties of extract and pulp were seen at the mash heating step. The total phenolic content, which was 1970,55 mg GAE/100 g for the fruit, was reduced to 323,06 mg GAE/100 g at the extract obtained from 1:1 fruit:water mix and increased to 823,90 mg GAE/100 g at the mash heated extract. Similarly total anthocyanin content was changed as 164,54, 10,07 and 94,88 mg MAL3Glu/kg respectively for the sample written above. The phenolic compounds were changed similarly with mash heating and quercetin-3-glucoside, as the main phenolics, was changed between 915,8 and 4342,4 mg/kg and myricetin-3-rhamnoside was changed from 391,12 to 2063,4 mg/kg. Pulps were affected with mash heating as in extracts and the total phenolic and anthocyanin contents of pulps were changed as 424,10-869,07 mg GAE/100g and 50,07-100,89 Mal3Glu/kg respectively. Enzymatic fermentation was also used in concentrate production after mash heating but no significant changes were determined between mash heated and enzyme treated samples. Concentrates were produced under vacuum and normal atmospheric conditions and there were quite quality losses at the samples which produced at normal atmospheric conditions. Total phenolic contents of concentrate, produced under vacuum, were changed between 2064,75-2403,10 mg GAE/100 while it was determined as 1767,86 mg GAE/100 g for sample produced at the normal atmospheric conditions. Similarly total anthocyanin content of concentrate were changed between 139,22 and 202,89 mg Mal3Glu/kg vacuum produced samples it was enormously reduced to 21,45 mg Mal3Glu/kg at the samples produced normal atmospheric conditions. While the sugar compositions of concentrates were found as insignificant, organic acid concentrations were increased at the samples produced normal atmospheric conditions. Although the phenolic compounds changed irregularly among vacuum produced concentrates, they were decreased similar to total phenolic content for the samples produced at normal atmospheric conditions. The production of marmalades were carried out at three different pulp:sugar content as 45:55, 55:55 and 65:35 and concentrated to 58-60°Bx under vacuum and at the normal atmospheric conditions. Total phenolic and anthocyanin contents, antioxidant activity and phenolic compounds were increased steadily with increasing pulp ratio at the marmalades. Additionally these components were higher at the marmalades produced under vacuum than normal atmospheric conditions. The highest point of consumers were given to marmalade produced under vacuum with 55:45 pulp:sugar ratio at the sensory analysis. As a result black myrtle fruits, with rich phenolic compounds and anthocyanins contents, were suitable to produce concentrate and marmalade productions and products were appreciated by consumers.