Free and bound aroma (precursors) compounds of the Muscat of Alexandria wines and the effect of skin contact (7 h, at 15 °C) on aroma composition have been investigated. The aroma compounds, extracted with the pentan-dichloromethane (2:1) method and Amberlite XAD-2 resin, were analysed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). A total of 41 free volatile compounds (12 esters, 8 acids, 7 terpenes, 5 alcohols, 4 phenols, 3 C-6 compounds, 2 carbonyl compounds) and 28 bound compounds (10 terpenes, 2 alcohols, 2 C-6 compounds, 5 fatty acids, 6 phenols, 2 C-13 norisoprenoids, 1 carbonyl compound) were identified in Muscat of Alexandria wines. Skin contact treatment increased the total free and bound aroma compound levels, and improved the wine quality by affecting the intensity as well as the quality of aroma.
This study was conducted to develop a low cost method to preserve papaya (Carica papaya L.) pulp at ambient temperature with a combination of treatments including acid, heat, and cinnamon oil. Papaya pulp processed without and with 200 ppm cinnamon essential oil at pH 5.1, 81 °C, 7 min (ST2 and ST3); pH 3.9, 69 °C, 13 min (ST4 and ST5); and pH 4.5, 75 °C, 15 min (ST6 and ST7) was stored for 8 weeks at ambient temperature (28±2 °C). The cinnamaldehyde content of the papaya pulp treated with cinnamon oil decreased significantly during storage. ST5 and ST7 retained significantly higher β-carotene contents and lightness values compared to ST4 and ST6 during storage. The results indicated that acidification of papaya pulp to pH 4.5 and pasteurization at 75 °C for 15 min with 200 ppm cinnamon oil can be applied to obtain safe and high quality product, which is stable for 8 weeks at ambient temperature.