2014 ASHS Annual Conference
20166:
Changes in Not-from-concentrate 'Wonderful' Pomegranate Juice through Pilot Plant Pressing, Ultrafiltration, and HTST Pasteurization and Storage
Color generally increased after crude pressing upon pasteurization, then a*, b* and C* decreased through 2 months storage at 4 °C. However, L*, b* and hue often increased through storage at 25 °C. Titratable acidity (% citric acid) increased from pasteurization (24.2) through 2 months storage at both 4 and 25 °C to 28.2 and 29.2, respectively. Oxalic acid decreased while malic and citric acids increased through storage at 4 °C. Delphinidin, cyanidin and pelargonidin all increased slightly from crude press through ultrafiltration then all decreased upon pasteurization, and markedly through 2 months storage at both 4 and 25 °C. Total anthocyanidins decreased 55.8% and 95.8% through 2 months storage at 4 and 25 °C, respectively. The following compounds decreased from pasteurization through storage, at both temperatures: 2-methyl-3-buten-2-ol, ethyl acetate, (Z) & (E)-3-hexenol, 1-hexanol, 1,4-cineole, linalool, 4-terpineol and α-terpineol. Yet, β-damascenone and 2,4-dibutylphenol increased, across the board. Ethanol and 1-octanol increased only at 25 °C. Compounds such as β-myrcene, ethyl hexanoate, α-cedrene, β-cedrene and italicene were observed in crude pressed and ultrafiltered juices, and sometimes immediately after pasteurization (day 0) but, were lost through storage. On the other hand, benzaldehyde, hexyl acetate and 2-ethyl-1-hexanol were only observed after 1 month storage. Statistical interpretation and attempts to correlate anthocyanins with quality and volatile compounds is underway.