Content of health-beneficial compounds and sensory properties of organic apple juice as affected by processing technology

Summary

Quality of cloudy organic apple juice processed by rack-and-frame press (RFP), water press (WP) or belt
press (BP) was evaluated in terms of sensory properties and instrumentally measured colour, content of
ascorbic acid (AsA), total soluble solids (TSS), titratable acidity (TA), polyphenols and total antioxidant
capacity (TAC).
‘Cortland’, ‘Krista’, ‘Krameri tuvi~oun’ and ‘Talvenauding’ apples from Estonia were separately processed
into juice by RFP, WP and BP. Juice was pasteurized at 85 �C. Pressing methods had a significant effect on
juice quality.
RFP-juices had the lowest TAC and content of health-beneficial polyphenols (chlorogenic acid, (�)
epicatechin, (þ)catechin, procyanidin B2). BP-juices had the highest content of these polyphenols, but
had the poorest sensory quality characterized as less sweet, more sour, bitter and astringent compared to
other juices. RFP- and WP-juices had no differences in sweetness, sourness, astringency and bitterness,
but WP-juices had the highest intensity of fresh aroma and -flavour, yellowness and clearness. Compared
to RFP-juices, WP-juices had higher TAC and content of several health beneficial polyphenols, especially
quercetin derivatives. Thus, WP is a good alternative to RFP in order to produce apple juice which would
have higher antioxidant capacity, better appearance and higher aroma intensity.