The effect of organic and conventional fruit cultivation system on mineral composition and sensory properties of cloudy apple juice

Summary

The aim was to determine the differences in mineral composition and sensory properties of cloudy apple juice depending on apple cultivation system. Three indigenous Estonian cultivars were chosen on condition that the same cultivars would be grown in organic and conventional orchards at the same geographical location. ’Krameri tuviõun’ and ’Talvenauding’ apples were harvested from old (over 30 years) low maintenance orchard and ‘Krista’ apples from 10-years old experimental orchard. 100 kg of apples per cultivar and cultivation system were stored at +3±2°C for two months and then pressed into juice using Lancman waterpress. Total soluble solids (TSS), titratable acidity (TA) and content of P, K, Ca and Mg were determined from apples and from juice. Descriptive sensory analysis of apple juice was carried out by a trained sensory panel.
’Krameri tuviõun’ and ’Talvenauding’ apples and respective juices from old organic orchard had significantly higher content of P, K and Mg compared to the conventional counterparts. Mineral composition of ’Krista’ apples from younger well- maintained organic orchard and respective juice was not significantly different from conventional ones except for P concentration, which was higher compared to conventional apples. Organic apples from old orchard had higher TSS compared to conventional ones, but this difference was no more significant in juice. Sensory properties of juices were most of all affected by cultivar: ‘Krameri tuviõun’ juice was sweeter and less sour compared to ‘Talvenauding’ and ‘Krista’. Cultivation system did not affect the sweetness, sourness as well as fresh- and apple flavour.
Our results indicate that even though the old organic apple orchards do not produce high quality apples for fresh consumption, cloudy apple juice made from those apples is better source of valuable mineral elements for humans than apple juice pressed from conventional or well-maintained organic orchards.