Project “Lagerapfel” VN

Extensive and in some cases very complex studies have shown that an extension of the storage time of apples through non-chemical treatment with hot water and/or ultrasound is in principle possible and only results in a slight loss of quality. It was proven that storage damage was minimized by spraying hot water on the apple varieties Elstar, Pinova and Topaz. The proportion of apples damaged by rot after three months of storage was reduced by up to 31%. Water temperatures between 51 – 53 °C with a treatment duration of 120 – 180 s were the most effective. Water temperatures above 55 °C proved to be too high. Effects on the internal quality of the fruit could only be observed to a limited extent. Of the flavorings tested, only 1-hexanol showed a heat-dependent change. The measured 1-hexanol content decreased with increasing temperature and treatment duration. Direct effects of the hot water treatment on quality parameters such as sugar and starch content or pulp firmness were not observed. The ultrasound tests also showed positive effects on the storage stability of the apples. With a treatment time of 300 s, the number of damaged apples decreased by 18%.

Hot water treatment of the apple variety PINOVA on the sorting line, spraying process

VDI/VDE ZIM network promotion out of network DIGIPRO-EW
Funding code: 16KN088401