Influence of hot water dipping on the fruit quality of organic produced 'Topaz' apples

D.A. Neuwald, D. Kittemann
'Topaz' apples grown on organic orchards in southern Germany have a limited storage life due to the high incidence of fungal rots; primarily Neofabraea spp. (syn. Gloeosporium spp.). Hot water dipping (HWD) after harvest but before longer-term storage, provides an effective control of storage rots and is now widely used on commercial organic orchards. However, there is little published information about the possible influence of HWD on fruit quality changes during storage. This work assesses the fruit quality of 'Topaz' organic apples after HWD and storage. In 2009, fruit were picked at two harvest dates from the organic orchard at the Competence Centre for Fruit Growing (KOB) at Lake Constance. Following harvest, fruit were treated in a commercial HWD system for 2 min at 51°C and then stored at 1°C in either regular air (RA) or controlled atmosphere (CA: 1.0 kPa O2, 2.5 kPa CO2). After 6 months storage, plus 7 days of shelf-life at 20°C, the incidence of fungal rots was reduced in both the RA and CA HWD treatments when compared to untreated controls (no HWD). There were no changes in the quality parameters of fruit firmness (g cm-2), total soluble solids (°Brix) and titratable acidity (g L-1). Fruit firmness under RA storage was lower when compared to CA. No negative effects from the HWD treatment (e.g., heat damage to the peel) were observed. HWD is an effective treatment to reduce the incidence of fungal rots on organic 'Topaz' apples, without having a negative influence on fruit quality.
Neuwald, D.A. and Kittemann, D. (2016). Influence of hot water dipping on the fruit quality of organic produced 'Topaz' apples. Acta Hortic. 1144, 355-358
DOI: 10.17660/ActaHortic.2016.1144.52
Malus domestica, regular air, controlled atmosphere storage, rots, fungal diseases

Acta Horticulturae