In order to preserve the quality of apple fruit, it is crucial to choose the most suitable storage technology. Nevertheless, it is also important to maintain the quality of apples during the shelf life period. In this study, changes in various biochemical quality parameters of ‘Golden Delicious’ and ‘Idared’ apples during a prolonged shelf life period, after conventional normal atmosphere (NA) and ultra-low oxygen (ULO) storage, were investigated. After the harvest, the fruit of examined cultivars were stored in two atmospheres for six months. Weight loss, changes in content of sugars, organic acids, total phenols, total flavonoids, pectic fractions, and antioxidant capacity were monitored. Samples were evaluated immediately after removal from the cold chambers and after 10 and 20 days of shelf life at 20 °C. ‘Golden Delicious’ apples stored in ULO exhibited better qualitative characteristics during 20 days of shelf life compared with apples of the same cultivar stored in NA. However, evaluated traits in ‘Idared’ apples from NA chambers were of higher quality in comparison with ‘Idared’ apples stored in the ULO atmosphere.
Because of the rising occurrence of extremely hot summers linked to climate change, there is a mass appearance of heat-damaged fruits of ‘Čačanska Lepotica’, which are unsuitable for fresh consumption and processing into products in which the fruits’ appearance is a critical quality attribute. To address this issue, the aim of the study was to examine the possibility of producing plum spirits from such fruits as one of the potential ways to utilize them. Heat-damaged fruits were processed in nine different ways, including a traditional one. All produced plum spirits met legal requirements. GC-MS analysis of 39 volatile compounds revealed that the plum spirits made from heat-damaged fruits had different aromatic profiles depending on the processing method applied. However, the plum spirit produced in the traditional way had various sensory defects; the most notable were a lack of freshness and a distinctly unpleasant ‘cooked plum’ aroma. Modifications to the production method led to an improvement in the sensory characteristics of the plum spirits. The obtained results indicate that modifications in small distilleries should include fruit crushing, stone removal and usage of baker’s yeast. In large distilleries, though, the best sensory characteristics for plum spirits made from heat-damaged fruits could be obtained using a production method that includes fruit pulping with stone removal and spontaneous alcoholic fermentation, with one additional step: lowering the pH of the mash before alcoholic fermentation to 3.0.