Black fruits, especially blackberries and black currants, are highly appreciated by consumers due to their nutraceutical properties, which have reported health benefits. This study aimed to assess the fruit quality of the blackberry (cv. ‘Čačanska Bestrna’) and black currant (cv. ‘Čačanska Crna’) created at the Fruit Research Institute, Čačak (Republic of Serbia) by evaluating basic quality parameters (fruit weight, soluble solids), and content of primary (sugars and organic acids) and secondary (phenolic compounds) metabolites. Additionally, the study examined the quality of frozen and long-term frozen storage (6, 9, and 12 months). The results showed that ‘Čačanska Crna’ contained a high level of total soluble solids (15.23°Bx), sugars (93.06 mg g⁻¹), and a high index of sweetness (159.48) as well as a high content of acids (34.35 mg g⁻¹) in the fruit. Both species were found to contain forty-seven phenolic compounds, including phenolic acids, flavanols, and anthocyanins, analyzed using high performance liquid chromatography-mass spectrometry (HPLC-MS). ‘Čačanska Bestrna’ had the highest amounts of phenolic acids (66.85 mg 100 g⁻¹) and flavanols (53.99 mg 100 g⁻¹), whereas ‘Čačanska Crna’ showed the highest levels of flavonols (8.57 mg 100 g⁻¹) and anthocyanins (139.11 mg 100 g⁻¹). Furthermore, the study revealed that anthocyanins were the most abundant phenolic group in both blackberries and black currants, and their levels remained constant during frozen storage. The sugar content in both species remained unchanged, while the acid concentration increased over time in blackberries but remained consistent in black currants. Overall, the findings highlight the superior phenolic content, particularly anthocyanins, of the cultivars with black fruits selected in Serbia. These cultivars have great commercial potential for the fresh market and processing. Moreover, the study suggests that frozen storage is an effective method for preserving their quality and beneficial properties.

The main objective of this study was to investigate and compare the effects of fertilizer types on the counts of soil microorganisms, the mineral leaf composition, and productivity of three strawberry cultivars in the period 2012–2013. Two types of fertilizers were applied—mineral and microbiological. Significantly higher number of Azotobacter, ammonifiers, oligonitrophils, and total microbial count were observed under biofertilizers treatment. Significantly higher counts of fungi and actinomycetes were obtained under mineral fertilizer treatment, compared to other fertilizer treatments. The use of mineral fertilizer led to the most favorable balance of macronutrients and micronutrients in the leaf. In 2012, the generative potential and yield increased after mineral fertilization, whereas in 2013 these parameters were positively affected by mineral fertilizer and Biofertilizer 1. Given the obtained results, in order to improve technology of strawberry production, a partial substitution of mineral fertilizers by microbiological ones can be recommended.

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.