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.

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.

Intensive agricultural development based on the long-term and excessive use of chemical nitrogen fertilizers significantly contributes to a series of undesirable effects and results in environmental pollution. In line with the above, there is a pressing need for major changes in agricultural production management. Bearing in mind that fertilization strategy, among other practices, plays an important role in improving the growing technology of different fruit crops, we considered that the above mentioned problems could be overcome by introducing an environmentally safe and innovative practice inplum growing technology as well. Accordingly, a comparative study was conducted to evaluate the effects of biofertilizer (a combination of nitrogen-fixing and phosphorus-mineralizing bacteria including Azotobacter chroococcum, Bacillus megatherium and Bacillus subtilis) and chemical fertilizer (a water-soluble chemical fertilizer supplemented with the microelements B, Cu, Fe, Mn and Zn)on ʻČačanska Lepotica' and 'Stanley' plum cultivars. Morphometric characteristics (fruit weight, length and width), internal quality traits (soluble solids content and firmness) and chemical properties (total phenolic content and total antioxidant activity) of the fruit of the tested plum cultivars were assessed. The obtained results indicate that the substitution of chemical fertilization with biofertilization in 'Čačanska Lepotica' and 'Stanley' is a justified practice. Furthermore, this approach seems to havepotential as an appropriate technique in commercial plum production, which may improve yield-attributing characteristics and the phytochemical content of plum fruits.

Anthracnose disease can be successfully controlled by chemical pesticides in conventional fruit growing. However, in organic farming, in order to maintain environmental safety and fulfill consumer demand for pesticide-free food, the control of this disease is a major problem. The use of biocontrol agents with the antagonistic mechanism of control of many phytopathogens is an innovative alternative for cost-effective and eco-friendly production. The antagonistic activities of Trichoderma viride and Bacillus subtilis were tested in vitro against Colletotrichum acutatum, one of major plant pathogens responsible for anthracnose. The microbial antagonists inhibited mycelial growth in the dual culture. T. viride exhibited strong antagonism against C. acutatum isolates (80%). The B. subtilis isolate also had a strong effect on inhibiting the development of C. acutatum (37.5%). The results of this study identified T. viride and B. subtilis as promising biological control agents for further testing against anthracnose disease in fruits.