Blackberry (Rubus fruticosus spp) is a fruit that has a significant antioxidant activity, due to its content in anthocyanins and antioxidant compounds. Emerging technologies are required as the thermoultrasound technique that ensures microbial reduction and release of compounds with antioxidant properties. The objective of this study was to evaluate changes in the antioxidant content and fatty acid profile of blackberry juice when it is subjected to conservation treatment (pasteurization and thermoultrasound). The blackberry juice and the extracted oil of blackberry juice with n-hexane (control, pasteurized and thermoultrasonicated) were evaluated in antioxidant activity, fatty acid profile and antioxidant content. The thermoultrasound juice had the highest (p < 0.05) amount of total phenols (1011 mg GAE/L), anthocyanins (118 mg Cy-3-GlE/L); antioxidant activity by ABTS (44 mg VCEAC/L) and DPPH (2665 µmol TE/L) compared to the control and pasteurized samples, as well as, as well as, oil extract of obtained of the thermoultrasound juice presented high antioxidant activity (177.54 mg VCEAC/L to ABTS and 1802.60 µmol TE/L to DPPH). The fatty acid composition of the oil extract showed the presence of myristic, linolenic, stearic, oleic, and linoleic acid, the fatty acid profile was similar in the different samples with the exception of stearic acid where this was higher in control sample. The thermoultrasound treatment can be an alternative to pasteurization treatments because keeps and releases antioxidant bioavailable compounds, preserving their fatty acids.

Drought is one of the leading abiotic factors limiting morphological and physiological activities in blackberry cultivation. We investigated the effect of silver nanoparticles (AgNPs) on morphological and physiological processes in the boysenberry crop (Rubus ursinus Chamisso &amp; Schlenhtendal) under drought stress. The experiment was performed with three drought stress levels (0% PEG, 4% PEG and 8% PEG) and three AgNPs treatments (0, 0.1, 0.2 mg L−1) invitro conditions. The results showed that drought stress induced by PEG, reduced root and shoot development of boysenberry plants grown invitro. The addition of AgNPs is significantly alleviated the adverse effect of drought stress and increased the plant growth parameters. Antioxidant activity of SOD and CAT enzymes increased in boysenberry leaves when treated with AgNPs under drought conditions, while the amount of MDA decreased. Therefore, the results obtained in this study suggest that 0.1 mg L-1 AgNPs added to the medium improve the growth and development of invitro boysenberry plants under drought stress.

This study aimed to evaluate the effect of convective and microwave drying on the content of bioactive compounds of blackberry (Rubus fruticosus), drying parameters and energy consumption. The fruit was dehydrated in a convective dehydrator at a temperature of 50 °C and 70 °C and a microwave oven at power levels of 90 V, 180 V and 240 V. The highest amount of anthocyanins, polyphenols and antioxidant capacity were obtained in microwave dried blackberry fruits at 90 V and 180 V. It turned out that microwave dehydration shortened the processing time and lower the energy consumption compared to the convective drying. Blackberry fruits dehydrated at 240 V showed the shortest dehydration time, minimal energy consumption and the most efficient diffusion.