The objective of this study was to assess the impact of pulsed electric field (PEF) treatment on the extraction of polyphenolics and antioxidant activity from downgraded date palm fruits. The PEF pretreatments (frequency: 30 Hz, time: 50 μs, pulse number: 240, the electric field strengths were found to be 1, 2, and 2.5 kV.cm⁻¹, and methanol (50%) and temperatures (20, 40, 50 °C)) were optimized and applied before extraction to produce an extract of date fruits with a high content of bioactive compounds. The extracts obtained immediately after pretreatments were analyzed for total polyphenolic content, antioxidant activity, and phenolic profiles. The results revealed that the PEF-assisted extracts at 2.5 kV.cm⁻¹ at T₅₀ °C exhibited higher polyphenol content (+27%) and antioxidant activity (+31%) and notably improved phenolic profiles compared to untreated extracts. PEF treatment processing significantly enhanced the bioactive components and antioxidant activities of date fruits over time, regardless of the treatment applied and the extraction’s temperature. Hence, the application of PEF combined with thermal processing can be an appropriate alternative treatment for a better extractability of bioactive compounds from fruit of dates and food byproducts. These biomolecules could be consumed as new food technology, incorporated as food additives, and nutraceuticals products.

Carob (Ceratonia siliqua L.) is a tree crop cultivated extensively in the eastern Mediterranean regions but that has become naturalized in other regions as well. The present study focused on the green synthesis of zinc oxide nanoparticles (ZnONPs) from Carob and their evaluation for antimicrobial activity in bacteria and fungi. The synthesized ZnONPs showed strong antibacterial activity against Staphylococcus aureus ATCC 25 923 (92%). The NPs inhibited the growth of pathogenic yeast strains, including Candida albicans ATCC90028, Candida krusei ATCC6258, and Candida neoformans ATCC14116, by 90%, 91%, and 82%, respectively, compared to the control. Fungal inhibition zones with the ZnONPs were 88.67% and 90%, respectively, larger for Aspergillus flavus 15UA005 and Aspergillus fumigatus ATCC204305, compared to control fungal growth. This study provides novel information relevant for plant-based development of new and potentially antimicrobial ZnONPs based on extracts. In particular, the development and application of phytogenic nanoparticles enhances the biocompatibility of nano-scale materials, thereby allowing to tune effects to prevent adverse outcomes in non-target biological systems.

There have been many challenges for plant science researchers to overcome the difficulties associated with soil, climate and environmental sucessful conditions, in order to improve crops quality, yields and productivity. The present study aimed to provide new insights into alfalfa germplasm in order to improve tolerance to arid conditions, along with high yield potential and forage quality. We compared the effect of harvesting time on forage yield and nutritional quality of eight alfalfa genotypes of different origins (native, selected and introduced). The results showed significant (p<0.05) genetic variability among the genotypes for the agro-morphological traits; dry matter yield, total plant height, number- and length of internodes at different harvesting times. Besides, harvesting at different phenological stages determined the biochemical composition in dry matter, ash, crude proteins, total soluble proteins and sugars and free amino acids. Our results, based on the multivariate cluster analysis and principal component analysis (PCA)-biplot may suggest the genotypes of alfalfa well adapted to stressful environments outside oasis of arid regions. This may bring insights into their use in culture or in breeding programs in attempt to improve adaptability of alfalfa crops to environmental arid conditions.

Pearl millet crop, reputed as one of the most important food sources cultivated in arid and semiarid parts of Africa and Asia, is known to be a source of many bioactive molecules with potential health-promoting properties. In Tunisia, this crop presented historically rich and diversified germplasm, which is being threatened by genetic erosion. The preservation programs of these species have been held for more than 20 years via participatory breeding schemes. A prospection was undertaken to collect pearl millet cultivars preserved in the last two decades from south-eastern Tunisian farmers to estimate their variability and performances. The aim of this study was to assess the profiles of phenolic compounds, antioxidant capacities, mineral composition, and dietary fiber contents of ten pearl millet cultivars in south-eastern Tunisia. The total phenolics and flavonoids in the free fraction ranged from 506.33 to 1287.71µg.g⁻¹ DM ferulic acid equivalent (FAE) and 4.17 to 12.53µg.g⁻¹ DM catechin equivalent (CE), respectively. The highest polyphenolic content from all genotypes was 1134.96µg·g⁻¹ DM (genotype Med.AG1.3). LC-MS analysis of individual phenol compounds allowed the identification of eight phenolic acids in millet grains. The quinic acid, p-coumaric acid, and caffeic acid were predominant phenolic acids, and six flavonoid compounds with cirsiliol and silymarin were the predominant flavonoids. The ranges of mineral contents variation were 693.10 to 1075.40 and 80.75 to 175.40μg·g⁻¹ for Ca and Mg, respectively, and 9.55 to 32.80, 0.75 to 8.60, 1.84 to 12.21, and 3.63 to 11.40μg·g⁻¹ for Na, Zn, Cu, and Fe, respectively. The content of NDF, ADF, and ADL per dry weight varied from 20 to 31, 1 to 4.2, and 0.4 to 2.3, respectively. Overall, considering the variability among the assessed attributes, heatmap analysis showed the association between each of the traits as related to the clustered genotypes.