Chemical Composition, Antioxidant and Antibacterial Activity of Tunisian Date Palm Seed

The seeds of 11 common dates (phoenix dactylifera L.) cultivars from the coastal oasis of Gabes, and the noble variety Deglet Nour from the oasis of Kebeli were evaluated for their chemical composition. Polyphenol, flavonoid, anthocyanin, antioxidant, and antimicrobial activity was recorded against 5 pathogen bacteria (Escherichia coli, staphylococcus aureus, staphylococcus epidermis, and Salmonella Typhinurium). The sugar content ranged between 1.20 g/100 gMS (Bouhattam) and 3.80 g/100 gMS (Khadhouri). The total phenolic content oscillates between 5.224 g/100 gMS (Baht) and 9.532 g/100 gMS (Khadhouri). Khadhouri also had the highest total flavonoids content (3.82 g/100 gMS). The higher antioxidant activity was found on the Khadhouri cultivar (55.47% of DPPH radical scavenging activity). It has been found that a linear relationship (p< 0.01) exists between total phenolic content and inhibition percentage. Antibacterial avtivities clearly show that all the extracts showed antibacterial activity except Enterococcus feacalis. PCA revealed that the first two principal components (PC1 and PC2) accounted for 54.23% of the total variance within the data set. These two principal components separated the studied cultivars into four different groups. This by- product of date processing industries could be regarded as an excellent source of food ingredients with interesting technological functionality that could also be used in medicinal preparation as an important source of oil.