Antioxidative, Antibacterial and Antifungal Activities of Tea Infusions from Berry Leaves, Carob and Doum
 
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Pol. J. Food Nutr. Sci. 2011;61(3):201–209
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ABSTRACT:
This study is carried out to evaluate the chemical composition and physicochemical properties of berry leaves, carob and doum tea infusions and their mixtures. Furthermore, the antioxidant activities of these extracts were investigated by scavenging of 1,1 diphenyl-2-picrylehydrozyl (DPPH) radicals. The proliferation inhibition activities on some types of bacteria and yeast were also measured for evaluating the antimicrobial activity of berry leaves, carob and doum tea infusions and their blends. The results showed that carob was characterized by its high protein content. The highest percentage of fiber was found in doum sample, followed by carob but ash was the highest in berry leaves samples. The levels of most elements were higher in carob sample, when compared with those of berry leaves and doum samples. The highest value of TSS was found in the tea infusions of doum and carob (22.5 Brix), meanwhile, the lowest was observed in the doum tea infusions (10.60 Brix). Acidity of berry leaves, carob and doum tea infusions was higher than that of the berry leaves +doum tea infusions, but lower than that of the berry leaves + carob + doum tea infusions. Total sugars formed the major components in doum and berry leaves + carob tea infusions. Doum and carob tea infusions had significantly higher non-reducing, but lower contents of reducing sugars than the other tested samples. The results indicated that berry leaves + carob + doum tea infusions sample showed higher quality attributes especially color, taste and overall acceptability. The berry leaves and berry leaves + carob tea infusions had a high level of vit. C (11.05 and 10.28 mg/100 g), while it was low in doum tea infusions. Blended samples showed a higher content of total phenol compounds compared to tea infusions of berry leaves, carob and doum. Data indicated that the berry leaves + carob + doum, berry leaves + carob, berry leaves + doum and doum + carob tea infusions samples were good antioxidants with strong DPPH radical-scavenging activity. The results confirmed that the investigated extracts had good antimicrobial activity, especially against bacteria.