In this study, the antioxidant activities of juice, peel, and seed parts of pomegranate were investigated by using DPPH scavenging activity, β-carotene bleaching method, reducing power, and metal chelating activity. Sample of pomegranates which are named Punica granatum L. cv. Hicaznar, genotype 19-121, genotype 17-67, and genotype 19-66 obtained from BATEM (West Mediterranean Agricultural Research Institute) in Anlalya. The EC 50 values of DPPH scavenging activities in peel extracts (PE) had 23.4-fold higher than the juice extracts (JE), and the seed extracts (SE) had 2.3-fold higher than JE. The reducing power in peel extracts was found to be 4.7-fold higher than SE and 10.5-fold higher than the JE. The highest metal chelating capacity (37.22%) was determined in peel, while the lowest (7.151%) in seed. Generally, in peel, the total polyphenol, flavonoid, tannin contents, and in juice, the total polyphenol, anthocyanin, tannin contents, and acidity significantly affected to antioxidant activities.

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Antioxidant activity, colour and some nutritional properties of hot air and freeze-dried strawberry tree (Arbutus unedo L.) fruits were investigated. Additionally, the effects of two pre-treatments, namely ethyl oleate and water blanching, were compared in terms of drying characteristics. For determination of antioxidant activities in ethanol extracts, two different analytical methods were used: 1,1-diphenyl-2-picrylhydrazyl scavenging activity and β-carotene bleaching activity. As a result, the ethyl oleate pre-treatment shortened the drying time by hot air method and gave a higher 1,1-diphenyl-2-picrylhydrazyl scavenging activity (82.16 ± 0.34%), total phenolic content (7.62 ± 1.09 µg GAE/g extract), ascorbic acid content (236.93 ± 20.14 mg/100 g), besides hydromethylfurfural was not observed. Freeze-dried fruits exhibited higher ascorbic acid content (368.63 ± 17.16 mg/100 g) than those fresh fruits (231.33 ± 19.51 mg/100 g) and nearly 1,1-diphenyl-2-picrylhydrazyl activity (93.52 ± 0.41 %) to fresh fruits (94.03 ± 1.18%). Colour characteristics, sugar content and mineral contents of fruits were significantly affected by pre-treatments and drying methods (p < 0.05). It is concluded that the drying of strawberry tree fruits should bring a valuable and attractive foodstuff to food industry due to the rich nutritional components, antioxidant activity and colour. Another conclusion from this study is that the freeze-drying is the best drying method to keep the nutritional value, antioxidant activity and sensory properties of fruits.

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Corn poppy (Papaver rhoeas L.) leaf has been extensively used as garniture in salads and drugs in folk medicine. In this study, the possible antioxidant properties of water (WE), ethanol (EE), and acetone (AE) extracts of corn poppy leaves were investigated using different antioxidant tests, including total antioxidant activity in linoleic acid system, DPPH • scavenging activity, reducing power, chelation activity, and hydrogen peroxide scavenging activity. In addition, the amount of total phenolics was also determined. Total antioxidant activities of all extracts were greater than 85% at 400 μg/mL concentration. The scavenging effects of WE and EE on DPPH • radical were found to be 88.46 ± 0.08% and 86.81 ± 0.37% at 800 μg/mL concentration, respectively, which was comparable to standard antioxidants, such as BHA and α-TP. The reducing power of extracts was in the order of WE > EE > AE. The percentage of metal chelating activity of 800 μg/mL concentration of WE was found to be 79.51 ± 4.05%. Our results indicated that the leaves of Papaver rhoeas L. showed the potential to be used as a natural antioxidant.

Lipase was isolated from bay laurel (Laurus nobilis L.) seeds, some biochemical properties were determined. The bay laurel oil was used as the substrate in all experiments. The pH optimum was found to be 8.0 in the presence of this substrate. The temperature optimum was 50°C. The specific activity of the lipase was found to be 296 U mg protein -1 in optimal conditions. The enzyme activity is quite stable in the range of pH 7.0-10. The enzyme was stable for 1 h at its optimum temperature, and retained about 68% of activity at 60°C during this time. K m and V max values were determined as 0.975 g and 1.298 U mg protein -1 , respectively. Also, storage stability and metal effect on lipolytic activity were investigated. Enzyme activity was maintained for 9, 12, and 42 days at room temperature, 4 and -20°C, respectively. Ca 2+ , Co 2+ , Cu 2+ , Fe 2+ , and Mg 2+ lightly enhanced bay laurel lipase activity.

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