In the current study, we examined the effects of boiling cauliflower in a pressure cooker, conventional boiling, conventional heating, and microwave heating on the chemical components, total phenol, flavonoids, antioxidant capacity (DPPH test), phenolic compounds, and mineral contents of cauliflower florets to reveal the differences between these cooking methods. Cauliflower is generally consumed either boiled or cooked in dry heat. In this study, different boiling and dry heat cooking methods were tried to reveal the changes in phytochemical composition and protein and mineral contents of cauliflower florets. Depending on the cooking methods of the cauliflower florets, the total phenolic and flavonoid contents of the cauliflower florets were determined to be between 273.72 (conventional heating) and 731.01 mg GAE/100 g (microwave heating) and 142.02 (conventional heating) and 797.10 mg/100 g (conventional boiling), respectively. The antioxidant capacity results of cauliflowers were found to be between 8.30 (conventional heating) and 33.69 mmol/kg (fresh). Statistically significant differences were detected in the moisture, total phenol, total flavonoid, and antioxidant activity values of cauliflower depending on the cooking techniques applied (p < 0.05). The gallic acid and 3,4-dihydroxybenzoic acid values of fresh and cooked cauliflowers were identified to be between 10.93 (microwave heating) and 194.79 mg/100 g (boiling in pressure cooker) and 17.58 (conventional heating) and 145.80 mg/100 g (boiling in pressure cooker), respectively. In general, the lowest amounts of phenolic compounds were defined in cauliflower samples boiled with a conventional heating system, followed by cauliflower samples cooked with the microwave heating method. Considering the component amounts as a result of cooking, the highest phenolic component amounts were specified in the cauliflower sample cooked by boiling in a pressure cooker. The protein quantities of fresh and cooked cauliflowers were determined to be between 16.11 (fresh) and 19.79% (microwave heating). The K and S contents of fresh cauliflowers and cauliflowers cooked with different blanching methods were specified to be between 19,647.62 (conventional boiling) and 35,130.01 mg/kg (conventional heating) and 3196.54 (boiling in pressure cooker) and 5105.65 mg/kg (microwave heating), respectively. The K, Mg, S, Fe, Cu, Mn, and Zn results of cauliflowers cooked in an oven and microwave were higher than those cooked using the control and boiling methods.

In this study, the role of different roasting temperatures on oil amount, total phenolic contents, total flavonoid quantities, antioxidant capacity, polyphenol, fatty acid and mineral profiles of roasted-carob fruit powders was revealed. The oil and protein amounts of the carob powders were specified to be between 0.40 (90 °C) and 0.85% (control) to 8.40 (120 °C) and 10.27% (control), respectively. Total phenolic and flavonoid quantities of the raw (control—unroasted) and roasted carob powders were defined to be between 781.16 (control) and 903.07 mg GAE/100 g (150 °C) to 663.81 (control) and 1141.90 mg/100 g (150 °C), respectively. In addition, antioxidant activities of the carob powders were measured to be between 9.27 (150 °C) and 10.30 mmoL/kg (control). Gallic acid and 3,4-dihydroxybenzoic acid amounts of the carob powders were specified to be between 45.16 (control) and 120.66 (150 °C) to 7.06 (control) and 20.46 mg/100 g (150 °C), respectively. Palmitic, oleic and linoleic acids were the key fatty acids of carob oils. It is thought that the fatty acid compositions of carob powder oil, which is generally subjected to heat treatment, are negatively affected by high temperatures. Especially, the linoleic and linolenic acid amounts of the oil samples decreased significantly after 90 °C. The highest element was potassium, followed by Ca, P, Mg, S, Fe, Na, Pb, Cu, Zn B and Mn, in descending order.

In this study, the effects of water bath and ultrasonic bath systems on bioactive properties, phenolic components and fatty acid profiles of unroasted and roasted pumpkin seeds were investigated. It is thought that determining the bioactive components, phenolic constituents and fatty acid profiles of unroasted and roasted pumpkin seeds will lead to the establishment of usage norms according to their composition characteristics. Total phenolic quantities of the pumpkin seed extracts obtained by water bath extraction of the seeds were defined to be between 7.58 (control) and 11.55 (25 min) and 10.20 (control) and 17.18 mg GAE/100 g (50 min), respectively. Phenolic content increased by 50% after 50 min of ultrasonic extraction, indicating the efficiency of this method. Also, total flavonoid amounts increased about 55% after 25 min of ultrasonic extraction, indicating the efficiency of this method. It was observed that the catechin contents of unroasted pumpkin seeds obtained in water and ultrasonic baths decreased significantly at the 50th minute of extraction compared to the control. The antioxidant activity values (DPPH) of roasted pumpkin seeds treated in water- and ultrasonic bath systems increased by approximately 10% compared to the control at 50 min of sonication in both systems, respectively. Also, the 3,4-dihydroxybenzoic acid amounts of the extracts obtained by both extraction systems of roasted pumpkin seeds were determined between 9.85 (50 min) and 17.22 mg/100 g (control) and 11.17 (25 min) and 13.74 mg/100 g (50 min), respectively. The linoleic acid amounts of unroasted pumpkin seed oils extracted in water- and ultrasonic baths varied between 52.34 (50 min) and 53.33% (control) to 52.90 (50 min) and 53.04% (control), respectively. The linoleic acid values of the roasted pumpkin seed oils were established to be between 52.30 (50 min) and 52.84 (25 min) and 52.32 (50 min) and 53.46% (25 min), respectively. In general, the phenolic compound amounts of roasted pumpkin seeds were higher than those of unroasted ones. The fatty acid amounts of pumpkin seed oils extracted with an ultrasonic bath were generally slightly higher than those extracted with a water bath. In future studies, changes in the phytochemical and bioactive properties of pumpkin seed oils obtained by applying different roasting techniques and extraction methods will be investigated.

This research revealed the effect of drying processes on the bioactive properties of marjoram leaves. The total carotenoid content in marjoram leaves ranged between 60.96 µg/g (fresh) and 189.78 µg/g (oven-dried), whereas the total flavonoid content ranged between 949.33 mg CE/100 g (control) and 16,958.59 mg CE/100 g (oven-dried). The total phenolic amounts in marjoram leaves were between 259.17 mg GAE/100 g (fresh) and 1264.17 mg GAE/100 g (oven-dried), while the antioxidant activity values were between 45.23% (fresh) and 77.29% (oven-dried). The 1,2-dihydroxybenzene and (+)-catechin amounts in marjoram leaves were between 19.54 (microwave-dried) and 165.26 (oven-dried) to 20.97 (fresh) and 46.99 mg/100 g (oven-dried), respectively. The kaempferol content in the marjoram plant was specified between 11.45 mg/100 g (fresh) and 43.05 mg/100 g (oven-dried). In general, the quantities of phenolic constituents in the marjoram leaves dried in both drying systems increased compared with fresh samples (except 1,2-dihydroxybenzene, p-coumaric acid, and resveratrol in the microwave-dried samples).

In this study, changes in total phenolic content, total flavonoids, tannin content and phenolic constituents, and mineral content of the leaves of five olive varieties (Ayvalık, Gemlik, Sarıulak, Çöpaşı and Delice) collected in Mersin province in Turkey were investigated. Tannin contents of olive leaves extracts were determined to be between 1.73 (Sarıulak) and 5.33% (Çöpaşı). Total phenolic and flavonoid amounts in olive leaves were assayed to be between 2122.02 (Sarıulak) and 2338.69 mgGAE/100 g (Çöpaşı), and between 9010.71 (Sarıulak) and 18,910.71 mg quercetin equivalent/100 g (Çöpaşı), respectively. Also, the antioxidant activities of methanol extracts of the olive leaves were discovered to be between 0.85 mmolTE/kg (Gemlik) and 21.04 mmolTE/kg (Sarıulak). The phenolic components of the olive leaves studied showed differences depending on the variety of olive. Catechin, rutin, and 3,4-dihydroxybenzoic acid were the most abundant phenolics in leaf extracts. Also, “Delice” olive leaves in the wild form generally had more caffeic acid, syringic acid and rutin, compared to the other olive varieties studied. While the olive leaves were determined to be high in macroelements, the microelement contents detected in olive leaves were low. In general, there was a linear connection between the total phenols and antioxidant activities of leaf samples. This connection was also exhibited between the total flavonoid content and antioxidant activities of olive leaves (except for Sarıulak).