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Refined sunflower oil has dissimilar shelf life compared to cold-pressed sunflower oil, which increases the use of refined oil, and it is more abundant in the diet. On the other hand, the production of cold-pressed oils does not require chemical processing. Moreover, these oils contain significant amounts of bioactive components with a beneficial health effect. Breeders are trying to create new sunflower hybrids for the production of cold-pressed oil with improved oxidative characteristics. This study aims to examine the rancidity of 24 cold-pressed sunflower oils of new hybrids under accelerated thermal stability test conditions (Rancimat and Schaal oven tests) and to compare the obtained results with refined sunflower oil. According to investigated oxidative parameters, the most similar to refined sunflower oil was the H20 sample with the induction period determined by the Rancimat test of 9.55 ± 0.00 h, compared to 9.49 ± 0.00 h, obtained in refined sunflower oil. The total oxidation value of the H20 sample amounted to 3.26 ± 0.12, while in refined sunflower oil this value was 2.12 ± 1.73.

This study aimed to investigate the effect of press temperature on physicochemical properties, fatty acid, sterol, phenolic composition, in-vitro cytotoxicity assay, and anti-inflammatory activity of pumpkin seed oil. For this aim, the oils obtained at 100 °C (PSO2) and 150 °C (PSO3) press temperature were compared with the cold press oil (PSO1). The application of press temperature at 150 °C caused a significant decrease in the amount of sterol, while the press application at 100 °C did not cause a significant change in the sterol composition. Total phenolic content, antioxidant capacity values, and individual phenolic content of PSO2 and PSO3 samples were significantly lower than those of PSO1. 30 mg/mL of PSO1, PSO2, and PSO3 samples exhibited a cytotoxic effect on the cells with an inhibition ratio of 75%, 48%, and 39%, respectively, indicating that press temperature reduced the cytotoxic effect of pumpkin seed oil. PSO1 showed anti-inflammatory activity ranged from 79% to 59%, while at the same concentrations PSO2 and PSO3 exhibited approximately from 58% to 49%. This study indicated that the bioactive properties of the cold press oil could be negatively affected by higher press temperature.

Cold pressed oils obtained from chia (Salvia hispanica L.), milk thistle (Silybum marianum L.), nigella (Nigella sativa L.), and white and black varieties of poppy (Papaver somniferum L.) seeds were character­ized. The nutritional quality was determined based on the analysis of fatty acids, tocochromanol and phytos­terol contents, as well as antioxidant activity and general physico-chemical properties. Among the oils analyzed the fatty acid composition most beneficial for health was found in chia seed oil, with 65.62% of α-linolenic acid and the n-6:n-3 fatty acid ratio of 1:3.5. Other oils studied were rich sources of linoleic acid (18.35-74.70%). Chia seed oil was also distinguished by high contents of phytosterols, mainly β-sitosterol (2160.17 mg/kg oil). The highest content of tocochromanols was found in milk thistle oil with dominant α-tocopherol (530.2 mg/kg oil). In contrast, the highest antioxidant activity was recorded for nigella oil (10.23 μM Trolox/g), which indi­cated that, in addition to tocopherols, other antioxidants influenced its antioxidant potential. Se caracterizaron aceites prensados en frío obtenidos de semillas de chía (Salvia hispanica L.), cardo mariano (Silybum marianum L.), nigella (Nigella sativa L.) y de variedades blancas y negras de amapola (Papaver somniferum L.). La calidad nutricional se determinó en base al análisis de ácidos grasos, el contenido de tococromanoles y fitosteroles, así como la actividad antioxidante y las propie­dades fisicoquímicas generales. Entre los aceites analizados, la composición de ácidos grasos más beneficiosa para la salud se encontró en el aceite de semilla de chía, con un 65,62% de ácido α-linolénico y una relación de ácido graso n-6:n-3 de 1:3,5. Los demás aceites estudiados fueron ricos en ácido linoleico (18,35-74,70%). El aceite de semilla de chía también se distinguió por el alto contenido de fitosteroles, principalmente β-sitosterol (2160,17 mg/kg de aceite). El mayor contenido de tococromanoles se encontró en el aceite de cardo mariano con α-tocoferol dominante (530,2 mg/kg de aceite). Por el contrario, se registró la mayor actividad antioxidante para el aceite de nigella (10,23 μM Trolox/g), lo que indica que, además del tocoferol, otros antioxidantes influyeron en su potencial antioxidante.

There is a growing interest in cold-pressed oils because they present high contents of bioactive compounds. These oils have the characteristic properties of seeds and are specific products of their regions. The aim of this study was to determine the compositions and contents of fatty acids, phytosterols, squalene, tocols, phenolic acids, carotenoids and phenolic bioactives, and the free radical scavenging as well as antioxidant activities of cold-pressed pumpkin (Cucurbita pepo L.) seed oils. Oil samples from raw pumpkin seeds cultivated in four different central Anatolia regions of Turkey were prepared using a laboratory screw-pressing machine. The results indicate that cold-pressed pumpkin seed oils (PSO) have excellent quality with high contents of polyunsaturated fatty acids (%ΣPUFAs) (53.60 ±0.06-53.73 ±0.05), total phytosterols (782.1±9.7–805.2 ±11.3 mg/100 g oil), squalene (591.3±10.6–632.5±11.4 mg/100 g oil), tocols (97.79 ±0.76?94.29 ±0.34 mg/100 g oil), phenolic acids (22.73 ±0.41–23.98 ±0.46 mg/100 g oil), carotenoids (6.95 ±0.03–7.60 ±0.03 mg/100 g oil), total phenolics (3.96 ±0.13 –5.82±0.15 mg GAE/100 g), free radical-scavenging activity (5.70 ±0.13?7.35 ±0.15 mg GAE/100 g) and total antioxidant activity (26.67±0.97-38.89±1.41 mg GAE/100 g) values. Thus, this study demonstrates that the cold- pressed PSOs from the central Anatolia regions of Turkey are an excellent source of natural bioactive compounds, free of chemical contaminants and nutritious. Existe un interés creciente en los aceites prensados en frío, ya que presentan altos contenidos de compuestos bioactivos. Estos aceites tienen las propiedades características de las semillas y son productos específicos de las regiones. El objetivo de este estudio fue determinar las composiciones y contenidos de ácidos grasos, fitoesteroles, escualeno, tocoles, ácidos fenólicos, carotenoides y bioactivos fenólicos, la actividad de eliminación de radicales libres, así como las actividades antioxidantes de aceites de semillas de calabaza prensados en frío (Cucurbita pepo L.). Las muestras de aceite de semillas de calabaza cultivadas en cuatro regiones diferentes de Anatolia central de Turquía se prepararon utilizando una máquina de laboratorio de prensado mediante tornillo. Los resultados indican que los aceites de semilla de calabaza prensados en frío (PSO) tienen una excelente calidad, con altos contenidos de ácidos grasos poliinsaturados (%ΣPUFA) (53,60±0,06–53,73±0,05), fitoesteroles totales (782,1±9,7–805,2±11,3 mg/100 g de aceite), escualeno (591,3 ± 10,6–632,5 ± 11,4 mg/100 g de aceite), tocols (97,79±0,76–94,29±0,34 mg/100 g de aceite), ácidos fenólicos (22,73 ± 0,41–23,98 ± 0.46 mg/100 g de aceite), carotenoides (6,95 ± 0,03–7,60 ± 0,03 mg/100 g de aceite), fenólico total (3,96 ± 0,13–5,82 ± 0,15 mg GAE / 100 g), actividad de eliminación de radicales libres (5,70 ± 0,13–7,35 ± 0,15 mg GAE/100 g) y la actividad antioxidante total (26,67±0,97–38,89 ± 1,41 mg GAE/100 g) valores. Por lo tanto, el estudio demuestra que los PSO prensados en frío de las regiones centrales de Anatolia de Turquía son una excelente fuente de compuestos bioactivos naturales, químicamente libres de contaminantes y nutritivos.