In this study, seeds from the safflower variety called ''Dinçer'' were roasted and microwaved before oil extraction by cold pressing. Some physico-chemical analyses (moisture, ash, oil content and color) were performed in safflower meals. Physico-chemical properties (refractive index, viscosity, turbidity, specific gravity, color, free acidity, peroxide value, iodine number), nutritional components (total phenolics, antioxidant capacity, tocopherol content), sterol composition and fatty acid composition of produced oils were also determined. Volatile components of the oils were detected by solid-phase microextraction/ gas chromatography-mass spectrometry technique. Quantitative descriptive analysis was accomplished with trained panelists by 11 definition terms. Cold pressing yielded less oil than solvent extraction, but oil quality was superior and a refining process was not required. There was no significant difference between samples for fatty acid composition and some physico-chemical parameters. Whereas, microwave treatment caused a decrease in oil turbidity, free acidity, a-tocopherol and some sterol contents and an enhancement in total phenolic content, antioxidant capacity and peroxide value. Moreover, microwave treatment led to an increased nutty aroma in the oil. In contrast, isot pepper aroma was decreased by microwave treatment. This study provides very important information about the safflower oils for the first time in the literature.

In this study, roasted and unroasted (control) tomato seeds were cold pressed and the seeds, oils, and seed presscakes (meals) were analyzed. Some physicochemical properties, total phenolic content and antioxidant capacity, thermal properties, mineral contents, fatty acids, sterols and tocopherols compositions, volatile compounds and sensory evaluation of the tomato seed oils were determined. The tomato seeds contained 3.3 % of ash, 17.3 % of oil and 27.2 % of protein. The cold press oil recovery rate was 7.2 and 10.28 % for control and roasted seeds, respectively. There were eight sensory terms defining the oils together with 34 different aromatic compounds quantified. The volatile compounds furfural, hexanal, benzaldehyde and 2‐isobutylthiazole were found with the highest frequency in the samples. Roasted, green and tomato were defined as characteristic sensory terms for tomato seeds oils. Fifteen different minerals, melting and crystallization temperatures and enthalpies of the oil samples were also quantified. This study provides important data for the tomato seed oils, and proves that pre‐roasted tomato seed oils are high quality, nutritious and aromatics oils with higher levels of consumer acceptability.

In this study, cold press‐produced capia pepperseed oil samples were characterized. Pre‐roasting and enzyme treatment against control group (no pre‐treatment) were applied to the seeds prior to cold pressing, and the oil yield, meal, and oil quality parameters were examined. The physico‐chemical parameters (refractive index, viscosity, turbidity, specific gravity, color, free acidity, peroxide and iodine values, antioxidant capacity, total phenolic content, and energy value), components composition (fatty acid, sterol, and tocopherol), thermal parameters (melting and crystallization temperatures and enthalpies), volatile aromatics composition, sensory properties (Flavor Profile Analysis), and consumer perception (hedonic test) of the oil samples were accomplished. It was found that cold pressing is low in efficiency, and oil sensory quality and consumer acceptability levels were also low. Although pre‐roasted seeds yielded a little more oil and had better sensory quality, it was determined that these oils need at least a deodorization or a physical refining for acceptable sensory quality. Practical applications: The results of this study indicated that capia pepperseeds obtained as waste during vegetable processing can be used as an alternative source for cold pressed oils and a raw material for animal feed. Moreover, these seed oils have economical impact due to their essential fatty acid (linoleic acid, 71.13%), sterol, and tocopherol content. Based on the sensory findings, full or partial refining is recommended in order to increase the sensory quality of the pepperseed oil. The capia pepperseeds pretreated by roasting and enzyme applications were extracted by a cold‐pressing technique. It was shown that both treatments caused a decrease in antioxidant capacity, total phenol content, viscosity, and turbidity but an increase in oil yield and iodine number of the oils.

In this study, the natural green tea extract, purified lycopene, purified resveratrol and purified γ-oryzanol were added into peanut oil and their antioxidant performances were evaluated during frying. Moreover, the sensory properties of fried dough were evaluated to determine the consumption feasibility. All natural antioxidants led to significant increase in the stability of the oil samples. The ranges of measurements in the treatment groups were as follows: free acidity 0.1-2.9 g of oleic acid per 100 g of oil, conjugated dienes 0.01-0.40 g per 100 g of oil, total polar material 8.8-73.8 g per 100 g of oil, total phenolics 0.1-4.2 mg of gallic acid equivalents per 100 g of oil, and antioxidant capacity 0.5-11.0 mM of Trolox equivalents per 100 g of oil. The fatty acid and sterol compositions indicated that antioxidant supplementation could slow the oxidative degradation of unsaturated fatty acids and reduce acid formation. Frying oil enriched with purified γ-oryzanol had higher sterol levels than the other enriched oil samples. The obtained quality of oil protection was in descending order: purified γ-oryzanol, green tea extract and purified lycopene.

The aim of this research was to evaluate the efficacy of extracts prepared from olive leaf (OLVL), hazelnut leaf (HAZL), and hazelnut green leafy cover (HGLC) in frying conditions. The extracts were added into canola oil at 200 ppm phenolic equivalence level and fried for seven consecutive days and analyzed. Generally, the lowest phenolic content and antioxidant capacity value were measured in HGLC extract, although, the best performance during frying was with HGLC extract. There were significant differences among the free acidity, conjugated dienoic acids, and total polar materials (TPM). The oil enriched with HGLC extract did not exceed the limit TPM value at the end of seventh day. Also the remaining antioxidant capacities in the frying oil samples were highest in HGLC enriched samples. The viscosity and turbidity values of the oils enriched with OLVL and HAZL extract were a little higher than a control sample. Generally trans‐fatty acid formation was lower in the enriched oil samples. Also significant decreases in the level of unsaturated fatty acids during frying period were observed. This study shows that enriching oils with easily found and cheap natural plant extracts can extend their usage life.Practical applications: The results of this study have shown that liquid frying oils can successfully be enriched with plant phenolic extract to enhance thermo‐oxidative stability. Addition of phenolic extract up to 200 ppm level have not created any problem in sensory quality of either the oil or fried dough. The HGLC and OLVL extract were found very suitable for this purpose. These materials are common agro‐food by‐products and can be produced very easily with low cost. Also, this type of enrichment may aid consumers to get some beneficial phenolic compounds through fried food consumption. In addition, these types of applications may open another area for marketing the named plant extracts.