Changes in the f j i n g medium (rapeseed oil) during controlled deep-frying of slicedpotatoes and codfillets and oil heated without them were compared. Fifteen f j i n g cycles were conducted each day for five days. Results showed that oil after f j i n g of cod fillets contained 10% less triacylglycerol (TAG) polymers and 40% less TAG dimers than other oils. Other parameters (iodine and anisidine values and absolption value at 233nm) showed that less thennooxidative products formed duringfjling of food rich in proteins. Oil after f j i n g of cod fillets was darker and its acid value was significantly higher than that for other oils. Content of TAG polymers and dimers for oil afterfjling of slicedpotatoes and oil heated without food was equal. The relative loss of C18:2 acid and decrease in iodine value showed that oil after heating without food underwent more intensive thermooxidative transformation than other oils.

The aim of the present study was to compare different rape varieties. For this purpose oil from six different varieties of rapeseeds was cold pressed under laboratory conditions. In the obtained rapeseed oils the fatty acids composition and minor components, characteristic values (acid value; AV and TOTOX), oxidative stability (DSC test), and volatiles were determined and a sensory evaluation was carried out. The highest oxidative stability was found for oil from sample 5 (IP ¼ 158 min), which also has the lowest amount of C18:3 (7.8%), chlorophylls (0.083 mg/kg), and metals (Cu 2þ 0.02 mg/kg and Fe 2þ 0.08 mg/kg). This oil has also the lowest AV (0.17 mg KOH/g), which may be related to the lowest moisture content of the seeds prior to extraction. It was characterized by the highest rapeseed flavor intensity. The lowest induction period was observed for samples 3 and 6 (100 min). Although sample 3 had the same low level of metals as sample 5 and the highest concentration of tocopherols (635 mg/kg), PUFA (33.9%), and AV (1.37 mg KOH/g) it also had the lowest intensity of rapeseed flavor among the analyzed oils. Sample 6, despite its low percentage of PUFA (24.7%), conjugated diens and triens, and the lowest content of total volatiles (0.4Vs), had the highest concentration of metals (Cu 2þ 0.04 mg/kg and Fe 2þ 0.34 mg/kg).

The content and composition of lipids in different byproducts (skins, heads, and backbones) from mechanically processed farmed Atlantic salmon were determined and compared with that obtained from wild salmon. Three different procedures were used to establish the optimal conditions of oil extraction (at high temperature −95°C, “cold” extraction at temperature not exceeding 15°C and enzyme assisted with Alcalase). “Cold” extraction at temperature not exceeding 15°C was very efficient, yielding almost 95% of the oil from skins. In the case of heads the obtained yield of about 71% was not lower than that from extraction performed at 95 °C or extraction supported by enzyme treatment. The peroxide value of oil isolated from the heads using “cold” extraction was at the same level as in oil of the enzyme assisted process, but four times lower than in oil extracted at high temperature. The results showed that the content of lipids from in the farmed salmon byproducts the content of lipids was about 45–55% higher than in byproducts of wild salmon, however the EPA + DHA content was 10–33% lower. Practical applications: With “cold” extraction heating which is commonly used for oil recovery in the fish industry could be eliminated and thus the cost of the process would be lower and oxidative changes in the oil reduced. Furthermore, this method based on rules of “green chemistry” can be more attractive and alternative procedure of oil isolation from fatty fish byproducts than those using organic solvents. The fatty fish byproducts such as heads, skins, and backbones may be used as a source of valuable oils rich in PUFA. The remaining material after oil isolation can be a source of collagen and gelatin used in the food, pharmaceutical, and cosmetic industries and finally of minerals preparation (in the case of heads and backbones) used for enriching animal feed. The oil was extracted from salmon byproducts: heads, backbones, and skins by using different methods. Conventional extraction of the oil at high temperatures ensures high yield but leads to low quality of the product. Enzymatic extraction is more preserving to oils rich in polyunsaturated fatty acids, but has special requirements. An attractive solution can be the “cold” extraction. This procedure allows achieving the oil from fatty fish byproducts with high yield and quality in a simple and cheap way.

Low‐calorie structured lipids (SL) containing behenic and oleic acids were prepared using interesterification of olive oil with hydrogenated high erucic acid rapeseed oil and acidolysis of olive oil with behenic acid. The reactions were catalyzed by the Lipozyme RM IM enzyme. Triacylglycerols (TAGs), obtained by interesterification (TAG SLHE ), contained 20.9 and 45.3% of behenic and oleic acids, respectively, whereas those obtained by acidolysis (TAG SLB ) contained 34.6 and 49.6% of these acids, respectively. In both cases, behenic acid was mainly incorporated in the sn‐1,3 positions of the TAG molecules (∼93%). The distribution of oleic acid in the individual positions was different for each product. The content of oleic acid in the sn‐2 position of TAG was 50.2 and 80.3% for TAGSLHEand TAGSLB, respectively. The melting temperature of TAGSLHE(45.5%) was higher than that of TAGSLB(37.5%). Because of the suitable solid fat content characteristics of TAGSLBas a function of temperature, it is possible to use TAGSLBin bakery and in confectionery industries for production of margarines and blends, among others.