Studies on chemical and sensory parameters of coconut oil and its olein blends with sesame oil and palmolein during wheat flour-based product frying

Iodine values, peroxide values and acid values of Bohai algae oil compared with other oils during the cooking

Objective

Bohai algae oil contains polyunsaturated fatty acids, such as EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), which are the very important polyunsaturated fatty acids for the human body. In Traditional Chinese Cooking, all cooking methods cannot do without oils. However, the heat of cooking may always lead to formation of large amounts of decomposition products that affect the sensory, nutritional and functional quality of the oils to be unhealthy and the products being cooked, especially the food or edible oil rich in polyunsaturated fatty acids. Therefore, the objective of this study was to research the effect and change of heating on the quality characteristics of Bohai algae oil comparison with soybean oil and olive oil.

Method

Quality characteristics such as the iodine values (IVs), peroxide values (POVs) and acid values (AVs) of Bohai algae oil, soybean oil and olive oil were measured, cooking conditions as factors of the study.

Result

The POVs percentage changes of Bohai algae oil were larger than the IVs and AVs percentage changes. Bohai algae oil was better heated in a microwave oven at microwave P-20 within 3min, microwave P-60 and P-H1 within 2min, or in induction cooker at 1500w within 1min, or on electric stove (direct heated) within 2min.

Conclusion

Bohai algae oil was suitable used for low-temperature and short-time cooking or for salad. This study has important significance for promoting the commercial value and extensive application of Bohai algae oil in daily cooking. It plays a theoretical significance role in Bohai algae oil's better processing and traditional chinese cooking. It can improve product quality to further expand the food processing research scope of Bohai algae oil and increase the richness, diversity and universality of edible methods of Bohai algae oil.

Fortified Cold-Pressed Oils: The Effect on Sensory Quality and Functional Properties

The aim of this study was to monitor sensory quality, stability, selected nutritionally interesting properties and their changes in cold-pressed oil blends after fortification with chia and sesame seeds and seed oils during repeated thermal treatments. Rapeseed (cv. Sidney) and sunflower (cv. Velox) seeds from the Czech Republic were used to produce cold-pressed oils, which were fortified with chia and sesame seeds and seed oils in the concentrations of 1% and 5%. In all oil blends, sensory evaluation (quantitative descriptive analysis and hedonic analysis) and chemical analyses (oxidation degree, hydrolytic stability, chlorophyll and carotenoid content) were carried out in order to perform separation of samples degraded by thermal treatment. Assessors representing consumers were able to differentiate between individual thermal treatments from the viewpoint of pleasantness. Interestingly, the overall pleasantness of all fortified oil samples was still acceptable until the second thermal treatment. On the other hand, the results of the study emphasized the problematic oxidation degree of cold-pressed oil blends. The fortification of cold-pressed oils with chia and sesame seeds and oils did not unambiguously lead to better stability during thermal treatment. The application of elevated temperatures during the culinary use of these types of products should be limited to only one thermal treatment since sensory and chemical changes occur after repeated heating.

Thermal degradation of groundnut oil during continuous and intermittent frying

The quality of refined groundnut oil, as affected by frying Poori, was assessed with respect to two types of frying operations viz., continuous frying and intermittent frying. Continuous frying was carried out consistently for 8 h, whereas intermittent frying was performed for 2 h everyday for 4 days for a total of 8 frying hours. The purpose of the study was to compare the level of deterioration that occurred during the two operations. Among the parameters studied, peroxide value (11.3 ± 0.26 meqO2/kg), anisidine value (172.4 ± 2.71), diene value (1.57 ± 0.095), oxidized fatty acid (2.6 ± 0.17%) and viscosity (103.8 ± 2.5 mPa s(-1)), were found to be higher after 8 h due to intermittent frying. The corresponding values 4.9 ± 0.15, 133.3 ± 0.49, 0.811 ± 0.04, 0.38 ± 0.023 and 81.8 ± 2.02 were observed in continuous frying. Parameters such as iodine value, unsaturated fatty acids, saponification value and smoke point decreased significantly (P < 0.5) due to intermittent frying. Results showed that intermittent frying caused more quality degradation to GNO than continuous frying.

Fatty acids profile and alteration of lemon seeds extract (Citrus limon) added to soybean oil under thermoxidation

This paper aimed at evaluating fatty acids profile and the total alteration of lemon seeds extract added to soybean oil under thermoxidation, verifying the isolated and synergistic effect of these antioxidants. Therefore, Control treatments, LSE (2,400 mg/kg Lemon Seeds Extract), TBHQ (mg/kg), Mixture 1 (LSE + 50 mg/kg TBHQ) and Mixture 2 (LSE + 25 mg/kg TBHQ) were subjected to 180°C for 20 h. Samples were taken at 0, 5, 10, 15 and 20 h intervals and analyzed as for fatty acid profile and total polar compounds. Results were subjected to variance analyses and Tukey tests at a 5% significance level. An increase in the percentage of saturated fatty acids and mono-unsaturated, and decrease in polyunsaturated fatty acids was observed, regardless of the treatments studied. For total polar compounds, it was verified that Mixtures 1 and 2 presented values lower than 25% with 20 h of heating, not surpassing the limits established in many countries for disposal of oils and fats under high temperatures, thus proving the synergistic effect of antioxidants.