Thiol-Ene Coupling of High Oleic Sunflower Oil towards Application in the Modification of Flexible Polyurethane Foams

High oleic sunflower oil-based polyol was obtained by thiol-ene coupling and applied in the preparation of flexible polyurethane foams. The photochemically initiated thiol-ene click reaction was carried out under UV irradiation using 2-mercaptoethanol. Bio-based polyol with hydroxyl value of 201.4 mg KOH/g was used as 30 wt% substituent of petrochemical polyether polyol in the formulations of flexible foams. Both reference foams, as well as foams modified with bio-based polyol, were formulated to have various isocyanate indices (0.85, 0.95, 1.05). Flexible foams were compared in terms of their thermomechanical properties and analyzed using FT-IR and SEM microscopy. Modification with bio-based polyol resulted in foams with superior compression properties, higher support factor, and lower resilience than reference foams. TGA and FT-IR curves confirmed the presence of urethane/urea and ether linkages in the polyurethane matrix. Moreover, double glass transition temperature corresponding to soft and hard segments of polyurethane was observed by DSC proving the phase-separated morphology.

Oil quality characterization of the Arauco variety from the main olive growing areas of Mendoza (Argentina)

‘Arauco’ forms part of the over two thousand olives (Olea europaea L.) varieties identified worldwide with the peculiarity of being the only recognized variety from Argentina. In this work, the fruit and oil characteristics from the ‘Arauco’ variety cultivated in the three main olive growing zones of Mendoza province (Argentina) were evaluated over two harvests (2016 and 2017). The characteristics assessed were oil and water concentrations, pulp/pit ratio, industrial yield, oxidative stability, fatty acid profile, total phenols and total flavonoids, among others. The results showed relatively high oleic acid and phenolic contents, together with low acidity and extinction coefficients (K232 and K270), as well as a well-balanced fatty acid profile. In addition, three interesting relationships among oxidative stability and ratios of monounsaturated fatty acids/polyunsaturated fatty acids (R2=0.96), oleic/linoleic (R2=0.96) and stearic acid (R2=0.93) were observed. These results showed that the ‘Arauco’ variety cultivated in Mendoza provides excellent oil quality.

Effects of Oils and Fats on the Quality Characteristics, Nutritional Value, and Storage Capacity of Cookies

Introduction. The quality profile and nutritional values of cookies depend on the raw material. The research objective was to study the effect of oils and fats on the quality characteristics and storage capacity of cookies. Study objects and methods. The study involved such types of oils and fats as margarine, confectionery fat, milk fat substitute, palm oil, sunflower oil, and high oleic sunflower oil. It was based on standard methods of sensory, physicochemical, structural, and rheological analyses. Results and discussion. The experimental formulations relied on contemporary dilatory recommendations, consumer acceptability, and traditionality of sensory indicators. The mass fraction of fat was limited to ≤ 18%; added sugars – to ≤ 22%; salt – to ≤ 0.3%. For each type of oil and fat, as set of experiments was performed to define the optimal technological emulsion and dough parameters. Other aspects involved the patterns of moisture transfer, indicators of oxidative spoilage, fatty acid composition, sensory properties, physicochemical and microbiological indicators, storage capacity, etc. The samples with vegetable oils instead of fat had a lower content of saturated fatty acids, which fell from 8–9 to 2–3 g/100 g. However, the risk of oxidative spoilage increased significantly. On storage day 104, the content of linoleic acid in the samples with sunflower oil decreased from 62.0 to 60.4%, while the samples with high oleic sunflower oil maintained the same level of linoleic acid. The samples with confectionery fat and palm oil demonstrated the lowest rate of oxidative processes, while those with margarine and milk fat substitute had the best sensory profile after storage. Conclusion. The cookies with sunflower oil and high oleic sunflower oil appeared to have a shelf life of two months, while for those with milk fat substitute, margarine, palm oil, and confectionery fat it was six months. Further research should focus on various emulsifiers and antioxidants capable of forming bonds with proteins and starch fractions of flour, which could increase the resistance of liquid vegetable oils to oxidation.