American Oil Chemists’ Society (AOCS)’s Official Method Cd 18-90 for p-Anisidine Value (pAV) is commonly used to evaluate secondary oxidation in fish oils. Flavoring agents in fish oil products may interfere with pAV and lead to inaccurate results. The Global Organization for EPA and DHA (GOED) recommends a protocol for calculating pAV of flavored fish oils, based on the assumption that flavors’ contribution to the pAV does not change over the course of oxidation. The objective of this study was to test this assumption. All fourteen flavors evaluated increased the pAV when added to fresh fish oil; chocolate-vanilla and lemon flavors generated the largest increase. Under accelerated oxidation conditions, both chocolate-vanilla and lemon flavors had a similar effect; oxidized flavored fish oils had lower pAV than oxidized fish oils with newly added flavors. This was due to either an antioxidant effect of the flavor or degradation of the flavor during oxidation. Following the GOED recommendation, we would have underestimated the oxidation in the flavored oils. For this reason, pAV of flavored fish oils should be considered with caution and used in combination with other secondary oxidation markers when possible.

The crystallization behavior of mango kernel fat (MKF) at 25 °C with and without the application of high-intensity ultrasound (HIU) (20 kHz, 125 W) was studied as a function of ultrasound amplitude level (30%, 50% and 70% of the maximum amplitude of 180 μm). The irradiation time was fixed at 5 s. It was found that HIU induced MKF crystallization. The crystallization induction time decreased with a decrease in crystal size and an increase in the number of crystals as the HIU amplitude increased. The β′→β transformation was also accelerated with HIU application. This work has shown that there is a great potential for the use of HIU in the food industry to achieve a shorter and more controllable crystallization process. In particular, HIU could be used as an efficient tool for controlling the polymorphic transition of fats.

The goal of the present study is to demonstrate 1H LF-NMR time relaxation measurements for efficient and rapid evaluation of Omega-3 polyunsaturated fatty acids (PUFA)-rich linseed oil (LSO) oxidative aging mechanisms, by monitoring primary chemical and structural changes occurring during thermal oxidative stress. The LF NMR monitors the different proton spin-spin coupling energy relaxation times, T2 within LSO molecular segments, from the initiation of free radical generation and hydroperoxide formation to the propagation of alkoxy radicals, and alpha, beta-unsaturated aldehydes formation, and a termination phase of crosslinked polymerization end products. The 1H LF NMR T2 values monitors both the covalent and secondary bonding interactions (e.g., electrostatic and hydrogen bonding) during the different oxidation phases. The present paper shows that LSO tail segments mobility in terms of T2 multi-exponential relaxation decays, generated by data reconstructing of 1H transversal relaxation components are providing a clear, sharp and informative understanding of LSO sample’s autoxidation aging processes. This is supported by high field band selective 1H NMR pulse excitation for hydroperoxide and aldehydes quantification of the same LSO samples at 25, 40, 60, 80, 100, and 120oC with pumped air for 168 h. Peroxide value, viscosity and self-diffusion, as well as fatty acids profile and by- products determined by GC-MS were also carried out, and correlated with the LSO tail T2 relaxation results. In conclusion the selective determination of LSO alkyl tail T2 energy relaxation time domain values was demonstrated as a rapid evaluation marker for following omega-3 PUFA-rich oils oxidative aging.

Quantitative analyses on the coefficient of friction of common coating waxes are necessary and essential for designing systems for coating, conveying, packaging operations, transporting and storing of papers and paperboards, while analyses on wear behavior can be helpful for predicting performance durability of the coating surface. In this study, we investigated the friction and wear behaviors of six waxes including four commercial waxes and two soybean oil-based wax developed in our lab for bulk coating on cardboard. The effect of normal load, sliding velocity, and environmental temperature was evaluated. The friction coefficient of different waxes varies with sliding conditions. Higher normal load, sliding velocity, and environmental temperature resulted in significantly greater wear loss. Crystalline morphology and crystallinity were affected by environmental temperature, and they correlate to the variations in friction coefficient and wear loss of these materials. Overall, the Estercoat developed in our lab had comparable frictional properties and much less wear than paraffin wax under tested conditions and can be a good substitute for paraffin wax.