Physical blends (PB) of high oleic sunflower oil and tristearin with 20 and 30% stearic acid and their interesterified (IE) products where 20 and 30% of the fatty acids are stearic acid at the sn‐2 position crystallized without and with application of high intensity ultrasound (HIU). IE samples were crystallized at supercooling temperatures (ΔT) of 12, 9, 6, and 3 °C while PB were crystallized at ΔT = 12 °C. HIU induced crystallization in PB samples, but not in the IE ones. Induction in crystallization with HIU was also observed at ΔT = 6 and 3 °C for IE C18:0 20 and 30% and at ΔT = 9 °C only for the 30% samples. Smaller crystals were obtained in all sonicated samples. Melting profiles showed that HIU induced crystallization of low melting triacylglycerols (TAGs) and promoted co‐crystallization of low and high melting TAGs. In general, HIU significantly changed the viscosity, G′, and G″ of the IE 20% samples except at ΔT = 12 °C. While G′ and G″ of IE 30% did not increase significantly, the viscosity increased significantly at ΔT = 9, 6, and 3 °C from 1526 ± 880 to 6818 ± 901 Pa.s at ΔT = 3 °C. The improved physical properties of the sonicated IE can make them good contenders for trans‐fatty acids replacers.

The objective of this study was to induce crystallization in enzymatically interesterified fats (IE) with 20 and 30% palmitic acid at the sn‐2 position using high intensity ultrasound (HIU). The physical blends (PB) used to prepare these two IE were consisted of tripalmitin and high oleic sunflower oil and contained 13.2 and 27.1% tripalmitin, respectively. Crystallization behavior of IE was compared with PB at supercoolings of 9, 6 and 3 °C. Results show that the melting point, SFC, and crystallization rate of PB were higher than IE and were driven mainly by tripalmitin content. HIU induced crystallization and generated small crystals in the IE samples. At 9 °C supercooling, sonication did not increase the viscosity of IE C16:0 20%, while that of the IE C16:0 30% increased significantly from 192.4 ± 118.9 to 3297.7 ± 1368.6 Pa·s. The elastic modulus (G’) for IE C16:0 30% increased from 12521 ± 2739.8 to 75076.7 ± 18259 Pa upon sonication at 9 °C supercooling, while the G’ of the IE C16:0 20% did not increase. Similar behavior was observed for the other supercoolings tested. This research suggests that HIU can improve the functional properties of IE with low content of C16:0 creating more viscous and elastic materials. These fats with low C16:0 content and improved functional properties could be used as trans‐free fat alternatives.

Conjugated linoleic acid (CLA) isomers in oils are currently measured as fatty acid methyl esters by a gas chromatography-flame ionization detector (GC-FID) technique, which requires approximately 2 h to complete the analysis. Hence, we aim to develop a method to rapidly determine CLA isomers in CLA-rich soy oil. Soy oil with 0.38-25.11% total CLA was obtained by photo-isomerization of 96 soy oil samples for 24 h. A sample was withdrawn at 30 min intervals with repeated processing using a second batch of oil. Six replicates of GC-FID fatty acid analysis were conducted for each oil sample. The oil samples were scanned using attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and the spectrum was collected. Calibration models were developed using partial least-squares (PLS-1) regression using Unscrambler software. Models were validated using a full cross-validation technique and tested using samples that were not included in the calibration sample set. Measured and predicted total CLA, trans,trans CLA isomers, total mono trans CLA isomers, trans-10,cis-12 CLA, trans-9,cis-11 CLA and cis-10,trans-12 CLA, and cis-9,trans-11 CLA had cross-validated coefficients of determinations (R2v) of 0.97, 0.98, 0.97, 0.98, 0.97, and 0.99 and corresponding root-mean-square error of validation (RMSEV) of 1.14, 0.69, 0.27, 0.07, 0.14, and 0.07% CLA, respectively. The ATR-FTIR technique is a rapid and less expensive method for determining CLA isomers in linoleic acid photo-isomerized soy oil than GC-FID.

Interesterified soybean oil was crystallized at 29, 34, and 35 C with and without the use of highintensity ultrasound. Samples were crystallized using either (1) continued agitation for the entire crystallization process (CA) or (2) agitation for 10 min (A10) followed by static crystallization. Sonication and agitation decreased the induction period of nucleation at higher temperatures and changed the crystal morphology, crystallization kinetics, and viscoelasticity of the sample. Sonication reduced the crystal sizes and significantly (P <0.05) increased the viscosity (5.2 AE 1.2 to 2369.6 AE 712.1 Pa s) and elastic modulus (83.2 AE 4.1 to 69,236.7 AE 26,765 Pa) of the crystalline networks obtained at 29 C under A10 condition. An increase in viscosity and elasticity was also observed for sonicated samples crystallized at 34 and 35 C under A10 and all CA conditions but these differences were not statistically significant (P >0.05). Sonication increased crystallization rates for all conditions tested. Kinetic constants obtained from an Avrami fit increased from1.3 × 10 −5 to 6.8 × 10 −5 min −n for samples crystallized at 29 C A10 without and with sonication, respectively, and from 2.6 × 10 −9 to 2.4 × 10 −7 min −n for samples crystallized at 34 C A10 without and with sonication, respectively. This increase in the crystallization rate was also observed for samples crystallized under the CA condition at 29 C. J Am Oil Chem Soc (2018) 95: 571-582 572 J Am Oil Chem Soc J Am Oil Chem Soc (2018) 95: 571-582

A conjugated linoleic acid (CLA)-rich soy oil has been produced by photoisomerization of soy oil linoleic acid. Nutritional studies have shown that CLA possesses health benefits in terms of reducing certain heart disease and diabetes risk factors. Potato chips are snacks that are readily produced in the CLA-rich soy oil containing CLA levels similar to those of the oil used for frying. The objective of this study was to develop an FTIR method to rapidly determine the CLA content of oil in potato chips. Photoirradiated soy oil samples with ∼25% total CLA were mixed with control soy oil, and 100 soy oil samples with total CLA levels ranging from 0.89 to 24.4% were made. Potato chips were fried using each of these 300 g CLA rich soy oil mixtures at 175 °C for approximately 3 min. Duplicate GC-FID fatty acid analyses were conducted on oil extracted from each batch of potato chips. The chip samples were ground and then scanned using ATR-FTIR spectroscopy with the aid of a high-pressure clamp, and duplicate spectra of each sample were averaged to obtain an average spectrum. Calibration models were developed using PLS regression analysis. These correlated the CLA isomer concentrations of potato chips obtained by GC-FID fatty acid analysis with their corresponding FTIR spectral features. The calibration models were fully cross validated and tested using samples that were not used in the calibration sample set. Calibrations for total CLA, trans,trans CLA, trans-10,cis-12 CLA, trans-9,cis-11 CLA, cis-10,trans-12 CLA, and cis-9,trans-11 CLA had coefficients of determinations (R2v) between 0.91 and 0.96 and corresponding root-mean-square error of prediction (RMSEP) ranging from 0.005 to 1.44. The ATR-FTIR technique showed potential as a method for the determination of the CLA levels in unknown potato chip samples.