Molecular Encapsulation of Hydrolyzed Chia Seed Oil by Ultrasonically Treated Amylose Inclusion Complexes

Abstract

: Chia ( Salvia hispanica L.) seed oil is a naturally rich source of α -linolenic (~65%) and linoleic (~20%) essential fatty acids, which are known for their beneficial effects on health. However, they are highly susceptible to oxidative deterioration. Amylose, the linear component of starch, has the ability to form inclusion complexes with hydrophobic molecules (ligand), which may act as delivery systems of sensitive bioactive compounds, including essential omega-3 and omega-6 fatty acids. In the present work, the hydrolytic effectiveness of Candida rugosa and porcine pancreatic lipases to obtain chia seed oil-free fatty acids was compared, which were complexed with high-amylose starch through the alkaline method with and without the incorporation of ultrasonic treatment. The highest level of free fatty acids released (>80%) was reached with Candida rugosa lipase. The inclusion complexes formed with this hydrolysate displayed a typical V-type X-ray diffraction pattern (peaks at ~7.5, 13, and 20 ◦ (2 θ )), which confirmed an effective complexation. Moreover, ultrasonically treated complexes displayed a small peak at ~21 ◦ , from crystallized saturated fatty acids. Through attenuated total reflectance Fourier-transform infrared spectroscopy, the presence of typical bands of fatty acids in the complexes was verified, whose intensity increased after the application of ultrasonic treatment. The dissociation temperature determined using differential scanning calorimetry was >90 ◦ C. According to this, Candida rugosa lipase showed better hydrolytic effectiveness on chia seed oil, and the fatty acids released were able to form amylose inclusion complexes with high thermal stability, whose properties varied after ultrasonic treatment.