Study on self-assembly molecules for innovative food structure design

In this Ph.D. thesis, the ability of selected self-assembly molecules to form structures as a function of system, environmental, and processing conditions was studied at different length scales (nano, micro, and macro). In particular, the attention was pointed on hydrophobic as well as a mixture of hydrophobic and hydrophilic media. Different analytical techniques were used to investigate the levels of the matter of the resulting materials. Synchrotron X-ray diffraction, powder X-ray diffraction, differential scanning calorimetry, pulsed nuclear magnetic resonance, dielectric spectroscopy, and dynamic laser light scattering were used to investigate the nano and molecular structuration of the obtained systems. The microscopic level was investigated using polarized light microscopy, cryo-scanning electron microscopy, ultra-small angle X-ray scattering, and magnetic resonance imaging. Finally, the macroscopic level was investigated using large and small deformation analysis, visual appearance, accelerated oil release test, and colorimetric analysis. Besides this structural analysis, emphasis was also pointed on some chemical analysis in the attempt to determine the formation of toxicant molecules (furans, acrylamide, peroxides) or the degradation of bioactive molecules. In this thesis, binary systems composed of fatty alcohols with different carbon chain length added to peanut oil, and monoglycerides added to different oils were studied. Fatty alcohols turned out to be promising building blocks in the attempt to structure an edible oil. Depending on cooling rate applied, fatty alcohol carbon chain length, and concentration, it is possible to obtain systems with different performances. On the other hand, monoglyceride structured systems showed that thermal, mechanical and microstructural characteristics were greatly affected by oil fatty acids composition and its dielectric properties. Ternary systems composed by oil, aqueous phase and monoglycerides were then studied. Results highlighted that the aqueous phase as well as the ratio among ingredients are of crucial importance to obtain a gelled emulsified structure. In particular the composition of the aqueous phase allowed to tune the resulting material in all the length scales studied depending on anions, proteins and salts present added to the system. The applicability of selected structured systems was studied in bakery products such as sweet bread and biscuits with the aim of reducing saturated fat and deliver high quantities of essential fatty acids. Thanks to monoglyceride gelled emulsions it was possible to obtain sweet bread samples with quality characteristics comparable to those of sweet bread control prepared using palm oil. Moreover, gelled emulsions containing PUFAs coupled with a vacuum baking process were able to obtain enriched biscuits allowing low levels of toxicants formation. The study was then pointed on selected bioactive molecules. In particular β-carotene and curcumin were able to alter the crystal morphology of solid lipids used as carriers. This alteration was then translated into different bioactive molecules degradation rates. Finally, transparent emulsions delivering bioactive molecules as well as essential oils were developed. Processing conditions and ingredients ratio were the key elements to obtain stable transparent systems. These systems were then diluted into fancy drink prototypes and thermally stressed. The protective ability of the carrier was basically dependent on the treatment applied