Nanoparticles (NPs) are used increasingly in many different areas such as medical, engineering, food and agricultural industries because their nanoscale dimensions exhibit unique properties and functionalities for novel commercial applications. In-depth understanding of the transformation of NPs, and the mechanism of their interactions with the biological targets are critical for ensuring their safety to human. Silica NPs were subjected to food processing conditions such as storing under room temperature (FG-RT), boiling (FG-Boil) and dry heating (FG-600C). These NPs were characterized for size and morphology, agglomeration, and surface chemistry using scanning electron microscope (SEM), DLS techniques and Fourier-transform infrared spectroscopy (FTIR), respectively. These particles were interacted with proteins of relevance to digestion and nutrition in order to understand the consequence of material transformation. NPs-proteins interactions were studied using spectroscopic and electrophoretic assays. In addition, the effects of nanoparticle interaction on the activity of trypsin were also studied. The results showed that NPs of silica get transformed in response to food processing conditions. The silanol group (Si-OH) was reduced by heating. Among the three processing conditions, the lowest level of Si-OH groups was found at FG-600C, which also showed relatively higher hydrophobicity among the tested particles. It is also noticed that FG-600C NPs have less negative charge than FG-Boil, FG-RT and SiO2(non-food grade silica NPs). Agglomeration size was highest for FG-600C followed by those subjected to boiling. The transformation of surface chemistry affects proteins-NPs interactions and therefore inhibits the trypsin activity. The FG-600C was the highest trypsin activity inhibitor while FG-μm (micro size food grade silica particles) and SiO2 did not inhibit enzyme activity with increasing NPs concentration. The data were proved by one-dimension gel electrophoresis and trypsin activity assay. The FG-RT, FG-Boil and FG-600C are non-competitive inhibitors according to Michaelis-Menten kinetics. It is observed that different food processing conditions have significant impacts on the transformation of food grade silica NPs. The transformation of the physicochemical properties of the ingested NPs can influence the functional properties of enzymes during their interactions with NPs, which will affect the process of nutrient uptake in human biological system.

Transformation of silica nanoparticles in response to food processing conditions and its effect on protein-nanoparticle interactions

256th National Meeting (2018)

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