Marcin Lukasiewicz

5-Hydroxymethyl-2-Furfural (HMF) – Heat-Induced Formation, Occurrence in Food and Biotransformation – a Review

Abstract The chemical structure of 5-hydroxymethyl-2-furfural (HMF), its physicochemical properties and reactions that lead to the synthesis of HMF were discussed. Special attention was paid to HMF formation in food during processing. The potential applications of this compound in industry were described as well. Moreover, this review outlines the most important sources of HMF in human diet and estimates the potential daily intake of HMF by consumers. The known and suggested metabolic pathways, as well as the impact of HMF and its metabolites on human health are also discussed.

Thixotropic properties of normal potato starch depending on the degree of the granules pasting

The aim of this paper was the study of the rheological instability (thixotropy and/or antithixotropy) of normal potato starch (NPS) pastes depending on their concentration (2-5%) and degree of pasting. Flow curves with hysteresis loops, apparent viscosity at constant shear rate and in-shear structural recovery tests were carried out. Granule size profiles, the pasting characteristic of corresponding starch suspensions and the transmittance of the pastes, the molecular weights and polydispersity of granular starch and its pastes prepared at 80, 95 and 121°C were also studied. The degree of pasting was dependent on the temperature and the concentration and influenced strongly the rheological behavior of the pastes. All pastes belonged to the non-Newtonian liquids thinned by shear and were rheologically unstable to the various extent. Thixotropic properties were connected to the size and the number of the starch granules in the pastes as well as depended on the measuring method used. In the 2 and 3% samples pasted at 80°C the swelling of the granules prevailed their destruction (thixotropy was observed). In the other samples the destruction predominated the swelling (antithixotropy observed).

β -Cyclodextrin as water-solubility enhancer for butylated hydroxytoluene

The phenomenon of the increase in solubility of the non-polar phenolic antioxidant — butylated hydroxytoluene (BHT) — in aqueous solutions containing β-cyclodextrin (CD) was studied. The complexation of BHT by CD was investigated using a phase solubility study. This method makes it possible to calculate the apparent formation constant for the host-guest complex. In addition, the thermodynamic properties were evaluated, revealing a spontaneous endothermic process of complex formation. Two solubility models were also used to verify their applicability to predicting the BHT concentration in solution. Those models included the modified Apelblat and Buchowski-Ksiazczak equations. In order to investigate the antioxidant properties of the BHT/CD/water ternary systems, a radical scavenging activity using a DPPH stable radical was performed. The experiments indicated that the antioxidant activity is temperature- and CD concentration-dependent. It was shown that complexation may inhibit the radical scavenging by BHT or change the scavenging stoichiometry.