Biography
Gallardo-Rivera R is currently pusuing his PhD in Biotecnology in the group of Biopolymers and Bioprocess of Agro-Industrial and Food By-products at Universidad Autonoma Metropolitana Campus Iztapalapa, under the supervision of full time Professor Dr. Keiko Shirai.
Abstract
Chitosan (CH), alginate (ALG) and aloe vera (Aloe barbadensis) Miller (AV) have applications in ice cream, beverages, syrup, dressing, bread making, meat products as thickening agents and as packaging materials. In this study polyelectrolyte complexes (PECs) with CH-ALG-AV were prepared at pH 4 and 6 using two types of CH, obtained by N-deacetylation of chitins extracted by biological method (BCH) and chemical method (QCH). pH was selected considering food applications and stability of AV. PECs were characterized using analysis of the FT-IR spectroscopy, which electrostatic interaction among AV, ALG, and CH were evidenced at 1595 cm-1. The formation of PEC was also corroborated by fluorescence microscopic analysis by using calcofluor white reagent that interact with 1,4-β-glucans as CH and induced fluorescence. Zeta potential measurements in PECs indicated polyanionic surface charge in the range of -20 to -24 mV, which suggested a stable system. The dynamic moduli exhibited a high dependence on angular frequency typical of macromolecular solutions. PECs morphologies were analyzed by scanning electron microscopy, which showed rough and lamellar structures of PEC at pH 4 and 6. The prepared PECs have potential application for formulation of nutraceutical foods.
Biography
Soleiman Abbasi has completed his PhD at the age of 33 years from Leeds University. He is currently Professor of Food Colloids at Tarbiat Modares University (Tehran, Iran) and Research Associate at the University of Manitoba (Canada). He has published more than 135 papers in reputed journals, two book chapters, over 200 conference presentations. He has been serving as an editorial board member of three Iranian journals. He has also filed a number of patents.
Abstract
Milk–fruit juice mixtures, as nutraceutical soft drinks mainly the acidic ones, usually suffer from phase separation due to aggregation of caseins at low pH. Therefore, in the present study, short chain inulin (SCI), native inulin (NI), long chain inulin (LCI), and a combination of long and short chain inulins (LCI:SCI) (MIX) in different ratios were added to milk–sour cherry juice mixture and their stabilization mechanisms were investigated using rheological, microstructural and zeta potential observations. In addition, gum tragacanth (GT) and Persian gum (PG) as adsorbing and guar gum (GG) as non-adsorbing hydrocolloids were combined with inulin to enhance their stabilizing properties. Finally, sensory analysis was carried out on the stabilized samples. According to our findings, LCI fully stabilized the mixture (8% w/v), while LCI: SCI and NI only reduced phase separation at very high concentrations, and SCI had no significant effect on the stabilization. Moreover, no inulin aggregates and rheological changes were observed with SCI. However, LCI, LCI: SCI and NI formed inulin aggregates and mixtures became even more viscous and thixotropic (LCI>LCI: SCL>NI). Based on these observations, it can be concluded that chain length and concentration are two important factors that affect the functionality of inulin. On the other hand, the combination of inulin with GT and PG did not have pertinent effect on the stabilization. However, the mixture of inulin and GG could stabilize the mixtures at certain ratios and concentrations. Furthermore, mixtures containing GG and SCI, GG played the main role in the stabilization by increasing the viscosity and forming gel network.