In vitro digestion of polysaccharide including whey protein isolate hydrogels

Hydrogels are great systems for bioactive agent encapsulation and delivery. In this study, polysaccharide blended whey protein isolate (WPI) based hydrogels were loaded with black carrot (Daucus carota) concentrate (BC) and in vitro gastrointestinal release measurements were performed. Prior to 6 h digestion in simulated intestinal fluid (SIF), all hydrogels were exposed to simulated gastric fluid (SGF) for 2 h. Pectin (PC), gum tragacanth (GT) and xanthan gum (XG) were the polysaccharides used with WPI to manipulate the release behavior. Physico-chemical changes of the hydrogels throughout the digestion were evaluated by Fourier transform infrared (FTIR) spectroscopy and nuclear magnetic resonance (NMR) relaxometry measurements. Each polysaccharide induced different physico-chemical interactions within the hydrogels due to their distinct structural characteristics. Polysaccharide blending to hydrogels also retarded the release rates in all samples in SIF (p < 0.05). Moreover, microstructural differences between hydrogels were evaluated by scanning electron microscope (SEM) images. © 2019 Elsevier LtdOrta Doğu Teknik Üniversitesi: DKT-314-2018-3596 --We would like to thank Ulku Ertugrul and Berkay Bolat for their contribution to the study. We also would like to acknowledge COST Action CA 15209 EURELAX - European Network on NMR Relaxometry since some of the findings were discussed in the action’s network meetings. A part of the funding also came from Dr. Oztop’s award of Science Academy’s Young Scientist Awards Program (BAGEP) and Middle East Technical University research funds with grant # DKT-314-2018-3596 . Appendix A -

Disintegration efficiency of pulsed electric field induced effects on onion (Allium cepa L.) tissues as a function of pulse protocol and determination of cell integrity by 1H-NMR relaxometry

PubMed ID: 21535538The influence of electrical pulse protocol parameters on cell rupture of onion tissues was investigated in order to improve fundamental understanding and to enhance the processing of plant tissues with pulsed electric fields (PEFs). The impact of PEF parameters on cell integrity of 20 mm dia, 4-mm thick disks of Don Victor onions (Allium cepa L.) was determined by ion leakage measurements. Electric field strength, pulse width, total pulse duration, and frequency effects were determined in relation to their effects on cell damage as a function of pulse protocol. Electric field strengths up to 500 V/cm increased the damage efficiency but there was no significant difference in efficiency beyond this field strength. Larger pulse widths increased the degree of tissue disintegration at a constant pulse number. Higher PEF efficiency was achieved with shorter pulse widths and a larger number of pulses at a constant total treatment time. Lower frequencies caused a greater degree of disintegration at constant number of pulses. 1H-NMR experiments were performed to determine the proton relaxation components of the PEF-treated onion samples and to obtain cell damage information nondestructively. Paramagnetic ion uptake by the onion sample was used to identify different proton relaxation components. Five different proton relaxation components were observed and changes in the 2 components representing different proton environments showed high correlations with ion leakage results (R2= 0.99), indicating that T2 distributions can be used to obtain information about cell membrane integrity in PEF-treated samples. 1H-NMR proved to be an effective method for nondestructive quantification of cell membrane rupture in onions. © 2010 Institute of Food Technologists®

Effect of high hydrostatic pressure in physicochemical properties and in vitro digestibility of cornstarch by nuclear magnetic resonance relaxometry

Starch is the major polysaccharide consumed by human being. It is not classified as a dietary fiber as it is digestible by the enzymes present in the saliva and small intestines. However, it is possible to modify starch with thermal and nonthermal techniques. High hydrostatic pressure (HHP) is a cold pasteurization technique that has increased application in food industry with minimum effect on nutritional quality of the food products. It is hypothesized that the use of HHP could be a modification strategy for starch. In this study, effects of different HHP parameters (400 and 500 MPa) at different temperatures (20, 30, and 40°C) for 5, 15, and 30 min on in vitro digestibility and physicochemical properties of cornstarch were studied by Nuclear magnetic resonance (NMR) relaxometry. Results showed that HHP treatment increased slowly digestible starch (SDS) and rapid digestible starch (RDS) significantly with pressure and temperature (p <.05). In addition, it was shown that HHP treatment decreased the solubility and swelling power of the cornstarch and it is proposed that 30 min HHP treatment at 500 MPa and 40°C is the onset for cornstarch gelatinization according to NMR relaxometry results. Practical Applications: High hydrostatic pressure (HHP) is a nonthermal processing technology that is commonly used in the food industry for extending the shelf life of food products by destroying vegetative cells, enzymes, microorganisms effectively, and it can modify the starch so the aim of this study was to investigate the effects of different HHP parameters on in vitro digestibility and physicochemical properties of cornstarch by nuclear magnetic resonance relaxometry. © 2019 Wiley Periodicals, Inc