scholarly journals Whey Protein Isolate-Xylose Maillard-Based Conjugates with Tailored Microencapsulation Capacity of Flavonoids from Yellow Onions Skins

Antioxidants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1708
Author(s):  
Ștefania Adelina Milea ◽  
Iuliana Aprodu ◽  
Elena Enachi ◽  
Vasilica Barbu ◽  
Gabriela Râpeanu ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Whey Protein ◽  
Maillard Reaction ◽  
Protein Isolate ◽  
Added Value ◽  
Whey Protein Isolates ◽  
The Impact ◽  
Β Lactoglobulin ◽  
Yellow Onion ◽  
Modelling Approach

The objective of this study is to encapsulate flavonoids from yellow onion skins in whey protein isolates (WPI) and xylose (X), by Maillard-based conjugates, as an approach to improve the ability to entrap flavonoids and to develop powders with enhanced antioxidant activity. WPI (0.6%, w/v) was conjugated to X (0.3%, w/v) through the Maillard reaction at 90 °C for 120 min, in the presence of a flavonoid-enriched extract. Two variants of powders were obtained by freeze-drying. The glycation of WPI allowed a better encapsulation efficiency, up to 90.53 ± 0.29%, corresponding to a grafting degree of 30.38 ± 1.55%. The molecular modelling approach was used to assess the impact of X interactions with α-lactalbumin and β-lactoglobulin on the ability of these proteins to bind the main flavonoids from the yellow onion skins. The results showed that X might compete with quercetin glucosides to bind with α-lactalbumin. No interference was found in the case of β-lactoglobulin. The microstructural appearance of the powders revealed finer spherosomes in powder with WPI–X conjugates via the Maillard reaction. The powders were added to nachos, followed by a phytochemical characterization, in order to test their potential added value. An increase in antioxidant activity was observed, with no significant changes during storage.

scholarly journals Exploring the Use of a Modified High-Temperature, Short-Time Continuous Heat Exchanger with Extended Holding Time (HTST-EHT) for Thermal Inactivation of Trypsin Following Selective Enzymatic Hydrolysis of the β-Lactoglobulin Fraction in Whey Protein Isolate

Foods ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 367 ◽  
Author(s):  
Laura Sáez ◽  
Eoin Murphy ◽  
Richard J. FitzGerald ◽  
Phil Kelly
Keyword(s):  
High Temperature ◽  
Heat Exchanger ◽  
Whey Protein ◽  
Protein Isolate ◽  
Holding Time ◽  
High Temperature Short Time ◽  
Incubation Periods ◽  
Short Time ◽  
Β Lactoglobulin ◽  
Hydrolysis Of

Tryptic hydrolysis of whey protein isolate under specific incubation conditions including a relatively high enzyme:substrate (E:S) ratio of 1:10 is known to preferentially hydrolyse β-lactoglobulin (β-LG), while retaining the other major whey protein fraction, i.e., α-lactalbumin (α-LA) mainly intact. An objective of the present work was to explore the effects of reducing E:S (1:10, 1:30, 1:50, 1:100) on the selective hydrolysis of β-LG by trypsin at pH 8.5 and 25 °C in a 5% (w/v) WPI solution during incubation periods ranging from 1 to 7 h. In addition, the use of a pilot-scale continuous high-temperature, short-time (HTST) heat exchanger with an extended holding time (EHT) of 5 min as a means of inactivating trypsin to terminate hydrolysis was compared with laboratory-based acidification to <pH 3 by the addition of HCl, and batch sample heating in a water bath at 85 °C. An E:S of 1:10 resulted in 100% and 30% of β-LG and α-LA hydrolysis, respectively, after 3 h, while an E:S reduction to 1:30 and 1:50 led >90% β-LG hydrolysis after respective incubation periods of 4 and 6 h, with <5% hydrolysis of α-LA in the case of 1:50. Continuous HTST-EHT treatment was shown to be an effective inactivation process allowing for the maintenance of substrate selectivity. However, HTST-EHT heating resulted in protein aggregation, which negatively impacts the downstream recovery of intact α-LA. An optimum E:S was determined to be 1:50, with an incubation time ranging from 3 h to 7 h leading to 90% β-LG hydrolysis and minimal degradation of α-LA. Alternative batch heating by means of a water bath to inactivate trypsin caused considerable digestion of α-LA, while acidification to <pH 3.0 restricted subsequent functional applications of the protein.

Morphological and physical properties of kefiran-whey protein isolate bionanocomposite films reinforced with Al2O3 nanoparticles

2020 ◽  
Vol 26 (8) ◽  
pp. 666-675
Author(s):  
Zahra Moradi
Keyword(s):  
Mechanical Properties ◽  
Whey Protein ◽  
Water Solubility ◽  
Whey Protein Isolate ◽  
Protein Isolate ◽  
Alumina Nanoparticles ◽  
Vapor Permeability ◽  
Al2o3 Nanoparticles ◽  
Bionanocomposite Films ◽  
The Impact

Considering environmental pollution caused by the non-biodegradable polymers used in food packaging, developing and enhancing the properties of biodegradable films seem to be necessary. For this aim, in the present study, kefiran-whey protein isolate bionanocomposite films were prepared and the impact of different concentrations (1, 3 and 5% w/w) of Al2O3 (alumina) nanoparticles on their physical, morphological, thermal and mechanical properties was studied. Based on the obtained results, an increase in the nanoparticles content led to a significant decrease (p < 0.05) in the water vapor permeability, moisture absorption, moisture content, and water solubility. Scanning electron microscope images showed a homogeneous structure, confirming the good dispersion of alumina nanoparticles with smooth surface up to concentration of 3%. In addition, both thermal stability and mechanical properties of the films were improved by the increased concentrations of alumina. The results of X-ray diffraction indicated that the intensity of the crystalline peaks of film increased with the addition of Al2O3 to kefiran-whey protein isolate matrix. By considering all results, the concentration of 3% was proposed as the appropriate concentration of Al2O3 for the nano-reinforcement of kefiran-whey protein isolate bionanocomposites.

scholarly journals Dairy-Inspired Coatings for Bone Implants from Whey Protein Isolate-Derived Self-Assembled Fibrils

2020 ◽  
Vol 21 (15) ◽  
pp. 5544
Author(s):  
Rebecca Rabe ◽  
Ute Hempel ◽  
Laurine Martocq ◽  
Julia K. Keppler ◽  
Jenny Aveyard ◽  
...  
Keyword(s):  
Whey Protein ◽  
Antimicrobial Properties ◽  
Whey Protein Isolate ◽  
Protein Isolate ◽  
Surrounding Tissue ◽  
Osteoblastic Cell ◽  
Bone Contact ◽  
Acidic Solutions ◽  
Main Component ◽  
Β Lactoglobulin

To improve the integration of a biomaterial with surrounding tissue, its surface properties may be modified by adsorption of biomacromolecules, e.g., fibrils. Whey protein isolate (WPI), a dairy industry by-product, supports osteoblastic cell growth. WPI’s main component, β-lactoglobulin, forms fibrils in acidic solutions. In this study, aiming to develop coatings for biomaterials for bone contact, substrates were coated with WPI fibrils obtained at pH 2 or 3.5. Importantly, WPI fibrils coatings withstood autoclave sterilization and appeared to promote spreading and differentiation of human bone marrow stromal cells (hBMSC). In the future, WPI fibrils coatings could facilitate immobilization of biomolecules with growth stimulating or antimicrobial properties.

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