Dynamic gastric stability and in vitro lipid digestion of whey-protein-stabilised emulsions: Effect of heat treatment

ABSTRACT: This study produced pectin microcapsules containing Lactobacillus acidophilus by external ionic gelation, followed by the adsorption of whey protein and pectin to form multilayers. The viability of free and microencapsulated lactobacilli was evaluated after in vitro exposure to gastrointestinal conditions. They were also assessed by heat treatment, and stability was examined at -18 °C, 5 °C and 25 °C for 120 days. Exposure to different pHs, simulating passage through the gastrointestinal tract, showed that treatment of the microcapsules with only pectin (LA/P0) and with one and two layers of whey protein (treatments LA/P1 and LA/P3, respectively), were able to protect Lactobacillus acidophilus , with microcapsules increasing the release of probiotics from the stomach into the intestines. Free cells showed a decrease in their counts over the course of the simulated gastrointestinal system. Regarding heat treatments, microcapsules with a layer of whey protein (LA/P1) maintained the viability of their encapsulated Lactobacillus acidophilus (9.57 log CFU/g-1). The best storage viability was at -18 °C, with a count of 7.86 log CFU/g-1at 120 days for microcapsule LA/P1,with those consisting of two layers of whey protein (LA/P3)having a 6.55 log CFU/g-1 at 105 days. This study indicated that external ionic gelation was effective and could be used for the production of pectin microcapsules, with multilayer whey protein promoting greater protection and viability of Lactobacillus acidophilus.

Download Full-text

Effect of Gel Structure on the In Vitro Gastrointestinal Digestion Behaviour of Whey Protein Emulsion Gels and the Bioaccessibility of Capsaicinoids

Molecules ◽

10.3390/molecules26051379 ◽

2021 ◽

Vol 26 (5) ◽

pp. 1379

Author(s):

Nan Luo ◽

Aiqian Ye ◽

Frances M. Wolber ◽

Harjinder Singh

Keyword(s):

Whey Protein ◽

Whey Proteins ◽

Micelle Formation ◽

Protein Isolate ◽

Gastric Digestion ◽

Lipid Digestion ◽

Gel Structure ◽

Oil Droplet ◽

Mechanical Strengths

This study investigated the effect of gel structure on the digestion of heat-set whey protein emulsion gels containing capsaicinoids (CAP), including the bioaccessibility of CAP. Upon heat treatment at 90 °C, whey protein emulsion gels containing CAP (10 wt% whey protein isolate, 20 wt% soybean oil, 0.02 wt% CAP) with different structures and gel mechanical strengths were formed by varying ionic strength. The hard gel (i.e., oil droplet size d4,3 ~ 0.5 µm, 200 mM NaCl), with compact particulate gel structure, led to slower disintegration of the gel particles and slower hydrolysis of the whey proteins during gastric digestion compared with the soft gel (i.e., d4,3 ~ 0.5 µm, 10 mM NaCl). The oil droplets started to coalesce after 60 min of gastric digestion in the soft gel, whereas minor oil droplet coalescence was observed for the hard gel at the end of the gastric digestion. In general, during intestinal digestion, the gastric digesta from the hard gel was disintegrated more slowly than that from the soft gel. A power-law fit between the bioaccessibility of CAP (Y) and the extent of lipid digestion (X) was established: Y = 49.2 × (X – 305.3)0.104, with R2 = 0.84. A greater extent of lipid digestion would lead to greater release of CAP from the food matrix; also, more lipolytic products would be produced and would participate in micelle formation, which would help to solubilize the released CAP and therefore result in their higher bioaccessibility.

Download Full-text

In vitro digestion of Pickering emulsions stabilized by soft whey protein microgel particles: influence of thermal treatment

Soft Matter ◽

10.1039/c5sm02998h ◽

2016 ◽

Vol 12 (15) ◽

pp. 3558-3569 ◽

Cited By ~ 123

Author(s):

Anwesha Sarkar ◽

Brent Murray ◽

Melvin Holmes ◽

Rammile Ettelaie ◽

Azad Abdalla ◽

...

Keyword(s):

Thermal Treatment ◽

Whey Protein ◽

Bile Salts ◽

In Vitro Digestion ◽

Pickering Emulsions ◽

Lipid Digestion ◽

Heat Treated ◽

Microgel Particles

The heat-treated “fused” whey protein microgel particles at the O/W interface was more beneficial in delaying lipid digestion in presence of pure lipase/bile salts as compared to intact one.

Download Full-text

“In vitro” and in Animal Model Studies on a Double Virus- Inactivated Factor VIII Concentrate

Thrombosis and Haemostasis ◽

10.1055/s-0038-1649839 ◽

1995 ◽

Vol 74 (03) ◽

pp. 868-873 ◽

Cited By ~ 9

Author(s):

Silvana Arrighi ◽

Roberta Rossi ◽

Maria Giuseppina Borri ◽

Vladimir Lesnikov ◽

Marina Lesnikov ◽

...

Keyword(s):

Heat Treatment ◽

Animal Model ◽

Factor Viii ◽

Hepatitis A ◽

Hepatitis A Virus ◽

Virus Inactivation ◽

Enveloped Viruses ◽

Model Studies ◽

Heat Treated

SummaryTo improve the safety of plasma derived factor VIII (FVIII) concentrate, we introduced a final super heat treatment (100° C for 30 min) as additional virus inactivation step applied to a lyophilized, highly purified FVIII concentrate (100 IU/mg of proteins) already virus inactivated using the solvent/detergent (SID) method during the manufacturing process.The efficiency of the super heat treatment was demonstrated in inactivating two non-lipid enveloped viruses (Hepatitis A virus and Poliovirus 1). The loss of FVIII procoagulant activity during the super heat treatment was of about 15%, estimated both by clotting and chromogenic assays. No substantial changes were observed in physical, biochemical and immunological characteristics of the heat treated FVIII concentrate in comparison with those of the FVIII before heat treatment.

Download Full-text

Bovine Milk-Derived Emulsifiers Increase Triglyceride Absorption in Newborn Formula-Fed Pigs

Nutrients ◽

10.3390/nu13020410 ◽

2021 ◽

Vol 13 (2) ◽

pp. 410 ◽

Cited By ~ 1

Author(s):

Kristine Bach Korsholm Knudsen ◽

Christine Heerup ◽

Tine Røngaard Stange Jensen ◽

Xiaolu Geng ◽

Nikolaj Drachmann ◽

...

Keyword(s):

Milk Fat ◽

Bovine Milk ◽

In Vitro Digestion ◽

Lipid Absorption ◽

Lipid Digestion ◽

Soy Lecithin ◽

Neonatal Piglets ◽

Milk Fat Globule Membranes

Efficient lipid digestion in formula-fed infants is required to ensure the availability of fatty acids for normal organ development. Previous studies suggest that the efficiency of lipid digestion may depend on whether lipids are emulsified with soy lecithin or fractions derived from bovine milk. This study, therefore, aimed to determine whether emulsification with bovine milk-derived emulsifiers or soy lecithin (SL) influenced lipid digestion in vitro and in vivo. Lipid digestibility was determined in vitro in oil-in-water emulsions using four different milk-derived emulsifiers or SL, and the ultrastructural appearance of the emulsions was assessed using electron microscopy. Subsequently, selected emulsions were added to a base diet and fed to preterm neonatal piglets. Initially, preterm pigs equipped with an ileostomy were fed experimental formulas for seven days and stoma output was collected quantitatively. Next, lipid absorption kinetics was studied in preterm pigs given pure emulsions. Finally, complete formulas with different emulsions were fed for four days, and the post-bolus plasma triglyceride level was determined. Milk-derived emulsifiers (containing protein and phospholipids from milk fat globule membranes and extracellular vesicles) showed increased effects on fat digestion compared to SL in an in vitro digestion model. Further, milk-derived emulsifiers significantly increased the digestion of triglyceride in the preterm piglet model compared with SL. Ultra-structural images indicated a more regular and smooth surface of fat droplets emulsified with milk-derived emulsifiers relative to SL. We conclude that, relative to SL, milk-derived emulsifiers lead to a different surface ultrastructure on the lipid droplets, and increase lipid digestion.

Download Full-text

Physicochemical and Microstructural Characterization of Whey Protein Films Formed with Oxidized Ferulic/Tannic Acids

Foods ◽

10.3390/foods10071599 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1599

Author(s):

Yaosong Wang ◽

Youling L. Xiong

Keyword(s):

Whey Protein ◽

Microstructural Characterization ◽

Protein Isolate ◽

Light Transmittance ◽

In Vitro Digestibility ◽

Protein Films ◽

Film Forming ◽

Protein Sulfhydryl ◽

Reduced Light

Protein-based biodegradable packaging films are of environmental significance. The effect of oxidized ferulic acid (OFA)/tannic acid (OTA) on the crosslinking and film-forming properties of whey protein isolate (WPI) was investigated. Both of the oxidized acids induced protein oxidation and promoted WPI crosslinking through the actions of quinone carbonyl and protein sulfhydryl, and amino groups. OTA enhanced the tensile strength (from 4.5 MPa to max 6.7 MPa) and stiffness (from 215 MPa to max 376 MPa) of the WPI film, whereas OFA significantly increased the elongation at break. The water absorption capability and heat resistance of the films were greatly improved by the addition of OTA. Due to the original color of OTA, the incorporation of OTA significantly reduced light transmittance of the WPI film (λ 200–600 nm) as well as the transparency, whereas no significant changes were induced by the OFA treatment. Higher concentrations of OTA reduced the in vitro digestibility of the WPI film, while the addition of OFA had no significant effect. Overall, these two oxidized polyphenols promoted the crosslinking of WPI and modified the film properties, with OTA showing an overall stronger efficacy than OFA due to more functional groups available.

Download Full-text

Effect of reducing sugars on the in-vitro glycation of goat milk whey protein by mass spectrometry

LWT ◽

10.1016/j.lwt.2021.111608 ◽

2021 ◽

pp. 111608

Author(s):

Lina Zhang ◽

Manik Chandra Roy ◽

Peng Zhou

Keyword(s):

Mass Spectrometry ◽

Whey Protein ◽

Reducing Sugars ◽

Goat Milk ◽

Milk Whey ◽

Milk Whey Protein

Download Full-text

Impact of the Simulated Gastric Digestion Methodology on the In Vitro Intestinal Proteolysis and Lipolysis of Emulsion Gels

Foods ◽

10.3390/foods10020321 ◽

2021 ◽

Vol 10 (2) ◽

pp. 321

Author(s):

Camila Mella ◽

Michelle Quilaqueo ◽

Rommy N. Zúñiga ◽

Elizabeth Troncoso

Keyword(s):

Heat Treatment ◽

Protein Isolate ◽

Gastric Digestion ◽

Human Gastrointestinal Tract ◽

Gel Structure ◽

Intestinal Digestion ◽

Food Digestion ◽

The Impact ◽

Digestion Methods

The aim of this work was to study the impact of the methodology of in vitro gastric digestion (i.e., in terms of motility exerted and presence of gastric emptying) and gel structure on the degree of intestinal proteolysis and lipolysis of emulsion gels stabilized by whey protein isolate. Emulsions were prepared at pH 4.0 and 7.0 using two homogenization pressures (500 and 1000 bar) and then the emulsions were gelled by heat treatment. These gels were characterized in terms of texture analysis, and then were subjected to one of the following gastric digestion methods: in vitro mechanical gastric system (IMGS) or in vitro gastric digestion in a stirred beaker (SBg). After gastric digestion, the samples were subjected to in vitro intestinal digestion in a stirred beaker (SBi). Hardness, cohesiveness, and chewiness were significantly higher in gels at pH 7.0. The degree of proteolysis was higher in samples digested by IMGS–SBi (7–21%) than SBg–SBi (3–5%), regardless of the gel’s pH. For SBg–SBi, the degree of proteolysis was not affected by pH, but when operating the IMGS, higher hydrolysis values were obtained for gels at pH 7.0 (15–21%) than pH 4.0 (7–13%). Additionally, the percentage of free fatty acids (%FFA) released was reduced by 47.9% in samples digested in the IMGS–SBi. For the methodology SBg–SBi, the %FFA was not affected by the pH, but in the IMGS, higher values were obtained for gels at pH 4.0 (28–30%) than pH 7.0 (15–19%). Our findings demonstrate the importance of choosing representative methods to simulate food digestion in the human gastrointestinal tract and their subsequent impact on nutrient bioaccessibility.

Download Full-text