Mulet-Cabero, A-I, Mackie, AR orcid.org/0000-0002-5681-0593, Wilde, PJ et al. (2 more authors) (2019) Structural mechanism and kinetics of in vitro gastric digestion are affected by process-induced changes in bovine milk. Food Hydrocolloids, 86. pp. 172-183. ISSN 0268-005X
Abstract
Bovine milk is commonly exposed to processing, which can alter the structure, biochemical composition, physico-chemical properties and sensory quality. While many of these changes have been studied extensively, little is known about their effect on digestive behaviour. In this study, heat treatments of pasteurisation at 72 °C for 15 s or Ultra-High-Temperature (UHT) treatment at 140 °C for 3 s and homogenisation at pilot-plant scale were applied to whole milk. The gastric behaviour was investigated using a recently developed semi-dynamic adult in vitro model. The emptied digesta were analysed to assess the nutrient delivery kinetics, changes in microstructure and protein digestion.
All samples showed protein aggregation and coagulum formation within the first 15 min of gastric digestion at which time the pH ranged from 5.5 to 6. Homogenised samples creamed regardless of heat treatment, whereas all non-homogenised samples exhibited sedimentation. The consistency of the coagulum of the heated samples was more fragmented compared to those of the non-heated samples. Rheological analysis showed that the higher the temperature of the heat treatment, the softer the obtained coagulum and the higher the protein hydrolysis at the end of digestion. The study also confirmed that gastric emptying of caseins from milk is delayed due to coagulation in the stomach, while β-lactoglobulin was emptied throughout the gastric phase, except for UHT-treated milk. The gastric behaviour also had an impact on the lipid and protein content of the emptied chyme. The homogenised samples seemed to release more nutrients at the end of gastric digestion.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2018 Elsevier Ltd. All rights reserved. This is an author produced version of an article published in Food Hydrocolloids. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Milk; Homogenisation; Heat treatment; Gastric behaviour; Nutrient delivery; Protein digestion |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Food Science and Nutrition (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 08 Nov 2019 12:16 |
Last Modified: | 08 Nov 2019 12:29 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.foodhyd.2018.03.035 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:153229 |