Cargando…

Interplay between Residual Protease Activity in Commercial Lactases and the Subsequent Digestibility of β-Casein in a Model System

One of the conventional ways to produce lactose-hydrolyzed (LH) milk is via the addition of commercial lactases into heat-treated milk in which lactose is hydrolyzed throughout storage. This post-hydrolysis method can induce proteolysis in milk proteins due to protease impurities remaining in commer...

Descripción completa

Detalles Bibliográficos
Autores principales: Zhao, Di, Le, Thao T., Larsen, Lotte Bach, Nian, Yingqun, Wang, Cong, Li, Chunbao, Zhou, Guanghong
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6721707/
https://www.ncbi.nlm.nih.gov/pubmed/31398828
http://dx.doi.org/10.3390/molecules24162876
_version_ 1783448403659718656
author Zhao, Di
Le, Thao T.
Larsen, Lotte Bach
Nian, Yingqun
Wang, Cong
Li, Chunbao
Zhou, Guanghong
author_facet Zhao, Di
Le, Thao T.
Larsen, Lotte Bach
Nian, Yingqun
Wang, Cong
Li, Chunbao
Zhou, Guanghong
author_sort Zhao, Di
collection PubMed
description One of the conventional ways to produce lactose-hydrolyzed (LH) milk is via the addition of commercial lactases into heat-treated milk in which lactose is hydrolyzed throughout storage. This post-hydrolysis method can induce proteolysis in milk proteins due to protease impurities remaining in commercial lactase preparations. In this work, the interplay between lactose hydrolysis, proteolysis, and glycation was studied in a model system of purified β-casein (β-CN), lactose, and lactases using peptidomic methods. With a lactase presence, the proteolysis of β-CN was found to be increased during storage. The protease side-activities mainly acted on the hydrophobic C-terminus of β-CN at Ala, Pro, Ile, Phe, Leu, Lys, Gln, and Tyr positions, resulting in the formation of peptides, some of which were N-terminal glycated or potentially bitter. The proteolysis in β-CN incubated with a lactase was shown to act as a kind of “pre-digestion”, thus increasing the subsequent in vitro digestibility of β-CN and drastically changing the peptide profiles of the in vitro digests. This model study provides a better understanding of how the residual proteases in commercial lactase preparations affect the quality and nutritional aspects of β-CN itself and could be related to its behavior in LH milk.
format Online
Article
Text
id pubmed-6721707
institution National Center for Biotechnology Information
language English
publishDate 2019
publisher MDPI
record_format MEDLINE/PubMed
spelling pubmed-67217072019-09-10 Interplay between Residual Protease Activity in Commercial Lactases and the Subsequent Digestibility of β-Casein in a Model System Zhao, Di Le, Thao T. Larsen, Lotte Bach Nian, Yingqun Wang, Cong Li, Chunbao Zhou, Guanghong Molecules Article One of the conventional ways to produce lactose-hydrolyzed (LH) milk is via the addition of commercial lactases into heat-treated milk in which lactose is hydrolyzed throughout storage. This post-hydrolysis method can induce proteolysis in milk proteins due to protease impurities remaining in commercial lactase preparations. In this work, the interplay between lactose hydrolysis, proteolysis, and glycation was studied in a model system of purified β-casein (β-CN), lactose, and lactases using peptidomic methods. With a lactase presence, the proteolysis of β-CN was found to be increased during storage. The protease side-activities mainly acted on the hydrophobic C-terminus of β-CN at Ala, Pro, Ile, Phe, Leu, Lys, Gln, and Tyr positions, resulting in the formation of peptides, some of which were N-terminal glycated or potentially bitter. The proteolysis in β-CN incubated with a lactase was shown to act as a kind of “pre-digestion”, thus increasing the subsequent in vitro digestibility of β-CN and drastically changing the peptide profiles of the in vitro digests. This model study provides a better understanding of how the residual proteases in commercial lactase preparations affect the quality and nutritional aspects of β-CN itself and could be related to its behavior in LH milk. MDPI 2019-08-08 /pmc/articles/PMC6721707/ /pubmed/31398828 http://dx.doi.org/10.3390/molecules24162876 Text en © 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Zhao, Di
Le, Thao T.
Larsen, Lotte Bach
Nian, Yingqun
Wang, Cong
Li, Chunbao
Zhou, Guanghong
Interplay between Residual Protease Activity in Commercial Lactases and the Subsequent Digestibility of β-Casein in a Model System
title Interplay between Residual Protease Activity in Commercial Lactases and the Subsequent Digestibility of β-Casein in a Model System
title_full Interplay between Residual Protease Activity in Commercial Lactases and the Subsequent Digestibility of β-Casein in a Model System
title_fullStr Interplay between Residual Protease Activity in Commercial Lactases and the Subsequent Digestibility of β-Casein in a Model System
title_full_unstemmed Interplay between Residual Protease Activity in Commercial Lactases and the Subsequent Digestibility of β-Casein in a Model System
title_short Interplay between Residual Protease Activity in Commercial Lactases and the Subsequent Digestibility of β-Casein in a Model System
title_sort interplay between residual protease activity in commercial lactases and the subsequent digestibility of β-casein in a model system
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6721707/
https://www.ncbi.nlm.nih.gov/pubmed/31398828
http://dx.doi.org/10.3390/molecules24162876
work_keys_str_mv AT zhaodi interplaybetweenresidualproteaseactivityincommerciallactasesandthesubsequentdigestibilityofbcaseininamodelsystem
AT lethaot interplaybetweenresidualproteaseactivityincommerciallactasesandthesubsequentdigestibilityofbcaseininamodelsystem
AT larsenlottebach interplaybetweenresidualproteaseactivityincommerciallactasesandthesubsequentdigestibilityofbcaseininamodelsystem
AT nianyingqun interplaybetweenresidualproteaseactivityincommerciallactasesandthesubsequentdigestibilityofbcaseininamodelsystem
AT wangcong interplaybetweenresidualproteaseactivityincommerciallactasesandthesubsequentdigestibilityofbcaseininamodelsystem
AT lichunbao interplaybetweenresidualproteaseactivityincommerciallactasesandthesubsequentdigestibilityofbcaseininamodelsystem
AT zhouguanghong interplaybetweenresidualproteaseactivityincommerciallactasesandthesubsequentdigestibilityofbcaseininamodelsystem