Improved digestibility of β-lactoglobulin by pulsed light processing: a dilatational and shear study

Abstract

Modifying the protein conformation appears to improve the digestibility of proteins in the battle against allergies. However, it is important not to lose the protein functionality in the process. Light pulse technology has been recently tested as an efficient non-thermal process which alters the conformation of proteins while improving their functionality as stabilizers. Also, in order to rationally design emulsion based food products with specific digestion profiles, we need to understand how interfacial composition influences the digestion of coated interfaces. This study has been designed to investigate the effects of pulsed light (PL) treatment on the gastrointestinal digestion of protein covered interfaces. We have used a combination of dilatational and shear rheology which highlights inter and intra-molecular interactions providing new molecular details on protein digestibility. The in vitro digestion model analyses sequentially pepsinolysis, trypsinolysis and lipolysis of β-lactoglobulin (BLG) and pulsed light treated β-lactoglobulin (PL-BLG). The results show that the PL-treatment seems to facilitate digestibility of the protein network, especially regarding trypsinolysis. Firstly, PL treatment just barely enhances the enzymatic degradation of BLG by pepsin, which dilutes and weakens the interfacial layer, due to increased hydrophobicity of the protein owing to PL-treatment. Secondly, PL treatment importantly modifies the susceptibility of BLG to trypsin hydrolysis. While it dilutes the interfacial layer in all cases, it strengthens the BLG and weakens the PL-BLG interfacial layer. Finally, this weakening appears to slightly facilitate lipolysis as evidenced by the results obtained upon addition of lipase and bile salts (BS). This research allows identification of the interfacial mechanisms affecting enzymatic hydrolysis of proteins and lipolysis, which demonstrates an improved digestibility of PL-BLG. The fact that PL treatment did not affect the functionality of the protein makes it a valuable alternative for tailoring novel food matrices with improved functional properties such as decreased digestibility, controlled energy intake and low allergenicity.

Assessing in vitro digestibility of food biopreservative AS-48

“…The OCTOPUS enables a sequential static digestion model in a single droplet as described in detail elsewhere . The in vitro digestion model used consists of 4 solutions mimicking digestive media following international consensus (Minekus et al, 2014) as in previous works (Del Castillo-Santaella et al, 2014;Maldonado-Valderrama et al, 2013)…”

“…Biosurfactants in the diet are emulsified along the gastrointestinal tract owing to the mixture with biosurfactants and peristaltic movements. Hence, it is important to study the enzymatic degradation both in bulk solution and at interfaces (Del Castillo-Santaella, Sanmartin, Cabrerizo-Vílchez, Arboleya, & Maldonado-valderrama, 2014;Hur, Lim, Decker, & McClements, 2011;Maldonado-Valderrama, Holgado-Terriza, Torcello-Gomez, & Cabrerizo-Vilchez, 2013;Maldonado-Valderrama, Torcello-Gómez, del Castillo-Santaella, Holgado-Terriza, & Cabrerizo-Vílchez, 2015). Based on the function and the biotechnological applications of AS-48, we have applied a standardized in vitro digestion model (Mitropoulos, Mütze, & Fischer, 2014).…”

Subphase exchange experiments with the pendant drop technique

“…In the same research line we have applied The OCTOPUS to investigate further the proteolysis of BLG and address the impact on digestibility of modifying the conformational structure of BLG [76]. AZTI-Tecnalia (Bilbao, Spain) has recently patented a method for improving functional properties by means of pulsed light (PL) treatment [77,78].…”

Processamento UV-C de proteínas do soro do leite: Efeitos na estrutura e digestibilidade

“…Não obstante, a β-lactoglobulina, principal proteína do soro, não é facilmente digerida, conferindo a este produto alto potencial alergênico, baixa biodisponibilidade de aminoácidos e déficit na qualidade nutricional do leite. Em vista disso, faz-se cada vez mais importante para a indústria o desenvolvimento de produtos adaptados a faixas etárias, saudáveis, funcionais e que ainda mantenham características organolépticas agradáveis aos consumidores (CASTILLO-SANTAELLA et al, 2014).…”

“…Entretanto, este produto apresenta grande potencial alergênico devido à indigestibilidade gástrica de proteínas como β-lactoglobulina e α-lactoalbumina e peptídeos bioativos (caseíno-morfinas) advindos da proteólise da β-caseína variante A1. A β-lactoglobulina, que corresponde a 9 % do total de proteínas do leite e 50 % das proteínas do soro de leite bovino, é responsável por aproximadamente 80% dos casos alergia e tem seu valor nutricional diminuído devido a rígida estrutura terciária e grande estabilidade conformacional em baixos pHs, o que dificulta a digestão (CASTILLO-SANTAELLA et al, 2014;RAHAMAN et al, 2017 et al, 2013). Cada proteína tem uma fotoreatividade intrínseca devido à quantidade, conformação e localização destes cromóforos.…”