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Poster De Conférence Année : 2013

Comparison of mammalian and fungic analogues of Human gastric lipase in infant simulated gastric [i]in vitro[/i] digestion

Résumé

The first stage of intestinal lipolysis is catalyzed by Human Gastric Lipase (HGL). This extremophilic lipase presents specific properties: a low optimal pH range (4-5), a stability to pepsin and pH denaturation down to 1.5, a high tensioactivity allowing its adsorption at interface with low surface tension, a stereospecificity for the sn-3 position of triacylglycerides. Very similar properties are shared by few other gastric mammalian lipases, among which Rabbit Gastric Lipase (RGL). However none of these lipases have been commercially available up to now, which favored the use of acid- and protease-resistant fungic analogues, though their action specificity has not been extensively compared to HGL. This study aimed at comparing a fungic lipase (A12, Aspergillus niger, Amano) with RGL during the semi-dynamic gastric infant in vitro digestion of a model infant formula based on bovine milk. The matrix disintegration, the hydrolysis kinetics and the evolution of lipid composition during digestion were monitored. The matrix disintegration was similar with the two lipases. A12 liberated 18 % of initially esterified Fatty Acids (FA) in 180 min. This was coherent with in vivo studies and in the range with RGL liberation. The released FA reflected the initial composition of the substrate with a ratio in short/medium/long chain FA of 8:22:59 % mol. No preferential enrichment in short chain FA, which are mainly distributed in the sn-3 position of bovine milk triacylglycerol, was observed, whereas it was the case with RGL. The lipid classes analysis confirmed the low sn-1,3 selectivity of A12 lipase which liberated 1.5 % mol glycerol at 180 min whereas lipolysis end-products were restricted to free FA and sn-1,2 diacylglycerols for RGL. A12 presented an annex proteolytic activity. The limits of use of A12 as a HGL analogue have been highlighted. Instead, mammalian or sn-3 stereospecific lipases should be favored, especially when the lipid composition of the digesta has to reflect precisely the in vivo composition.
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Dates et versions

hal-01209538 , version 1 (02-10-2015)

Identifiants

  • HAL Id : hal-01209538 , version 1
  • PRODINRA : 226028

Citer

Claire Bourlieu-Lacanal, Olivia Ménard, Alix de Langle, Florence Rousseau, Marie-Noelle Madec, et al.. Comparison of mammalian and fungic analogues of Human gastric lipase in infant simulated gastric [i]in vitro[/i] digestion. Food Structures, Digestion and Health International Conference, Oct 2013, Melbourne, Australia. , 2013. ⟨hal-01209538⟩
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