In vitro digestion of galactolipids from chloroplast-rich fraction (CRF) of postharvest pea vine field residue (halum) and spinach leaves

Wattanakul, Jutarat; Sahaka, Moulay; Amara, Sawsan; Mansor, Syamila; Gontero, Brigitte; Carri�re, Fr�d�ric; Gray, David

Abstract

The removal of intact chloroplasts from their cell wall confinement offers a novel way to obtain lipophilic nutrients from green biomass, especially carotenoids and galactolipids. These latter are the main membrane lipids in plants and they represent a major source of the essential α-linolenic acid (18:3; ALA). Nevertheless, knowledge on their digestion is still limited. We have developed a physical method of recovering a chloroplast-rich fraction (CRF) from green biomass and tested its digestibility in vitro under simulated gastrointestinal conditions. Using a two-step static model, CRF from both spinach leaves and postharvest, pea vine field residue (haulm) were first exposed to enzymes from rabbit gastric extracts and then either to pancreatic enzymes from human pancreatic juice (HPJ) or to porcine pancreatic extracts (PPE). The lipolysis of monogalactosyldiacylglycerol (MGDG) and digalactosyl diacylglycerol (DGDG) was monitored by thin layer chromatography and gas chromatography of fatty acid methyl esters. For both CRF preparations, MGDG and DGDG were converted to monogalactosylmonoacylglycerol (MGMG) and digalactosylmonoacylglycerol (DGMG), respectively, during the intestinal phase and ALA was the main fatty acid released. Galactolipids were more effectively hydrolysed by HPJ than by PPE, and PPE showed a higher activity on MGDG than on DGDG. These findings may be explained by the higher levels of galactolipase activity in HPJ compared to PPE, which mainly results from pancreatic lipase-related protein 2. Thus, we showed that CRF galactolipids are well digested by pancreatic enzymes and represent an interesting vehicle for ALA supplementation in human diet.

Citation

Wattanakul, J., Sahaka, M., Amara, S., Mansor, S., Gontero, B., Carrière, F., & Gray, D. (2019). In vitro digestion of galactolipids from chloroplast-rich fraction (CRF) of postharvest pea vine field residue (halum) and spinach leaves. Food and Function, 10(12), 7806-7817. https://doi.org/10.1039/C9FO01867K

• Journal Article Type: Article
• Acceptance Date: Nov 6, 2019
• Online Publication Date: Dec 3, 2019
• Publication Date: Dec 1, 2019
• Deposit Date: Nov 28, 2019
• Publicly Available Date: Dec 2, 2020
• Journal: Food and Function
• Print ISSN: 2042-6496
• Electronic ISSN: 2042-650X
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 10
• Issue: 12
• Pages: 7806-7817
• DOI: https://doi.org/10.1039/C9FO01867K
• Keywords: Chloroplast, Galactolipase, Galactolipid, Human pancreatic juice, Porcine pancreatic extract
• Public URL: https://nottingham-repository.worktribe.com/output/3428097
• Publisher URL: https://pubs.rsc.org/en/content/articlelanding/2019/FO/C9FO01867K#!divAbstract
• Additional Information: : This document is Similarity Check deposited; : Supplementary Information; : Jutarat Wattanakul (ORCID); : Syamila Mansor (ORCID); : Brigitte Gontero (ORCID); : Frédéric Carrière (ORCID); : Frédéric Carrière (ResearcherID); : David Gray (ORCID); : Single-blind; : Received 15 August 2019; Accepted 6 November 2019; Advance Article published 3 December 2019; Version of Record published 11 December 2019