title: Cross-linking of interfacial casein layer with genipin prevented pH-induced structural instability and lipase digestibility of the fat droplets.
abstract: The present study provided a new approach to enhance the stability of protein-emulsified nanoemulsions and to control the lipase digestibility of lipid droplets through spontaneous cross-linking of the interfacial layer with genipin, a functional ingredient isolated from the fruit of Gardenia jasminoides E. Cross-linking casein-emulsified nanoemulsions under different genipin/casein mass ratios (1:20, 1:10, 1:5) significantly (p < 0.05) or very significantly (p < 0.01) enhanced their stability under harsh gastric pH environments and prevented nanoemulsion flocculation. As observed by transmission electron microscope (TEM), under the pH 1.2 condition, the genipin cross-linked nanoemulsion showed more compact microstructure with clear and defined contour as well as "core-shell" structure caused by the swelling of the surface protein film. Interestingly, the intestinal digestibility of lipid droplets was delayed very significantly (p < 0.01) after cross-linking the interfacial casein layer with genipin, which was enhanced by the increase in genipin/casein mass ratio and cross-linking time.
authors: College of Food Science and Technology and §Laboratory of Electron Microscopy, Nanjing Agricultural University , Nanjing 210095, People's Republic of China.
authors: Bing
authors: B
authors: Hu
authors: Liying
authors: L
authors: Zhang
authors: Rong
authors: R
authors: Liang
authors: Fengze
authors: F
authors: Chen
authors: Liping
authors: L
authors: He
authors: Bing
authors: B
authors: Hu
authors: Xiaoxiong
authors: X
authors: Zeng
mesh_terms: D002364:Caseins / Q000737:chemistry* / Q000378:metabolism; D003432:Cross-Linking Reagents / Q000737:chemistry*; D004063:Digestion; D005223:Fats / Q000378:metabolism*; D032062:Gardenia / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007413:Intestinal Mucosa / Q000378:metabolism; D039823:Iridoids / Q000737:chemistry* / Q000378:metabolism; D008049:Lipase / Q000737:chemistry / Q000378:metabolism*; D008954:Models, Biological; D010936:Plant Extracts / Q000737:chemistry* / Q000378:metabolism; D055550:Protein Stability
chemical_list: D002364:Caseins; D003432:Cross-Linking Reagents; D005223:Fats; D039823:Iridoids; D010936:Plant Extracts; C007834:genipin; D008049:Lipase
keywords: casein; gastrointestine; genipin cross-linking; lipase digestibility; nanoemulsion; structure behavior