Characterization of an effective drug carrier system for improved oxidative and thermal stability of essential fatty acids: a review

Figures & data

Figure 1. SEM of multi-layered microencapsulation structure of antioxidants (AOX) and wall material (WM).

Figure 2. Mechanism and factors of lipid oxidation in the oil-in-water emulsions.

Figure 3. Schematic illustration of different types of emulsions: conventional emulsions (a), multilayer emulsions (b), gelled emulsions (c), pickering emulsions (d), and multi-layered microencapsulation structure (e).

Table 1. Emulsifier modification in different ways to improve the oxidative stability of omega 3 fatty acids.

Modification methods	Applications	Preparation approaches	Characteristics	References
Maillard reaction	Pea protein isolate-gum Arabic,Caseinate-dextran, Sodium caseinate–galactose, Glucose-hydrolyzed β-lactoglobulin WPI-dextran	Dry-heating treatment: moderate temperature and long treatment time Heat-moisture treatment: high temperature and short treatment time Pulsed electric field processing: extremely short processing time	Enhanced antioxidative capability and adsorption efficiency of conjugates; Smaller droplet size; Dense interfacial layer; Higher oxidative stability of omega 3 fatty acids in emulsions.	(Corzo-Martínez et al., 2012; Guan et al., 2010; Vhangani& Van,2016; Wong, Day, & Augustin, 2011)
Free radical grafting	Egg albumin–catechins, Catechin–egg white proteins, Epigallocatechin gallate–WPI, Protocatechuic acid–chitosan	Ascorbic acid/hydrogen peroxide redox pair as an initiator system	Better antioxidative activity, emulsifying properties and thermal stability of conjugates; No limits of the type of reactants; Smaller droplet size, Better protection of PUFAs and MUFAs.	(Curcio, Puoci, & Iemma,2009; Gu et al.,2017; Fan et al.,2018; Feng et al., 2017)
Enzymatic Cross-linking	Sodium caseinate, Gelatin–catechin, Catechin	Transglutaminase⋅Laccase	Enhanced antioxidative capability of conjugates; Denser interfacial layer; Reduced concentration of oxidative products; depended on the dosage of enzyme; Ecofriendly and highly specific.	(Kurisawa et al.,2003; Phoon et al.,2014; Xiao et al.,2017)
Genipin- mediated cross-linking	Legume protein isolates, Epigallocatechin gallate–WPI	Genipin⋅25 to 37 ^◦C for 24 hr	Reduction in interfacial tension; Increased creaming stability; Larger droplet size; Higher oxidative stability of omega 3 fatty acids in emulsions; Convenient and ease of preparation.	(Fan et al.,2018; Johnston, Nickerson, & Low,2015)
High pressure processing	Sodium caseinate, Gliadin, WPI	34.5 to 140 MPa 1 to 8 cycles	Interfacial protein aggregation; Cross-linking between adsorbed and unadsorbed proteins; Formed a gel-like structure; Promoted interactions between proteins and lipid; Improved oxidative stability of emulsions; Facile preparation approach.	(Lee et al.,2007; Liu et al.,2017; Phoon et al.,2014)
Noncovalent interaction	WPI-gum Arabic, Tannic acid-cuttlefish skin gelatin, Gliadin-proanthocyanidins	Electrostatic interaction ⋅Antisolvent technology	Be able to prepare Pickering particles; Compact interfacial layer; More antioxidative emulsifiers; Higher oxidative stability of sensitive lipids in emulsions.	(Aewsiri et al.,2010; Huang et al., 2017; Yao et al., 2016)
Multilayered microencapsulation	Catechin–egg white proteins, Epigallocatechin gallate–WPI, Protocatechuic acid–chitosan, lipid combinations	Multilayering of wall material and matrix with covalent cross linking, spray drying	Enhanced antioxidative and emulsifying ability of microencapsulates Enhanced oxidative stability of PUFAs and MUFAs in emulsions; Innovative approach.	(Maria Jenita et al, 2020)

PUFAs, polyunsaturated fatty acids; MUFA, monounsaturated fatty acids; WPI, whey protein isolate.

Figure 4. Multilayering coating ratios- antioxidants (AOX) and wall material (WM).

Figure 5. Drug diffusion profile of multi-layered microencapsulation structure of antioxidants (AOX) and wall material (WM) with respect to time.