Table 4.

Critical assessment of the conventional and unconventional techniques for tailoring the structures of lipids, oleogels and fat replacers.

Technique	Advantage	Limitation	Impact on Human Nutrition	Commercial Products
CONVENTIONAL
Fractionation	prevent (olein fraction) or ensure (stearin fraction) solidification at ambient T enrichment of the oil with unsaturated/saturated TAGs obtaining of fractions with narrow melting point	sustainability issues linked to tropical fats high use caused by the high demand of solid fat big capital costs high saturated fatty acids (SFA) of stearin fraction	no changes in TAG composition, thus no adverse effects on humans health on balanced diets high intake rates of foods containing stearin fraction are linked to coronary diseases	frying oils salad oils salad dressing salad mayonnaise formulation cream ice cream shortenings buttercreams infant formulas chocolate
dry	minimum operating costs high olein yields	incomplete phase separation—“entrapment” of oil		cooking and salad oils
solvent	less viscous suspension faster crystallization smaller crystallizer volume high separation efficiencies	recovery of the solvent flavor problems associated with solvent residues		cocoa butter replacers
detergent	transfer the crystallized material from the oil phase to the aqueous phase in order to facilitate subsequent separation			milk fat fractionation
Hydrogenation	increases the melting point of the fat change liquid oil into solid fat stops the decomposition or rancidity of unsaturated fats	catalyst selectivity catalyst deactivation during storage mass transfer limitations	formation of trans-fatty acids correlated to coronary diseases increase low-density lipoproteins (LDL), and decrease good high-density lipoproteins (HDL) side effects of trans-fatty acids: allergic reactions, arteriosclerosis, risk of cancer, decrease in insulin response, and slight immune dysfunction	dressings for salads cooking and frying products bakery coatings emulsions and spreads chocolate and confectionery products coffee creamers fried foods ready-to-use dough packaged snacks
hydrogenation with sc CO2	enhance the mass transfer enhance hydrogenation efficiency decreasing oil viscosity milder conditions of processing	pure CO2—low solubility for higher fatty acids high pressure is required to achieve supercritical conditions, which significantly increase the cost	reduced trans-fatty acids content in hydrogenated oils and fats; however, health concerns still present
Chemical Interesterification (CIE)	modification of the physicochemical properties of fatty materials change the overall melting profiles to improve the compatibility of the different TAGs in the solid state modification of the plasticity of a product by changing its crystallization behavior	drastic operational conditions high temperature or pressure degradation of fats and introduction of side products	possibility of acute health effects due to the random esterification	spreads, bakery products confectionary products infant formula (Betapol)
NONCONVENTIONAL
Enzymatic Interesterification (EIE)	high selectivity mild reaction conditions less side reactions less waste and ease of product recovery environmental benefits such as elimination of the use of potentially toxic chemicals and elimination of by-products and waste	high cost of the enzymatic process poor enzyme stability poor oxidative stability of the structured lipids	improved absorption/digestibility of saturated fatty acids possibility of negative affect on lipoprotein metabolism, glycemic control, immune function, and serum liver enzymes due to the alterations of FA on glycerol backbone	margarine shortening research studies: plastic fats human milk fat substitutes low calorie structured lipids cocoa butter substitutes and cocoa butter equivalents edible film applications
Genetic modification	compositional modifications of crop plant oils through traditional breeding techniques higher proportion of lauric acid eliminates the need of hydrogenation producing oil with higher fraction of SFC and higher melting point	possibility to compromise the ability of the seed to grow and develop limitation the crop yield induction of cross-pollination affect biodiversity the cost of raw materials regulatory issues the acceptance of the consumers	better oxidative stability in deep frying applications extended shelf life zero trans-fat low saturated FAs high oleic content liquid at room temperature excellent taste and flavor	high- oleic sunflower oil high-lauric canola oil (Laurical®) high-oleate phenotype of cultivated peanut research studies: human milk from model oilseed Arabidopsis thaliana
Oleogelation	transformation of liquid oils into a gel like structure which has rheological properties, viscoelasticity, spreadability, and firmness of a solid fat without containing large amount of saturated fats formation of three-dimensional gel network which mimic TAG crystallization prevention of oil migration between lipid-containing phases of composite food products	scaling up the process the lack of commercial applications	increase in unsaturated fat content reduction in saturated fat content lower mean serum triacylglycerol and FFA levels	Crisco—trans fat-free shortening Coasun—zero trans, low-saturate, oil-in-water structured emulsion, alternative to baking margarine. research studies: baking fats margarine and spreads meat products chocolate and chocolate pastes confectionary fillings ice cream yogurt cream cheese
direct dispersion	most commonly used process for creating oleogels one step process network formation with high oil binding capacity at much lower mass fraction of crystalline phase	low stability of the gel during storage due to the crystal aggregation
oil binding method	porous cryogel could absorb oil at more than 100 times its own weight formation of strong gel	deformable gel non-self-standing gels
emulsion template method	entrapment a large amount of liquid oil without showing any oil leakage over extended period of storage	limited dispersion of hydrophilic polymers in oil—ineffective in structuring oils lot of processing steps producing weak gels sensitive to homogenations, shearing, etc.
bigel	thickening of water phase to add body to the emulsion while decreasing solid fat and/or total fat content of the product	rarely match the expected sensation by the consumer difficulty in controlling phase separation not thermo-reversible, not stable at higher temperatures
bioengineered oleogels	obtaining microbial oils or organogelators by means of biotechnology valorization of food industry side streams and by-products sustainable technology	not studied enough low stability over storage period
Fat mimetics from nonlipid origin protein-based carbohydrate-based	create creamy, smooth texture similar to fat stabilize water in the food product in a gel-like matrix provide creamy mouthfeel similar to that of full fat products	cannot be used in cooking oils or in products subject to frying conditions as the proteins are denatured and lose their functionality cannot provide all the functional and sensory advantages of conventional fats can be applied in low fat systems	digested and absorbed as protein/carbohydrate/dietary fiber low caloric value do not increase the risk of heart disease do not adversely affect blood lipid levels	Simplesse—fat replacer whey protein Dairy Lo—fat replacer whey protein K-Blazer—fat replacer protein N-Oil—maltodextrins fat replacer Maltrin M040—hydrolyzed starch fat replacer Paselli SA−2—enzyme modified potato starch fat replacer Oatrim—carbohydrate-based fat replacer Z-Trim—carbohydrate-based fat replacer