Mayonnaise lipids

It should be noted that Cypridina luciferin emits a fairly strong chemiluminescence in aqueous solutions in the presence of various lipids and surfactants, even in the complete absence of luciferase. The luminescence is especially conspicuous with cationic surfactants (such as hexadecyltrimethylammonium bromide) and certain emulsion materials (such as egg yolk and mayonnaise). Certain metal ions (especially Fe2+) and peroxides can also cause luminescence of the luciferin. Therefore, great care must be taken in the detection of Cypridina luciferase in biological samples with Cypridina luciferin. 

JACOBSEN C, HARTVIGSEN K, THOMSEN M K, HANSEN L F, LUND P, SKIBSTED L H, H0LMER G, ADLER-NissEN J and MEYER A s (2001) Lipid oxidation in fish oil enriched mayonnaise calcimn disodium ethylenediaminetetraacetate, but not gallic acid, strongly inhibited oxidative deterioration, J Agric Food Chem, 49, 1009-19. 

Emulsions are mixture of two (or more) immiscible substances. Everyday common examples are milk, butter (fats, water, salts), margarine, mayonnaise, skin creams, and others. In butter and margarine, the continuous phase consists of lipids. These lipids surround the water droplets (water-in-oil emulsion). All technical emulsions are prepared by some kind of mechanical agitation or mixing. Remarkably, the natural product, milk, is made by organisms without any agitation inside the mammary glands. 

Many food colloids are stabilized from proteins from milk or eggs [817]. Milk and cream, for example, are stabilized by milk proteins, such as casein micelles, which form a membrane around the oil (fat) droplets [817]. Mayonnaise, hollandaise, and bearnaise, for example, are O/W emulsions mainly stabilized by egg-yolk protein, which is a mixture of lipids (including lecithin), proteins, and lipoproteins [811,817]. The protein-covered oil (fat) droplets are stabilized by a combination of electrostatic and steric stabilization [817]. Alcohols may also be added, such as glycerol, propylene glycol, sorbitol, or sucrose sometimes these are modified by esterification or by... 

The use of surfactants in the food industry has been known for centuries. Naturally occurring surfactants such as lecithin from egg yolk or soybean and various proteins from milk are used for the preparation of many food products, such as mayonnaise, salad creams, dressing, and desserts. Polar lipids such as monoglycerides have been introduced as emulsifiers for food products. More recently, synthetic surfactants such as sorbitan esters (Spans) and their ethoxylates (Tweens), sucrose esters, have been used in food emulsions. It should be mentioned that the structures of many food emulsions is complex, and in... 

Multiphase Systems Antioxidant activity depends very much on the lipid substrate used for evaluation and the hydrophilic/lipophihc nature of the anti-oxidative compound. Solubility and partition properties of the compound in the medium affect the activity of antioxidants in the bulk hpid systems. As most foods cannot be related to bulk oil systems (e.g., meat, fish, eggs, mayonnaise, salad dressings, etc.), evaluation of antioxidants in multiphase systems is more relevant to their physical and chemical nature. Because of the very same reasons, several studies have found that compounds exhibiting strong activity against oxidation of lipids in bulk systems are often inefficient in colloidal and emulsion systems. 

Other common forms of spoilage in mayonnaise are a result of oxidative degradation of various components, especially vegetable oil and egg lipids. Microbial... 

Lipids contribute to foam structure of whipped cream and constitute an essential phase in food emulsions, such as milk, mayonnaise, and gravy. Lipids also provide a pleasant creamy or oily mouth feel to many food products and contribute to the juiciness of meat. They prevent crystallization and provide smoothness to crystalline candies and frozen desserts. 

As is the case with sorbic acid, benzoic acid penetrates the cell wall in the undissociated form. As a consequence, it is active at lower pH values only (pKa at 25°C = 4.19) and therefore serves as a preservative for sour products such as fruit juices and jams. In shrimp preservation it is applied as a powder that is spread over the shrimps, passes cell walls, and then ionizes in the intracellular fluid to yield protons that acidify the alkaline interior of the cell. The main cause of its activity, however, is biochemical effects (Eklund, 1980) such as inhibition of oxidative phosphorylation and of enzymes from the citric acid cycle (Chipley, 1983). In mayonnaise preserved by benzoic acid, the undissociated acid is mainly present in the lipid phase, which can be considered as a reservoir for the aqueous phase. 

LENNERSTEN M and LINGNERT H (2000), Influence of wavelength and packaging material on lipid oxidation and colour changes in low-fat mayonnaise , Lebensm-Wiss u-Technol, 33, 253-260. 

FIGURE 2.21 Cryo-SEM micrograph of mayonnaise. Film surrounding lipid droplets (11) connection between droplets (co). 

Because many foods are emulsified materials (e.g., milk, mayonnaise, coffee creamers, salad dressings, butter, and baby foods), an understanding of the mechanisms of lipid oxidation in emulsions is crucial for the formulation, production, and storage of food products. Oil-in-water emulsions consist of three different components water (the continuous phase), oil (the dispersed phase), and surface-active agent (the interface). 

Egg yolk Phosvitin, egg yolk lecithin Dispersible and heat sensitive Both the protein and the lipids contribute to the functionality Emulsifier (e.g. mayonnaise and dressings), baking products... 

Salad dressings and mayonnaise can be stabilized by ionic surfactants, which provide some electrostatic stabilization as described by DLVO theory, or by nonionic surfactants which provide a viscoelastic surface coating. The protein-covered oil (fat) droplets tend to be mostly stabilized by steric stabilization (rather than electrostatic stabilization) [34,126,129], particularly at very high levels of surface protein adsorption, in which case the adsorption layer can include not just protein molecules but structured protein globules (aggregates). In some cases, lipid liquid crystal layers surround and stabilize the oil droplets, such as the stabilization of O/W droplets by egg-yolk lecithins in salad dressing [34,135]. 

Timm-Heinrich, M., Xu, X., Skall N.N. and Jacobsen, C. Oxidative stability of mayonnaise and milk drink produced with structured lipids based on fish oil and caprylic acid. Europ. Food Res. Technol. 219, 32-41 (2004). 

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