1.2- Diglyceride

Derivatization has been widely used to enhance the ionization efficiency and selectivity of mono- and diglyceride species in order to be sensitively and specifically analyzed by ESI-MS [12-14]. The fragmentation features of the derivatized mono-and diglyceride species are mentioned in the chapter if they are available. 

It should be borne in mind that the majority of glycolipid species with or without derivatization were characterized by many other ionization techniques prior to the utilization of ESI-MS. Those kinds of information are well documented in the books written by Murphy [15, 16], and Christie and Han [17]. The interested readers could consult these books for any further information. 

A fragment ion at [M+NH4 35]+, corresponding to the sequential loss of ammonia and then water. 

A cluster of abundant fragment ions resulting from the loss of free fatty acid(s) plus an ammonia molecule (i.e., [M+NH4-(RCOOH+NH3)]+) or other combinations are present. (However, the ammonia-loss ion is generally the base peak. This is likely due to the preferable loss of the proton along with the carboxyl moiety from the a-hydrogen atom of the adjacent FA chain as occurred in the fragmentation process of many lipids in the positive-ion mode including PC and TAG species [8, 18] (see Chapter 7).) 

The introduction of a quaternary ammonium cation to the hydroxyl moieties of DAG species, using A-chlorobetainyl chloride, was reported [12]. This derivatization not only affords an increased ionization efficiency of two orders compared to their underivatized sodium adducts but also makes the ionization efficiency independent of FA chains present in DAG species because of the existence of a fixed charge site after derivatization. The fragmentation pattern of A-chlorobetainyl-derivatized DAG species is essentially identical to that of PC species (see Chapter 7). 

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Fig. 6. Melting points of mono-, di-, and triglycerides, where H is fatty acid I, triglyceride 1,3-diglyceride and, 1-monoglyceride.

Smoke, Flash, and Fire Points. These thermal properties may be determined under standard test conditions (57). The smoke poiat is defined as the temperature at which smoke begias to evolve continuously from the sample. Flash poiat is the temperature at which a flash is observed whea a test flame is appHed. The fire poiat is defiaed as the temperature at which the fire coatiaues to bum. These values are profouadly affected by minor coastitueats ia the oil, such as fatty acids, moao- and diglycerides, and residual solvents. These factors are of commercial importance where fats or oils are used at high temperatures such as ia lubricants or edible frying fats. 

Fat. Milk fat is a mixture of triglycerides and diglycerides (see Fats and fatty oils). The triglycerides are short-chain, C. —C., medium-chain, 24 46 ... 

The quaHty, ie, level of impurities, of the fats and oils used in the manufacture of soap is important in the production of commercial products. Fats and oils are isolated from various animal and vegetable sources and contain different intrinsic impurities. These impurities may include hydrolysis products of the triglyceride, eg, fatty acid and mono/diglycerides proteinaceous materials and particulate dirt, eg, bone meal and various vitamins, pigments, phosphatides, and sterols, ie, cholesterol and tocopherol as weU as less descript odor and color bodies. These impurities affect the physical properties such as odor and color of the fats and oils and can cause additional degradation of the fats and oils upon storage. For commercial soaps, it is desirable to keep these impurities at the absolute minimum for both storage stabiHty and finished product quaHty considerations. 

Glycerol Esters. Commercial glycerol esters, though named after the most abundant species, almost always are mixtures of isomeric mono-and diglycerides (see Glycerol). Trade names and compositions of typical commercial products are given in Table 16. 

Polyoxyethylene Esters. This series of surfactants consists of polyoxyethylene (polyethylene glycol) esters of fatty acids and aUphatic carboxyhc acids related to abietic acid (see Resins, natural). They differ markedly from mono- and diglycerides in properties and uses. 

The oleoresins are available in various standardized forms in which 1 kg of oleoresin is equal to 10—30 kg of paprika. Paprika oleoresins are typically standardized by dilution with vegetable oil or mono- or diglycerides. 

It is important to note that diet is a complex mixture that contain compounds with varying activity. Chemical stimulators of colon cancer growth include bile acids, 1,2-diglycerides and prostaglandins which stem from consumption of fat. In contrast, fruits and vegetables contain substances such as carotenoids, flavonoids and fibre, which may inhibit cancer cell growth, and the risk of colon cancer appears to be mirrored by the ratio of plant sterols to cholesterol in the... 

Up to 25% by weight of the product is ethylidene diacetate. The diacetate can be detected by gas chromatographic analysis using a column of the diglyceride of 6,6,6-trifluorohexanoic acid on firebrick at 120°.10 The checkers obtained yields ranging from 24% in a 0.75-scale experiment to 47% on a three-fold increase in scale. 

If there is one fatty acid, you get a monoglyceride. If there are two fatty acids, you get a diglyceride. When there are three fatty acids, you get a triglyceride. 

Diglycerides are also emulsifying agents. You will see mono- and diglycerides as ingredients in many foods that combine oil and water. 

Shortening also contains pieces of fats called monoglycerides and diglycerides. These are emulsifying agents that allow water and air to be whipped into the shortening and help to thicken it and make it gel. 

Glyceryl stearate mono- and diglycerides monostearin octade-canoic acid monoester with 1,2,3-propanetriol... 

A monoglyceride is a fat that is missing two of its fatty acids. It is often used with diglycerides, which are fats that are only missing one of their fatty acids. 

Temperature, on the other hand, has no influence on the ratio of reaction products but influences the rate of reaction and the forming of colored byproducts [14]. The preparation of surfactants by reaction of P4O10 with fats, oils, and diglycerides is described in early patents [1,15,16]. Surfactants were prepared by the neutralization of higher fatty alcohol-mixed phosphates [17]. 

The addition of acetic acid anhydride or acetyl chloride was found to accelerate the reaction. In certain instances other solvents are also used. Phosphates of higher molecular weight alcohols was formed by reaction with P4O10 or POCl3 in the presence of benzene [18-20]. Specific examples describe the reaction of P4O10 with diglycerides from vegetable oil in the presence of isopro-... 

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