Diglyceride fatty acids

Decreased uptake as a mechanism of resistance was also observed in houseflies resistant to organochlorine, organophosphate, and carbamate insecticides. Resistant strains had higher total lipids, monoglycerides, diglycerides, fatty acids, sterols, and phospholipids in the cuticle than did the susceptible strain (Patil and Guthrie, 1979). 

Triglycerides + water <—> diglyceride + fatty acid Diglyceride + water <—> monoglyceride + fatty acid Monoglyceride + water <—> glycerol + fatty acid... 

A similar method separated the following lipids from human fibroblasts into the following groups CE, TAG, phytols, C, diglycerides, fatty acids, ceramides, PE, PS, SM, and LPC on a silica column (ELSD). Working curves were shown for CE, TAG, C, ceramide, PC, and SM fractions. A two-ramp 60-min 99/1/0/0/0-+ 0/0/20/80/0 -> 0/0/0/50/50 hexane/THF/chloroform/IPA/water gradient was used. Samples containing 30 nmol total lipid phosphorus were used [433],... 

Advantages of SEC include the on-line nature of the process of extraction, chromatography, and fractionation, the mild conditions of both SEE and SEC, and the low cost and nonpolluting properties of CO2. Semipreparative SEC coupled with SEE has been used to fractionate the lipids of palm oil, including triglycerides, diglycerides, fatty acids, carotenoids, tocopherols, and tocotrienols... 

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. 

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. 

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. 

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. 

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. 

Cherry and Crandall in 1932 (86) used olive oil as substrate with gum acacia as the emufsTfier. This method has served as the basis for a number of modifications that increased the stability of the emulsion, decreased incubation time and gave better precision. When a serum sample is incubated with a stabilized olive oil emulsion, lipase acts at the interface of substrate and water to hydrolyze olive oil into fatty acid plus diglycerides, and to a small extent to monoglycerides and glycerol. The bile salt sodium deoxycholate activates the reaction. These methods measure the liberated fatty acids by titration with a standardized NaOH solution. An indicator such as phenolphatalein, thymolphthalein or methyl red or a pH meter are used to detect the end point. 

Mono- and diglycerides of fat-forming fatty acids Sodium benzoate... 

Figure 5.15 GALDI mass spectra of (a) linseed oil (35 years airtight storage from THF solution) and (b) linseed oil as in (a) after 2 weeks of natural ageing (from THF solution). Signal groups of free fatty acids, their oxidation products, and monoglycerides (m/z <500) can be distinguished from diglycerides (m/z 500 800), and triglycerides (m/z 800 1000) (see Table 5.7)...

A stable foam is likely to have ingredients that are in a low energy state at the air-liquid interface. Substances that fit this description include proteins, emulsifiers some fats and fat components such as diglycerides monoglycerides and fatty acids. Food law uses the term emulsifier and stabiliser to cover the situation where the ingredient is stabilising an emulsion rather than helping to form it. 

TLC spots with marker reveal the presence of free fatty acids (FFA), diglyceride (DG), monoglyceride (MG) but negligible amount of TG. GCMS of fatty acid— methyl esters (FAME) from lion mane presented evidence for fatty acids ranging from C9-C24 (Figs. 5.3- 5.6). Low volatility molecules like nonanedioic acid (Fig. 5.3), tridecanoic acid (Fig. 5.4), 12-methyl tridecanoic acid were also present in lion hair lipids. In addition fatty acids such as myristic, pentadecanoic, palmitic, heptanoic, stearic and octadecenoic acids (Fig. 5.5) have also been detected. Erucic... 

---