Fresh Fat

The process was best adapted to fresh fat. Stocks in which hydrolysis occurred were difficult to process because of the formation of soap in the aqueous phase. The soap was derived only from already liberated free fatty acids. Under the mild conditions of this digestion process, there was no appreciable saponification of neutral fat. The fat was also alkali refined to produce a final product free of acidity. A typical final product had a free fatty acid content of 0.01% and a Fovibond color of 2 yellow and 0.3 red. This process gave improved yields over conventional wet rendering (59, 60). 

Animal tissue cells grown in culture medium in the form of a monolayer are a useful biological living model to observe physiological, morphological or metabolic changes in the presence of compounds added to the medium. Bird and Alexander (15, 37) reported on effects of thermally oxidized corn oil and olive oil on in vitro heart cells. The DNUA from fat thermally oxidized as described earlier (7) was isolated. Free fatty acids from the fresh fat controls or from the DNUA of the heated fats were prepared (38). 

Figure 1. Histological scores for organs of rats intubated with fresh fats (O) or DNUA of heated fats (%). (Reproduced with permission from Ref. 31. Copyright...

HCO, when the incubation period was extended beyond 12 hr, there was a decline in the radioactivity retained in the TG fraction of the heart cells. When the two fresh fats were compared for C incorporation into the lipid classes, the 00 resulted in at least three times as much activity in the TG fraction. 

The most consistent change in cultures exposed to heated fats was associated with intracellular lipid accumulation, which occurred rapidly (Figure 6). Prolonged exposure produced abnormal spherical cells filled with lipid droplets. They contained constricted, centrally located nuclei. Karyorrhexis and karyolysis were observed, and vacuolation and a network appearance were pronounced due to oxidized fat (Figure 7). The pyknotic nuclei as a percentage of the total number of cells in 20 random fields were increased due to heated fat fractions (Table IX), and accompanied the cytoplasmic changes seen earlier. Lipid droplet accumulation was estimated as shown in Table X, and the free fatty acids from the fresh fats induced less lipid accumulation. Nevertheless, the values for 00 were as high as those for HCO. 

Tom Dixon s Fresh Fat furniture and bowls are made by folding extruded tubes of polyester while warm. 

Supercritical Fluid Extraction. Supercritical fluid (SCF) extraction is a process in which elevated pressure and temperature conditions are used to make a substance exceed a critical point. Once above this critical point, the gas (CO2 is commonly used) exhibits unique solvating properties. The advantages of SCF extraction in foods are that there is no solvent residue in the extracted products, the process can be performed at low temperature, oxygen is excluded, and there is minimal protein degradation (49). One area in which SCF extraction of Hpids from meats maybe appHed is in the production of low fat dried meat ingredients for further processed items. Its apphcation in fresh meat is less successful because the fresh meat contains relatively high levels of moisture (50). 

The sale of fresh cream as a table item for serving has decreased greatiy siace the 1970s, primarily as a result of changing customer demand based on diet. A variety of cream and fat substitutes are available for spreads, toppiags, whiteners, and cooking (see Dairy substitutes). 

Butter, fresh and salted, was once a primary trade commodity, but is no longer in as high a demand. There has been a shift in emphasis from fat content to the protein, mineral, and vitamin content of milk and milk products, particularly in developed countries. 

Nuts are rich in protein and fat most commercially important nuts supply about 28 MJ /kg (6600 kcal/kg) of kernel, more than most other foods (Table 2) cereals supply about 15 MJ /kg (3640 kcal/kg) meats about 7.5 MJ /kg (1790 kcal/kg) and fresh fmits less than 2.8 MJ /kg (660 cal/kg). The energy content in kilojoules (1 food calorie or cal = 4.184 kJ) per kilogram of food is calculated by the following formula ... 

Stale bread tastes and feels dry, even though the moisture content is actually the same as in fresh bread. The recrystallization of the starch in bread is what makes it go stale. To combat this, fats and oils are added to bread to form a complex with the starch in its gelled form, slowing down the recrystallization process and keeping the starch in its flexible gel form. 

Trichloroethylene has been detected in dairy products (milk, cheese, butter) at 0.3-10 pg/kg (0.3-10 ppb), meat (English beef) at 12-16 ppb, oils and fats at 0-19 ppb, beverages (canned fruit drink, light ale, instant coffee, tea, wine) at 0.02-60 ppb, fruits and vegetables (potatoes, apples, pears, tomatoes) at 0-5 ppb, and fresh bread at 7 ppb (McConnell et al. 1975). Samples obtained from a food processor in Pennsylvania contained trichloroethylene concentrations of 68 ppb in plant tap water, 28 ppb in Chinese-style sauce,... 

Skimming fresh whole milk allowed us to obtain milk fat globules with natural membranes that were blended at a concentration of 35 g/L with hydrated skim milk powder (35g/L). This reconstituted milk was coded CREAM. 

Davidow (19), of the Food and Drug Administration, has described a colorimetric method applicable to technical chlordan. The method is based on the observation that when technical chlordan is heated with a mixture of diethanolamine and methanolic potassium hydroxide, a purple color is produced. When known amounts of this insecticide were added to cabbage, pears, and fresh and rancid rat fat, recoveries of 74 to 104% of the insecticide were obtained. However, because two crystalline isomers of chlordan isolated from the technical product do not give a colored reaction product with the reagent, further investigation of the method is being made. The red color obtained when technical chlordan is heated with pyridine, alcoholic alkali, and ethylene glycol monoethyl ether, as described by Ard (2), likewise fails with the crystalline isomers of this insecticide. 

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