Egg preservation

Water glass is usually sold in the form of clear syrupy solutions and is used as an egg preservative, as a cement in the manufacture of cardboard boxes, as a fireproofing agent, in the manufacture of soaps and cleaners, and so forth. 

USE In mortar, plaster, cement and other building and paving materials in lubricants, drilling fluids, pesticides, fireproofing coatings, water paints as egg preservative manuf of paper pulp in SBR rubber vulcanization in water treatment dehairing hides. 

Sodium Silicate Solution, Sodium silicate solns of varying composition with respect to the ratio bstween sodium and silica, as well as of various densities, are available. One of the most commonly used sodium silicate solns, also known as egg preserver", contains about 40% NajSijO,. Solns of sodium silicate are strongly alkaline and are readily dec by acids with separation of silicic acid. The greater the ratio of NazO to Si03 (the greater the alkalinity) the more tacky is the soln. 

Some other sealing methods have been employed in egg preservation as wrapping eggs in waxed paper, coating with paraffin, varnishing with collodion, etc., and coating with vaseline. 

Fossilized stacks of mats, called stromatolites, are 2.5 to 3.5 billion years old. Some stromatolites look, from the side, like a stack of plates (I was going to say records, and then CDs, but both of those technologies are ebbing away). Sometimes geology deforms a stack into nested, curved swirls that bring to mind Celtic art or the labyrinth on a cathedral floor. Some are conical, and some are little rounded mounds like a dozen eggs preserved in rock. On Belcher Island, Canada, there s a series of them big enough to be seen from an airplane. 

Sodium and potassium benzoate are substances that may be added direcdy to human food and are affirmed as GRAS (33—35). Benzoic acid and sodium and potassium benzoate are now used as preservatives in such foods as sauces, pickles, cider, fmit juices, wine coolers, symps and concentrates, mincemeat and other acidic pie fillings, margarine, egg powder, fish (as a brine dip component), bottled carbonated beverages, and fmit preserves, jams, and jellies. The popularity of diet soft drinks has led to increased demand for both benzoate salts. 

Whipping aids help to preserve the whipping properties of dried egg white. Sodium lauryl sulfate [151 -21 -3] is preferred, but other approved whipping aids include triethyl citrate, triacetin [102-76-17, and sodium desoxycholate [302-95 ]. These additives are effective at levels of less than 0.02% on a soHds basis. 

Dried blends of whole egg and yolk with carbohydrates have sucrose or com symp added to the Hquids before spray-drying. Such carbohydrates (qv) preserve the whipping properties of whole egg and yolk by keeping the fat in an emulsified state. Com symp also gives anticaking characteristics, better flowabiHty, and improved dispersibiHty in water. Dried blends of egg and carbohydrate function weU in emulsified, as weU as unemulsified, sponge cakes. 

Sputum, for Nematode larvae or Paragonimus eggs Break up mechanically or digest 1 part sputum plus 5 parts 3% NaOH for 1 h. Centrifuge, and preserve the sediment in an equal volume of 10% buffered Formalin. 

The permeabilities of the acid examples rise with increasing phospholipid content, up to 20% lipid, with rank ordering preserved (data not shown). Naproxen and ketoprofen show the most dramatic increases in going from 2% to 10% lipid membranes - somewhat higher in soy than in egg. Piroxicam shows less... 

Colouring acts as a preservative (seals porous egg shell). 

Only food colouring should be used (redwood or onionskin have minimum sealing properties so eggs are poorly preserved). 

IV Use only lidocaine injection without preservatives, clearly labeled for IV use. Monitor EGG constantly to avoid potential overdosage and toxicity. 

Calcium hydroxide has wide industrial applications. It is used to make cement, mortar, plaster, and other building materials. It also is used in water soluble paints, and for fireproofing coatings and lubricants. Other applications are in the manufacture of paper pulp as a preservative for egg in vulcanization of rubber as a depilatory for hides and in preparation of many calcium salts. 

Eiser et al. (2009) have recently reported on the pH-induced transformation of a hard-boiled egg from a white, brittle particulate gel to a transparent, elastic polymer gel (see Figure 6.20). Eggs were incubated in their hard protective shells for up to 26 days in a strong alkaline solution (0.9 M NaOH + 0.5 M NaCl, pH 12) at room temperature. These harsh experimental conditions are apparently rather similar to those used in a traditional Chinese method developed over two thousand years ago as a way of preserving eggs so that they would remain safely edible for many months. 

The silicates of sodium and potassium dissolve in water. A concentrated solution of sodium silicate (Na.SiOj) is sold in hardware stores under the name of waterglass. It is used as a glue, for fireproofing wood and for preserving eggs. 

---