Flour stability

Butter is used in some, usually more expensive, bakery foods, and is prized for its flavor contribution. Fats are used in some products such as pie cmst, croissants, or puff pastry, up to 60%, based on flour. Stability of fats and oils in perishable items such as breads, cakes, or pastries is of no consequence because shelf life is so limited that rancidity does not occur. In cookies and crackers, however, stable fats must be used in the formula since prolonged shelf life could lead to product deterioration with fats that develop rancidity. 

Nearly half of the U.S. domestic food consumption of peanuts in 1993 was as peanut butter salted peanuts, at 27.3%, and peanut candy, at 23.9% made up the other half (137). Although the per capita domestic peanut consumption in the United States has increased steadily, the consumption in recent years has not kept pace with production. Domestic food use of peanuts has been confined almost entirely to roasted peanuts. A number of investigations and developmental efforts are being made to extend the use of nonroasted peanut products such as flour and meal flakes. As of the mid-1990s, market outlets for these latter products are neither sizable nor firmly established. The food-use patterns emphasize the uniqueness and demand for products having a distinct roasted-peanut flavor. The development of the desired flavor as well as the storage stability of such flavor in peanut-food products are therefore important. 

Uses. Commercial monocalcium phosphate is available as both the anhydrous and the monohydrate salts. Most uses are based on acidic properties. Monocalcium phosphate is used to control acidity in powdered drink mixes, as an ingredient in effervescent tablets, as a plastics stabilizer, and in ceramics. Its single largest appHcation is as a leavening agent in bread, cake mixes, and self-rising flour. 

Butylated Hydroxyanisole. 2- and 3-/ i -Butyl-4-methoxyphenol (butylated hydroxyanisole (BHA)) is prepared from 4-methoxyphenol and tert-huty alcohol over siUca or alumina at 150°C or from hydroquinone and tert-huty alcohol or isobutene, using an acid catalyst and then methylating. It is widely used in all types of foods such as butter, lard, and other fats, meats, cereals, baked goods, candies, and beer as an antioxidant (see Antioxidants Eood additives). Its antioxidant properties are not lost during cooking so that flour, fats, and other BHA-stabiLized ingredients may be used to produce stabilized products. 

As discussed in Chapter 10, a wide variety of additives is used in the polymer industry. Stabilizers, waxes, and processing aids reduce degradation of the polymer during processing and use. Dyes and pigments provide the many hues that we observe in synthetic fabrics and molded articles, such as household containers and toys. Functional additives, such as glass fibers, carbon black, and metakaolins can improve dimensional stability, modulus, conductivity, or electrical resistivity of the polymer. Fillers can reduce the cost of the final part by replacing expensive resins with inexpensive materials such as wood flour and calcium carbonate. The additives chosen will depend on the properties desired. 

Type of flour Water absorption (%) Development time (min) Stability ( min) Resistance (BU) Area (cm3)... 

NMR is an incredibly versatile tool that can be used for a wide array of applications, including determination of molecular structure, monitoring of molecular dynamics, chemical analysis, and imaging. NMR has found broad application in the food science and food processing areas (Belton et al., 1993, 1995, 1999 Colquhoun and Goodfellow, 1994 Eads, 1999 Gil et al., 1996 Hills, 1998 O Brien, 1992 Schmidt et al., 1996 Webb et al., 1995, 2001). The ability of NMR to quantify food properties and their spatiotemporal variation in a nondestructive, noninvasive manner is especially useful. In turn, these properties can then be related to the safety, stability, and quality of a food (Eads, 1999). Because food materials are transparent to the radio frequency electromagnetic radiation required in an NMR experiment, NMR can be used to probe virtually any type of food sample, from liquids, such as beverages, oils, and broth, to semisolids, such as cheese, mayonnaise, and bread, to solids, such as flour, powdered drink mixes, and potato chips. 

It is common practice to stabilize full-fat products by preheating the seed, or by extrusion as in the case of full-fat soybean flour (6). Heat treatment deactivates lipases and lipoxygenases... 

To further evaluate the stability of flours during long term storage, flour fractions from the optimum roasting treatment were selected and stored at two temperatures (20°C, 37.7°C) and three preadjusted moisture contents (6%, 9%, 12% db). It was concluded that flours of all fractions stored at less than 0.75 aw for two months at ambient temperature resulted in stable quality. Long term storage indicated that the flours stored up to 24 months with 6% and 9% moisture at 20°C or with 6% moisture at 37.7°C retained good quality. 

These techniques have been used successfully in the micro-Zdman degradation of the enzyme mouse sarcoma dihydrofolate reductase to obtain the amino acid sequence of the first 25 amino acids 455). Similarly, RPC has been used in coqjunction with the automated Edman technique for sequencing 32 residues of myoglobin 456). Methionine and its oxidation products, methionine sulfoxide and methionine sulfone, in methionine fortified foods have been analyzed as their dansyl derivatives 457). Lysine has been determined as its dansyl derivative in a study in which the stability of lysine in fortified wheat flour was evaluated (458). 

The lethality of ionizing radiation is proportional to the complexity of the organism. Humans, for example, cannot survive more than 800 r., but it may take 2 million r. to inactivate a microorganism. Insect life, of the type which infests field crops, show intermediate stability. Information gleaned from the best available sources (B15, Bl, H9) indicate that a 1000-r. exposure will kill all eggs, 1300 r. will kill all larvae, and 3,000 r. will destroy all young pupae. The resistance of insects to radiation increases with age. For example, to kill some adult species requires 50 to 60,000 r. Adult flour beetles succumb at 10,000 to 16,000 r. 

Microscopic structure of texturized water-extracted soy flour and texturized soy concentrate were quite similar to that of texturized soy flour. Scanning electron microgrpahs showed that water extraction of soy flours had little effect on morphological characteristics of texturized soy products (Figure 10). Solubility of soluble sugars was not affected by texturization, whereas solubility of proteins decreased sharply when soy flour was texturized (Table VII). It appears that soluble sugars did not interact with proteins during texturization. Based upon results of microscopy and solubility studies, it is reasonable to speculate that natural soluble carbohydrates are not required (do not play an important role) in development of texture or stabilization of structure. 

Figure 5. Foam viscosity and stability properties of glandless cottonseed flour...

Figure 7. Experimentally observed and mathematically simulated regression lines of foam stability at different percentages of glandless cottonseed flour in suspensions at various pH values. See Figure 6 for further explanation of the data.

Compared to the nontreated sample, all three succinylation treatments of flour improved foam stability at pH 6.5. At pH... 

In most cases, foam stabilities of suspensions at pH 2.5 and 5.0 indicated that 10% and 40% succinylated flours were not different from the nontreated sample. The pH 5.0 suspension containing flour that was treated with 80% succinic anhydride formed very stable foams. 

Lin et al. (68) investigated the effects of supplementing wieners with sunflower flour and diffusion-extracted protein concentrates. The sunflower products showed good emulsion stability, less shrinkage, and less cooking loss than all-meat controls. 

Figure 2. Response contours for optimization of nutritional, flavor, and stability indicies of extruded full-fat soy flour (46)...

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