Peanut defatted

Paanat lAlso see PEANUTS. Defatted peanut meal is ground into a flour. Heasant tasbng, light cream calorad powder. 

Nut Products. Peanut products iaclude peanut flour, Hpoproteia, proteia, milk, and partially defatted peanuts (109). Pecan butter is made from dry roasted meats, ground to a very fine state, and mixed with salt (2% of final weight), hydrogenated fat (1.5%), and the antioxidant butylated hydroxyanisole (BHA) (131). 

Partially Defatted Nuts. There is considerable demand for nuts and nut products of reduced fat content. Almond meal and peanut meal are examples of products having low fat content achieved by pressing oil from the nuts and by grinding the cake. Much of the flavor is in the oil defatted nuts are thus less tasty. 

A process has been developed (139) whereby up to 80% of the oil can be removed from whole, raw peanuts without the use of solvent. In this process, the blanched peanuts are brought to a proper moisture content, pressed mechanically, and then reshaped or reconstituted by dipping in hot water subsequently they can be roasted and salted, or used in confections or other formulations. Defatted peanuts may also be ground into meal and added to cookies, cakes, and many other products, where they impart a distinctly nutty flavor and cmnchy texture. On the other hand, the resulting high grade oil is refined and employed in cooking and industrial products. This process can also be used for pecans, walnuts, almonds, Brazil nuts, cashews, and other nuts (140-142). 

Defatted peanuts are high in protein, low in moisture, contain only 20% of the naturally occurring fat, and have better stability than whole peanuts. Monosodium glutamate (MSG) has been used as a flavor enhancer for defatted nuts, but the result has not been entirely satisfactory as the addition of MSG produces a meaty rather than nutty flavor. This meaty flavor is more compatible with salted butter and nuts than with candy. 

Minor Constituents. All four oilseeds contain minor constituents that affect the use of the defatted seeds, especially in feeds and foods. Percentages of phytic acid [83-86-3] (3), for example, are soybean, 1.0—1.5 (30) cottonseed kernels, 2.2—3.8 (25) peanut kernels, 0.8 (25) and sunflower, 1.6-1.7 (31). 

The edible oilseed protein industry is comparatively small and is restricted to peanut and soybean proteins. One company manufactures partially defatted peanut flours made by hydraulic pressing. The products contain 40—42% protein. Production estimates for edible soybean proteins in the United States in 1993—1994 (56) and wholesale prices as of November 1995 are given in Table 15. 

Figure 3. Representative sugar cookies prepared from defatted peanut, soybean, and field pea flours at 0, 10, 20, and 30% wheat flour replacement levels. Reproduced with permission from Ref. 3. Copyright 1978, American Association of Cereal Chemists.

Follow-up studies utilized finely-milled legume flours and the addition of soybean flour as a fat-control agent in an effort to improve doughnut quality (5). The legume products and doughnuts prepared from them are shown in Figure 5. On a dry weight basis, peanut flour from solvent extracted peanuts (PF-SE) contained 0.9% fat and 54.4% protein while cowpea flour (CF) contained 1.4% fat and 25.5% protein. Peanut flour from partially defatted untoasted peanuts (PF-PD-U) contained 34.5% fat and 34.9% protein while peanut flour from partially defatted peanuts toasted at 160°C contained 34.4% fat and 37.6% protein. 

Figure 5. Representative doughnuts prepared from peanut flour-solvent extracted (PF-SE), peanut flour-partially defatted-untoasted (PF-PD-U), peanut flour-partially defatted-toasted (PF-PD-T), and cowpea flour (CF). WFR = wheat flour reference,...

Typically, full-fat flours are made by hammer milling the seed to pass through 80-mesh or smaller size screens. However, grinding of oilseeds containing over 25% oil results in sticky flours. Thus, partially-defatted peanut and sunflower seed flours are made by first screw pressing the seed to reduce the oil to 6-18% fat content. 

Defatted flours are especially attractive as protein sources, since 10-12% substitution of wheat flour with 50% protein flour will raise total protein content of typical wheat breads by approximately 50%, and 25% substitution will almost double the protein content of cookies. Preparation of protein-enriched breads has been reported in the literature using soy flours and protein concentrates (25), peanut flours and peanut protein concentrates C26, 27), glandless cottonseed flours, concentrates and isolates (28), sunflower seed flours and seed protein concentrates (27) and sesame flours and protein concentrates (26). 

High-protein, low-cost Nigerian foods, chin-chin, puff-puff, akara (9), akamu, sugar cookies and yeast bread (10) were developed using raw full-fat cottonseed (Table I), defatted cottonseed (Table V), soybean, peanut or sesame flours as protein supplements. 

Figure 14. Foam capacity and protein solubility properties of defatted soybean, peanut, field pea, and pecan seed flour suspensions at various pH values (4T)...

The effects of fungal fermentation on the moisture adsorption and retention properties of defatted peanut flour have been reported (28). At 8 and 21OC, little difference was noted between the moisture contents of freeze-dried ferments and untreated samples equilibrated at relative humidities ranging from 14 to 75%. However, marked changes were noted above 75% equilibrium relative humidity (ERH), where the control samples did not adsorb as much moisture as did the ferments. These differences were attributed to an increased ratio of exposed hydrophilic to hydrophobic groups resulting from fermentation. 

Beuchat (60) investigated the performance of enzyme-hydrolyzed defatted peanut flour in a cookie formula. Flour slurries were treated with pepsin at pH 2.0, bromelain at pH 4.5, and trypsin at pH 7.6. After readjustment to pH 6.9, materials were freeze-dried, pulverized (60-mesh), and then substituted for wheat flour at 5, 15, and 25%. Adjustment of peanut flour to pH 2.0, as well as treatment with pepsin at this pH, greatly improved the handling characteristics of dough in which these flours were incorporated. Use of peanut flours treated at pH 4.5, with or without bromelain, and at pH 7.6, with or without trypsin, improved handling properties of cookie dough. These doughs did not tend to crumble... 

McWatters and Holmes ( ) developed multiple regression models of the effects of pH and salt concentration on functional properties of soy flour. Design of the experiment and selection of the factors to be Included were based. In part, on earlier findings that emulsion capacity of defatted peanut meal was Inhibited around the Isoelectric point (ca pH 4.0)... 

Soluble proteins in various aqueous fractions of glandless cottonseed flour (hexane-defatted) and peanut products (whole peanuts, and full-fat and hexane defatted meal and flour) were determined by methods of Cherry et al (10), and McWatters et... 

Lin et al. (15) showed that sunflower meal was superior to soybean and sunflower concentrates or isolates In emulsion capacity. McWatters and Cherry (9) compared select functional properties of defatted soybean, peanut, field pea, and pecan flours and showed that major seed storage proteins were important in emulsifying and foaming properties. Protein solubility was related to the quality of the emulsions and foams. Behavioral characteristics contributed by nonprotein components that occur naturally In the seeds, especially carbohydrates, were Implicated. 

Suknark, K., Phillips, R.D., and Chinnan, M.S. (1997). Physical properties of directly expanded extrudates formulated from partially defatted peanut flour and different types of starch. Food Res. Ini. 30, 575-583. 

A qualitative PCR assay was developed for the detection of peanut in foods and validated further with the collaboration of six participant laboratories (Watanabe et al., 2007). Autoclaved, roasted, boiled, and nonprocessed doughs made out of Japanese yam spiked with different levels of defatted peanut flour (0, 0.001, 0.01, 0.1%) were used as food models. Results were compared with ELISA, which showed decreased protein levels in the processed food models, especially in the autoclaved dough. No protein was detected in aU of the nonspiked dough. PCR results from the six labs correctly identified dough samples (processed and nonprocessed), which correlated with results obtained from ELISA analysis. The assay was shown to be specific, reproducible, reliable, and applicable for the detection of peanut in the model processed food. 

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