Leaf protein concentrates

Table 9. Selected Processes for Leaf Protein Concentrate Production, 1993...

Whole leaf protein concentrate, 16.5% nitrogen-free extract and 7.9% soluble soHds. 

Table 11. Nutritive Value of Leaf Protein Concentrates and Other Protein Products ...

Of the 190 accessions evaluated after one year s growth in Florida, 38 showed tuber formation. Tender leaves are incorporated in the food preparations in the South Asian region. Leaf protein concentrate (crude protein 51.9%) prepared from leaves yielded a PER value of 2.2 in comparison to 2.7 for corn-soy control. International Winged Bean Trials conducted in 19 countries recommend 5 varieties as having the best yield potential under varying environmental conditions. 

The solubility of P-carotene in supercritical fluids has been studied extensively [81 to 85], The extraction of P-carotene from a wide varieties of natural sources has also been described like alfalfa-leaf protein concentrates [86], carrots [34,87], sweet potatoes [88], and algae [89],... 

Favati, F., King, J.W., Friedrich, J.P., and Eskins, K. 1988. Supercritical CO2 extraction of carotene and lutein from leaf protein concentrates. J. Food Sci. 53 1532-1536. 

Lipids are often a nuisance in extraction of proteins. For example, in preparing leaf protein concentrate a protein-lipid complex is formed frequently affecting the protein extraction efficiency (16). Nutritionally, the complex is disadvantageous because it resists digestion by proteases (17). Shenouda and Pigott (18) found that the formation of protein-bound lipids can cause a low efficiency of extraction of protein from fish. Hydro-phobic bonding probably plays an important role in protein-lipid interactions. Mohammadzadeh-k et al. (19) reported protein interaction with completely apolar compounds such as aliphatic hydrocarbons. 

Succinylation significantly enhances the rate of hydration of soy, peanut and cottonseed proteins (12,38,43). It causes a marked improvement in the water solubility of soy protein and also of leaf protein concentrate (12). It decreased the isoelectric point of both soy and peanut proteins by approximately 0.5 pH unit (from pH 4.5 to 5.0) significantly enhanced solubility between the isoelectric point and pH 6, but progressively reduced solubility of both soy and peanut protein below the isoelectric point (12,43). 

H. T. Ostrowski-Meissner, Protein concentrates from pasture herbage and their fractionation into feed- and food-grade products, in L. Telek, H.D. Graham (Eds.), Leaf Protein Concentrates, AVI Publishing Co., Westport, CT, 1983 (Chapter 15). 

Some examples of successful commercial selective extractions are the removal of caffeine from coffee or the solubilization of nicotine from tobacco both accomplished on moist matrices to aid in selectively solubilizing the alkaloid component. Selective extraction has been demonstrated for the segregation of essential oil from other lipid components in natural extracts derived from fruits and for the separation of aroma components in cocoa butter from the base oil. Other enrichment SEE schemes that have been reported include the fractionation of carotenoid from leaf protein concentrate [25], the fortification of sterols in seed oils [26], and the isolation of lecithin (phospholipid-containing fraction) from triglycerides [27]. 

Leaves and subterranean plant organs are additional sources of protein materials. Potato proteins are largely available as a by-product of the starch extraction. A promising source of soluble proteins is represented by the leaves of many species leaves contain about 80-90% water and 10-20% organic material, a small part of this (10-30%) is made of proteins. About 50% of the proteins are water soluble and can be extracted and purified as a crystalline protein fraction with a molecular weight in the range 10-60 kDa, suitable for food and cosmetic purposes (leaf protein concentrate) (18). 

MINIMIZING THE SAPONIN CONTENT OF ALFALFA SPROUTS AND LEAF PROTEIN CONCENTRATES... 

Alfalfa leaf protein concentrates (LPC) have been shown to be excellent sources of amino acids (Blckoff al., 1975) and other nutrients for swine (Cheeke, 1974 Cheeke et al., 1977a Cheeke and Myer, 1973) and poultry (Kuzmlcky and Kohler, 1977) and potentially for human consumption. However, the possible concentration of naturally occurring biologically active compounds In alfalfa sprouts and leafy protein concentrates makes It essential to develop procedures for minimizing such compounds during... 

Cheeke et al , (1977b) evaluated the effects of high and low saponin alfalfa leaf protein concentrates in the diets of rats, rabbits and swine. He concluded that low saponin leaf protein concentrates support a higher growth rate of rats and swine than the high saponin protein concentrates. In the case of rats and rabbits he attributed the lower growth rate to decreased palata-bility of the high saponin concentrates. 

In the course of our study on saponin in leaf protein concentrates we had occasion to examine a number of common vegetable food products regarding their saponin contents. We were impressed by the very high saponin contents of commercially grown alfalfa sprouts found in the market place and accordingly have made further study on possible methods to minimize the saponin in alfalfa... 

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