Abstract
Loss of β carotene from moist leaf protein stored with a preservative, is closely simulated by the destruction of β carotene by acetone extracted chloroplasts (stroma) suspended in acetone containing 30% water. During this exposure, stroma lose destructive ability, but it is restored by mercaptoacetate and other reducing agents. Stroma can therefore be used repeatedly. This catalytic process is activated by removing intrinsic inhibitors, predominantly calcium, by extraction at pHs less than 4, or by alum. The objective is to find inhibitors which would be acceptable in a food. That restricts choice. Citrate, tartarate and phosphate are among the more attractive possibilities.
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References
Butler JB (1982) An investigation into some causes of the differences of protein expressibility from leaf pulps. J Sci Fd Agric 33: 528–536.
Coulter BS, Talibudeen O (1968) Calcium: aluminium exchange equilibria in clay minerals and acid soils. J Soil Sci 19: 237–250.
Hanczakowski P, Skraba B (1985) The effect of different precipitating agents on quality of leaf protein concentrate from lucerne. Animal Feed Sci Technol 12: 11–17.
Heizmann CW, Hunziker W (1991) Intracellular calcium-binding proteins: more sites than insights. Trends Biochem Sci 16: 98–103.
Jennings AC, Pusztai A, Synge RLM, Watt WB (1968) Fractionation of plant material, III: Two schemes for chemical fractionation of fresh leaves, having special applicability for isolation of bulk protein. J Sci Fd Agric 19: 203–213.
Mejbaum-Katzenellenbogen W (1962) Immunochemical properties of the serum proteins after regeneration from the protein-tannin compound. Nature (Lond) 193: 1288–1289.
Pirie NW (1936) Some chemical methods for the detection and rough estimation of agar in biological materials. Br J exp Path 17: 269–278.
Pirie NW (1984) Factors affecting β carotene destruction in moist leaf protein. Plant Foods Hum Nutr 34: 229–237.
Pirie NW (1987a) Some preliminary observations on treatments which increase and decrease the stability of β-carotene in preserved, moist leaf protein. Plant Foods Hum Nutr 36: 263–272.
Pirie NW (1987b) Leaf protein and its by-products in human and animal nutrition. London: Cambridge University Press.
Pirie NW (1990) Food utilisation of leaf protein in Europe, America and Africa. Proc Third Internat Conf Leaf Protein Res 188–192.
Webber AN, Gray JC (1989) Detection of calcium binding by photosystem II polypeptides immobilized onto nitrocellulose. FEBS Letters 249: 79–82.
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Pirie, N.W. Some factors controlling carotene destruction by chloroplasts in vitro. Plant Food Hum Nutr 45, 35–46 (1994). https://doi.org/10.1007/BF01091227
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DOI: https://doi.org/10.1007/BF01091227