Leaf protein concentrate
Encyclopedia
Leaf protein concentrate (LPC) is a concentrated
form of the protein
s found in the leaves
of plants. It has been examined as a human or animal food source, because it is potentially the cheapest, most abundant source of available protein. Although humans can derive some protein from the direct consumption leaves as leaf vegetable
s, the human digestive system would not be able to deal with the enormous bulk of leaves needed to meet dietary protein requirements with leaf vegetables alone.
based animal rearing to satisfy human appetites for meat has increased demand for cheaper vegetable protein sources. This has recently led to renewed interest in LPC to reduce the use of human-edible vegetable protein sources in animal feed.
s, with methionine
being a limiting factor. Leaf proteins can also be rich in polyphenol
s. The challenges that have to be overcome before LPC becomes a viable protein source for humans include the high fiber
content and other antinutritional factor
s, such as phytate, cyanide
and tannin
s.
Concentration
In chemistry, concentration is defined as the abundance of a constituent divided by the total volume of a mixture. Four types can be distinguished: mass concentration, molar concentration, number concentration, and volume concentration...
form of the protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
s found in the leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
of plants. It has been examined as a human or animal food source, because it is potentially the cheapest, most abundant source of available protein. Although humans can derive some protein from the direct consumption leaves as leaf vegetable
Leaf vegetable
Leaf vegetables, also called potherbs, green vegetables, greens, leafy greens or salad greens, are plant leaves eaten as a vegetable, sometimes accompanied by tender petioles and shoots...
s, the human digestive system would not be able to deal with the enormous bulk of leaves needed to meet dietary protein requirements with leaf vegetables alone.
Application
LPC was first suggested as a human food in the 1960s, but it has not achieved much success, despite early promise. Pirie (1971,1975), the Nobel Prize winner from UK, reviewed and emphasized importance of its benefits which brought the subject forward. The increasing reliance on feedlotFeedlot
A feedlot or feedyard is a type of animal feeding operation which is used in factory farming for finishing livestock, notably beef cattle, but also swine, horses, sheep, turkeys, chickens or ducks, prior to slaughter. Large beef feedlots are called Concentrated Animal Feeding Operations . They...
based animal rearing to satisfy human appetites for meat has increased demand for cheaper vegetable protein sources. This has recently led to renewed interest in LPC to reduce the use of human-edible vegetable protein sources in animal feed.
Health issues
Leaf protein is a good source of amino acidAmino acid
Amino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...
s, with methionine
Methionine
Methionine is an α-amino acid with the chemical formula HO2CCHCH2CH2SCH3. This essential amino acid is classified as nonpolar. This amino-acid is coded by the codon AUG, also known as the initiation codon, since it indicates mRNA's coding region where translation into protein...
being a limiting factor. Leaf proteins can also be rich in polyphenol
Polyphenol
Polyphenols are a structural class of natural, synthetic, and semisynthetic organic chemicals characterized by the presence of large multiples of phenol structural units...
s. The challenges that have to be overcome before LPC becomes a viable protein source for humans include the high fiber
Dietary fiber
Dietary fiber, dietary fibre, or sometimes roughage is the indigestible portion of plant foods having two main components:* soluble fiber that is readily fermented in the colon into gases and physiologically active byproducts, and* insoluble fiber that is metabolically inert, absorbing water as it...
content and other antinutritional factor
Antinutritional factor
Anti-nutritional factors are natural or synthetic substances found in the human diet or animal feed that have the potential to adversely affect health and growth by preventing the absorption of nutrients from food.-Classes of Anti-nutrients:...
s, such as phytate, cyanide
Cyanide
A cyanide is a chemical compound that contains the cyano group, -C≡N, which consists of a carbon atom triple-bonded to a nitrogen atom. Cyanides most commonly refer to salts of the anion CN−. Most cyanides are highly toxic....
and tannin
Tannin
A tannin is an astringent, bitter plant polyphenolic compound that binds to and precipitates proteins and various other organic compounds including amino acids and alkaloids.The term tannin refers to the use of...
s.