Plant for profit

Protein is essential for life and required for new cell growth and tissue repair. Adequate intake is particularly important during growth, or when we're stressed through athletic activity. Protein quality is expressed as biological value. This is assessed by the quantity of eight essential amino acids the body can't make. These are: isoleucine; leucine; lysine; methionine; phenylalanine; threonine; tryptophan and valine. Children also need histidine.

A protein supplying all the essential amino acids has a high biological value - milk casein, egg albumen and soya are examples. Cereal proteins tend to be low in lysine and legumes low in methionine, although plant breeding can improve levels.

Beside nutritional value, digestibility may also be quoted - this indicates availability to the body. Here plant protein is considered slightly inferior to animal protein. Beyond nutritional enrichment of food, certain plant peptide isolates may help satiety - appetite reduction for weight control.

Western diets are high in animal protein which involves an expensive and slow transition from plants, through grass and grain, into meat - which also delivers saturated fats. So there is considerable interest in providing high quality protein from plants. It also makes economic sense since the rising global demand for protein cannot be sustained from meat and fish.

Beside nutrition, proteins are a functional ingredient added to food, where they control water and fat binding. They help emulsification and provide texture control though whipping and gelation. Increasingly, plant proteins can provide all these functions. They are also lactose and cholesterol free and come in grades with kosher and halal certification. Processing quality helps remove anti-nutritional factors such as tannins, phytates and lectins, trypsin inhibitors and phytosterols.

Plant options

The world's chief oilseed crop, soya has a good biological value and is the standard against which other plant proteins are benchmarked. Textured vegetable soy protein has been on the menu for over 20 years and soy milks have built up a substantial representation in the chilled dairy sector. Soy represents the nutritional ideal for vegetarians. Soy flour is predominant in bakery for its lipoxygenase bleaching activity as well as for a range of protein concentrate isolates.

European consumers have only recently been exposed to soy in quantity, hence its allergen status on product labelling - but that also goes for milk, eggs and wheat. Other consumers also like to know about the supply chain, in case their food contains genetically modified (GM) ingredients.

Recent health studies have also claimed that phytosterols could cause male testosterone to fall - termed an anti-nutritional effect. So despite soy's dominance, natural alternatives are sought.

Pea protein

Yellow split peas are a popular northern European crop across France, Belgium and the UK. One of the traditional crops, peas combine starch with protein and being a legume they fix soil nitrogen and don't require much support from chemical crop protection. Also peas are not on the EU list of allergens.

Cosucra's Pisane pea protein isolate with a balanced amino acid profile is GM-free, low in anti-nutritional factors, and can be labelled as 'vegetable' or 'pea protein'. With a protein content of 90%, it can be used to correct or increase the protein content of a recipe, and it is lower in anti-nutritional factors compared to soy.

Nutritionist Helena Hall, account manager with Cosucra's UK agent, says: "We have noticed an increased interest in ingredients for weight management, sports nutrition and appetite reduction products. Pisane offers food manufacturers a near complete amino acid profile. "Unlike soya protein, pea protein is a clean-label product, allowing the food industry to offer a unique product to consumers with real health benefits. It is high in lysine and arginine, amino acids which help maintain lean body mass and increase muscle mass whilst reducing body fat."

Since the end of 2006 Roquette has also been progressing its Nutralys pea protein, citing excellent water and fat binding with high nutritional value. And its digestibility exceeds de-hulled pea flour. The non-dusting powder is easily dispersed and has a good solubility across a wide pH range.

Roquette senior market development manager Bruno Gehin says: "Nutralys has high functionality and can partially or totally replace other proteins - for example to reduce water loss in sausages and improve juiciness.

Higher in lysine than soya, it's also high in arginine, the branched chain amino acids good for sports recovery." Roquette's extraction process eliminates most of the legume off-taste to give a clean taste in most applications. It works well in bakery and is being looked at for ice cream.

Canola

The North American variety of rapeseed, canola, is grown world-wide. After oil extraction it leaves a protein-rich meal. Winnipeg-based Burcon NutraScience is developing the application and has patents around extraction and purification. Fractionation is achieved through a process using few chemicals.

It is considered environmentally friendly and an alternative to the existing industry standard iso-electric precipitation. Burcon's extraction depends on an ionic shift with water and salt, to yield pure protein isolate micelles.

The firm, which is working with ADM to commercialise canola protein to compete with soy, dairy and egg proteins in prepared foods and nutritional supplements, is now preparing to make a Novel Food application to gain access to the European market.

Toxicology studies are also underway in order to apply for GRAS (generally recognised as safe) status in the US, says the company. "The required scientific studies will be initiated within the next quarter."

The world's second largest oilseed crop after soybeans, canola has a high level of protein purity without high fat levels, while its amino acid content is comparable to animal proteins and superior to soy. Its high protein efficiency ratio is double that of soy, according to Burcon. The cholesterol-lowering and antioxidant activity of canola protein are also well-documented.

Burcon's protein will complement soy, dairy and egg. Indeed the protein mimics many of the functions of egg white.However, for Europe the novel foods process will present a regulatory hurdle. While rape oil has a history of human consumption, this is not the case for rape protein.

Potatoes

So far we have considered seeds, now let's look at a root crop, the potato. The potato is 18% starch and 2% protein, but starch giant Avebe has established a new company Solanic to fractionate and purify potato protein down stream, following starch extraction. With the world's number one potato starch company behind it, Solanic has an immediate advantage of scale and breadth.

Frank Goovaerts, Solanic's director of commerce, says: "Protein recovered from seeds suffers through the natural drying process, which lowers quality. Potatoes are moist, growing in the damp soil.

"With innovative processing we can recover excellent quality protein with extremely high functionality." Simply put, the original potato protein is not lost by drying out.

Nutritionally the potato's profile can't get any better for a plant protein, putting even soy in the shade. Perfectly natural, potato has no allergen status. Depending on the fraction, functional properties such as solubility, emulsification, foaming and gelation at least match or even exceed the best animal or other plant proteins.

Paul Hart is general manager of ingredients consultancy Nutraceuticals Ltd. Contact him at: paul.m.hart@btopenworld.com

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