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11.7 Types of Nonmeat Proteins and Their Limitations
Due to many limitations and rationales of animal protein, the meat alternative
sources or meat supplements are in demand. Normally plant proteins and fungal
proteins are in the race for developing meat substitutes. Plant proteins which are
promising as meat substitutes are soy proteins, legume proteins, oilseed proteins,
and cereal proteins. Subsequently fungal proteins (mycoproteins) are gaining
momentum for developing meat substitutes, along with the above-said plant
proteins.
11.7.1 Soy Proteins
Glycine max – soybean – is a traditional food crop belonging to leguminous plants.
The leguminous plants are known for their protein content, and this soybean in particular is a rich dietary source for proteins. Various food products are available from
soy like soy milk (Fukushima 1994), tofu, and tempeh, a fermented soy product of
Indonesian origin. Soybeans’ nutritional value is calculated as 35–40% of proteins
(high-quality proteins with balanced amino acids), 15–20% of fat, 30% of carbohydrates, and 10–30% moisture. It is also rich in fiber, iron, calcium, zinc, and vitamins, which makes it as a very special meat alternative. The main disadvantage of
soya proteins is their strong flavor of the products. The flavors such as grass and
bean flavor and the bitter and astringent flavor reduce the taste of the meat alternatives. Their off-flavors intensify in the stepwise processing (Okubo et al. 1992).
Heat treatment and germination can remove this objectionable odor and flavor
(Suberbie et al. 1981). The allergic reactions caused by consumption of soy proteins
are also a main disadvantage for developing meat substitutes.
11.7.2 Legume Proteins
Legume proteins are the edible seeds of leguminous plants which includes beans
and pulses (Oboh et al. 2009). These seeds supply a high amount of protein. These
legume seeds are easily available even for the economically poor people, and so it
is also called as poor man’s meat. The amount of protein accounts to 20–30% in its
total dry weight. The underdeveloped and developing countries always try to
improve the nutritional content and the functional properties.
Main disadvantages of the legume proteins are the low amount of sulfurcontaining amino acids and the allergenic food products in many legume crops such
as peanuts, soybeans, lentils, beans, chickpeas, tree nuts, etc. (Sing et al. 2008,
Riascos et al. 2010). Moreover, the legume seeds are inherited with protein inhibitors to resist and to protect itself from degradation, and this resistant power inhibits
11 Fungi: A Potential Future Meat Substitute
11.7 Types of Nonmeat Proteins and Their Limitations
Due to many limitations and rationales of animal protein, the meat alternative
sources or meat supplements are in demand. Normally plant proteins and fungal
proteins are in the race for developing meat substitutes. Plant proteins which are
promising as meat substitutes are soy proteins, legume proteins, oilseed proteins,
and cereal proteins. Subsequently fungal proteins (mycoproteins) are gaining
momentum for developing meat substitutes, along with the above-said plant
proteins.
11.7.1 Soy Proteins
Glycine max – soybean – is a traditional food crop belonging to leguminous plants.
The leguminous plants are known for their protein content, and this soybean in particular is a rich dietary source for proteins. Various food products are available from
soy like soy milk (Fukushima 1994), tofu, and tempeh, a fermented soy product of
Indonesian origin. Soybeans’ nutritional value is calculated as 35–40% of proteins
(high-quality proteins with balanced amino acids), 15–20% of fat, 30% of carbohydrates, and 10–30% moisture. It is also rich in fiber, iron, calcium, zinc, and vitamins, which makes it as a very special meat alternative. The main disadvantage of
soya proteins is their strong flavor of the products. The flavors such as grass and
bean flavor and the bitter and astringent flavor reduce the taste of the meat alternatives. Their off-flavors intensify in the stepwise processing (Okubo et al. 1992).
Heat treatment and germination can remove this objectionable odor and flavor
(Suberbie et al. 1981). The allergic reactions caused by consumption of soy proteins
are also a main disadvantage for developing meat substitutes.
11.7.2 Legume Proteins
Legume proteins are the edible seeds of leguminous plants which includes beans
and pulses (Oboh et al. 2009). These seeds supply a high amount of protein. These
legume seeds are easily available even for the economically poor people, and so it
is also called as poor man’s meat. The amount of protein accounts to 20–30% in its
total dry weight. The underdeveloped and developing countries always try to
improve the nutritional content and the functional properties.
Main disadvantages of the legume proteins are the low amount of sulfurcontaining amino acids and the allergenic food products in many legume crops such
as peanuts, soybeans, lentils, beans, chickpeas, tree nuts, etc. (Sing et al. 2008,
Riascos et al. 2010). Moreover, the legume seeds are inherited with protein inhibitors to resist and to protect itself from degradation, and this resistant power inhibits
11 Fungi: A Potential Future Meat Substitute