**5. Common meat – substitutes available in the market**

#### **5.1 Soy-based products**

Soy is considered as one of the raw material used traditionally for the preparation of various meat substitutes. From soy flour to soy protein concentrate and isolate, they have acquired quiet a significant position among the recipes. Among different soy proteins ingredients, its isolates are not only highly pure, but also has a light color with bland flavor, which makes them more approachable in product development, even though degree of purity does not play much role in the meatanalog applications. Properties like water-holding capacity, gelling property, fat-absorbing capacity, emulsifying capacity and other functional properties of soy ingredients makes them more reliable in this industry and are available in numerous forms like toasted flour, full-fat, de-fatted (about 50% of protein content and are produced from grinding defatted soy flakes), etc. By fractionating defatted soy flakes, soy protein concentrates (protein content is found to be 70%) and isolates (protein content is 90%) are obtained through aqueous alcohol extraction and alkaline extraction followed by precipitation in acidic pH, respectively [26].

#### **5.2 Tofu**

Soybean derived tofu or soy curd, being an excellent source of protein and minerals like iron and calcium, is the mostly utilized meat substitute world-wide and are available in block form. Production of tofu is said to be simple, clean, convenient and controllable process. Nutritional profile of tofu includes 8% of total proteins, 2% of carbohydrates and lipids about 4 to 5% on fresh weight basis. Absence of cholesterol, low energy value, high amount of vitamins and minerals and presence of dietary fibers (about 1%) are some of the relevant factors for the high demand of soy curd. Traditionally, tofu is prepared by protein coagulation of hot soy milk with the assistance of a coagulant: salt-induced(CaSO4, CaCl2or MgCl2) or acid-induced

**77**

cancer and prostate cancer) [28].

*Plant Proteins as Healthy, Sustainable and Integrative Meat Alternates*

vital role in determining its quality; yet controversies are still existing.

(Glucono Delta-Lactone (GDL) – also known as gluconolactone) to obtain a gel-like product. Some studies says that coagulant used for the production of tofu plays a

The complex process starts from soaking and grinding of soybeans followed by filtering to extract the milk. Then it undergoes methods like boiling, coagulation, breaking of curd, pressing and reforming the gel. However, packed or filled tofu involves addition of coagulant to the cooled soy milk and is then heated and coagulated in a suitable package, without undergoing any further processing methods. Some studies says that, presence of isoflavones, oligosaccharides, trypsin inhibitors in soymilk cause allergic reactions, off-flavor and flatulence, respectively in some people. As a result, soy protein isolate (SPI) has gained a considerable demand as raw material for packed tofu, as it has better health benefits to consumers. Apart from coagulant used, some other influential factors in tofu-making are the processing conditions, concentration of coagulant used, and two major storage proteins:

Tempeh, a traditional soy fermented product, is considered as the food that can provide the most health benefits among other soy products and higher consumption percentage in many places. Countries like Indonesia (70% of households), Australia, China, Japan, and Taiwan and also in some places of Europe, America and Africa are reported to have higher consumption of tempeh. Presence of high quantity of crude protein and essential amino acids, fatty acids, carbohydrates, folic acid (416.4 μg/100 mg), isoflavones, vitamin B12 (3.9 μg/100 g), and tocopherols (α-, β-, γ- and δ-), along with reduction of antinutritional factors such asphytates, saponins, trypsin inhibitors, hemagglutinins, and flatus factors, with increased facilitating, detoxification properties, bioavailability of minerals and many otherhealth benefits, tempeh is considered as a better choice for healthy diet [28]. Presence of umami taste (a basic taste that can be detected by human receptors) is

Tempeh, in general, is a collective name for combination of cooked and fermented raw material (cereals, beans or a byproduct of food processing) with any suitable culture ofmycelium of a living molds, yeasts, lactic acid bacteria (LAB) or various gram-negative bacteria. Even though *Rhizopus oligosporus*is the dominant microorganism used for the production of tempeh, molds like *R. oryzae* and *Mucorspp* are also used for enhancing flavor, texture and nutritional characteristics. Production of tempeh involves acidification of soybeans using lactic acid or acetic acid to inhibit the growth of undesired microorganisms by lowering the pH (5 or below), followed by boiling and cooling (30–38°C). Inoculation at 25–30°C process is carried out and a compact, creamy, white, fresh tempeh cake will be resulted after 1–2 days. Due to the production of different proteases secreted by *R. microsporus var. oligosporus*such as 'aspartic acid protease' or known as 'acidic protease' and another endopeptidase called 'serine protease' helps to break complex soy proteins at aspartic acid residues (when at 3–4 pH) and at small/side chains like glycine and alanine residue (at neutral to alkaline pH, i.e. 7–11), respectively. However, for commercial purpose, mixed cultures are also used for better and quality yield [29]. In addition, fermentation process not only helps to improvise the nutritional and sensory profile of the final product, but also imparts health benefits including enhanced antioxidant property, and plays a role in fighting dementia, cardiovascular diseases andcancer (especially, colorectal cancer and hormone-depended cancers like breast

*DOI: http://dx.doi.org/10.5772/intechopen.94094*

glycinin (11S) and β-conglycinin (7S) [27].

also said to be a factor for its increased demand.

**5.3 Tempeh**

#### *Plant Proteins as Healthy, Sustainable and Integrative Meat Alternates DOI: http://dx.doi.org/10.5772/intechopen.94094*

(Glucono Delta-Lactone (GDL) – also known as gluconolactone) to obtain a gel-like product. Some studies says that coagulant used for the production of tofu plays a vital role in determining its quality; yet controversies are still existing.

The complex process starts from soaking and grinding of soybeans followed by filtering to extract the milk. Then it undergoes methods like boiling, coagulation, breaking of curd, pressing and reforming the gel. However, packed or filled tofu involves addition of coagulant to the cooled soy milk and is then heated and coagulated in a suitable package, without undergoing any further processing methods. Some studies says that, presence of isoflavones, oligosaccharides, trypsin inhibitors in soymilk cause allergic reactions, off-flavor and flatulence, respectively in some people. As a result, soy protein isolate (SPI) has gained a considerable demand as raw material for packed tofu, as it has better health benefits to consumers. Apart from coagulant used, some other influential factors in tofu-making are the processing conditions, concentration of coagulant used, and two major storage proteins: glycinin (11S) and β-conglycinin (7S) [27].
