**5. Other industrial applications**

In addition to above mentioned applications, tannins are also used in diverse types of industries, such as paper industry where high pressure mimosa tannin impregnated alpha cellulose paper is prepared. This impregnated paper offer more abrasive resistance, adhesion properties, water vapor resistance, and staining properties [50]. Recently, natural tannin-based foam without any formaldehyde is prepared that used as acoustic absorbers, metal ion adsorption, panels crash protection, packaging, etc., but low mechanical strength of tannin foams is major impediment in its further applications [51].

Beverage industry is well known for tannins applications particularly, in case of the wine making. Like leather industry, wine making is also very old industry since historic time. Tannins are used in wine to provide color formations, antioxidants, aroma, proteins precipitations, and flavor development. The source of tannins in the wine is grapes skin, seeds, and addition of oak flakes which add market values to wine [52].

#### **6. Future prospectus**

Tannins are phenolic-based secondary metabolites that are present in the plant kingdom, including algae. Actually, tannins produced in the plant body and involved in the plant protections and act as antimicrobial, antiparasitic, anthelmintic, antiviral, antioxidant, and deferred cattle. Hence, they help plants to fight various types' infections. In addition to biological roles, they also play very important roles in industrial sector, animal feeding, mining, chemical industry, and tanning industry. But there are several limitations associated with the tannins. The main negative effect of tannins as food is their absorptions and binding with various types of biomolecules such as proteins, starch, and metal ions in the digestive system, hence hinders their nutritional availability to human and animals, for example, proanthocyanidins. Some experiments show that complex of tannins and proteins are resistant to various types of proteases in animal digestive system that make proteins unavailable for livestock nutrition. Dietary tannins bind with the proline-rich proteins and as result two types of soluble and insoluble complexes formed which is responsible for astringent sensation [53]. The astringency feeling is perceived by the tongue in the form of diffuse feeling associated with extreme dryness and roughness in mouth [54]. Some experiments also show that tannins also decrease activities of intestinal microflora, consequently less absorption of

organic matter and soluble fiber that attributed to damage the mucosal lining of the digestive system. Moreover, high dose of tannins like catechin used in supplements can cause renal failure, hepatitis, fever, hemolytic anemia, thrombocytopenia, and skin disorders. Due to the structural complexities, tannins are also considered as potential pollutants in industries, where tannins are used as the major substrate.

Single-meal bioavailability studies have shown major antinutrient activity of tannins is metal ions chelation that cause severe deficiency of essential minerals in human. In this series iron deficiency is most prevalent in population particularly in the developing countries. Recently, single-meal studies in case of hydrolysable and oligomeric catechin and epicatechin tannins (tea and tannic acid) have conducted. It shows reduced iron bioavailability in diet particularly in long term, but it needs more investigation by using appropriate animal model systems in order to study antinutritional role of tannins [55]. Moreover, tannins not only affect iron availability, but also iron metabolism; the ferritin, an iron transport protein, is adversely affected by tannin binding in soybean seed ferritin (SSF) and consequently changes the tertiary/quaternary structure of the protein.

In view of current scientific investigation, it has now become possible that tannins can be exploited in a better way because they are major sustainable raw materials for green chemistry in future. Recently, several tannase or tannin acyl hydrolase enzymes have isolated, characterized, and classified from microorganism and fungi, hence toxic effect of tannins is reduced through hydrolysis and oxidation [56, 57]. Various species of filamentous fungi that produced tannase are used for bioremediation in leather tannin industries.

Several studies have been conducted to overcome the adverse effect of tannins in the food item like, fruit and vegetable. In a major breakthrough, lactic acid bacteria fermentation-like incubation is exploited in *Xuan Mugua* fruits, as a result up to 70% tannin content reduced with substantially reduced astringency, hence that method can be used in the food industry [58].

#### **7. Conclusions**

Tannins are phenolic-based secondary metabolites that are present in the plant kingdom, including algae. Actually, tannins produced in the plant body involved in the plant protections and act as antimicrobial, antiparasitic, anthelmintic, antiviral, antioxidant, and deferred cattle. Hence, they help plants to fight various types of infections. In addition to biological roles, they also play very important roles in industrial sector, animal feeding, mining, chemical industry, and tanning industry. But there are several limitations associated with the tannins applications. The main negative effect of tannins as food are their absorptions and binding with various types of biomolecules such as, proteins, starch, and metal ions in the digestive system; hence, they hinder their nutritional availability to human and animals.

#### **Acknowledgements**

I would like to thank to my Institution, GGD SD College (Panjab University) India, for providing me all the facilities and support for preparation of this manuscript.

**131**

**Author details**

Akhlash P. Singh1

India

\* and Sunil Kumar2

(ICAR-CIPHET), Abohar, Punjab, India

provided the original work is properly cited.

1 Department of Biochemistry, GGD SD College, Panjab University, Chandigarh,

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

Authors also acknowledge the contribution of publications which could not be

MALDI-TOF electron spray ionization and matrix-assisted laser desorption

2 ICAR-Central Institute of Post-Harvest Engineering and Technology

\*Address all correspondence to: akhlash@gmail.com; akhlash@ggdsd.ac.in

*Applications of Tannins in Industry*

*DOI: http://dx.doi.org/10.5772/intechopen.85984*

**Notes/Thanks/Other declarations**

**Acronyms and abbreviations**

PA proanthocyanidins

EGCG epigallocatechin gallate

HSV-2 herpes simplex virus 2

included in the reference section due to lack of space.

LLDPE linear low-density polyethylene WVP water vapor permeability SDF soluble dietary fiber

LDPE polyethylene and low-density polyethylene

MRSA methicillin-resistant *Staphylococcus aureus* TFPR tannin-rich fraction from pomegranate rind

ionization time of flight mass

TA-AgNPs silver nanoparticles with tannic acid

#### **Conflict of interest**

Authors declare no conflict of interest.

*Applications of Tannins in Industry DOI: http://dx.doi.org/10.5772/intechopen.85984*

*Tannins - Structural Properties, Biological Properties and Current Knowledge*

the tertiary/quaternary structure of the protein.

bioremediation in leather tannin industries.

method can be used in the food industry [58].

**7. Conclusions**

**Acknowledgements**

**Conflict of interest**

Authors declare no conflict of interest.

organic matter and soluble fiber that attributed to damage the mucosal lining of the digestive system. Moreover, high dose of tannins like catechin used in supplements can cause renal failure, hepatitis, fever, hemolytic anemia, thrombocytopenia, and skin disorders. Due to the structural complexities, tannins are also considered as potential pollutants in industries, where tannins are used as the major substrate. Single-meal bioavailability studies have shown major antinutrient activity of tannins is metal ions chelation that cause severe deficiency of essential minerals in human. In this series iron deficiency is most prevalent in population particularly in the developing countries. Recently, single-meal studies in case of hydrolysable and oligomeric catechin and epicatechin tannins (tea and tannic acid) have conducted. It shows reduced iron bioavailability in diet particularly in long term, but it needs more investigation by using appropriate animal model systems in order to study antinutritional role of tannins [55]. Moreover, tannins not only affect iron availability, but also iron metabolism; the ferritin, an iron transport protein, is adversely affected by tannin binding in soybean seed ferritin (SSF) and consequently changes

In view of current scientific investigation, it has now become possible that tannins can be exploited in a better way because they are major sustainable raw materials for green chemistry in future. Recently, several tannase or tannin acyl hydrolase enzymes have isolated, characterized, and classified from microorganism and fungi, hence toxic effect of tannins is reduced through hydrolysis and oxidation [56, 57]. Various species of filamentous fungi that produced tannase are used for

Several studies have been conducted to overcome the adverse effect of tannins in the food item like, fruit and vegetable. In a major breakthrough, lactic acid bacteria fermentation-like incubation is exploited in *Xuan Mugua* fruits, as a result up to 70% tannin content reduced with substantially reduced astringency, hence that

Tannins are phenolic-based secondary metabolites that are present in the plant kingdom, including algae. Actually, tannins produced in the plant body involved in the plant protections and act as antimicrobial, antiparasitic, anthelmintic, antiviral, antioxidant, and deferred cattle. Hence, they help plants to fight various types of infections. In addition to biological roles, they also play very important roles in industrial sector, animal feeding, mining, chemical industry, and tanning industry. But there are several limitations associated with the tannins applications. The main negative effect of tannins as food are their absorptions and binding with various types of biomolecules such as, proteins, starch, and metal ions in the digestive system; hence, they hinder their nutritional availability to human and animals.

I would like to thank to my Institution, GGD SD College (Panjab University) India,

for providing me all the facilities and support for preparation of this manuscript.

**130**
