**4.3 Acidulant**

Acidulants are essential ingredients or additives that are generally used to improve the taste of food and make it sharper. There are naturally occurring acidulants such as acetic acid, citric acid, malic acid, fumaric acid, lactic acid, tartaric acid, succinic acid, phosphoric acid etc. having different taste profiles. Many fruits such as orange, lemon, apples, tomatoes and yogurt contain natural acids with the most common example being citric acid. Citric acid comes with lemon flavour, acetic acid with strong familiar vinegar flavour, tartaric acid gives sharp taste and lactic acid comes with a smooth taste [10]. Apart from taste enhancement, acidulants also act as a food preservative. The choice of the acidulant is usually made based on its characteristic flavour and the physical state and solubility. Some food formulations require solid acidulants. In general, inorganic acids such as sulphuric acid, phosphoric acid, monosodium orthophosphate and diphosphates are used as dry acidulants in controlled concentrations. The composition of the acidulants is based on their selection and different concentrations calculated by total titratable acid. Acetic acid is mainly used in the form of vinegar with the pungent smell. As it appears in the liquid state, it is used as a preservative in pickles. It is also used in the manufacture of cheese to improve the shelf life period, good mouthfeel and taste [15].

#### **4.4 Edible packing**

Acidulants are also used as food coating, which may be edible or non-edible to prevent food from contamination with the surrounding environment, to protect it from bacterial infection and to improve the shelf life of the food. These films are easily biodegradable. The water-soluble non-edible coating is used for the packing of food [16]. The edible coating is used for breath freshening agent, in drug delivery and as flavour. Acetic acid is used in edible films to enhance sour flavour. Various compositions of acetic acid are used to develop antimicrobial food coating to stop the outgrowth of bacterial and fungal cells. It is also used in meat coating and preservation of meat products. The chitosan-based edible food coatings along with aqueous acetic acid are used to enhance anti-listerial activity.

#### **4.5 Antibacterial agent**

Acetic acid is commonly used in medicine since ancient times. The low concentrations (3%) of acetic acid can be used as a local antiseptic against various microorganisms. Acetic acid is always considered as an alternative. It can be utilized as *in vitro* antimicrobial agent combined with other antiseptics. Acetic acid covers the wide range of spectrum with Gram-positive as well as Gram-negative bacteria.

### **5. Conclusion**

Acetic acid has remained one of the key chemical molecules associated with human life. It is one of the main building blocks for developing several chemical

**289**

**Author details**

**Acknowledgements**

**Conflict of interest**

Belfast, UK

Gunjan Deshmukh and Haresh Manyar\*

provided the original work is properly cited.

\*Address all correspondence to: h.manyar@qub.ac.uk

School of Chemistry and Chemical Engineering, Queen's University Belfast,

© 2020 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,

*Production Pathways of Acetic Acid and Its Versatile Applications in the Food Industry*

acetic acid in food preservations and improved quality of food.

Fuels from wastewater', R1043CCE, for postdoctoral funding for GD.

The authors declare no conflict of interest.

entities. Cavita process shares a major part of the production to meet the global demand. The process utilizes methanol as a raw material, which is obtained from biogas. Though the process utilizes bio-derived feedstock, it utilizes high energy and manpower with multiple separation steps. The innovative and simple technologies for separation of acetic acid can improve the overall process. The other well-known process, that is, fermentative route, is slow and commercially unsuitable to meet the global demand. The fermentation process is globally followed to generate the food-grade acetic acid commonly known as vinegar. The demand for acetic acid will always keep growing, which necessitates the development of an eco-friendly process. Utilization of CO2 and syngas may offer excellent alternatives as a sustainable feedstock to develop innovative technologies to develop commercial processes. This offers development of 100% bio-derived feedstock process. Further, the modern food industry has come up with different innovative applications of the

The authors gratefully acknowledge the financial support from the UK Catalysis hub and EPSRC for the project, 'Catalysis at the Water-Energy Nexus: Energy and

*DOI: http://dx.doi.org/10.5772/intechopen.92289*

*Production Pathways of Acetic Acid and Its Versatile Applications in the Food Industry DOI: http://dx.doi.org/10.5772/intechopen.92289*

entities. Cavita process shares a major part of the production to meet the global demand. The process utilizes methanol as a raw material, which is obtained from biogas. Though the process utilizes bio-derived feedstock, it utilizes high energy and manpower with multiple separation steps. The innovative and simple technologies for separation of acetic acid can improve the overall process. The other well-known process, that is, fermentative route, is slow and commercially unsuitable to meet the global demand. The fermentation process is globally followed to generate the food-grade acetic acid commonly known as vinegar. The demand for acetic acid will always keep growing, which necessitates the development of an eco-friendly process. Utilization of CO2 and syngas may offer excellent alternatives as a sustainable feedstock to develop innovative technologies to develop commercial processes. This offers development of 100% bio-derived feedstock process. Further, the modern food industry has come up with different innovative applications of the acetic acid in food preservations and improved quality of food.
