**3.1 CO and CO2 as valuable feedstock**

Utilization of CO2 and syngas can offer sustainable alternatives to produce acetic acid. BP has announced the breakthrough process, wherein, acetic acid will be manufactured from syngas as a feedstock derived from natural gas. This will give an alternative to SaaBre process that produces acetic acid in three integrated steps. The production of acetic acid from syngas will avoid the purification of CO and purchase of methanol. Though the technology is not fully developed, it provides better alternatives in terms of sustainability. Similarly, acetic acid can be synthesized via reacting CO2 and H2 to give methanol followed by subsequent carbonylation step. This route gives liberty to utilize CO2 as value-added feedstock.

#### **3.2 Membrane-based technologies**

The membrane technology can offer the separation of liquid, vapour and gas selectively with controlled mass transfer rates. These processes are easy to operate and simple to design. The technology can offer development on energy intensification. Several types of processes are reported based on the pore size of the membrane for separation of different components. These are namely microfiltration, ultrafiltration

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**Figure 5.**

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

membrane can help in separation of acetic acid to avoid the self-inhibition.

and nanofiltration membrane. The operating pressure (varying from 1 to 20 bar) of the system varies according the pore size of the membrane are used. Reverse osmosis is another membrane technology with non-porous membrane. This process operates at pressure more than 20 bar. The membrane technologies collectively can be applied in downstream processing for separation of acetic acid in chemical process as well as fermentation processes. The combination of fermenter with acetic acid permeable

Direct applications of acetic acid are reported from ancient times. It was used as a medicine and food preservative. Over the period, applications of acetic have diversified as per the demands of modern life. Using different concentrations, it is utilized in food additives, food preservation, antimicrobial agent, acidulant, flavour and taste enhancer, edible packaging material, artificial food ripening agent, etc. Some of the applications such as acidulant and as acetification agents are described in detail here.

Acetification is simply the bacterial oxidation of ethanol to produce acetic acid and water (**Figure 5**). The process is also termed as oxidative fermentation. The rate of the reaction in acetification mainly depends on the type of microorganism used

There are different types of microorganisms that occur naturally in food and are responsible for the different natural processes such as acetification, alcoholism, proteolysis and enzymatic reactions, which alter the natural condition of the food. This bioprocess technology is studied and systematically utilized to improve the quality of food s in terms of texture, taste, mouthfeel, colour and prolonged shelf life. The overall concept has grown into generating different types of food and

Acetification of different food categories using acetic acid bacteria (AAB) has led to the production of several food products [14]. AAB are naturally found on fruits, flowers, and plants, which naturally react and convert carbohydrate sugars into organic acids in the presence of oxygen. The same concept is biotechnologically

Different parts of the world have utilized the acetification process to generate a variety of foods and beverages. The famous Lambic beer is produced from malted barley, aged dry hops and unmalted wheat. The different AAB and yeast are responsible for the generation of this beer, which is matured for over a period of 3 years. The typical acidic flavour of the beer is achieved with the help AAB

to catalyse and the concentration of available oxygen in the media [13].

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

**4. Application of acetic acid in food industry**

beverages produced in a cheap and sustainable way.

*Production of acetic acid by fermentative oxidation of alcohol.*

utilized to prepare a diverse variety of food and beverages.

**4.1 Acetification**

**4.2 Flavouring agent**

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

and nanofiltration membrane. The operating pressure (varying from 1 to 20 bar) of the system varies according the pore size of the membrane are used. Reverse osmosis is another membrane technology with non-porous membrane. This process operates at pressure more than 20 bar. The membrane technologies collectively can be applied in downstream processing for separation of acetic acid in chemical process as well as fermentation processes. The combination of fermenter with acetic acid permeable membrane can help in separation of acetic acid to avoid the self-inhibition.
