Maarg Manthan · Topic 11.5

Bioprocessing, Bioreactors and Enzyme Manipulation in the Food Industry

Science & Technology › Biotechnology – Applications · Topic 11.5

Bioprocessing in the food industry uses microbes, cells and enzymes in controlled vessels called bioreactors to make, improve or preserve foods and ingredients. Enzymes are biological catalysts, and enzyme manipulation means choosing, producing, immobilising or engineering them for food uses such as brewing, baking, dairy, fruit juice and sweetener production. Amylases break starch, proteases break protein, lipases break fat, pectinases clear juices, lactase splits milk sugar, and glucose isomerase turns glucose into fructose. Many food enzymes are now made by recombinant microbes grown in fermenters, for example chymosin for cheese, which has largely replaced animal rennet. Food enzymes in India are regulated by the Food Safety and Standards Authority of India.

5 min read · UPSC Prelims · Science & Technology · Biotechnology – Applications

At a Glance

Tool Enzymes and bioreactors
Key enzymes Amylase, protease, lipase, lactase
Cheese enzyme Chymosin
Sweetener enzyme Glucose isomerase
Regulator FSSAI
Exam link UPSC Prelims, Science & Technology: Biotechnology – Applications

Where Does It Fit?

This topic follows bio-composting and carbon capture. It returns to the industrial use of microbes and enzymes first seen in bioprocess and fermentation, now specifically in food. Previous topic: Bio-Composting and Carbon Capture Techniques. Next topic: Single-Cell Protein Production and Food Fortification.

Which Enzymes Are Used in Food?

Enzyme	Use in food
Amylase	Breaks starch into sugars. Used in baking, brewing and syrup making
Protease	Breaks proteins. Used for meat tenderising, beer clarification and baby food
Chymosin or rennin	Clots milk protein for cheese. Now made by recombinant microbes
Lipase	Breaks fats. Develops flavour in cheese and chocolate
Pectinase	Breaks pectin. Clears fruit juice and increases juice yield
Lactase	Splits lactose. Used to make lactose free milk
Glucose isomerase	Converts glucose to sweeter fructose. Used to make high fructose syrup

How Are Bioreactors and Enzyme Techniques Used?

Stirred tank bioreactor: a vessel with an impeller for mixing and air supply, used for enzymes, yeast and organic acids
Airlift bioreactor: mixing by rising gas bubbles, suited to delicate or shear sensitive cells
Packed bed bioreactor: a column filled with immobilised enzymes or cells through which substrate flows
Fluidised bed reactor: particles with enzymes kept moving by the flow of liquid
Membrane bioreactor: a membrane keeps the enzyme in the reactor while product passes out
Immobilisation: enzymes are fixed on beads, gels or membranes by entrapment, adsorption or cross linking, so that they can be reused
Protein engineering: altering amino acids to make enzymes more stable or active in heat or acid
Downstream processing: separating and purifying the enzyme or product before use

What Else Should You Remember?

Baking: amylases improve dough rise and crust colour, and extend freshness
Brewing: malt enzymes break starch into fermentable sugar, and added enzymes help in low calorie beer
Dairy: chymosin for cheese, lactase for lactose free milk and lipases for flavour
Fruit juice: pectinases and cellulases give clear juice with higher yield
Meat and fish: proteases tenderise meat and make protein hydrolysates
Sweeteners: starch is broken to glucose by amylases and part is converted to fructose by glucose isomerase
Advantages of enzymes: they work at mild temperature, are specific, and produce less waste than chemical methods
Limitations: enzymes can be costly, may lose activity and may cause allergy in rare cases
Recombinant enzymes: chymosin from genetically engineered microbes was the first approved recombinant food enzyme in the United States in 1990
Kinetics: enzyme speed depends on temperature, pH, substrate and inhibitors, and has an optimum
Safety rules: enzymes used in food must meet FSSAI standards, and genetically modified sources need clear approval, as in Public Acceptance and Safety of New Biotechnology Foods
Link: reactor types are described in Bioprocess and Fermentation Technology
Food enzymes in India: India has a growing enzyme industry, and demand comes from dairy, bakery, brewing, starch and juice makers
Detergent and textile enzymes: the same families of enzymes are also used in laundry, leather and textile processing, which share production technology with food enzymes
Acrylamide control: the enzyme asparaginase reduces acrylamide formation in fried and baked starchy foods
Gluten and baking: enzymes can improve dough strength, and some are tested to break down gluten, though such foods need careful labelling
Cost side: enzymes are used in tiny amounts, so they add little to the cost while saving energy and raw material
Regulation of enzyme sources: enzyme preparations must name their source organism, and processing aids that do not remain in the final food are treated differently from additives

Why Does It Matter for the Exam?

Match enzyme with use: amylase, lactase, chymosin, pectinase
Concepts: immobilised enzymes and reuse
Reactors: stirred tank, airlift, packed bed
Current affairs link: lactose free and fortified foods and precision fermentation
Common errors: saying that chymosin is a plant enzyme or that lactase breaks fat

As an analytical point, enzyme technology makes food processing cleaner and cheaper. Labelling, safety checks and support for Indian enzyme producers help to keep standards high and reduce imports.

Why Is This Topic Important?

Enzymes Uses asked
Reactors Types
Industry Food processing

What Came Next?

The next topic covers single-cell protein and food fortification. Next topic: Single-Cell Protein Production and Food Fortification.

Key People and Terms

Enzyme Biological catalyst
Substrate What the enzyme acts on
Immobilisation Fixing enzyme to a support
Hydrolysate Protein broken into pieces
Chymosin Milk clotting enzyme
Optimum Best temperature or pH

Exam Corner

Points to Remember

Lactase splits lactose.
Pectinase clears juice.
Chymosin is for cheese.
Glucose isomerase makes fructose.
Immobilised enzymes can be reused.

Do Not Confuse With

Lactase and lipase Milk sugar versus fat
Amylase and protease Starch versus protein
Stirred tank and packed bed Mixed liquid versus fixed enzyme column

Memory Hook

Amylase for starch, protease for protein, lipase for fat, lactase for milk; fix them on beads and reuse.

Mains Angle

Questions ask for enzymes and their uses. These points help.

Use Baking to dairy
Benefit Clean and specific
Safety Labelling and approval

A Question You May Face

An original practice question, not a past paper question.

“Discuss the role of enzymes and bioreactors in the food processing industry and the safety issues they raise.”

How to Answer

Enzymes Types and uses.
Reactors Stirred, packed bed.
Benefits Clean, specific.
Safety FSSAI standards.

GS Relevance

Prelims: enzymes and uses, bioreactor types, immobilisation. GS Paper 3: science and technology, biotechnology, food processing.

Frequently Asked Questions

What are food enzymes?

Food enzymes are biological catalysts used in making and processing food. Examples include amylase for breaking starch in baking and brewing, protease for tenderising meat, lactase for lactose free milk, pectinase for clearing juice and chymosin for cheese. They are usually produced by microbes grown in fermenters.

What is an immobilised enzyme?

An immobilised enzyme is one that has been fixed on a solid support such as beads, a gel or a membrane. This lets the enzyme stay in the reactor while the product flows out, so it can be used many times, and it often makes the enzyme more stable. It is widely used in making sweetener syrups.

Why is chymosin used in cheese making?

Chymosin is an enzyme that clots milk by cutting casein protein, forming the curd from which cheese is made. It was traditionally taken from the stomach of calves as rennet, but is now produced by genetically engineered microbes, which provides a reliable and animal free supply.

How is lactose free milk made?

Lactose free milk is made by adding the enzyme lactase to milk, which splits lactose into glucose and galactose that people with lactose intolerance can digest. The enzyme may be added directly or used in an immobilised form. The milk tastes slightly sweeter because the products are sweeter than lactose.

What types of bioreactors are used for enzymes?

Common types are the stirred tank bioreactor, which mixes with an impeller, the airlift bioreactor, which mixes with gas bubbles, and the packed bed reactor, which holds immobilised enzymes in a column. The choice depends on the product, the sensitivity of cells and whether the enzyme is free or fixed.

PYQ Practice — Statement Analysis

1 Lactase breaks down lactose into glucose and galactose.

True

Used for lactose free milk.

2 Pectinase is used to clear fruit juices.

True

By breaking pectin.

3 Chymosin is used to break starch in baking.

False

It clots milk for cheese.

4 Immobilised enzymes cannot be reused.