23.7 Industrial Chemistry in Food Production | Industry | Chemistry 12

Industrial chemistry plays a central role in modern food production — from preserving food to controlling its pH. This topic examines two key dimensions: the ethical considerations surrounding chemical use in food production, and the role of buffer solutions (particularly the bicarbonate buffer) in food chemistry and human physiology.

Ethical Considerations in Food Chemistry (C-12-A-02)

The use of chemical substances in food production raises important ethical, health, and environmental questions.

Benefits of Industrial Food Chemistry

Extended shelf life through preservatives (e.g., sodium benzoate, sulfur dioxide) reduces food waste.
Fortification of foods with vitamins and minerals (e.g., iodised salt, vitamin D in milk) addresses nutritional deficiencies.
Food safety is improved through controlled use of approved additives that inhibit microbial growth.
Increased food availability through industrial-scale production helps feed growing populations.

Risks and Ethical Concerns

Some synthetic additives (e.g., artificial colours, certain preservatives) have been linked to adverse health effects in sensitive individuals.
Trans fats produced during partial hydrogenation of vegetable oils are associated with cardiovascular disease — raising questions about corporate responsibility.
Environmental impact: large-scale food chemical production generates industrial waste and greenhouse gases.
Regulatory role: Governments and bodies like the FDA and EFSA set permissible limits for food additives. Scientists and companies have a responsibility to conduct safety testing and comply with regulations.
Consumer rights: Labelling laws require disclosure of additives, but consumers may not fully understand chemical names on ingredient lists.

Responsibility of Scientists and Companies

Scientists must conduct rigorous, unbiased safety assessments before new food chemicals are approved.
Companies must prioritise public health over profit, avoiding the use of cheaper but potentially harmful substitutes.
Regulatory frameworks (e.g., GRAS — Generally Recognised As Safe in the USA) provide legal standards, but ethical responsibility extends beyond mere legal compliance.

Buffer Solutions in Food Production (C-12-B-25)

What is a Buffer Solution?

A buffer solution is a solution that resists significant changes in pH when small amounts of acid ( $H^{+}$ ) or base ( $O H^{-}$ ) are added to it.

Buffers are essential in food production to maintain the correct pH for flavour, texture, microbial safety, and chemical reactions.

How is a Buffer Made?

A buffer is typically prepared by mixing:

A weak acid and its conjugate base (acidic buffer), e.g., ethanoic acid ( $C H_{3} C O O H$ ) and sodium ethanoate ( $C H_{3} C O O N a$ ).
A weak base and its conjugate acid (basic buffer), e.g., ammonia ( $N H_{3}$ ) and ammonium chloride ( $N H_{4} C l$ ).

How Does a Buffer Control pH?

Consider an acidic buffer made from $C H_{3} C O O H$ and $C H_{3} C O O^{-}$ :

$C H_{3} C O O H ⇌ C H_{3} C O O^{-} + H^{+}$

When acid ( $H^{+}$ ) is added: The conjugate base ( $C H_{3} C O O^{-}$ ) reacts with the added $H^{+}$ : $C H_{3} C O O^{-} + H^{+} \to C H_{3} C O O H$ The $H^{+}$ is consumed, so pH changes very little.
When base ( $O H^{-}$ ) is added: The weak acid ( $C H_{3} C O O H$ ) reacts with the added $O H^{-}$ : $C H_{3} C O O H + O H^{-} \to C H_{3} C O O^{-} + H_{2} O$ The $O H^{-}$ is neutralised, so pH changes very little.

Uses of Buffer Solutions in Food Production

Application	Buffer Used	Purpose
Soft drinks	Citric acid / citrate	Maintains tartness and prevents spoilage
Cheese making	Lactic acid / lactate	Controls pH during fermentation
Baking	Sodium bicarbonate / carbonic acid	Controls leavening reaction
Jams and preserves	Citric acid / sodium citrate	Maintains gel formation and prevents microbial growth

The Bicarbonate Buffer in Blood

The most important physiological buffer is the bicarbonate buffer system, which maintains blood pH at approximately 7.4.

The system involves carbonic acid ( $H_{2} C O_{3}$ ) and the bicarbonate ion ( $H C O_{3}^{-}$ ):

$H_{2} C O_{3} ⇌ H^{+} + H C O_{3}^{-}$

When blood pH falls (too acidic): $H C O_{3}^{-}$ acts as a base and accepts $H^{+}$ : $H C O_{3}^{-} + H^{+} \to H_{2} C O_{3} \to H_{2} O + C O_{2}$ The $C O_{2}$ is expelled via the lungs, raising pH back toward 7.4.
When blood pH rises (too basic): $H_{2} C O_{3}$ acts as an acid and donates $H^{+}$ : $H_{2} C O_{3} \to H^{+} + H C O_{3}^{-}$ The released $H^{+}$ lowers pH back toward 7.4.

This buffer system is critical in food chemistry contexts too — for example, carbonated beverages lower blood pH slightly, and the bicarbonate system compensates.

Ethical Considerations in Food Chemistry (C-12-A-02)

The use of chemical substances in food production raises important ethical, health, and environmental questions.

Benefits of Industrial Food Chemistry

Extended shelf life through preservatives (e.g., sodium benzoate, sulfur dioxide) reduces food waste.
Fortification of foods with vitamins and minerals (e.g., iodised salt, vitamin D in milk) addresses nutritional deficiencies.
Food safety is improved through controlled use of approved additives that inhibit microbial growth.
Increased food availability through industrial-scale production helps feed growing populations.

Risks and Ethical Concerns

Some synthetic additives (e.g., artificial colours, certain preservatives) have been linked to adverse health effects in sensitive individuals.
Trans fats produced during partial hydrogenation of vegetable oils are associated with cardiovascular disease — raising questions about corporate responsibility.
Environmental impact: large-scale food chemical production generates industrial waste and greenhouse gases.
Regulatory role: Governments and bodies like the FDA and EFSA set permissible limits for food additives. Scientists and companies have a responsibility to conduct safety testing and comply with regulations.
Consumer rights: Labelling laws require disclosure of additives, but consumers may not fully understand chemical names on ingredient lists.

Responsibility of Scientists and Companies

Scientists must conduct rigorous, unbiased safety assessments before new food chemicals are approved.
Companies must prioritise public health over profit, avoiding the use of cheaper but potentially harmful substitutes.
Regulatory frameworks (e.g., GRAS — Generally Recognised As Safe in the USA) provide legal standards, but ethical responsibility extends beyond mere legal compliance.

Buffer Solutions in Food Production (C-12-B-25)

What is a Buffer Solution?

A buffer solution is a solution that resists significant changes in pH when small amounts of acid ( $H^{+}$ ) or base ( $O H^{-}$ ) are added to it.

Buffers are essential in food production to maintain the correct pH for flavour, texture, microbial safety, and chemical reactions.

How is a Buffer Made?

A buffer is typically prepared by mixing:

A weak acid and its conjugate base (acidic buffer), e.g., ethanoic acid ( $C H_{3} C O O H$ ) and sodium ethanoate ( $C H_{3} C O O N a$ ).
A weak base and its conjugate acid (basic buffer), e.g., ammonia ( $N H_{3}$ ) and ammonium chloride ( $N H_{4} C l$ ).

How Does a Buffer Control pH?

Consider an acidic buffer made from $C H_{3} C O O H$ and $C H_{3} C O O^{-}$ :

$C H_{3} C O O H ⇌ C H_{3} C O O^{-} + H^{+}$

When acid ( $H^{+}$ ) is added: The conjugate base ( $C H_{3} C O O^{-}$ ) reacts with the added $H^{+}$ : $C H_{3} C O O^{-} + H^{+} \to C H_{3} C O O H$ The $H^{+}$ is consumed, so pH changes very little.
When base ( $O H^{-}$ ) is added: The weak acid ( $C H_{3} C O O H$ ) reacts with the added $O H^{-}$ : $C H_{3} C O O H + O H^{-} \to C H_{3} C O O^{-} + H_{2} O$ The $O H^{-}$ is neutralised, so pH changes very little.

Uses of Buffer Solutions in Food Production

Application	Buffer Used	Purpose
Soft drinks	Citric acid / citrate	Maintains tartness and prevents spoilage
Cheese making	Lactic acid / lactate	Controls pH during fermentation
Baking	Sodium bicarbonate / carbonic acid	Controls leavening reaction
Jams and preserves	Citric acid / sodium citrate	Maintains gel formation and prevents microbial growth

The Bicarbonate Buffer in Blood

The most important physiological buffer is the bicarbonate buffer system, which maintains blood pH at approximately 7.4.

The system involves carbonic acid ( $H_{2} C O_{3}$ ) and the bicarbonate ion ( $H C O_{3}^{-}$ ):

$H_{2} C O_{3} ⇌ H^{+} + H C O_{3}^{-}$

When blood pH falls (too acidic): $H C O_{3}^{-}$ acts as a base and accepts $H^{+}$ : $H C O_{3}^{-} + H^{+} \to H_{2} C O_{3} \to H_{2} O + C O_{2}$ The $C O_{2}$ is expelled via the lungs, raising pH back toward 7.4.
When blood pH rises (too basic): $H_{2} C O_{3}$ acts as an acid and donates $H^{+}$ : $H_{2} C O_{3} \to H^{+} + H C O_{3}^{-}$ The released $H^{+}$ lowers pH back toward 7.4.

This buffer system is critical in food chemistry contexts too — for example, carbonated beverages lower blood pH slightly, and the bicarbonate system compensates.