APM Welcome, APM North West Network Conference, Synergies Across Sectors
Food Processing & Preservation Methods Through History
1. BioSC & PhySC
CHEMISTRY
Food processing and preservation
FIS2012024 Fu Zi Yang
FIS2012091 Mohammed Ameen
FIS2012083 Fathimath Fithra Moosa
FIS2012026 Chan Jay-Sern
3. ANCIENT
PERIOD
Early human life, with basic technology
and scientific innovation
Drying was widely used asearly as as early as 9600 BC/1200 BC
Refrigeration in caves or under cool water was also
commonly used.
Smoking of fish and meat was also widely used as
early as 9600 BC/1200 BC
4. MIDDLE AGES
Early human life, with basic technology
and scientific(chemical) innovation
Pickling(usually of vegetables) in an acid solution
(usually vinegar) to form a low pH pickle.
Curing (salting) of foods such as meat is the addition
of salt to remove the moisture out of the food
Fermentation is when microorganisms convert carbs
into alcohol or acid that act as a preservative
5. MODERN ERA
Modern world technology with
scientific(chemical) knowledge with
advanced accurate machinery. Canning where food is placed in jars and heated to
take out microorganisms and create a vacuum seal.
Freeze drying by freezing the food and extracting water via sublimation
Addition of chemical preservatives and food
irradiation to inhibit microbial decomposition activity
6. FOOD PRESERVATIVES
• Inhibits or stops an active fermentation process
before dryness and acidification takes place
• Stops food from microbial decomposition giving them
a longer shelf life
• Harmless to the human body
• Food preservatives are classified into 2 groups:
• Class I: Includes table salt, vegetable oil and sugar
• Class II: Includes chemicals such as sodium benzoate
and sodium metabisulfate (SMBS)
7. • Salting is mainly used for the preservation of fish, meat and vegetables
• Sugar is used for the preservation of jam and jellies
• Inhibits microbial growth, by drawing water and bacteria out of the food cells by a process
called osmosis
• Water being reduced in the food slows down bacterial growth and reproduction
• High concentration of salt or sugar ruptures bacterial cells due to the pressure difference
inside and outside of the microorganism
PRESERVATION BY USING SALT & SUGAR
8. SODIUM BENZOATE
• Produced by the chemical reaction between sodium hydroxide and benzoic acid
• Occurs naturally in food such as: cranberries, prawns, cheese and yoghurt
• Inhibits bacterial growth making it a good food preservative
• Enters individual cells in the food and balances its pH level, increasing the overall acidity of
the food
• Lowers the intracellular pH level of some foods creating an environment where fungi cannot
grow
9. SODIUM METABISULFITE (SMBS)
• Produced by the chemical reaction
between sulfer dioxide and sodium
carbonate
• Proved to be safe for human
consumption by the FDA (the US Food
and Drug Administration)
• Commonly used for the preservation of
dried and fresh fruits, vegetables and
also to preserve wine
10. SODIUM METABISULFITE (SMBS) CONT...
• Works by inhibiting the oxidase in the food and by
blocking the normal oxidation process at microbes,
resulting in the inhibition of the reproduction of
microorganisms in the food
• It is a strong reducing agent it reacts with oxygen in fruits
and vegetables while simultaneously inhibiting oxidase
activity, preventing oxidation-related food spoilage and
protecting vitamin C levels.
• It also reduces the coloured food to a fresh colour or
prevents oxidative browning
12. used to make yogurt, sauerkraut, kimchi, and
pickles
Lactic acid Fermentation
used to make bread, wine, and beer
Alcoholic Fermentation
Fermentation
15. Two
steps
• Pyruvate is removed from pyvurate
to form carbon dioxdie and acetaldehye
2. acetaldehye NADH donates it electron to
acetaldehyde, forming NAD+ and ethanol.
17. Freezing
• Temperature is low
• water in the food turns into ice
crystals
• micoorgarnism enter a dormant stage
18. • uses ionising radiation to destroy bacteria and insects in food
• extends shelf life and makes it safer for humans
• US Food and Drug Administration (FDA) must first approve the source of the radiation
• An electron beam (or e-beam) is a stream of high-energy electrons that is used in this
technique
Food Irradiation
19. Food
Irradiation
• prevents food poisoning by eradicating organisms that cause food poisoning.
• eliminates or inactivating organisms that cause decomposition and rotting
• kills insects, reduces pest-control methods that are harmful to the fruits
• uses ionizing radiation to kill microorganisms and insects in food, extends shelf life and is safe for human consumption
• used to sterilize milk and canned fruits and vegetables
21. REFERENCES
• Timetoast. (1750, June 8). Food Preservation History timeline. Timetoast Timelines.
https://www.timetoast.com/timelines/food-preservation-history--2
• Medieval Food Preservation Methods. (2019, August 19). ThoughtCo. https://www.thoughtco.com/medieval-
food-preservation-1788842
• Licarriea, V. A. P. B. (2015, May 10). Evolution of Food Preservation in the Kitchen and the Affect on Functionality.
Kitchen of The Future. https://kitchenofthefuture.wordpress.com/2015/05/09/evolution-of-food-preservation-in-
the-kitchen-and-the-affect-on-functionality/
