Prof ElecPrelim
Prof ElecPrelim
Prof ElecPrelim
Boiling – the process of using the liquid with a food Burial- the process of preserving food due to a
items that can kill any existing microbes. Milk and variety of factors: lack of light, lack of oxygen, cool
water are often boiled to kill any harmful microbes temperatures desiccants in the soil. Burial may be
that may be present in them. combined with other methods such as salting or
fermentation. Most foods can be preserved in soil
Heating – the process of using the temperatures that is very dry and salty (thus a desiccant) such as
that are sufficient to kill microorganisms inside the sand, or soil that is frozen.
food is a method used to perpetual stews. Milk is
also boiled before storing to kill many Example: Century eggs are traditionally created by
microorganisms. placing eggs in alkaline mud (or other alkaline
substance), resulting in their “inorganic”
Sugaring – the earliest cultures have used sugar as fermentation through raised pH instead of spoiling.
a preservative. This is used to preserve fruits, either
in an antimicrobial syrup with fruit such as apples, Fermentation – some foods, such as many cheeses,
pears, peaches, apricots, and plums, or in wines, and beers, use specific micro-organisms that
crystallized form where the preserved material is combat spoilage from other less-benign organisms.
cooked in sugar to the point of crystallization and These micro-organisms keep pathogens in check by
stored dry. This method is used for the skins of creating an environment toxic for themselves and
citrus fruit, jam and jelly. other micro-organisms by producing acid or
alcohol.
Pickling – is a method of preserving food in an
edible, antimicrobial liquid. Pickling can be broadly
Canning process – this involves placing foods in jars
Illustration of fermentation in making wine. or cans/similar containers and heating them to a
temperature that destroys micro-organisms that
cause food to spoil. … This vacuum seal prevents air
from getting back into the product bringing with it
contaminating micro-organism
Pasteurization
Pasteurization is a process for preservation of liquid
food. It was originally applied to combat the
souring of young local wines. Today, the process is
mainly applied to dairy products. Milk is also
processed and stored in sterilized bottles or
pouches in cold places. This method was invented
by Louis Pasteur, a French chemist, in 1862