Importance of Food Drying

Introduction to Food Processing

Why process foods?Extend edible time frame -PreservationMake better tasting foodsMake more varieties of foodConvenience

DryingExtraction of moisture by sun, air, heat or

vacuum to inhibit the growth of molds, bacteria and yeastsName 3 dried foods

SaltingThe addition of salt or a brine solution to

foods to decrease the activity of molds, bacteria and yeasts.Name 3 salted foods

CuringThe addition of a chemical compound

(sodium nitrate or sodium nitrite) to food to slow the growth of bacteria.Name 3 cured foods

FermentationThe use of special bacteria, molds or yeasts

to prevent spoilage by converting the elements of food that spoil easily to stable elements that act as preservatives.Name 3 fermented foods

Freeze DryingThe freezing of food and the subsequent

removal of water from the frozen food through the use of heat and a vacuum.

SmokingThe addition of smoke and heat to preserve

food by the action of the chemicals from the smoked wood and the partial drying of the food.Name 3 smoked foods

Canning/Aseptic PackagingThe packing of food in a container, sealing

the container and heating it to sterilize the food.Name 3 canned foods

PasteurizationThe heating of milk and other liquids

which reduces the number of disease-producing bacteria.Name 3 pasteurized foods

RefrigerationThe lowering of the temperature of food to

inhibit the growth of bacteria, molds and yeasts.Name 3 refrigerated foods

FreezingThe lowering of the temperature of food to

temperatures below 28 degrees F to stop the growth of bacteria, yeasts and molds and to kill parasites.Name 3 frozen foods

Food concentrationHeating food until it boils and removing the

water or partially freezing food and removing water in the form of ice crystals.Name 3 concentrated foods

IrradiationPassing energy through food to destroy

insects, fungi, or bacteria that cause human disease or cause food to spoil.Name 3 irradiated foods

Food SafetyHAACP: Hazard Analysis Critical Control

PointWhat safety risk is present for each food

Pathogenic microorganismsBacteria, viruses

Spoilage microorganismsFungi, bacteria

What foods are at greatest risk for contamination?

Most important qualities to controlpH

Bacteria thrive in a pH neutral environment (7)

Items with pH above 8 tend to be very bitter & toxic

Foods with pHs below 6 tend to be tart or sour

1 7 14

Bacteria

Yeast/Fungi

Qualities to controlTemperature40 – 140°F = the temperature danger zone

Rapid multiplication of microorganisms<40°F very slow growth<28°F – no growth – no death>140°F – death of microorgamisms

Qualities to ControlMoisture content & Protein contentBacteria need a high moisture contentFungi can grow in lower moisture

Dry foods won’t make you sickDry foods do spoil

Bacteria need protein, fungi less soCandy & carbohydrates may spoil but don’t

won’t make you sick

Food DeteriorationEnzymes break down proteins over time

Must deactivate enzymes before food can be stored

Heat destroys enzymesFats and oils can oxidize in storage

Gives off flavorsNeed airtight packaging or antioxidant

additives