Hurdle technology in food technology

HURDLE TECHNOLOGY:Hurdle technology is a method of ensuring that pathogens in food products can be eliminated or controlled.. Lowering the water activity or Redox potential V.. Common sa

HURDLE CONCEPT-INTERMEDIATE MOISTURE

FOODS

HURDLE TECHNOLOGY:

Hurdle technology is a method of ensuring that pathogens in food products can be eliminated or controlled

Means

1 Food products will be safe for consumption

2 Shelf life will be extended

Hurdle technology usually works by combining more than one

approach These approaches can be thought of as "hurdles" the

pathogen has to overcome if it is to remain active in the food The right combination of hurdles can ensure all pathogens are eliminated

in the final product

HURDLES IN A FOOD SYSTEM ARE:

I high temperature during processing

II Low temperature durining storage

III Increasing the acidity

IV Lowering the water activity or Redox potential

V Presence of preservatives

According to the type of pathogens and how risky they are, the intensity of the hurdles can be adjusted individually to meet consumer preferences in an economical way, without compromising the safety of the product

Each hurdle aims to eliminate, inactivate or at least inhibit unwanted microorganisms Common salt or organic acids can be used as

hurdles to control microbials in food Many natural antimicrobials such as nisin, natamycins and other bacteriocins, and essential oils derived from rosemary or thyme, also work well

Principal hurdles used for food preservation

Parameter Symbol Application

High temperature F Heating

Low temperature T Chilling, Freezing

Reduced water activity aw Drying, curing, conserving

Increased acidity pH Acid addition or formation

Reduced redox potential Eh Removal of Oxygen Or addition of ascorbate

Biopreservatives Competitive flora such as microbial fermentation Other preservatives Sorbates, sulfites, nitrites

PHYSICAL HURDLE

Aseptic packaging, electromagnetic energy (microwave, radio

frequency, pulsed magnetic fields, high electric fields), high

temperatures(blanching, pasteurization, sterilization, evaporation,

extrusion, baking, frying), ionizing radiation, low temperature

(chilling, freezing), modified atmospheres, packaging films (including active packaging, edible coatings), photodynamic inactivation, ultra-high pressures, ultrasonication, ultraviolet radiation

PHYSIOCHEMICAL HURDLE

Carbon dioxide, ethanol, lactic acid, lactoperoxidase, low pH, low

redox potential, low water activity, Maillard reaction products, organic acids, oxygen, ozone, phenols, phosphates, salt, smoking, sodium

nitrite/nitrate, sodium or potassium sulphite, spices and herbs,

surface treatment agents

MICROBIAL HURDLE

Antibiotics, bacteriocins, competitive flora, protective cultures

INTERMEDIATE-MOISTURE FOODS (IMF)

Adjustment and control of water activity to preserve semimoist foods has attracted increasing attention Intermediate-moisture foods or semimoist foods, in one form or another, have been important items of diet for a very long time Generally, they contain moderate levels of moisture, of the order

of 20- 50% by weight, which is less than is normally present in natural fruits and 'vegetables, but more than is left in conventionally dehydrated products.

In addition, 'intermediate-moisture foods contain sufficient dissolved solutes

to decrease water activity below that required to support microbial growth.

As a consequence, intermediate-moisture foods do not require refrigeration

to prevent microbial deterioration There are various kinds of intermediate-moisture foods: natural products such as honey; manufactured confectionery products high in sugar, jellies, jams, and bakery items such as fruit cakes; and partially dried products including figs, dates etc In all of these products, preservation is partially from high osmotic pressure associated with the high concentration of solutes; in some, additional preservative effect is contributed by salt, acid, and other specific solutes.