Aseptic processing
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two substances used to sanitize packaging
hydrogen peroxide and ultraviolet light
other types of “thermal” processes include
microwave heating, Ohmic heating, Pulsed electric fields
Cold processing
reduces the activity of microorganism and enzymes but it only slows the deterioration of food does not kill microbes or denature enzymes
The more rapidly the food is chilled..
the better the quality and nutritive value
replacing oxygen with carbon dioxide
prevents the chemical reaction that causes food spoilage
Freezing
has minimal effects on characteristics Significantly extends shelf life up to months Changes in PH
Water is food products freezes at 0 degrees?
Never! freezing point depression bc of bound water in foods
eutectic point
all the water in the food product is frozen once temp drops below this point for most foods this point is around -50 degrees ( not economical and feasible )
commercial products are held at what temperature
-18 degrees ( where most water in food products is frozen but not all ) however since there is still small % of water is still in liquid state so some degradation in food still occurs ( this is why frozen meat doesn’t last forever)
Solubiliity reduction
ex) crystallization of lactose of ice cream
Basic rule: slow freezing produces ______ ice crystals-damages tissues, fast freezing produces______ ice crystals- less damage
Large Small
Cryogenic freezing
chemicals that have low freezing point example: liquid nitrogen (-198 degrees) however not cost effective
base cost of freezing is about ___ % of the product
10%
freezer fluctuation
-22 to -12
most quality deterioration spikes during
thawing
why is microwave thawing a good option
reduces thawing time