Meat+Poultry - February 2022 - 62

MEAT PERSPECTIVES
If optimal mechanisms
for freezing and thawing
meat can be used without
sacrificing quality, then
freezing of raw materials
may help address supplyand-demand
issues.
been used, including the use of frozen products.
This made the industry start questioning some
of the long-standing purchasing practices. For
example, the US beef industry has historically
purchased and marketed primarily fresh
(non-frozen) products, especially retail and
foodservice products, but the uncertainty
of supply during the pandemic made people
question the role of freezing meat.
It's no secret that freezing is an easy,
effective and frequently used method for
extending the shelf life of many foods. When
freezing meat, it is important to remember that
freezing slows bacterial
growth, but it does not
kill bacteria, therefore,
appropriate handling during
thawing is required to
prevent bacterial growth.
Freezing does stop the aging
process that contributes to
meat tenderness; therefore,
the desired aging period
should occur before
freezing. Additionally, freezing has little to no
impact on the nutritive value of meat. However,
frozen meat has historically been considered
inferior, especially in quality, and less desirable
than fresh meat. For many, the thought was
that something must have been wrong with the
product for it to be frozen rather than sold in
the chilled/refrigerated state.
To protect quality characteristics of
meat, the " freeze fast, thaw slow " technique
is a simple-sounding phrase often used to
describe the most-recommended practice of
freezing and thawing meat. Unfortunately, this
technique is not as simple as it sounds. There
are various methods for freezing and thawing
meat products used across the industry leading
to inconsistencies in product handling, as well
as variability in quality of frozen products. We
know that product handling before freezing,
freezing rate, conditions during frozen storage,
and thawing conditions and rate can all
influence quality characteristics. In general, the
freeze-fast, thaw-slow approach is designed
to prevent cell lysing which can lead to
dehydration, freezer burn, oxidative rancidity,
excessive purge and excessive cooking losses -
all of which negatively impact quality.
Given the different freezing and thawing
methodologies in use, it is important to
62 MEAT+POULTRY | 02.22 | www.meatpoultry.com
understand the relationships between freezing
rate and various meat quality factors, such as
drip loss, water-holding capacity, tenderness
and color. Methods for freezing meat,
may include:
* Still air - air is the heat transfer medium.
* Blast freezer - cold air, in rooms or
tunnels, equipped with fans to provide rapid
air movement.
* Plate freezer - product is placed on
trays that are in direct contact with metal
freezer plates.
* Liquid immersion/sprays - like sodium
chloride brine, glycols and glycerol.
* Cryogenic freezing - condensed or
liquefied gases, like liquid Nitrogen.
Still air is often the slowest freezing
method, while contact freezers, such as direct
contact (immersion freezers) and in-direct
(plate freezers) are very efficient with regard to
heat transfer rate. There are multiple research
articles written about the impact of freezing on
meat quality. One study showed that freezing
M. longissimus by calcium chloride immersion
resulted in decreased purge but had no effect
on shear force values when compared to air
freezing (Kim et al., 2015). Wang et al. (2020)
compared freezing of a manufactured beef
steak product in a refrigerator freezer, an
immersion (ethanol, propylene glycol, NaCl)
freezer, and with a plate freezer, and reported
immersion freezing as optimal.
If optimal mechanisms for freezing and
thawing meat can be used without sacrificing
quality, then freezing of raw materials may
help address supply-and-demand issues, such
as increased needs around holidays, during
marketing promotions, or during times when
there are fluctuations in availability, such
as those seen during COVID-19. Therefore,
commercial freezing and thawing systems,
such as the Spiral Immersion System (SIS),
which uses a water or brine solution to both
freeze and thaw products in a controlled
and effective manner may change the way
the industry views and uses frozen meat.
Incorporating the most efficient freezing
systems designed to preserve meat quality
should be of greatest importance rather than
using out-of-date freezing programs that have
been used historically to save products when
supplies exceed demand and products are near
the end of their shelf life.
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Meat+Poultry - February 2022

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