World Grain - November 2017 - 52

FEATURE

a
advancements in controlling pathogenss

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hile human illnesses caused by Salmonella, E. coli
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the issue remains a concern after two outbreaks in
recent years in the United States and Canada. Further, the
need for preventive microbial control and testing has been
heightened by new rules under the Food Safety Modernization
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matter is complicated by the fact that some consumers conWLQXHWRSXWWKHPVHOYHVDWULVNE\HDWLQJXQFRRNHGÀRXUXVXally in cookie dough or cake batter, despite label directions to
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at the consumer level.
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are major factors limiting microbe reduction on a broader
scale, said Debi Rogers, PhD, director of baking services at
$,% ,QWHUQDWLRQDO LQ 0DQKDWWDQ .DQVDV 86 7KH ODWWHU ²
FRQVXPHUDFFHSWDQFH²PD\EHDPDMRUKXUGOHIRUQHZPLcrobial treatments now in the testing phase, she said.
Heat treatment currently is the most widespread method
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temperature, time and water activity. Some treatment may be
referred to as pasteurization, which also utilizes heat. A major
drawback of the heat treatment method of microbial reduction
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on gluten, including electron beam and cold plasma, both of
which face major obstacles in scaling up to commercial levels.
Irradiation also is a possible treatment method that has been
approved by the U.S. Food and Drug Administration for pest
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have not been approved.
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hard wheats are not treated. Flour from soft wheat used in cake
mixes, cookies, breadings, soups and similar applications is
more likely to be heat treated because the process does not have
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&RQWDPLQDWLRQ LQ ÀRXU LV UDUH EHFDXVH LW KDV D ORZ PRLVture content that is not conducive to microbial growth. Flour
52

by Ron Sterk

Cost, impact on flour functionality
and consumer acceptance are
major factors limiting microbe
reduction on larger scale
typically has a water activity below 0.85aw, with activity of
0.95aw or above needed for bacterial pathogen growth. Low
water activity only inhibits microbial growth. It doesn't kill
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all the way to the end user.
Expense certainly is a factor in decisions about whether to
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and pastries, frying coatings or toasting ready-to-eat cereals, it
is hard to justify the cost treatment in most cases. As a result,
PLFURELDOFRQWHQWRIÀRXUW\SLFDOO\KDVQRWEHHQDQLVVXHEHcause it is considered an ingredient, not a food product that is
directly consumed in its raw form.
But that doesn't mean microbial contamination hasn't been
DQLVVXHDVÀRXUKDVPDQ\RSSRUWXQLWLHVWREHFRPHFRQWDPLQDWHGIURPWKHIDUPWRWKHHQGXVHU$UHFDOORIÀRXUE\*HQeral Mills in May 2016 that was expanded in June 2016 was
due to E. coli. Another recall of Smucker Foods of Canada's
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related to cases that occurred from November 2016 to late
February 2017. Food scientists suggest the microbial contamiQDWLRQUHÀHFWHGLQWKRVHWZRLQFLGHQWVLVQ¶WQHFHVVDULO\QHZWR
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testing methods may be uncovering what already was there.
While increased testing will be necessary under new FSMA
rules, sample testing isn't foolproof because it sometimes
misses a concentrated area of microbial presence since microbes are not necessarily distributed evenly throughout the
product, especially in the case of large commercial loads.
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PhD, Morse Alumni Distinguished Professor of Food Science
and Engineering at the University of Minnesota, who is pioneerLQJWKHXVHRIFROGSODVPDDVDPLFURELDOWUHDWPHQWIRUÀRXU
November 2017 / World Grain / www.World-Grain.com
http://www.World-Grain.com
World Grain - November 2017

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