|
Food Protection Trends
Abstracts - July 2004
Validation of a Procedure Using CO2 for Rapid Cooling
of Cheese Sauce
Acid and Alkaline pH Enhance Adhesion of Spores of
Alkaline-tolerant Bacillus cereus to Different Surface Types
Pilot-plant Evaluation of Acidified Sodium
Chlorite for Sanitizing Beef Trim
Ethics of Differences in Risk Perception and
Views on Food Safety
Validation of a Procedure Using CO2 for Rapid Cooling
of Cheese Sauce
Peter Snyder, Jr.,* andRobin Mark Johnson
Hospitality Institute of Technology and Management, 670 Transfer Road,
Suite 21A, St. Paul, MN 55114, USA; 16658 Hearthside Way, Lakeville, MN 55440,
USA
SUMMARY
Cheese sauces are commonly produced in commercial kitchens. These sauces must
be handled as potentially hazardous foods, unless challenge tests with Clostridium
botulinum and Bacillus cereus
are performed to demonstrate their microbial stability. Although there
are inhibitors in many cheese sauces (e.g., salt and exudates from lactic acid
bacteria fermentations), the FDA 2001 Food Code requires that all potentially
hazardous food be cooled from 140 to 70°F in 2 hours and from 70 to 41°F in
4 hours. Actually, this is a straight-line exponential cooling curve from 140
to 41°F in 6 hours. Because cooling a large quantity of cheese sauce in
2-inch pans requires overnight refrigerated storage, during which time the sauce
may be handled multiple times, the cooling process increases the risk of bacterial
growth while placing a burden on the cooling capacity of refrigeration units.
This study examined two cooling methods: cooling of cheese sauce in an ice bath
followed by further cooling in refrigerated storage, and addition of CO2 (dry
ice) to cheese sauce to cool it rapidly.
The latter method of cooling was found to be more rapid, less labor intensive,
and more cost effective. CO2 (dry ice) can also be used for cooling other potentially
hazardous liquid or semi-liquid food products.
Acid and Alkaline pH Enhance Adhesion of Spores of
Alkaline-tolerant Bacillus cereus to Different Surface Types
D. Lindsay,2* V. S. Brözel,2 andA. von Holy1
1-School of Molecular and Cell Biology, University of the Witwatersrand, Private
Bag 3, Wits 2050, South Africa
2-Laboratory for Biofilm Physiology, Department of Microbiology and Plant Pathology,
University of Pretoria, Pretoria 0001, South Africa
SUMMARY
Few studies have addressed the effect of pH on adhesion of Bacillus
(B.) spores to surfaces. In this study, spore adhesion of B.
cereus DL5, isolated from alkaline dairy wash solutions, and B.
cereus NCTC 2599 was studied at pH 4, 7 or 10 on stainless steel, glass
and polyurethane surfaces. Spores of each strain were suspended in sterile distilled
water adjusted to pH 4, 7 or 10 and stored at 4°C overnight. Stainless steel,
glass and polyurethane surfaces that had been conditioned with one-tenth strength
Tryptone Soya Broth were then exposed to the spore suspensions at each pH value
for 1 hour. Adhering spores were enumerated by the standard plate count
method at all pH values. Results indicated that pH had little effect on adhesion
of B. cereus NCTC 2599 spores to any
of the surface types. By contrast, B.
cereus DL5 spores showed enhanced adhesion at pH 4 and 10 to polyurethane
and glass surfaces. Acid or alkaline pH values in food processing environments
may exist on food contact surfaces after cleaning-in-place procedures, such
as in dilute cleaning solution residues overnight. The adhesion of spores
of Bacillus spp. to food contact surfaces
constructed of materials such as stainless steel and polyurethane is already
a concern for food manufacturers. Thus, enhanced spore adhesion potential
of B. cereus strains under certain
pH conditions may have important spoilage and safety implications.
Pilot-plant Evaluation of
Acidified Sodium Chlorite for Sanitizing Beef Trim
K. R. SCHNEIDER,1* C. C. WARF,2 P. L. BAXTER,3 B. R. WARREN,1 and G. K. KEMP2
1-University of Florida, Department of Food Science and Human Nutrition, 359
FSHN Bldg., Newell Dr., Gainesville, FL 32611, USA 2-Alcide Corporation, 8561
154th Ave. N.E., Redmond, WA 98052, USA
3-Florida Department of Agriculture and Consumer Services, 3125 Conner Blvd.,
Bldg. 9, Tallahassee, FL 32399, USA
SUMMARY
Citric acid activated acidified sodium chlorite (C-ASC) has been approved for
sanitizing beef trim. In this study, the efficacy of 1000 ppm C-ASC spray treatments
against total aerobic microorganisms and E.
coli was evaluated while optimizing a newly developed SANOVA® system for
spraying beef trim. Spray treatments consisted of combinations of 74,
147, or 221 ml C-ASC/kg delivered during 5, 10, or 15 s. Additionally,
two feed rates, 0.75 kg/s and 2.5 kg/s, were investigated. Reductions by C-ASC
spray treatments on 90% lean/10% fat [90/10] beef trim were compared to reductions
by the same treatment on 50% lean/50% fat [50/50] beef trim. At a feed
rate of 0.75 kg/s, the SANOVA® system reduced total aerobic microorganisms by
as much as 1.2 log CFU/50 cm2 (treatment with 221 ml C-ASC/kg for 10 s) and
reduced E. coli by as much as 1.4
log CFU/50 cm2 (treatment with 221 ml C-ASC/kg for 15 s). At a feed rate of
2.5 kg/s, the SANOVA® system reduced total aerobic microorganisms by as much
as 1.3 CFU/50 cm2 (treatment with 221 ml C-ASC/kg for 15 s) and reduced
E. coli by 2.3 CFU/50 cm2 (treatment
with 147 ml C-ASC/kg for 10 s). Reductions of both aerobic microorganisms and
E. coli were higher at feed rates
of 2.5 kg/s than at 0.75 kg/s for most matrices tested. Preliminary evaluations
suggest that higher reductions may be possible on [50/50] beef trim than on
[90/10] trim.
Ethics of Differences in Risk Perception and
Views on Food Safety
Michiel Korthals
Wageningen University, The Netherlands,
Hollandseweg 1, 6706 KN Wageningen
SUMMARY
Conventional risk analysis presupposes that uniform definitions of risks can
be reached on the basis of scientific consensus; it does not take consumers’
definitions of risks seriously. However, risk definitions can vary widely, depending
on national cultures and their influence on scientific communities. In addition,
risks must be accepted by members of society, both individually and jointly.
The issue is then no longer one of costs and benefits, but of mutual respect
of rights and of achieving trust and reasonable agreement among members of society.
In this paper the controversies between scientific and cultural risk perception
will be considered, and the issue of the ethical acceptability of different
risk definitions. A key element for consumers is trust in the authority that
defines and sets out the risks for policy purposes, and trust is not upheld
by dismissing their definitions as irrational. For consumers, but for
scientists as well, cultural background, basic assumptions, expectations, and
lifestyles play a major role here. Subsequently, the ethical legitimation of
pluralism in risk perception is discussed. Consumers not only have money
to buy products but hold varying views about freedom of food choice and diversity
of the food supply. In democratic societies, legitimately developed risk definitions
of consumers are entitled to recognition, and such definitions cannot be set
aside by scientific, free-market, or utilitarian considerations (such as cost-benefit
analyses prepared by others). Implications for risk assessment and risk communication
are explained in detail.
|
