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SproutNet
International Specialty Supply
September 18, 2009
ISS Seed Screening Seen
Theoretically as Substantial Log Reduction
SproutNet.com
September 17, 2009
Bob Rust, reviewed/edited by Martin Cole
In his keynote address to
the June 9, 2009 Scientific Session of the ISGA Convention in Chicago Dr. Martin
Cole (Chairman of the International Commission
on Microbiological Specifications for Foods (ICMSF)
and Director, National Center for Food Safety and
Technology (NCFST)),
discussed the theoretical possibility that
ISS Seed Screening protocol may be
equivalent to a 2.34 log reduction or better.
Risk can never be
completely eliminated, but it can be controlled or reduced to an appropriate
level of protection (ALOP). The FDA stated in the
White Papers that commercial sprout producers need to
implement a series of procedures that reduce the risk of contamination by five
logarithms, or “log”. This appears to be their ALOP.
Log reductions in sprouts
are based on either real or theoretical levels of contamination. In experiments
with chlorine, for example, either naturally contaminated seed with known levels
of contamination are used, or seed is inoculated with pathogens to a known level
of contamination.
In practice the seed is
usually not contaminated, so the chlorine is not reducing any pathogen level at
all. But theoretically it would if contamination were present.
In the case of seed
screening, one can calculate the probabilities of capturing a contaminated seed
at theoretical levels of contamination. Conversely, you can also look at what
contamination level you will find with a certain probability. For example,
according to ISS' calculations, if you sample 880 bags of seed at 25 grams per
sample, 99% of the time you will capture a pathogen in seed that is contaminated
at the rate of 1 contaminated seed per 5 kg. That is only 4606 contaminated
seeds per truckload, or 1 contaminated seed per 4.78 kg. This is assuming
non-homogeneous distribution throughout the lot but is assuming homogeneous
distribution throughout those bags with contamination.
Dr. Cole calculated that
sampling 25 grams from 120 bags of seed (3kg composite sample) would capture for
detection with 95% certainty contamination as low as 1 cell per 4.57 kg. His
program calculates probabilities of acceptance for materials with different
microbial loads and population standard deviations. The pathogens are assumed
to be log-normally distributed with a standard deviation of 0.8. This is a high
standard deviation used when distribution is expected to be uneven throughout
the population (seed lot).
"A standard deviation = 0.2 log10 CFU g-1 is
used to describe a food in which microbes would be expected to be rather
homogenously distributed within a batch (e.g., for liquid food with a high
degree of mixing). A standard deviation of 0.4 log10 CFU g-1 is
assumed for a food of intermediate homogeneity (e.g., ground beef) and a
standard deviation = 0.80 log10 CFU g-1 for an inhomogenous food
(e.g., solid food)." 1
For the purpose of
illustration, Martin compared this to a worst case contamination scenario of 100
cfu per kilogram of seed. Sampling 25 grams from 120 bags with a standard
deviation of 0.8 was 2.34 logs less than 100 cfu/kg, or a 2.34 log reduction.
120 x 25g samples (=3kg)
sprouted and tested would be able to reject a lot with -3.66 log cfu/g, or 1
cell in 4.57kg (SD=0.8). Operating Character (OC) Curve is scaled to relate
mean log count to the microbiological limit.
ISS often samples up to
eight times the amount that Dr. Cole ran through his analysis. ISS asked Dr.
Cole if he could run larger samples. Unfortunately, his program was only
designed to go up to 160 samples so he ran a few examples at various sample
sizes.
|
Samples |
Total
Sample |
Log cfu/g |
cfu/g |
|
120X25g |
3kg |
-3.66 |
(1cell in 4,57kg) |
|
160x25g |
4kg |
-3.80 |
(1cell in 6.3kg) |
|
5x1kg |
5kg |
-3.34 |
(1cell in 2.2kg) |
|
10x1kg |
10kg |
-3.85 |
(1cell in 7.1kg) |
|
15x1kg |
15kg |
-4.12 |
(1cell in 13.2kg) |
|
20x1kg |
20kg |
-4.30 |
(1cell in 20kg) |
|
30x1kg |
30kg |
-4.53 |
(1cell in 33.8kg) |
|
60x500g |
30kg |
-4.61 |
(1cell in 40.7kg) |
|
120x250g |
30kg |
-4.66 |
(1cell in 45.7kg) |
Note that the three models
of 30 kilograms show the importance of increasing the number of samples compared
to the size of the samples. The 30kg from 120 samples gave a 0.13 better log
reduction than 30 samples of 1kg.
ISS will typically take
880 samples of a full truckload of seed. Dr. Cole is working to change his
modeling program to accommodate these numbers. ISS estimates they will be in
the range of a 3.5 log reduction.
These
theoretical log reductions are for capturing a pathogen. It does not take
into account the very real possibility of a not detecting captured pathogens.
To reduce this risk ISS' Seed Screening Protocol now involves
testing the
sprouts in one lab as well as the spent irrigation water in a separate lab.
This too is no guarantee that the seed is not contaminated. It is a risk
reduction step that should be employed along with Good Manufacturing Practices
including sanitizing the seed and an effective microbiological hold, test, and
release program.
The
NCFST will shortly be re-convening a task force on sprout safety in
collaboration with FDA and the industry to further develop this approach and to
evaluate it in the context of the original guidance given by FDA in 1999.
1(Relating
microbiological criteria to food safety objectives and performance objectives;
Food Control, The International Journal of HACCP and Food Technology, Vol 20,
Issue 11, Nov 2009, page 970; M. van Schothorst, M.H. Zwietering, T. Ross, R.L.
Buchanan, M.B. Cole, International Commission on Microbiological Specifications
for Foods (ICMSF))
FDA Opens the
Reportable Food Registry Electronic Portal for Industry
Food facilities now required to report potentially dangerous
products
The U.S. Food and Drug Administration has a new way to
head off potential cases of foodborne illness – the
Reportable Food Registry (RFR), where food industry officials must use to alert the FDA quickly, through
an electronic portal when they find their products might sicken or kill people
or animals. The requirement, a result of legislation, took effect with the
launch of the portal.
Facilities that manufacture, process or hold food
for consumption in the United States now must tell the FDA within 24 hours if
they find a reasonable probability that an article of food will cause severe
health problems or death to a person or an animal.
The opening of the RFR electronic portal reflects a
fundamental principle of the President’s Food Safety Working Group that
“preventing harm to consumers is our first priority.”
"President Obama has pledged to strengthen food
safety,” said Commissioner of Food and Drugs Margaret A. Hamburg, M.D. “The
opening of the Reportable Food Registry electronic portal represents a
significant step toward that pledge.”
The requirements apply to any person who has to submit
registration information to the FDA for a food facility that manufactures,
processes, packs, or holds food for human or animal consumption in the United
States. These people are termed responsible parties.
A responsible party:
- Must investigate the cause of the adulteration if
the adulteration of food may have originated with the responsible party
- Must submit initial information; followed by
supplemental reports
- Must work with the FDA authorities to follow up as
needed
A responsible party is not required to report if
it found the problem before the food was shipped, and corrected the problem or
destroyed the food.
For more information see the RFR Guidance at
www.fda.gov/ReportableFoodRegistry
Research ~ Health and Nutrition
- Why we do what we do
There is a continuous flow of health related
research to show sprouts as an extraordinary food with nutraceutical properties.
Below is recent research indicating sprouts aid in the prevention of
oxidative stress,
tumors, ulcers, inflammation, prostate cancer,
colon cancer, breast cancer, H. pylori, and Parkinson's disease.
This is just the recent research. There is
an extensive library of other nutritional research available under the
navigation bars at at the top of
http://www.sproutnet.com/nutrition_of_sprouts.htm
Ethyl acetate extracts of
alfalfa (Medicago sativa L.) sprouts inhibit lipopolysaccharide-induced
inflammation in vitro and in vivo.
J Biomed
Sci. 2009 Jul 14;16(1):64.
Hong YH,
Chao WW,
Chen ML,
Lin BF.
This study aimed to
investigate if food components that exert anti-inflammatory effects may be used
for inflammatory disorders by examining alfalfa sprout ethyl acetate
extract (ASEA). The cytokine profile and life span of BALB/c mice with
acute inflammation after intra-peritoneal (ip) injection of 15 mg/kg BW
lipopolysaccharide (LPS) were determined. The results showed that the life span
of LPS-induced inflammatory mice were negatively correlated with serum levels of
TNF-alpha, IL-6, and IL-1beta at 9 hr after LPS-injection, which indicated that
suppressing these cytokines in the late phase of inflammation may be beneficial
for survival. The in vitro experiment then showed that ASEA significantly
reduced IL-6 and IL-1beta production and the NF-kappaB trans-activation activity
of mitogen-stimulated RAW264.7 cells. To further evaluate the anti-inflammatory
effects of ASEA in vivo, BALB/c mice were tube-fed with 25 mg ASEA/kg BW/day in
50 mul sunflower oil, while the control and PDTC (pyrrolidine dithiocarbamate,
an anti-inflammatory agent) groups were tube-fed with 50 mul sunflower oil/day
only. After one week of tube-feeding, the PDTC group was injected with 50 mg/kg
BW PDTC and one hour later, all of the mice were injected with 15 mg/kg BW LPS.
The results showed that the ASEA and PDTC groups had significantly
lower serum TNF-alpha, IL-6, and IL-1beta levels at 9 hr after LPS challenge,
and significantly higher survival rates than the control group. This study
suggests that ASEA supplementation can suppress the production of
pro-inflammatory cytokines and alleviate acute inflammatory hazards.
Effect of Protein Hydrolysates from Germinated
Soybean on Cancerous Cells of the Human Cervix: An In Vitro Study.
Plant Foods Hum Nutr. 2009 Aug 18.
Mora-Escobedo R, Robles-Ramírez MD, Ramón-Gallegos E, Reza-Alemán R.
Escuela Nacional de Ciencias Biológicas, IPN. Carpio y Plan de Ayala, Col. Sto.
Tomás, México, D.F., México, C.P. 11340
Consumption of soybeans can reduce the risk of different types of cancer.
Little is known about the effect of germination on the anticancer properties of
soya. This study was done to determine if germination improves the anticancer
properties of soybean protein through generation of amino acids or bioactive
peptides. Soybean was germinated for 0, 2, 3, 4, 5, and 6 days and
proteins were isolated from the seeds. Isolates with and without ethanol-soluble
phytochemicals were hydrolyzed with digestive enzymes and their effect on growth
in HeLa and C-33 (epidermoid cervical carcinoma) and HaCaT (non-cancerous human
keratinocytes) cells were evaluated with the Alamar Blue method. Germination
induced degradation of the alpha and alpha' fractions of beta-conglycinin and
acid fraction of glycinin, generating low molecular weight peptides. Degrees of
hydrolysis ranged from 73-77%. Hydrolysates inhibited the growth of HeLa cells
and C-33 at concentrations exceeding 1.25 mg/ml. Major inhibition was
observed with the hydrolysate germinated for 2 days and containing
ethanolsoluble phytochemicals (IC(50) 2.15 and 2.27 mg/ml for HeLa and C-33,
respectively). Interestingly, hydrolysate cytoxicity for normal cells was
minimal in comparison to cancer cells.
Pharmacokinetics and pharmacodynamics of broccoli
sprouts on the suppression of prostate cancer in transgenic adenocarcinoma of
mouse prostate (TRAMP) mice: implication of induction of Nrf2, HO-1 and
apoptosis and the suppression of Akt-dependent kinase pathway.
Pharm Res. 2009 Oct;26(10):2324-31
Keum YS, Khor TO, Lin W, Shen G, Kwon KH, Barve A, Li W, Kong AN.
Department of Pharmaceutics and Ernest Mario School of Pharmacy, Rutgers The
State University of New Jersey, 160 Frelinghuysen Road, Piscataway, New Jersey
08854, USA.
PURPOSE: In the present study, we have evaluated the pharmacokinetics and
the in vivo prostate chemopreventive activity of broccoli sprouts.
METHODS: The in vivo pharmacokinetic profiles of sulforaphane (SF) and
SF- glutathione (GSH) conjugate in rats after oral administration of 200 mg and
500 mg broccoli sprouts were analyzed. Next, 8-week old TRAMP mice were fed with
dietary broccoli sprouts at two dosages (60 and 240 mg/mouse/day) for 16 weeks,
and the mice were sacrificed to examine the pharmacodynamic response on prostate
tumor and some biomarkers.
RESULTS: SF was readily released and conjugated with GSH in the rats
after oral administration of broccoli sprouts. TRAMP mice fed with 240 mg
broccoli sprouts/mouse/day exhibited a significant retardation of prostate tumor
growth. Western blot analysis revealed that the expression levels of
Nrf2, HO-1, cleaved-Caspase-3, cleaved-PARP and Bax proteins were increased, but
that of Keap1 and Bcl-XL proteins were decreased. In addition, the
phosphorylation and/or the expression level of Akt and its downstream kinase and
target proteins, e.g. mTOR, 4E-BP1 and cyclin D1, were reduced.
CONCLUSIONS: Our findings indicate that broccoli sprouts can serve as a
good dietary source of sulforaphane in
vivo and that they have significant inhibitory effects on prostate tumorigenesis.
Dietary sulforaphane-rich broccoli
sprouts reduce colonization and attenuate gastritis in Helicobacter
pylori-infected mice and humans.
Cancer Prev Res (Phila
Pa). 2009 Apr;2(4):353-60
Yanaka A, Fahey JW,
Fukumoto A, Nakayama M, Inoue S, Zhang S, Tauchi M, Suzuki H, Hyodo I, Yamamoto
M.
Division of
Clinical Pharmacology, Faculty of Pharmaceutical Sciences, Tokyo University of
Science, Chiba-Ken, Tokyo, Japan.
The isothiocyanate
sulforaphane [SF; 1-isothiocyanato-4(R)-methylsulfinylbutane] is
abundant in broccoli sprouts in the form of its glucosinolate precursor (glucoraphanin).
SF is powerfully bactericidal against Helicobacter pylori infections, which are
strongly associated with the worldwide pandemic of gastric cancer. Oral
treatment with SF-rich broccoli sprouts of C57BL/6 female mice infected with H.
pylori Sydney strain 1 and maintained on a high-salt (7.5% NaCl) diet reduced
gastric bacterial colonization, attenuated mucosal expression of tumor necrosis
factor-alpha and interleukin-1beta, mitigated corpus inflammation, and prevented
expression of high salt-induced gastric corpus atrophy. This therapeutic
effect was not observed in mice in which the nrf2 gene was deleted, strongly
implicating the important role of Nrf2-dependent antioxidant and
anti-inflammatory proteins in SF-dependent protection. Forty-eight H.
pylori-infected patients were randomly assigned to feeding of broccoli sprouts
(70 g/d; containing 420 micromol of SF precursor) for 8 weeks or to consumption
of an equal weight of alfalfa sprouts (not containing SF) as placebo.
Intervention with broccoli sprouts, but not with placebo, decreased the levels
of urease measured by the urea breath test and H. pylori stool antigen (both
biomarkers of H. pylori colonization) and serum pepsinogens I and II (biomarkers
of gastric inflammation). Values recovered to their original levels 2 months
after treatment was discontinued. Daily intake of sulforaphane-rich broccoli
sprouts for 2 months reduces H. pylori colonization in mice and improves the
sequelae of infection in infected mice and in humans. This treatment seems to
enhance chemoprotection of the gastric mucosa against H. pylori-induced
oxidative stress.
Improved health-relevant
functionality in dark germinated Mucuna pruriens sprouts by elicitation with
peptide and phytochemical elicitors.
Bioresour Technol.
2009 Oct;100(19):4507-14. Epub 2009 May 19
Randhir R, Kwon YI,
Shetty K.
Department of
Food Science, Chenoweth Laboratory, University of Massachusetts, Amherst, MA
01003, USA.
The health-relevant
functionality of Mucuna pruriens [velvet bean] was improved by
priming the seeds with elicitors of the pentose phosphate pathway (PPP) such as
fish protein hydrolysates (FPHs), lactoferrin (LF) and oregano extract (OE)
followed by dark germination. FPH elicited the highest phenolic
content of 19 mg/g FW on day 1, which was 38% higher than control sprouts. OE
enhanced Parkinson's disease-relevant L-DOPA content by 33% on day 1
compared to control sprouts. Anti-diabetes-relevant alpha-amylase inhibition
percent (AIP) and alpha-glucosidase inhibition percent (GIP) were high in the
cotyledons and decreased following elicitation and sprouting. For
potential anti-diabetic applications, low AIP and high GIP with moderate
L-DOPA content on day 4 of dark germination could be optimal.
Improved L-DOPA concentrations in a soluble phenolic and antioxidant-rich M.
pruriens background on day 1 sprouts have potential for Parkinson's
disease management.
Induction of cell cycle arrest in
prostate cancer cells by the dietary compound isoliquiritigenin.
J Med Food. 2009 Feb;12(1):8-14
Lee YM, Lim do Y, Choi HJ, Jung JI, Chung WY, Park JH.
Department of Food Science and
Nutrition, Hallym University, Chuncheon, Republic of Korea.
Isoliquiritigenin (ISL), a flavonoid
chalcone that is present in licorice, shallot, and bean
sprouts, is known to have antitumorigenic activities. The present study
examined whether ISL alters prostate cancer cell cycle progression. DU145 human
and MatLyLu (MLL) rat prostate cancer cells were cultured with various
concentrations of ISL. In both DU145 and MLL cells treated with ISL, the
percentage of cells in the G1 phase increased, and the incorporation of
[(3)H]thymidine decreased. ISL decreased the protein levels of cyclin D1, cyclin
E, and cyclin-dependent kinase (CDK) 4, whereas cyclin A and CDK2 expressions
were unaltered in cells treated with ISL. The expression of the CDK inhibitor
p27(KIP1) was increased in cells treated with 20 micromol/L ISL. In addition,
treatment of cells with 20 micromol/L ISL for 24 hours led to G2/M cell cycle
arrest. Cell division control (CDC) 2 protein levels remained unchanged. The
protein levels of phospho-CDC2 (Tyr15) and cyclin B1 were increased, and the
CDC25C level was decreased by ISL dose-dependently. We demonstrate that
ISL promotes cell cycle arrest in DU145 and MLL cells, thereby providing
insights into the mechanisms underlying its antitumorigenic activities.
Membrane estrogen
receptor-alpha-mediated nongenomic actions of phytoestrogens in GH3/B6/F10
pituitary tumor cells.
J Mol Signal. 2009
Apr 28;4:2
Jeng YJ, Kochukov
MY, Watson CS.
Department of
Biochemistry and Molecular Biology, University of Texas Medical Branch,
Galveston, Texas, USA.
BACKGROUND:
Estradiol (E2) mediates various intracellular signaling cascades from the plasma
membrane via several estrogen receptors (ERs). The pituitary is an
estrogen-responsive tissue, and we have previously reported that E2 can activate
mitogen-activated protein kinases (MAPKs) such as ERK1/2 and JNK1/2/3 in the
membrane ERalpha (mERalpha)-enriched GH3/B6/F10 rat pituitary tumor cell line.
Phytoestrogens are compounds found in plants and foods such as soybeans,
alfalfa sprouts, and red grapes. They are structurally similar to E2 and
share a similar mechanism of action through their binding to ERs. Phytoestrogens
bind to nuclear ERs with a much lower affinity and therefore are less potent in
mediating genomic responses. However, little is known about their ability to act
via mERs to mediate nongenomic effects.
METHODS: To
investigate the activation of different nongenomic pathways, and determine the
involvement of mERalpha, we measured prolactin (PRL) release by
radio-immunoassay, MAPK activations (ERK1/2 and JNK1/2/3) via a quantitative
plate immunoassay, and intracellular [Ca2+] by Fura-2 fluorescence imaging in
cells treated with E2 or four different phytoestrogens (coumestrol, daidzein,
genistein, and trans-resveratrol).
RESULTS:
Coumesterol and daidzein increased PRL release similar to E2 in GH3/B6/F10
cells, while genistein and trans-resveratrol had no effect. All of these
compounds except genistein activated ERK1/2 signaling at 1-10 picomolar
concentrations; JNK 1/2/3 was activated by all compounds at a 100 nanomolar
concentration. All compounds also caused rapid Ca2+ uptake, though in unique
dose-dependent Ca2+ response patterns for several aspects of this response. A
subclone of GH3 cells expressing low levels of mERalpha (GH3/B6/D9) did not
respond to any phytoestrogen treatments for any of these responses, suggesting
that these nongenomic effects were mediated via mERalpha.
CONCLUSION:
Phytoestrogens were much more potent in mediating these nongenomic responses
(activation of MAPKs, PRL release, and increased intracellular [Ca2+]) via
mERalpha than was previously reported for genomic responses. The unique
non-monotonic dose responses and variant signaling patterns caused by E2 and all
tested phytoestrogens suggest that complex and multiple signaling pathways or
binding partners could be involved. By activating these different nongenomic
signaling pathways, phytoestrogens could have significant physiological
consequences for pituitary cell function s.
Modulation of
histone deacetylase activity by dietary isothiocyanates and allyl sulfides:
Studies with sulforaphane and garlic organosulfur compounds.
Environ Mol Mutagen. 2009 Feb 5.
Nian H, Delage B, Ho E, Dashwood
RH.
Linus Pauling Institute, Oregon
State University, Corvallis, Oregon.
Histone deacetylase (HDAC)
inhibitors reactivate epigenetically-silenced genes in cancer cells, triggering
cell cycle arrest and apoptosis. Recent evidence suggests that dietary
constituents can act as HDAC inhibitors, such as the isothiocyanates found in
cruciferous vegetables and the allyl compounds present in garlic. Broccoli
sprouts are a rich source of sulforaphane (SF), an isothiocyanate that
is metabolized via the mercapturic acid pathway and
inhibits HDAC activity in
human colon, prostate, and breast cancer cells. In mouse preclinical
models, SF inhibited HDAC activity and induced histone hyperacetylation
coincident with tumor suppression.
Inhibition of HDAC activity
also was observed in circulating peripheral blood mononuclear cells obtained
from people who consumed
a
single serving of broccoli sprouts. Garlic organosulfur compounds can
be metabolized to allyl mercaptan (AM), a competitive HDAC inhibitor that
induced rapid and sustained histone hyperacetylation in human colon cancer
cells. Inhibition of HDAC activity by AM was associated with increased histone
acetylation and Sp3 transcription factor binding to the promoter region of the
P21WAF1 gene, resulting in elevated p21 protein expression and cell cycle
arrest. Collectively, the results from these studies, and others reviewed
herein, provide new insights into the relationships between reversible histone
modifications, diet, and cancer chemoprevention.
Wheat sprout extract-induced
apoptosis in human cancer cells by proteasomes modulation.
Biochimie. 2009 Sep;91(9):1131-44. Epub
2009 Jun 13
Bonfili L , Amici M,
Cecarini V,
Cuccioloni M,
Tacconi R,
Angeletti M,
Fioretti E,
Keller JN,
Eleuteri AM.
University of Camerino, Department of Molecular, Cellular
and Animal Biology, Via Gentile III da Varano, 62032 Camerino (MC), Italy.
Natural occurring modulators of proteasome functionality
are extensively investigated for their implication in cancer therapy. On the
basis of our previous evidences both on proteasomal inhibition by monomeric
polyphenols, and on the characterization of wheat sprout hydroalcoholic extract,
herein we thoroughly report on a comparative study of the effect of wheat sprout
extract on both normal and tumour cells. Treatment of isolated 20S proteasomes
with wheat sprout extracts induced a gradual inhibition of all proteasome
activities. Next, two wheat sprout extract components were separated: a
polyphenol and a protein fraction. Both components exerted an in vitro
inhibitory effect on proteasome activity. HeLa tumour cells and FHs 74 Int
normal cells were exposed to both fractions, resulting in different rates of
proteasome inhibition, with tumour cells showing a significantly higher degree
of proteasome impairment and apoptosis induction. Furthermore, a decrease in
proteasome activities and in cell survival of the human plasmacytoma RPMI 8226
cell line, upon the same treatments, was observed. Collectively, our
results provide additional evidences supporting the possible use of natural
extracts as coadjuvants in cancer treatments .
Feeding
Tomato and Broccoli Powders Enriched with Bioactives Improves Bioactivity
Markers in Rats
J Agric Food Chem. 2009 Aug 3.
Liu AG, Volker SE, Jeffery EH, Erdman JW.
Division of Nutritional Sciences and Department of Food
Science and Human Nutrition, 905 South Goodwin Avenue, University of Illinois at
Urbana-Champaign, Urbana, Illinois 61801.
Many studies have evaluated the cancer -preventive
potential of individual bioactives from tomatoes and broccoli, but few have
examined them within the context of a whole food. Male Copenhagen rats were fed
diets containing 10% standard tomato powder, tomato enriched with lycopene or
total carotenoids, standard broccoli floret, broccoli sprouts, or
broccoli enriched with indole glucosinolates or selenium for 7 days. All
broccoli diets increased the activity of colon quinone reductase (NQO1). Indole
glucosinolate-enriched broccoli and selenium-enriched broccoli increased hepatic
NQO1 and cytochrome P450 1A activity (P < 0.05). Standard broccoli and lycopene-enriched
tomato diets down-regulated prostatic glutathione S-transferase P1 mRNA
expression. Different tomato diets resulted in altered hepatic accumulation of
lycopene, phytofluene, and phytoene. These results demonstrate that the
bioactive content of vegetables affects both tissue content of bioactives and
activity of detoxification enzymes. Enhancing bioactive content of
tomatoes and broccoli may enhance efficacy in the prevention of prostate cancer.
Research ~ Food
Safety
There is still the daunting
challenge of reducing the risk of food borne illness from sprouts.
Conditions for elimination of Escherichia coli O157:H7 on alfalfa seeds through
a combination of high hydrostatic pressure and mild heat
Applied and environmental
microbiology. 01/03/200903/2009;
Hudaa Neetoo, Thompson Pizzolato,
Haiqiang Chen
Escherichia coli O157:H7 have been
associated with contaminated seed sprout outbreaks. The majority of these
outbreaks have been traced to sprout seeds contaminated with low levels of
pathogens. Sanitizing sprout seeds presents a unique challenge in the arena of
produce safety in that even a low residual pathogen population remaining on
contaminated seed after treatments appears capable of growing to very high
levels during sprouting. In this study, the effectiveness of high pressure
treatment in combination with low and elevated temperatures was assessed
for its ability to eliminate E. coli O157:H7 on artificially contaminated
alfalfa seeds. Inoculated seed samples were treated at 600 MPa for 2 min at 4,
20, 25, 30, 35, 40, 45 and 50 degrees C. The pressure-sensitivity of the
pathogenic bacteria was strongly dependent on the treatment temperature. At 40
degrees C, the process was adequate in eliminating a 5 log population on
the seeds with no adverse effect on the seed viability. Treatments
carried out at reduced pressure levels and/or extended treatment time, 550 MPa
for 2 min at 40 degrees C, 300 MPa for 2 min at 50 degrees C, and 400 MPa for 5
min at 45 degrees C were equally lethal to the pathogen. When all the three
treatments were compared in terms of their impact on the seed viability, the
process of 550 MPa for 2 min at 40 degrees C was the most desirable achieving
final germination percentages and sprout sizes statistically similar to control
untreated seeds (P > 0.05).
Characterization of
mundticin L, a Class IIa anti-Listeria bacteriocin from Enterococcus mundtii
CUGF08
Appl Environ Microbiol. 2009 Jul 6.
Feng G, Guron GK, Churey JJ, Worobo RW.
Department of Food Science and Technology, Cornell
University, Geneva, NY 14456.
Enterococcus mundtii CUGF08, a lactic acid bacterium
isolated from alfalfa sprouts, was found to produce mundticin L, a new
Class IIa bacteriocin that has high inhibitory activity against the genus
Listeria. The plasmid-associated operons containing genes for the
mundticin L precursor, ATP binding cassette (ABC) transporter and immunity were
cloned and sequenced. The fifth residue of the conservative consensus YGNGX in
the mature bacteriocin is leucine in place of valine compared to the homologous
mundticin KS (ATO6) and enterocin CRL35. The primary structure of the ABC
transporter and immunity protein are homologous but unique.
Combination treatments for killing
Escherichia coli O157:H7 on alfalfa, radish, broccoli, and mung bean seeds.
J Food Prot. 2009 Mar;72(3):631-6
Bari ML, Nei D, Enomoto K, Todoriki S, Kawamoto S.
National Food Research Institute,
Kannondai-2-1-12, Tsukuba 305-8642, Japan.
In this study, the effectiveness of prolonged
dry-heat treatment (50 degrees C) alone or in combination with chemical
treatments (1% oxalic acid, 0.03% phytic acid, 50% ethanol, electrolyzed acidic
water, and electrolyzed alkaline water) in eliminating Escherichia coli O157:H7
on laboratory-inoculated alfalfa, radish, broccoli, and mung bean seeds was
compared with that of dry-heat treatment in combination with irradiation
treatment. Dry-heat treatment for 17 or 24 h alone could reduce E. coli
O157:H7 numbers to below detectable levels in radish, broccoli, and alfalfa
seeds, but was unable to reduce the pathogen numbers to below the detectable
level in mung bean seeds. In addition, dry-heat treatment for 17 h plus
sanitizer treatments were effective in greatly reducing pathogen populations on
radish, broccoli, and alfalfa seeds, without compromising the quality of the
sprouts, but these treatments did not eliminate the pathogen from radish and
alfalfa seeds. Seventeen hours of dry heat followed by a 1.0-kGy dose of
irradiation completely eliminated E. coli O157:H7 from radish and mung bean
seeds, whereas only a minimum radiation dose of 0.25 kGy was required to
completely eliminate the pathogen from broccoli and alfalfa seeds. Dry heat in
combination with radiation doses of up to 1.0 kGy did not negatively impact the
seed germination rate or length of alfalfa, broccoli, and radish seeds or the
length of alfalfa, broccoli, and radish sprouts, but did decrease the length of
mung bean sprouts.
Interlaboratory validation of a
real-time PCR 24-hour rapid method for detection of Salmonella in foods.
J Food Prot. 2009
May;72(5):945-51
Cheng CM, Van Khanh
T, Lin W, Ruby RM.
U.S. Food and Drug
Administration, Office of Regulatory Affairs, Pacific Regional Laboratory
Southwest, 19701 Fairchild, Irvine, California 92612, USA.
The
efficacy of a 24-h Salmonella real-time, or quantitative, PCR (qPCR) detection
method was assessed through a collaborative effort involving eight Federal and
state laboratories. Eleven foods including mashed potatoes, soft
cheese, chili powder, chocolate, eggs, sprouts, apple juice, fish,
shrimp, ground beef, and ground chicken were tested. For each food, seven blind
samples were distributed to each participant for testing. These included six
samples equivalently inoculated with 1 to 5 CFU/25 g of various serotypes of
Salmonella (Gaminara, Weltevreden, Heidelberg, Senftenberg, Enteritidis,
Newport, Typhimurium, and Kentucky for each food) and 10 to 50 CFU/25 g of the
competitor Enterobacter cloacae. The seventh sample was inoculated with 10 to 50
CFU/25 g of the competitor, E. cloacae, only. These samples were tested for
Salmonella by using four methods in parallel: (i) 24-h qPCR method detecting
Salmonella from modified buffered peptone water enrichment medium; (ii) 48-h
qPCR method detecting Salmonella from a secondary selective enrichment broth;
(iii) modified Bacteriological Analytical Manual method; and (iv) VIDAS, an
immunoassay system. The results of the statistical analysis showed there
was no significant (P > or = 0.05) differ ence
between either of the qPCR methods and the modified Bacteriological Analytical
Manual method for 10 of 11 foods.
For the one exception, sprouts, detection by qPCR required 48 h.
Both qPCR methods showed a detection limit of 0.08 to 0.2 CFU/g.
These results provide a solid basis for using this 24-h qPCR rapid
screening method to detect Salmonella in foods.
Flow-through imaging cytometry for
characterization of Salmonella subpopulations in alfalfa sprouts, a complex food
system.
Biotechnol J. 2009
Jun;4(6):880-7
Bisha B,
Brehm-Stecher BF.
Rapid Microbial
Detection and Control Laboratory, Department of Food Science and Human
Nutrition, Iowa State University, Ames, IA 50011, USA.
We recently
developed an approach combining fluorescence in situ hybridization (FISH) and
flow cytometry for detecting low levels of Salmonella spp. (approximately 10(3)
cells/mL sprout wash) against high levels of naturally occurring sprout flora
(approximately 10(7)-10(8) CFU/g sprouts). Although this "FISH and flow"
approach provided rapid presence/absence testing for Salmonella in this complex
food system, it was not capable of more nuanced tasks, such as probing the
phenotypic complexity of the microbes present in sprouts or determining the
physical interactions of Salmonella with these microbes, or with sprout debris.
In the present study, we have combined rapid FISH-based labeling of
Salmonella spp. in sprout washes with flow-through imaging cytometry (FT-IC),
using the ImageStream 100, a commercial FT-IC instrument. This approach enables
image-based characterization of various subpopulations of interest occurring
within these samples. Here, we demonstrate the ability of FT-IC to
unambiguously identify cells, cell aggregates and other events within these
subpopulations based on both cell morphology and hybridization status
after reaction with a Salmonella-targeted probe cocktail. Our ability to
directly explore the nature of these events expands the layers of information
possible from cytometric analyses of these complex samples and clearly
demonstrates that "a picture is worth a thousand dots".
Potential use of supercritical
carbon dioxide to decontaminate Escherichia coli O157:H7, Listeria
monocytogenes, and Salmonella typhimurium in alfalfa sprouted seeds.
Int J Food Microbiol. 2009 Aug
19.
Jung WY, Choi YM, Rhee MS.
Division of Food Bioscience and Technology,
College of Life Sciences and Biotechnology, Korea University, 5-1 Anam-dong,
Sungbuk-gu, Seoul, 136-713, South Korea.
We sought to develop a method of decontaminating
alfalfa sprouts of Escherichia coli O157:H7, Listeria monocytogenes, and
Salmonella typhimurium without altering the seed germination capability using
supercritical carbon dioxide (SC-CO(2)). Samples were treated with SC-CO(2) at
10, 15, or 20MPa and temperatures of 35, 40, or 45 degrees C for 5, 10, or
15min. The germination percentage was measured after three days of germination.
Generally, treating seeds with SC-CO(2) at higher pressures, temperatures, or
for longer treatment times resulted in greater microbial reductions than
treatments at lower pressures, temperatures, or for shorter treatment times.
SC-CO(2) treatment clearly reduced the microorganism levels in alfalfa seeds; in
particular, treatment at 20MPa and 45 degrees C for 15min reduced levels of the
three pathogens by >7.0log colony forming units (CFU)/g. However, SC-CO(2)
treatment at a high pressure and high temperature, especially treatment at 20MPa
and 40 or 45 degrees C, impaired the seed germination capability in some cases.
Without impairing the germination capability, the maximum reduction level of
E. coli O157:H7 was 3.51CFU/g with SC-CO(2) treatment at 15MPa and 35
degrees C for 10min. Maximum reductions of L. monocytogenes and S.
typhimurium were 2.65 and 2.48log CFU/g, respectively, with treatment at
10MPa and 45 degrees C for 5min. Therefore, our results indicate that SC-CO(2)
treatment can be used to effectively improve alfalfa seed safety.
Evaluation of ISO enrichment
real-time PCR methods with internal amplification control for detection of
Listeria monocytogenes and Salmonella enterica in fresh fruit and vegetables.
Lett Appl Microbiol.
2009 Jul;49(1):105-11. Epub 2009 Apr 22.
Badosa E, Chico N,
Pla M, Parés D, Montesinos E.
Institut de Tecnologia
Agroalimentària - CeRTA-CIDSAV, Universitat de Girona, Girona, Spain.
AIMS: To
provide with a quick method for qualitative detection, in less than three days,
of Salmonella enterica and Listeria monocytogenes in fresh fruit and vegetables.
METHODS AND
RESULTS: The method was based on coupling International Standard
Organization (ISO) enrichment to a real-time PCR with internal amplification
control (IAC), in a duplex format, without additional DNA purification. The
performance was tested on different plant products. Both bacterial pathogens
were consistently detected with a limit of detection (LOD) of 1 CFU in 25 g
after enrichment, except for soybean sprouts. Levels of S. enterica, ranging
from 1 to 10 CFU in 25 g after enrichment were detected with different
enrichment broths.
CONCLUSIONS:
For both pathogens, the LOD was similar to that of the corresponding ISO method,
while decreasing the analysis time and handling needs.
SIGNIFICANCE AND
IMPACT OF THE STUDY: The agreement between standard ISO and the enrichment
real-time PCR(IAC)-based methods make the latter method as a
promising
alternative for quick and reliable detection of food-borne pathogens in fresh
fruit and vegetables in routine laboratories.
Scale-up seed decontamination process to inactivate Escherichia coli O157:H7 and
Salmonella enteritidis on mung bean seeds
Foodborne
Pathogens and Disease, 07.sep.09
Md. Latiful Bari, Katsuyoshi Enomoto, Daisuke Nei, Shinnichi Kawamoto
A majority of the seed sprout–related outbreaks have been associated with
Escherichia coli O157:H7 and Salmonella spp. Therefore, it is necessary to find
an effective method to inactivate these microorganisms on the seeds before
sprouting. When treatment with hot water at 85°C for 40sec followed by dipping
in cold water for 30sec and soaking into chlorine water (2000ppm) for 2h was
performed, no viable pathogens were found in the enrichment medium and during
the sprouting process. The germination yield of the seed was not affected
significantly (p>0.05). Therefore, these treatments could be useful for the
decontamination method of mung bean seeds intended for sprout production.
Use of 1% Peroxyacetic Acid Sanitizer in an
Air-Mixing Wash Basin to Remove Bacterial Pathogens from Seeds
Foodborne
Pathog Dis. 2009 Jul 24.
Rajkowski KT ,
Ashurst K.
1 Food Safety Intervention
Technologies Research Unit, Eastern Regional Research Center , Agricultural
Research Service, U.S. Department of Agriculture, Wyndmoor, Pennsylvania.
To achieve the
production of pathogen-free sprouts, there must be appropriate mixing of liquid
sanitizer with the seeds to assure contact. Commercial treatments by irradiation
or ozone gas of Salmonella spp. artificially inoculated seeds were compared, and
these resulted in a 1 log reduction after all treatments. Use of peroxyacetic
acid (1%) sanitizer on Salmonella spp. or Escherichia coli O157:H7 inoculated
alfalfa seeds consistently resulted in a greater than 1 log reduction. In
addition, during these studies debris was noted after the seeds were removed.
Based on this observation, an air-mixing wash basin was developed for commercial
use. Validation was done by commercial growers using 1% peroxyacetic acid
sanitizer to wash seeds in the air-mixing basin, followed by sprouting the
seeds. No positive or false-positive pathogen results were reported after the
required testing of the sprout water (run-off during sprouting). Use of 1%
peroxyacetic acid sanitizer in the air-mixing wash basin does provide the sprout
grower an effective means of sanitizing sprout seeds.
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