The pesticide residue changes during food processing and ...

The pesticide residue changes duringThe pesticide residue changes during

food processing and storagefood processing and storage

Fengshou Dong Ph.D.Fengshou Dong Ph.D.

Institute of Plant ProtectionInstitute of Plant Protection

Chinese Academy of Agricultural Sciences, Chinese Academy of Agricultural Sciences,

20 February 2012

OutlineOutline

. Introduction

. Effects of storage on pesticide residues

Effects of processing on pesticide residues. Effects of processing on pesticide residues

. Conclusion

. Future scopeⅤ

Part Ⅰ Introduction

Food safety

Part Ⅰ Introduction

y

Part Ⅰ IntroductionPart Ⅰ Introduction Pesticide is any substance or mixture of substances intended for preventing,

destroying, repelling, or mitigating any pest.y g p g g g y p

“Pesticide” includes herbicides, fungicides, insecticides, or any other substance used to control pests.

Part Ⅰ IntroductionPart Ⅰ Introduction The pesticide residues, left to variable extent in the food materials after

harvesting, are beyond the control of consumer and have deleterious effect on human health. The presence of pesticide residues is a major bottleneck in the international trade of food commodities. The localization of pesticides in foods varies with the nature of pesticide molecule, type and portion of food material and environmental factors The food crops treated with food material and environmental factors. The food crops treated with pesticides invariably contain unpredictable amount of these chemicals, therefore, it becomes imperative to find out some alternatives for decontamination of foods.

MRL: Maximum Residue LimitsMRL: Maximum Residue Limits

Part Ⅰ IntroductionPart Ⅰ Introduction • Raw Agricultural Commodity (RAC): Any food in its raw

or natural state, including all fruits that are washed, colored, or otherwise treated in their unpeeled natural form prior to marketing.

• MRLs t h d l d diti• MRLs are set on unwashed, unpeeled commodities

Part Ⅰ IntroductionPart Ⅰ Introduction • Processed Agricultural Commodity (PAC): raw

agricultural commodity that has been subject to processing, like tomato paste, wine, and orange juice.

Part Ⅰ IntroductionPart Ⅰ Introduction

IncreaseIncrease

dddecreasedecrease metabolitesmetabolitesDrying, concentration

P li hiPeeling, washing More toxic substance

The effect of processing


PF P i F t P ti l tPF = Processing Factor = Proportional amount by which residues change when processed

)Kgmg(commodity raw in theion concentrat residue)Kgmg(commodity processed in theion concentrat residuePF 1

-1

PF<1：REDUCTION FACTOR

PF>1: CONCENTRATION FACTORPF 1: CONCENTRATION FACTOR

Part Ⅰ IntroductionPart Ⅰ Introduction How Do Pesticides Get Into Processed Foods?

• Direct Treatment of raw commodities prior to harvest or after harvestharvest or after harvest

• treatment of storage facilities for processed foods

This talk will focus on the fate of pesticide residues when treated raw p

commodities are processed.


• Determine whether residues concentrate or reduce when raw commodity is processed

• Determine whether MRLs are needed in theDetermine whether MRLs are needed in the processed commodities

• Refine dietary exposure assessment• Refine dietary exposure assessment

Part Ⅱ Effects of storage on pesticide residuesProper storage of unprocessed food of plant origin includes maintaining at appropriate temperatures, away from light, under the proper percentage of humidity and in such a way tounder the proper percentage of humidity and in such a way to keep it clean and safe prior the further management of the product.

Temperature control

cold storage

Part Ⅱ Effects of storage on pesticide residues

1

2

Pesticide volatilizationPesticide volatilization

Pesticide penetrationPesticide penetration

TemperatureTemperature

2

3

Pesticide penetrationPesticide penetration

Pesticide metabolismPesticide metabolism

4 Certain microbial growthCertain microbial growth

5 The reduction of moisture lossThe reduction of moisture loss

Part Ⅱ Effects of storage on pesticide residuesGrains are frequently stored long term (3-36 months) at ambient temperatures in bulk silos whereat ambient temperatures in bulk silos where insecticides may be applied post-harvest to reduce losses from storage pests . Grain based foodslosses from storage pests . Grain based foods therefore have the potential to be a major source of residues in the diet for these insecticides.residues in the diet for these insecticides.


organophosphates •pesticide nature

• type of applied f l ti

malathionformulation

•storage temperature

pirimiphos methyl

chlorpyrifos methyl•storage temperature and humidity

(Uygun et al., 2005; Uygun et al., 2007)


Most high moisture unprocessed foods must be held in g pchillers or refrigerators (0 to 5 ) for short to medium storage or deep frozen (-10 to -20 ) for longer periods.


Pesticide volatilization1

Slow acidic hydrolysis2

Studies on a variety of pesticides on whole food-stuffs under cool or frozen storage often have shown thatunder cool or frozen storage often have shown that residues are stable or degraded slowly.

(Athanasopoulos et al., 2000; Athanasopoulos et al., 2005)

Part Ⅲ Effects of processing on pesticide residues

processing of food commodities

generally implieswashingjuicing

generally implies the transformation of the perishable

raw commodity to value-added

product.

Processing PeelingWine making

comminutioncooking

Part Ⅲ Effects of processing on pesticide residuesWashing: The preliminary step in both household and commercial food preparationRinesability


the location of the residue

The effectiveness

of

the age of the residue

of

washing the water solubility of the pesticide

the temperature and type of wash

Part Ⅲ Effects of processing on pesticide residuesPeeling is an important step in the processing of most fruits andvegetables.

Chemical peeling

Mechanical peeling

lipeeling

steam peeling freeze peeling

(Toker & Bayindirli, 2003)

Part Ⅲ Effects of processing on pesticide residuesjuicing: Commercial juicing operations generally use whole fruit. The residue levels in juices from fruits or vegetables are generally reduced by 70-100% and their reduction depends on the partitioning ratio of the pesticide between the fruit skin, pulp and the juice Th l b d t hi h ft i l d th ki t i b t ti l idThe pulp or pomace by-products, which often include the skin, retain a substantial residues.

Clarification by filtration or centrifugation in juice processing may further eliminate pesticide residues retained in suspended particles;pesticide residues retained in suspended particles;

juice concentration by vacuum may concentrate the pesticides in juice product.


Comminution: comminution of tissues in chopping, blending etc. leadstissues in chopping, blending etc. leads to release of enzymes and acids which may increase the rate of hydrolytic and other degradative processes on residues. F l fi h i fFor example, fine chopping of crop samples leads to rapid degradation of EBDC fungicide However mostEBDC fungicide. However most pesticides are relatively stable in acidic tissue.

S. Kontoua etc. 2004;

Food Additives and Contaminants


b lfcarbosulfanthiodicarb

Acid sensitivedioxacarb EBDCssensitive pesticide

dioxacarb EBDCs

benfuracarb pymetrozine

Part Ⅲ Effects of processing on pesticide residuesCooking: the act of preparing food for eating by the application of heat. Pesticide residues might be vaporized, hydrolyzed and thermal degraded during cooking.

TIME

SYSTEM WATER

CONDITION

MOISTURE TEMPERATURE

Part Ⅲ Effects of processing on pesticide residuesWine making: pesticide residue present on grapes often remain adsorbed in lees at relevant levels, and it could transferred to the wine in low percentages after fermentation Mainly on the initialwine in low percentages after fermentation. Mainly on the initial partition of a pesticide residue between the must and lees.

i iWine making


Drying: The Drying is the oldest method of preserving food. As compared with other methods, drying is quite simple. Food can be dried in several ways, for example, by the sun or in an oven or a food dryer can also be used. Drying has been found to reduce the pesticide residues considerably.considerably.

Sun Dryingy g

Part Ⅲ Effects of processing on pesticide residuesMETABOLITES : the metabolites of pesticide during the food processing is a hot issue, particularly those involving use of heat or chemicals. Although no examples are available of pesticides where food processing has resulted in theexamples are available of pesticides where food processing has resulted in the production of new metabolites, the proportions of various metabolites may change from those found in field or laboratory studies on whole plants.

Part Ⅲ Effects of processing on pesticide residuesDegradation of acephate and its metabolite methamidophos in rice during processing and storage

Commercial processing Simulating Home processing


Name

Paddy rice Drying Hulling polishing

Raw Rice Brown Rice Brown Rice Brown Rice PolishRawrice

Ricehull

Brownrice

Ricehull

Brownrice

Ricehull

Brownrice

Ricebran

Polishedrice

Acephate

3.71±0.04

11.7±0.2

0.92±0.04

9.42±0.2

0.84±0.01

8.92±0.3

0.8±0.02

1.26±0.07

0.51±0.022

Methamidophos

0.61±0.04

0.88±0.02

0.54±0.02

0.8±0.02

0.43±0.02

0.75±0.01

0.42±0.02

0.6±0.03

0.31±0.02

Amount of acephate and methamidophos residues (mg kg-1) recovered from rice grains after various commercial processes (mean ± SD).

Treatment Acephate Methamidophos

Polished rice 0.51±0.02 0.31±0.02

Water from washingFirst time 0.084±0.002 0.055±0.002

Second time 0.024±0.002 0.029±0.0005

Third time 0.022±0.001 0.014±0.0007

Washed polished rice 0.33±0.009 0.2±0.008

Cooked polished rice 0.082±0.006 0.093±0.006

Distillate 0.078±0.004 0.061±0.002

Amount of acephate and methamidophos residues (mg kg-1) recovered from rice samples after home processes (mean ± SD).


Brown rice Polished rice Cooked riceRaw rice


0.6

C 0 4648 0 0229t

0.4

0.5

entra

tion

g/kg

) Ct = 0.2798e-0.0148t

Ct = 0.4648e-0.0229t

0.2

0.3Con

ce (mg

Acephate

Methamidophos

0

0.1

0 10 20 30 40 500 10 20 30 40 50

Time (days)

The methamidophos was found to be more

persistent than acephate


0.3000 0.3500 0.4000 0.4500

0.5000

Concentra 0.2000

0.2500

0.3000

10

50.0500 0.1000 0.1500 0.2000 0.2500

Time

ation (mg/kg)

50.0500

0.1000

0.1500

Time (m

i

Concentration ( m

30

100.0000

(min)

30

100.0000

n)

mg/kg)

Washing

Concentration of acephate ft hi

Concentration of th id h ft hi

Washing

after washing methamidophos after washing

Part Ⅲ Effects of processing on pesticide residuesDetermination of difenoconazole residue in tomato during

home canning by UPLC-MS/MS


peeling juicing

simmeringsterilization simmeringsterilization


Sample difenoconazoleConcentration (mg kg-1) Processing factorConcentration (mg kg 1) Processing factor

Raw tomatoes 6.19 -Washed tomatoes 5.19 0.84Tomato pulp 0.28 0.045Tomato skin 36.06 5.83Tomato puree 0 25 0 040Tomato puree 0.25 0.040Tomato juice 0.15 0.024Tomato seeds LOD -Tomato paste 0.44 0.071Canned tomato paste 0.38 0.061

Table: Residue levels of difenoconazole in raw tomatoes and its products (mg kg-1) and experimental processing factorsTable: Residue levels of difenoconazole in raw tomatoes and its products (mg kg 1) and experimental processing factors.


7

5

6

kg-1

)

3

4

tratio

n (m

g k

2conc

ent

0

1

Raw Washing Peeling Juicing Concentration Sterilization


(IF: 2.812)

Part Ⅳ Conclusion

Washing (tap water) 2222--60%60%

Wi ki

7373--91%91%Juicing

Wine making

Peeling

7070--100%100%

Peeling 7070--100%100%

Critical Reviews in Food Science and Nutrition, 51:99–114 (2011)

Part Ⅴ Future scope

• It is necessary to optimize the processing techniques with regard to pesticide residue dissipation and nutrient content.

• Further the bioavailability of nutrients in pesticide id t i t d f d d t b i ti t dresidue contaminated food needs to be investigated as

this aspect has not been explored as yet. • Detailed studies on the fate of metabolites during foodDetailed studies on the fate of metabolites during food

processing are lacking for most of the pesticides. • Some pesticides MRLs should be set on processed

agricultural commodity to perfect the dietary exposure assessment for human health.

Th k f ttTh k f ttThanks for your attenThanks for your atten

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