MEETING FOOD SAFETY TARGETS WHEN SHIFTING FROM TRADITIONAL TO NEW FISH SMOKING SYSTEMSA FOOD SAFETY TECHNICAL NETWORK (FSTN) WEBINAR/SEMINAR – 16TH SEPTEMBER 2016

Meeting Food Safety Targets in Shifting from Traditional to New Fish Smoking

Systems: A Case Study in Ghana

Kennedy Bomfeh

Univ. of Ghana | Ghent University

Kennedy.Bomfeh@UGent.be; kbomfeh@gmail.com

Supervision: prof. Bruno De Meulenaer – prof. Liesbeth Jacxsens

Dr. Wisdom Amoa-Awua2

1Department of Food Safety and Food Quality, Ghent University

2Food Research Institute, Ghana

OUTLINE

• Background

• Study Overview

• Preliminary Findings• Consumer survey• Microbiological hazards• Biogenic amines• Heavy metals• Polycyclic aromatic hydrocarbons

• Effect of smoking fuel type on PAH levels

• Effect of FTT Parts on PAH Levels

• Preliminary Risk Assessment

• Limitations

• Conclusions

• Acknowledgments3

BACKGROUND

4

Fish in Ghanaian Diets

• Fish makes up about 60% of animal protein in Ghanaian diets

• Average per-capita intake was estimated at 27kg in 2011. World average is 20kg; that for Africa is 10kg

• Fish makes up about 22% of food expenditure in all households, and 26% in poor household

• It is estimated that between 70 – 80% of domestic fish catch is traditionally smoked

• Remaining consumed fresh, fried, fermented, salted, dried,, or combination of processes

5

Traditional Smoking

• Traditional fish smoking relies on the use of mud kilns and metal drums with firewood as fuel

Disadvantages

• Low capacity

• Inefficient fuel use

• Health risks for processors

• Time consuming

• Easily wears out (mud kiln)

6

Metal drum kiln

Chorkor Smoker

• Between 1969 – 1971, FAO collaborated with Ghana’s Food Research Institute and the women of Chorkor, a fishing community in Accra, to develop a new kiln, rightly named “Chorkor Smoker”

Advantages

• Large capacity (15 trays x 18kg fish)

• Fuel efficiency

• Long life span (15y block; 8y cement-faced mud)

• Less time and labour input7

Chorkor smoker

Safety of Traditionally Smoked Fish

• Although Chorkor smoker offered throughput and economic gains, the same cannot be said about thesafety of the products

• The use of firewood as smoking fuel is known to result in high levels of polycyclic aromatic hydrocarbons (PAHs), which are carcinogenic food safety hazards associated with incomplete combustion

• This compromises the safety of the products and is therefore a public health concern

8

FTT-Thiaroye

• FTT was built on the strengths of existing improved kilns

Benefits Envisaged

• Safe products (low PAHs)

• Higher income for processors

• Ancillary employment

• Mainstreaming gender concerns

• Environmental protection

FTT-Thioroye will be referred to as FTT from hereon 9

Traditional vs. FTT

Some key operational and design differences

10

FTT in Ghana

• In December 2014, FAO, in collaboration with SNV Ghana, introduced FTT-Thiaroye in Ghana

• This study was therefore conducted to investigate the efficacy of FTT in reducing PAH levels in fish• A collaboration among FAO, University of Ghana

and Ghent University, Belgium

• Overall expected output: small-holder guidelines and policy advice on fish smoking

11

STUDY OVERVIEW

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Objectives

1. Determine levels of selected chemical and microbiological hazards in smoked Sardinella sp (“herrings*”) and Sphyraenasp (barracuda) on informal markets in Accra

• PAH – Benzo(a)pyrene, benzo(b)fluoranthene, benzo(a)anthracene, chrysene

• Biogenic amines – Histamine, putrescine, cadavarine, tyramine, phenylethylamine

• Microbiology – E. coli, Salmonella sp., Vibrio parahaemolyticus, Pseudomonas sp.

• Heavy metals – Lead, cadmium, mercury

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*Herrings are actually Clupeidea sp., but Sardinella sp are wrongly called herrings on informal markets in Ghana

2. Determine the effect of kiln type on hazard levels

• Metal drum vs. Chorkor vs. FTT

3. Effect of smoke fuel type on PAH levels

• Two wood fuel types and charcoal

4. Effects of FTT parts on PAH levels

5. Preliminary Risk Assessment for PAH

Objectives

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• Consumer survey: 212 respondents in two communities in Accra

• Informal market fish screening for hazards

• Experimental smoking• Comparison of kilns• Evaluation of effects fuel and parts of FTT on PAH levels

• Laboratory analysis (pooling and homogenization of 10 fishes per sample)• PAH: GC-MS• Biogenic amines: HPLC• Heavy metals: Atomic Absorption Mass Spectrometry• Microbiology: Plating methods specific to organisms

• Data analysis• @Risk for distribution fitting for Monte Carlo Simulations• SPSS v 23 for descriptives on survey data, and comparison of means of

other data where appropriate

Brief on Methods

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PRELIMINARY FINDINGS

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Consumer Survey

• Modal quantity of smoked fish (across product types) reportedly consumed per sitting was 100g

• Modal frequency of consumption

• Herring products – Once per week

• Barracuda products – Once per month

• For risk assessment purposes, this implies estimated daily consumption of 14.2g for herrings and 3.2g for barracuda

• Hazard levels generally higher in samples from informal markets than those from processing sites• E. coli: 1 – 4logcfu/g in market samples, <1logcfu/g for

processing point samples

• Pseudomonas sp.: 1 – 3logcfu/g for market samples, <1logcfu/g for processor samples

• This suggests post-processing contamination, and poor hygiene and handling practices on the informal markets

• Salmonella sp and V. parahaemolyticus were not detected in any market nor processing point sample

Microbiological Hazards

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• Biogenic amine (BA) levels generally higher in samples from informal markets than those from processing sites. E.g. for histamine:

• Market: 11 – 450mg/kg

• Processing point: <10 – 26mg/kg

• Higher BA levels corresponded with higher counts for Pseudomonas sp in market samples

• Post-processing microbiological contamination potentially linked to elevated levels of biogenic amines in the products

Biogenic Amines

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Heavy Metals

• Levels generally below EU maximum limits

• Only smoked herring from market exceeded EU limits marginally

• Hg: 0.34mg/kg in product against ML of 0.30mg/kg

• Cd: 0.14mg/kg in product against ML of 0.05mg/kg

• Levels in fresh fish samples ranged from <0.01–0.02 mg/kg

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PAHs: Informal Markets

Table 1: PAH levels in smoked fish on informal markets and comparison to EU maximum limits (ML)

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Comparison of market product PAH levels to EU MLs

• BaP: up to 48 times the EU ML

• PAH4: by up to 67 times the EU ML

References made to EU MLs since Europe is the major destination for smoked fish exports

from Ghana

PAHs: FTT vs. Traditional Kilns

Fig 1: Effect of kiln type and product form on PAH levels22

50

37

0.6

69

61

0.90

25

50

75

100

Chorkor Metaldrum

FTT Chorkor Metaldrum

FTT

Ba

P(µ

g/kg

)

PAH levels in FTT products were significantly lower than in

products from traditional kilns

EFFECT OF FUEL TYPE ON PAH LEVEL

23

Effect of Fuel Type on PAH

1. No significant differences between esa & neem* (p>0.05)

2. Use of charcoal in Chorkor smoker resulted in significant reduction (p<0.05) of PAH levels; however EU limits were exceeded

24*Esa = Pterocarpus erinaceous Neem = Azadirachta indica

Fig.2:

Chorkor smoker & Metal drum

Effect of Fuel Type on PAH

1. PAH levels differed significantly (p<0.05) between fuel types

2. Use of wood resulted in violation of EU MLs

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Fig. 2:

PAH

0.23

8

39

29

2

*Esa = Pterocarpus erinaceous Neem = Azadirachta indica

FTT

EFFECT OF FTT PARTS ON PAH LEVEL

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Effect of charcoal

• PAH contribution from charcoal appears minimal

• Levels less than LOQ at end of charcoal cooking, but BaP0.36µg/kg and PAH4 1.46µg/kg at the end of smoke flavouring

Impact of Fat Collector

• Processing without fat collector resulted in significantly higher PAH levels and violation of EU limits.

• BaP: 2.90 vs. 0.50µg/kg

• PAH4: 38.38 vs. 4.53µg/kg

Smoke filter and type of smoke generation fuel had minimal effects on PAH levels

Effect of FTT Parts on PAH Level

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PRELIMINARY RISK ASSESSMENT

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Brief on Risk Assessment Approach

• Focused on PAH since hazard level directly linked to smoking kiln type

• Margin of Exposure (MoE) approach used

• If MoE is less than 10,000 there is a concern for potential adverse effects on consumer health

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Table 2: Margin of Exposure for PAH4

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Results suggests consumers may be protected from PAH health

risks from smoked fish if FTT instead of traditional kilns is used for

fish smoking

Preliminary Risk Assessment

CONCLUSIONS

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Conclusions

Informal market situation

Smoked fish on informal markets

1. had higher levels of microbiological hazards and biogenic amines than those sampled directly from processing points, possibly due to post-processing contamination

2. had unsafe levels of PAH that exceeded EU BaP maximum limits by up to 48 times

Comparison of Kilns

1. Smoked products from traditional kilns (Chorkor smoker and metal drum) had high PAH levels that exceeded EU BaP maximum limits by up to 35 times

2. Smoked products from FTT had very low PAH levels that were below EU maximum limits 32

Conclusions

FTT parts and PAH Level

• Use of charcoal and fat collection tray have the greatest impacts on PAH levels

• Use or non-use of filter; and type of smoke generation fuel have minimal impacts

Preliminary risk assessment

• consumers may be protected from health risks of PAH to a significantly higher degree when they consume fish smoked with FTT instead of traditional kilns

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Limitations

• Informal market sampling:

• limited coverage (two markets in Accra)

• small sample size

• Consumer survey: limited coverage (two communities in Accra)

• Limited scope of risk assessment

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Acknowledgements

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Thank You

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THANK YOU FOR WATCHING

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A FOOD SAFETY TECHNICAL NETWORK (FSTN) WEBINAR/SEMINAR – 16TH SEPTEMBER 2016