Fresh Fruit and Vegetable
Sampling for Laboratory Testing

---

Table of Contents

• Review
• Amendment Record
• Distribution
• Introduction
• Scope and Field of Application
• Definitions
• Legislative Authority to Take Samples
• Sampling Instructions
  1. Preparation of the lot for sampling
  2. Sampling equipment
  3. Choosing the samples
  4. Sample size
  5. Steps for drawing samples
     • 5.1 General instructions
     • 5.2 Specific instructions
  6. Marking of the samples
  7. Storage and transportation of samples
     • 7.1 General Instructions
     • 7.2 Storage and transportation of refrigerated samples
     • 7.3 Frozen samples
  8. Shipping temperature of the samples
  9. Shipping the samples

---

Review

The sampling procedures described below are for the testing of fresh fruits and vegetables and are based on the following documents: ISO 7002 Agricultural Food Products - Layout for a Standard Method of Sampling from a Lot, ISO 874 Fresh Fruits and Vegetables - Sampling, Chapter 9, of the Microorganisms in Food 2 - Sampling for Microbiological Analysis, and Chapter 1 of the United States Food and Drug Administration, Bacteriological Analytical Manual (BAM).

These sampling instructions have been circulated to the Canadian Food Inspection Agency's (CFIA) Laboratories Directorate and to all program area network specialists for their comments. The author and contact person for these sampling instructions is René Cardinal.

Amendment Record

The following sampling instructions for the testing of fresh fruits and vegetables replace the Dairy, Fruit and Vegetable Division Directive F-96-6 which was issued on June 25, 1996, and replace Section 15.3.6 - Sampling and Shipping Procedures of the Fresh Fruit and Vegetable Inspection Manual.

Distribution

• CFIA Area Network Specialists
• CFIA Operations Branch
• CFIA laboratory Directorate
• CFIA's Intranet & Internet

Introduction

One of the CFIA's objectives is to contribute to a safe food supply for Canadian consumers. To achieve this objective, the Fresh Fruit and Vegetable Section of the Food of Plant Origin Division has developed inspection strategies that monitor the compliance of domestic and imported fresh fruits and vegetables with the Fresh Fruit and Vegetable Regulations, pursuant to the Canada Agricultural Products Act, and theFood and Drugs Act and Regulations.

The main inspection strategy of the Fresh Fruit and Vegetable Section consists of sampling and testing domestic and imported fresh fruits and vegetables to detect excess pesticide residues, chemical contaminants, pathogens, food additives and food preservatives and treatments, and to detect irradiated produce. The number of samples and the compliance actions on the products vary according to the type of contaminants and the risk associated with them.

The objective of this document is to provide guidance to operations staff, who sample fresh fruits and vegetables, on how to sample produce and maintain sample integrity. The instructions provided in this document are recognized as good practices, and thus should be adhered to whenever possibly. While certain situations may warrant deviation from the sampling instructions, the principles of sample integrity, on which the instructions are based, must be applied to all situations.

Scope and Field of Application

This document lists sampling instructions for domestic and imported fresh fruits and vegetables in view of detecting excess pesticide residues, chemical contaminants, pathogens, food additives and food preservatives and treatments, and for detecting irradiated produce. The testing of fresh fruits and vegetables also determines their compliance with the Fresh Fruit and Vegetable Regulations and the Food and Drugs Act and Regulations.

The field of application for monitoring samples is defined under Section 2.1 (1) of the Fresh Fruit and Vegetable Regulations:

"...these Regulations (the Fresh Fruit and Vegetable Regulations) apply in respect of all produce that is marketed in import, export or interprovincial trade, supplied fresh to the consumer or for food processing."

Definitions

For the purpose of this document fresh fruits and vegetables are defined as: fresh fruits, fresh vegetables, fresh herbs, sprouts, fresh mushrooms as well as minimally processed ready-to-eat fruits and vegetables.

Minimally processed ready-to-eat fruits and vegetables: fresh fruits or fresh vegetables which have been sliced, chopped or shredded prior to packaging.

Domestic minimally processed ready-to-eat fruits and vegetables: fresh domestic or imported fruits or vegetables that have been sliced, chopped or shredded in Canada.

Imported minimally processed ready-to-eat fruits and vegetables: fresh fruits or vegetables that have been sliced, chopped or shredded outside of Canada.

Domestic fresh fruits and vegetables: fresh fruits and vegetables that are grown in Canada.

Imported fresh fruits and vegetables: fresh fruits and vegetables that are grown outside of Canada. They would also include imported produce prepared and packaged in Canada.

Shipment or load: a quantity of fresh fruits and/or vegetables shipped or received at one time and covered by a particular contract or shipping document. It may be composed of one or more lots.

Lot: a stated quantity of fresh fruits or vegetables that has a uniform characteristic (i.e., same shippers, same brand names, same variety, same marks on packages, etc.). A lot could also be considered as a shipment or a load.

Sample: a quantity of fresh fruits or vegetables taken from a lot and intended for laboratory analysis.

Sample unit: a sample unit is an individual portion or container of fresh fruits or vegetables randomly taken from a lot. A sample may consist of one or more "sample units". A sample unit may also be referred to as a "sub sample."

Legislative Authority to Take Samples

Section 21 (1) (b) of the Canada Agricultural Products Act provides the authority for an inspector to take samples free of charge:

Sampling Instructions

Each sample submitted for laboratory analysis is considered an official sample. Laboratory results will determine which compliance action must be taken on a lot of fresh fruits and vegetables that is in violation with the Fresh Fruit and Vegetable Regulations or the Food and Drugs Act and Regulations. Therefore, all CFIA samples should be representative of the lot. Appropriate measures should be taken to prevent any contamination of the individual sample during its handling, storage and transport to the laboratory. If samples are improperly collected or mishandled, or are not representative of the sampled lot, the laboratory results will be inaccurate and inconclusive.

1. Preparation of the lot for sampling

The lot will be prepared for sampling in such a way that sample(s) can be taken without hindrance. Each lot will be sampled separately. The lot to be sampled will be uniform, i.e., same shippers, same brand names, same variety, same markings on packages, etc. The inspector should record any information concerning the condition and the surroundings of the lot which have some bearing on the results of the laboratory analysis on the Food Product Sampling Submission form.

2. Sampling equipment

Sample containers: for all sampling purposes, use clean, dry, sterile and leakproof containers where the capacity is adequate for the desired sample unit.

Instruments for opening food packages: sterile scissors or knives are needed to open large packages of fresh fruits and vegetables for microbiological sampling purposes.

Sampling devices: when sampling for microbiological purposes, sterile scoops, spoons, triers or forks can be used for collecting sample units. Sterile scissors or knives may be needed to cut portions from a large product.

Sterilized disposable gloves: when sampling for microbiological purposes, sterilized disposable gloves will be used for collecting fresh fruits and vegetables that are in bulk. When sampling for food additives, preservatives and treatments or for the detecting food irradiation, do not use sterilized disposable gloves that contain talcum powder. The talcum powder may interfere with the laboratory testing.

Shipping containers: an insulated container of sufficient capacity is needed for holding and transporting samples that have been chilled or frozen for pesticide monitoring programs. Appropriate packing materials such as scrunched up newspaper, shredded paper, Styrofoam nuggets, or other suitable material may be needed to secure samples within the shipping container.

Coolants: plastic containers filled with refrigerant are needed to keep sample units cool. Dry ice is needed to keep frozen samples frozen.

3. Choosing the samples

Sampling will be carried out in such a way that the samples represent all the characteristics of the lot. Therefore, the sample will be taken randomly, i.e., from various locations (top, middle and bottom). Open, broken or damaged containers not representative of the lot will not be sampled. For microbiological sampling purposes, inspectors should not sample products that are past the "use by" date or the "best before" date. Also, samples should be collected in such a way that they can be tested before the "use by" or "best before" date. If at all possible, the inspector should collect samples that are five (5) days before their "best before" date. This ensures that the samples collected, especially during monitoring, represent an accurate profile of the product, as retailers should not be selling products that are past its "best before" or "use by" date.

If at all possible, samples should be collected from the prepackaged product that would be purchased by the consumer. Where products are in bulk, samples may be collected directly from the packing line or bulk containers. The samples, however, must be collected at the end of the line before packing. It would be preferable to take the sample directly from an unclosed container. Do not collect samples from the cull bin because they might not have gone through the preparation and packing steps.

4. Sample size

The size of the sample depends on the laboratory tests to be carried out.

1. Pesticide residues, chemical contaminants, food additives, preservatives and treatments
    
   The sample size for the above purpose should consist of one kilogram of produce or as otherwise indicated in the sampling plan.

2. Irradiation
    
   The sample size for the detection of irradiated produce is indicated in the sampling plan. For example: the 2000/2001 sampling plan requires 250 grams of garlic, ten mangoes, five papayas and four pints of strawberries.

3. Microbiological
    
   The sample size is one melon or five (5) prepackaged product weighing at least a total of 500 grams. Bulk products can be sampled for laboratory analysis. In such cases, five (5) sample units of 100 grams each will be randomly collected. Do not combine any of the sample units into one single sample. Keep the five sample units segregated and individual.

5. Step for drawing samples

5.1 General instructions Inspectors should wear clean clothing to minimize the risk of accidentally contaminating the sample. Inspectors should wash their hands prior to sampling a lot. Only trained inspectors should collect samples. Samples should be taken randomly, i.e., from various locations (top, middle and bottom). When sampling master containers, choose the desired number of master containers at random, and from each of these, choose random packages within the master container. Take care to not overfill the sample container or to permit punctures by wire closure. Sample containers must be securely sealed after filling so that they cannot leak or become contaminated during normal handling. It is a good practice to place one bag inside another (double thickness) to resist punctures. The packaging of the sample should be done directly at the site to avoid possibilities of contamination. Do not repackage produce that has already been packaged. To maintain product integrity, samples must be well packed. 5.2 Specific instructions A. Pesticide residues, chemical contaminants, food additives, preservatives, treatments, and irradiation The following instructions are to be used while sampling fresh fruits and vegetables for pesticide residues, chemical contaminants, food additives, preservatives, treatments and irradiation testing. Except for potatoes, the product should be wrapped in aluminum foil, and placed in a polyethylene bag (4 mil or thicker). It is necessary to wrap the product immediately in aluminum foil because the polyethylene might interfere with the contaminant. Do not place potatoes in a polyethylene bag. Wrap them in aluminum foil and place them in paper or another type of bag which will permit air circulation. Do not use sterilized disposable gloves that contain talcum powder. The talcum powder may interfere with laboratory testing. Where there is the potential of cross-contamination, change the gloves before proceeding to collect the next sample. For instance, the transferability of sulphites is high, therefore, when testing for sulphites, the inspector should change gloves in between samples.   B. Microbiological Special care should be taken by inspectors while sampling fresh fruits and vegetables for microbiological testing. Whenever possible, submit samples to the laboratory in the original unopened containers. If a prepackaged product is sampled, ensure that the container will not break during transportation. If the product is in bulk or in containers too large for submission, a representative portion of the product to be sampled must be transferred to a sample container under aseptic conditions. Aseptic conditions means the inspector must have clean clothing and use sterilized disposable gloves, sterilized sample containers and sterilized sampling equipment. Inspectors should bring enough sterilized equipment to collect the desired number of samples. The gloves must be put on using surgical techniques. Do not reuse the sterilized gloves to sample another lot. Contact with surfaces other than those of the product itself should be avoided. Place the product immediately in the sample container using the sampling equipment. If products fall outside of the sample container, do not place it back in the container. If a bag is used as a sample container, do not blow into the bag to open it, as it will introduce microorganisms commonly found in the throat.

6. Marking of the samples

Immediately identify each sample unit with a sample number. Immediately affix a label to the sample container or use a strip of masking tape to mark the sample number. The marking must be legible and permanent. Do not use a felt pen on plastic sample containers because the ink might penetrate the container.

7. Storage and transportation of samples

7.1 General instructions Storage and transportation of the laboratory samples must be carried out in conditions that help avoid any changes in the product. The instructions described below should be followed: Deliver samples to the laboratory promptly. Microbiological samples, however, should be collected and sent to laboratories at the beginning of the week as the laboratories would have enough time to analyse them. Otherwise, inspectors should consult with laboratory staff to determine when it is appropriate to send microbiological samples. If samples are not shipped immediately, they should be stored in either a refrigerator or freezer. Cool samples rapidly at a temperature between 0 and 5o Celsius prior to shipping. Transport frozen or refrigerated samples in approved insulated shipping containers of rigid construction so that they will arrive at the laboratory in good condition. The size of the shipping container should be sufficient to hold the samples. Shipping containers, refrigerant and packing materials are to be clean, dry and sanitary. Transport samples in a shipping container with suitable refrigerant capable of maintaining the samples at a temperature between 0 and 5o Celsius. During summer months, place shipping containers, if possible, in a freezer long enough to chill them thoroughly. Samples should be packed tightly to prevent shifting within the shipping container but not too tightly as to compress or damage the samples during transport. Use scrunched up newspaper, shredded paper, Styrofoam nuggets, or other suitable material. Unless otherwise specified, do not freeze refrigerated products. 7.2 Storage and transportation of refrigerated samples Samples which require refrigeration must be kept between 0 and 5o Celsius. Sufficient ice packs must be used to keep the product cool. Care must be taken when packing with ice so as not to freeze the product. Ice packs should not be placed directly on the samples. A layer of packaging material can be used. Place the samples in an insulated cardboard box or a ventilated moulded polystyrene cooler or other insulating material. 7.3 Frozen samples Surround frozen samples with dry ice wrapped in newspaper or brown paper to avoid contact between samples and the dry ice. Sufficient dry ice must be used to keep the product frozen. Place the frozen samples in an insulated cardboard box, a ventilated moulded polystyrene cooler or other insulating material.

8. Shipping temperature of the samples

Temperature abuse may increase the deterioration or breakdown of the product. For microbiological testing, it may result in the replication or death of the targeted microorganism to be tested, and may render invalid analytical results.

A.	Pesticide residues, chemical contaminants, food additives, preservatives and treatments Samples for pesticide residues, chemical contaminants, food additives, preservatives and treatments analysis should be maintained at a temperature that prevents product deterioration. This generally means that the product must reach the laboratory without any deterioration or breakdown. The product can be refrigerated. If the product is highly perishable or in an advanced stage of maturity, the product must be frozen in order to prevent further deterioration.
B.	Irradiation Samples intended for irradiation testing should be maintained at a temperature to prevent product deterioration. Do not freeze samples, even if the product is highly perishable or in an advanced stage of maturity. However, samples can be refrigerated.
C.	Microbiological All samples must be refrigerated, i.e., kept at a temperature between 0 and 5o Celsius. Samples must not be frozen. The laboratory may refuse to analyse any samples that they deem compromised, and/or samples that they believe to have been stored at inappropriate temperatures during shipment. Refrigerated samples that arrive at the laboratory with a temperature between 5 and 7o Celsius may be analysed at the discretion of the laboratory. However, samples that arrive at the laboratory with a temperature above 7o Celsius will not be analysed.

9. Shipping the samples

Before placing samples in a shipping container, ensure that each sample is properly identified with a sample number. Place the sampling report(s) in a sealed envelope outside of the shipping container or in a plastic bag inside of the shipping container.

Ensure that the shipping container is properly labelled and sealed. Mark on the shipping container the following statement: "PERISHABLE, HANDLE WITH CARE." Ship the container by the appropriate means of transportation. Advise the carrier of the need for refrigeration and the presence of dry ice, if used. Samples should be shipped within a reasonable time. If the samples are to be delivered during a weekend and there is no one at the laboratory to receive them, it may be advisable to keep the samples under appropriate storage temperature at the work site, and ship them on an early day in the week, rather than shipping the samples over the weekend.