Chutneys, Pickles, Flavoured Oils, Jams and Fermented Foods
Cases of food poisoning have been widely reported due to the consumption of contaminated chutney, food preserved with oil and fermented products. This failure to recognise hazards associated with the production and storage of these products has led to severe moral, legal and financial consequences. One of the largest outbreaks of food poisoning in the UK resulted in more than 400 people reporting symptoms of food poisoning, including diarrhoea, abdominal pain and vomiting. A thorough investigation into the cause of the outbreak found raw curry leaves used in chutney were contaminated by a number of pathogenic bacteria, including Salmonella, E.Coli and Shigella. This single incident resulted an insurance company paying out more than £400,000 in civil claims.
Potential hazards include pathogenic bacteria, harmful physical hazards, unintentional allergenic ingredients and chemicals. A widely known illness implicated in outbreaks of food poisoning involving preserved foods is Botulism. This is a very rare but life-threatening condition is caused by a neurotoxin produced by Clostridium botulinum. This pathogen attacks the body’s nervous system and is fatal in around 5 to 10% of cases. Clostridium botulinum grows under obligate anaerobic conditions (without oxygen) and can produce a harmful toxin in low acid foods (>4.6). Flavoured oils are particularly dangerous because they normally have a higher pH than 4.5 and provide an oxygen free environment.
General Food Safety Controls
Food containers must be in good condition, clean, disinfected and dry. Only use glass or food grade plastic containers because metal can react with acids in the finished product or those created during fermentation.
Visually inspect jars before use and discard any with cracks or chips. Disinfect them by placing them in a preheated oven for 160OC for 10 minutes or by passing them through the hot cycle of a dishwasher (e.g. 820C for 30 seconds)1. Invert jars to prevent foreign body contamination1. Make sure lids/stoppers are tight fitting. Do not reuse an old lid as it cannot be effectively cleaned and disinfected1.
Raw Materials and Standardised Recipes
Wash hands before preparing and handling food and ensure production equipment (e.g. chopping boards, knives, etc.) is clean and kept in good condition. Thoroughly wash fruit, vegetables and herbs under running water, dry and if necessary remove any outer skin.
Follow standardised recipes and cooking methods. Set ratios of salt, sugar and vinegar are essential to inhibit the growth of harmful pathogens. Put a lid on any hot products (e.g. jam ) immediately after bottling to form a tight vacuum seal1.
Shelf-life and Product Labelling
Determining the correct shelf-life of your product is important. Send your product to a UKAS accredited laboratory for testing or follow Food Standards Agency guidance. The Food and Drink Federation have produced an excellent guidance document on setting product shelf-life. This information can be found on their website at: https://www.fdf.org.uk/corporate_pubs/shelf-life-guidance.pdf
Make sure your product is correctly labelled with the appropriate information, for example storage guidance. This is particularly important if you supply other businesses because you must be able to identify specific information (e.g. lot/batch number) in case you need to recall the product in the event of a problem. Check with your local council for specific advice for labelling preserved food products.
Documentation and Records
Safe methods for producing jams, pickles, chutney and fermented products must be validated and documented within the food safety management system. These procedures must be communicated to those responsible for producing these products, for example chefs. Keep records of each batch produced, such as product name, temperature, pH measurements, date of production, etc. If applicable, keep records of validation studies such as references to industry or government codes of practice, onsite production trials and results of microbiological testing. Use a calibrated pH meter to check to pH level for chutneys, pickles, fermented and other acidified products.
Jams, Pickles and Chutneys
Cooking ingredients at a high temperature will destroy a significant number of pathogenic bacteria, but not spore formers. Use a calibrated probe or jam thermometer to ensure ingredients in jam reaches the correct temperature (setting point 105OC)1. Jam with less than 65% sugar will require storage in the fridge after opening1. To control the risk of C. Botulinum in pickles and chutneys it is important to ensure the pH is 4.5 or lower and/or water activity is <0.9 throughout the product during its shelf-life1. If these critical limits cannot be guaranteed, the product should be refrigerated, even before its opened.1 Do not add raw curry leaves to chutney as they may be contaminated with pathogenic bacteria. Cook them thoroughly2.
Moisture levels must be kept to a minimum. Use dried herbs, spices and vegetables or thoroughly dry ingredients, and check bottles are completely dry before filling1. Ensure the pH throughout the product is at 4.5 or lower including added ingredients1. Phosphoric, citric or acetic acid can be added to oil to lower the pH1. Use a calibrated pH meter to check this critical control point. The maximum shelf life of the product should be 10 days. It can be kept for longer if the pH is shown to be 4.5 or lower for the duration of its shelf-life1. This must be determined for each product by an independent analysis conducted by a UKAS accredited laboratory.
Fermentation is a natural process where bacteria found convert carbohydrates into lactic acid. Grate or shred vegetables to help lactic acid penetrate dense ingredients such as carrot or beetroot3. Leave to ferment in a cool dark place at room temperature (18-20OC) or refrigerate if applicable. If the product is too warm or cold it can stall the fermentation process3. Check the pH during the fermentation process to achieve a final equilibrium pH of 4.6 or below3. The product must reach a pH lower than 4.6 within 24 hours of the start of fermentation3. Keep ingredients below the liquid surface to prevent the growth of mould. Refrigerate (5OC) the finished product3. Remember always use a proven recipe and safe method from a reputable source.
We discuss safe methods for preserving food on all our food safety courses. Contact us now to find more on how we can support your team. Accredited courses include food safety and HACCP.
1. Dover District Council. Labelling Chutneys, pickles, flavoured oils and jams: Food safety and labelling advice for small scale home producers of chutneys, pickles, flavoured oils and jams. [Online]. Available at: https://www.dover.gov.uk/Environment/Environmental-Health/Food-Safety/Chutneys.aspx ( Accessed on 26 January 2019)
2. Public Health England (2013). Street Spice Festival outbreak investigation concludes. [Online].Available at: https://www.gov.uk/government/news/street-spice-festival-outbreak-investigation-concludes. (Accessed on 26 January 2019)
3. Queensland Health (2018). Fermented Food. [Online]. Available at: https://www.health.qld.gov.au/__data/assets/pdf_file/0014/702410/fermented-food-fs.pdf (Accessed on 26 January 2019)