Fermentation Gabrielle Allen - Senior Food Science Officer Food Safety Unit - Department of Health and Human Services, Victoria Today’s topics What is fermentation What is fermented Where do we find fermented foods Food safety of fermented food and drink Pub quiz SCOBY Pub quiz Oenophobia The return of tradition http://www.penn.museum/blog/collection/125th-anniversary-object-of-the-day/7000-year-old-wine-jar-object-of-the-day-24/ Foodborne illness incidence Food Country Year Sick Deaths Pathogen Cause Home pickled turshi (middle US 2013 4 0 C. botulinum Unsatisfactory fermentation eastern fermented vegetables) Pruno (prison alcohol) US 2011 8 0 C. botulinum Untested recipe. Potato added increasing pH allowing C. botulinum to grow. Pruno US 2016 26 C. botulinum Tofu US C. botulinum bulk tofu which had been kept unrefrigerated, uncovered, and in water- filled bins Home-canned pickled vegetables US 2016 1 C. botulinum Seal flipper US 2015 4 Beaver tail US 2016 1 C. botulinum Fermented blackbeans (douchi) China 2014 139 0 B. cereus Unsatisfactory fermentation Kimchi – raddish and cabbage Korea 2012 1642 0 E. coli 0169 variants Hazelnut yoghurt UK 1989 27 1 C. botulinum Contaminated hazelnut conserve Salami and metwurst AUS 1995 150 + 1 E. coli and Traceability, back sloping etc etc Salmonella Source: Barblog Foodborne illness incidence Food Country Year Sick Death Pathogen Cause s Fresh garlic in oil US 36 0 C. botulinum Unsatisfactory acidification, anaerobic conditions Olives Italy 2016 Unknown 1 C. botulinum Semi dried tomatoes AUS 2009 140 Hepatitis a processing expired tomatoes Fermented seal flipper US (Alaska) 3 0 C. botulinum Change of process, creating anaerobic conditions Home pickled tomatoes Azerbaijan 2015 8 1 C. botulinum Unsatisfactory fermentation Home preserved mushrooms in oil Italy 1998 1 1 C. botulinum Unsatisfactory acidification, anaerobic conditions Olives Finland 2011 2 0 C. botulinum Process failure Source: Barblog What has changed? So if the principles and processes are the same, and there are few instances of foodborne illness, why are we worried about food safety? • supply chain • wider distribution • industrialisation Skinned seal flippers ready to be fermented. Note the plastic rubbish bin bag. Image: NativeTech. • consumer expectation, in regards to rigorous food safety systems • increase of cottage industries in recent years – Masterchefitis • breakdown in the generation to generation knowledge exchange, loss of knowledge • changes to traditional processes • changes to traditional recipes A manufacturer of wine… Activity 1: Changes in traditional processes Botulism from fermented seal flipper… Skinned seal flippers ready to be fermented Image: NativeTech. Activity 2: Changes in traditional recipes Botulism from drinking pruno (otherwise known as prison wine, jailhouse hooch, juice, or brew)… A manufacturer of wine… Image barfflog Why do we ferment food? • flavour development • nutritive value • preservation (pH control for food safety) What is fermentation? Fermented food and beverages undergo a microbial process, where yeasts, bacteria or moulds degrade or break them down into by-products. What is fermentation? Sugar becomes food acid (yoghurt, sauerkraut/kimchi, kombucha) Sugar becomes alcohol Alcohol becomes food acid and acid (beer, wine) (vinegar) Different types of fermentations Source: Fermentation and food safety. Martin R Adams, MJ Robert Nout Activity 3 - Back to school The products – the diversity of fermentation The products – the diversity of fermentation Worldwide: alcohol, wine, vinegar, olives, yogurt, bread, cheese Asia • East and Southeast Asia: amazake, atchara, bai-ming, belacan, burong mangga, com ruou, dalok, doenjang, douchi, jeruk, lambanog, kimchi, kombucha, leppet-so, narezushi,miang, miso, nata de coco, nata de pina, natto, naw-mai-dong, oncom, pak-siam-dong, paw-tsaynob, prahok, ruou nep, sake, seokbakji, soju, soy sauce, stinky tofu, szechwan cabbage, tai-tan tsoi, chiraki, tape, tempeh, totkal kimchi, yen tsai, zha cai • Central Asia: kumis (mare milk), kefir, shubat (camel milk) • South Asia: achar, appam, dosa, dhokla, dahi (yogurt), idli, kaanji, mixed pickle, ngari, hawaichaar, jaand (rice beer), sinki, tongba, paneer Africa: fermented millet porridge, garri, hibiscus seed, hot pepper sauce, injera, lamoun makbouss, laxoox, mauoloh, msir, mslalla, oilseed, ogi, ogili, ogiri, iru Americas: sourdough bread, cultured milk, chicha, elderberry wine, kombucha, pickling (pickled vegetables), sauerkraut, lupin seed, oilseed, chocolate, vanilla, tabasco, tibicos, pulque, mikyuk (fermented bowhead whale) Middle East: kushuk, lamoun makbouss, mekhalel, torshi, boza Europe: rakfisk, sauerkraut, pickled cucumber, surströmming, mead, elderberry wine, salami, sucuk, prosciutto, cultured milk products such as quark, kefir, filmjölk, crème fraîche,smetana, skyr, rakı, tupí. Oceania: poi, kaanga pirau (rotten corn), sago What about pickles? Quiz question one – How do acids act as preservatives? 1. By cooking the food 2. By stopping or slowing the growth of food poisoning and spoilage bacteria 3. By providing anaerobic conditions 4. By making the food taste nice Answer - Food acids act as preservatives by reducing the food’s pH and thus stopping or slowing the growth of many food poisoning and spoilage bacteria. Quiz question three – Which food poisoning bacteria is the most significant concern for acidified foods? 1. Escherichia coli 2. Clostridium botulinum 3. Bacillus cereus 4. Salmonella Answer - Clostridium botulinum Quiz question two – What pH limits the growth of Clostridium botulinum? 1. 7.01 2. 4.6 3. 10.3 4. 4.2 Answer - The risk of Clostridium botulinum spores germinating and producing toxins is increased if the pH is above pH 4.6. pH can rise as it equalises with the product, a stating pH of 4.2 is recommended to account for this. Quiz question five – Are all food poisoning bacteria limited by pH 4.6? 1. Yes 2. No Answer - Some microorganisms are more acid tolerant than others Bacterial pathogens of concern in acidified products – acid tolerance Limits for Growth of Some Common Bacterial Pathogens Source: Fermentation and food safety. Martin R Adams, MJ Robert Nout Food safety threats – not just microorganisms Source: Fermentation and food safety. Martin R Adams, MJ Robert Nout Food acid alone is not enough for adequate food safety Key barriers in preventing food borne diseases in many cases are: • good manufacturing practices (GMP), • a robust hazard analysis and control process food safety program and • good hygiene practices (GHP) Food acid alone is not enough for adequate food safety - hurdles Food safety in acidification and fermentation specifically relies on: •good quality undamaged raw materials •contamination prevention (before, during and after processing) •well controlled fermentation processes Food safety steps and examples of suitable parameters Good quality undamaged raw materials • trusted raw materials suppliers • removing dirt and bacteria from raw produce by washing produce in potable water, or removing contaminated outer leaves or skins • heat treatment, to eliminate competing bacteria prior to acidification, such as using pasteurised milk for making yoghurt Food safety steps and examples of suitable parameters Contamination prevention • good hygiene practices (such as handwashing) • cleaning and sanitising procedures Food safety steps and examples of suitable parameters Well controlled fermentation processes • use a proven recipe • accurately follow recipe each time • the correct fermentation temperature • refrigeration of finished product • heat treatment (where appropriate) of finished product • addition of other ingredients such as salt Food acid alone is not enough for adequate food safety - hurdles Ingredients and processes that can be used in combination with acid are: • salt and/or sugar • preservatives (additives such as sorbic acid, benzoic acid) • heat treatment • refrigeration Some examples of the fermentation process Sauerkraut 1. Preparation of raw materials 2. Core, trim and shred Inoculate, if using Salt 1.0 to 3.5 (typically 2.25) % ww 3. Fermentation process Anaerobic Temp 18-22 ºC for 2-6 weeks 4. Pack Some examples of the fermentation process Yoghurt Heat pasteurised milk to eliminate competitive flora and cool 30-32 ºC Inoculate Fermentation process Temp 30-40 ºC for 6-20 hours Cool Pack and refrigerate Fermented soft drinks Some examples of the fermentation process Kombucha Boil water and steep tea Cool Inoculate with starter culture (SCOBY - Fermentation process Sugar for symbiotic colony Temp 18 – 26 ºC for 10 – 14 of bacteria and yeast) days Sweeten and flavour Pack and refrigerate Spoilers……. Proportion of drinks compliant with the Code – national survey Spoilers……. Multiple factors influence the alcohol content of brewed soft drink These include: • drink type • shelf life • secondary fermentation • flavouring • temperature • measurement Group discussion Where, in your role as an EHO, might you find products that have been fermented? Activity 4: Spot the ferment ` Bistro Blackwood – Rundle Street Adelaide The pot by Emma McCaskill - Hyde Park 94º West, Findon The flying fig - North Adelaide Assessing skills and knowledge Assessing skills and knowledge - the key points How are they controlling pH? Is the pH under 4.6? How are they controlling alcohol? Activity 5 Assessing skills and knowledg - what questions should you ask your fermented food producer? • Sauerkraut • Yoghurt • Kombucha Some examples of the fermentation process