Traditional fermented foods in Iraq are regionally diverse due to the rich history of the country. For example, in the ancient city of Babylon, fermented foods are derived from date (Phoenix dactylifera L) fruits. The ancient city of Nineveh, a former capital of the Assyrian Empire, is known for fermented foods prepared from vegetables, wheat, and barley. In the southern city of Basrah located in the vicinity of the Arabian Gulf, traditional fermented foods are prepared from fish, such as mackerel (Scomber scombrus) and cobia (Rachycentron canadum). The preparation techniques are another source of diversity of Iraqi fermented foods as they show significant cross-regional differences. This section will highlight the preparation methods and the raw materials applied to the reviewed traditional fermented foods in Iraq.
Basturma
Basturma or Bastirma is traditional fermented meat prepared using minced lamb or minced beef that is mixed with several spices, salt, and garlic and stuffed in cow intestine [19]. The stuffed intestines are hanged on hooks and kept at room temperature for fermentation for 7–14 days. The traditional method for preparing Basturma is demonstrated in Fig. 2A. Minced beef or lamb should contain at least 10% fat as this significantly improves the aroma and enhances taste of the finished product. The finished product is safe to consume, and the quality remains stable for 7–10 days at 10–20 °C. After this period, it is recommended to freeze Basturma in order to maintain its quality and extend its shelf life.
Basturma is commonly consumed during the winter season after being fried in oil. It is consumed mainly during breakfast, and it is served with fried scrambled eggs. In recent years, the growing population of Iraq and high demand for Basturma has caused shortage of supplies for cow intestines used as casing. Synthetic casings are suggested as a safe alternative with added benefits of increased safety and reduced microbial contamination [20]. However, according to this study’s informants, consumers in Iraq refuse to use synthetic casing to produce traditional Basturma.
The challenge of preparing Basturma is safety as meat products are rich in nutrients which increases probability of contamination with Salmonella spp., Staphylococcus aureus, and Escherichia coli [21]. The microbial risk analysis for similar fermented food known as fermented sausage (salami) demonstrates low risk of contamination due to low water activity [22]. However, some studies have reported significantly higher risks of contamination of dry fermented meat products by several food-borne pathogens with the potential for outbreaks [23]. According to Ingham et al. [19], traditional Basturma, if prepared under strict hygiene control using meat from freshly slaughtered animals, offers non-significant risks of food-borne contamination and outbreaks. Therefore, the recommended production process for enhanced safety involves the implementation of strict hygienic conditions, utilization of fresh meat, and preservation of finished product by freezing.
Smoked Liban (yogurt)
Liban (yogurt) is traditional fermented milk produced via the lacto-fermentation process using well defined starter cultures. The history of yogurt is not well known, but scholarly evidence indicates that yogurt has originated in the Mesopotamia at around 5000 BC. [24]. In several Middle Eastern countries, including Iraq, yogurt is known as the Liban; it is consumed with bread daily as a main dish for breakfast [25]. There are several varieties of Liban in Iraq that are traditionally prepared via back-slopping fermentation and made using different types of milks including cow’s, sheep’s, and goat’s milk. Traditional smoked Liban is unique for Iraq, and the most authentic product can be found in the north of Iraq, i.e. in the city of Erbil. Smoked Liban is well known among the Iraqi as the Liban Erbil due to its high quality and unique flavour.
Smoked Liban is prepared using sheep’s milk, i.e. milk of higher cost and quality compared to cow’s milk. According to this study’s informants, sheep’s milk is preferred by the locals due to its aroma. The Liban prepared from sheep’s milk has high physiochemical qualities and is rich in flavours because of high content of protein, solids, lipids, and polyunsaturated fatty acids [26]. Unique organoleptic properties of smoked Liban are due to a unique processing technique practiced by local producers (Fig. 2B).
There are two traditional methods to develop the unique flavour for smoked Liban. The first method is by sterilizing milk in a large copper pot; then, 90% of this milk is removed to smaller pots, and the other 10% is subjected to excessive sterilization without stirring. This is required to scorch milk and obtain a unique flavour. The second method to develop flavour is via burning twigs of oak trees inside the pot without touching milk. This sterilized milk is then cooled down to 35–40 °C and mixed with yogurt from previous batches of the best flavour known by local producers as the Khothra. Khothra is prepared from unsterilized fresh milk curd, and the curd is transferred (by the method of back-slopping) 3–4 times to develop the dominant starter cultures of preferred flavours. The technique was observed to improve quality and refine safety of dairy products by establishing the dominant starter cultures with antimicrobial and probiotic properties [12]. However, milk mixed with the yogurt from the previous batch is incubated for 18–20 h and sold fresh at local markets. The shelf life of the product is 7 days at room temperature, and 30 days at 4 °C. Liban is consumed by the local people in Iraq daily and mostly in the morning during breakfast.
Aushari cheese
Aushari is traditional semi-hard cheese made of sheep’s and goat’s milk in the mountains of northern Iraq [27]. Aushari is mainly produced by the Kurdish tribes and can be found in the Kurdistan region, especially in Sulaymaniyah and Erbil. The villagers collect sheep’s or goat’s milk early in the morning, and milk is heated for 10–15 min and then cooled down for 30–45 min. This sterilized milk is used to prepare soft cheese using rennet enzymes from the fourth stomach of calves (abomasum). The curd is pressed using muslin clothes to remove the whey and reduce moisture content. The curd is shaped as cheese balls weighing 300–400 g each. The pressed soft cheese balls are placed in bags made of sheep stomach that have been pre-cleaned using water and salt. A traditional herb known locally as the Jaje belonging to the Thyme (Thymus capitatus) family is added to the bags to enhance flavour of Aushari. The bags are placed in sheepskin and transferred to the caves at the top of the mountains that have high humidity and low temperature. The cheese is matured for 6–8 months. During maturation, the cheese develops special aroma and taste. The ripening process is due to rennet enzymes, i.e. the enzymes from the sheep stomach, the enzymes from herbs, and natural microflora.
The cheese is commonly prepared in the summer and harvested from the caves during the winter. The ripened Aushari cheese has yellowish colour and a very strong, “sharp” aroma which is due to prolonged aging and added herbs (Fig. 2C). There are no accurate studies to profile the bioactive compounds and microbial load of Aushari. Generally, most aged cheeses are safe for consumption [28], but risk analysis of the Aushari cheese is yet to be performed. The cheese can be stored for 6 months at room temperature during the winter. The Aushari cheese is very popular with the Kurdish and less popular with other ethnic groups in Iraq.
Turshi
Turshi is the most popular fermented food in Iraq. It is consumed daily and made of fermented mixed vegetables, such as cucumbers (Cucumis melo var. flexuosus), cauliflower (Brassica oleracea var. botrytis), cabbage (Brassica oleracea var. oleracea), green olive (Olea europaea L.), Jerusalem artichoke (Helianthus tuberosus L.), bell pepper (Capsicum annuum), and garlic (Allium sativum) [8]. There are two main preparation methods that can only be found in Iraq: the method from the city of Al-Najaf al-Ashraf which is known as the Turshi Medabis and the method known as the Turshi Mahshi from the historical city of Nineveh. Turshi is prepared via back-slopping fermentation using a portion of the previous batch that is added to the new batch. Turshi Medabis has a sweet–sour taste due to the mixture of flavouring ingredients including date syrup, apple cider, and tamarind.
A traditional recipe for preparing 10 kg of the finished product involves 3 kg cucumber, 2 kg cucumber, 2 kg cauliflower, 1 kg green olive, 1 kg Jerusalem artichoke, and 1 kg green chilli. Vegetables are washed and transferred to fermentation tanks to be covered with brine (12% salt). The first spontaneous fermentation is carried out for 30–40 days. The product is then kept in water for 24 h to remove impurities and extra salt. The fermented vegetables are subjected to second fermentation with water and date syrup (25% v/v) and kept at room temperature for 5–15 days.
Turshi Mahshi is prepared following the first fermentation process of Turshi Medabis using cucumbers and bell pepper only. In the second stage of fermentation, vegetables are stuffed with coriander, parsley, garlic, celery, and chilli. The stuffed vegetables are placed in a tank and fermented for 3–5 days with water containing 5% lemon juice and 10% date vinegar. The traditional Iraqi Turshi is served with a special condiment known as the Amba that is made by mixing pickled green mangoes, white vinegar, turmeric, fenugreek, and salt (Fig. 2D). Amba is, thus, a fermented condiment that is consumed with Turshi and as a sauce for sandwiches such as Kebab (minced beef grilled on charcoal) and Falafal (patties made of ground chickpeas).
Turshi is commonly consumed in Iraq as an appetizer during lunch and dinner, with consumption frequency increasing in the winter. Due to low acidity provided by lemon and vinegar, the product has long shelf life (10 days at room temperature). However, acidity can reduce quality and preferred texture of fermented vegetables. Therefore, Turshi is recommended to be consumed within 2–3 days. Burris et al. [29] report high risks of consuming cucumbers due to frequent outbreaks caused by Salmonella enterica. Cauliflower, cabbage, and bell pepper are also prone to outbreaks due to potential contamination with Listeria [30]. Recently, Turshi has been reported responsible for an outbreak of food-borne Botulism caused by Clostridium botulinum among the immigrants to the USA [31]. There are no studies determining safety of the traditional Turshi in Iraq. However, no outbreaks have been recorded due to consumption of Turshi for a long time. This can be a result of strict hygienic conditions maintained in local production facilities.
Sour Khobz
Sour Khobz is traditional sour bread in Iraq made of whole wheat flour. The art of this bread’s production has been practiced for centuries by ancient civilizations in southern Iraq, such as the Babylon, Sumerian, Uruk, Lagash, and Ur. These ancient civilizations utilized date fruits as a starter culture for dough preparation because date fruits were believed to have exceptional health benefits [32]. Date fruits contributed to leavening the dough due to their significant microbial diversity including yeasts, acetic acid, and lactic acid bacteria [33]. Currently, this ancient art of bread preparation is rarely practiced nowadays. Lifestyle changes and the development of baking yeast have impacted on the production of the traditional sour Khobz. Importantly, bread made using date fruits or syrup can be found in several Arab countries including Bahrain where it is known as the Khubez Tamer [34]. Addition of date fruits to the dough has been reported as a novel method to extend shelf life and improve safety of sour bread [35].
The traditional production method is simple and begins by mixing whole wheat flour (1 kg) with 1 cup of water (250 mL) to prepare the dough. The starter culture is prepared by mixing ripen date fruits (10–15 pieces) with 250 ml water which is kept at room temperature overnight. The starter culture is added to the dough at the recommended ratio of 1:5 w/w to ensure good fermentation. The dough is kept overnight for leavening and baked in the oven at 180–220 °C to produce thick sour bread (Fig. 2E). This bread has long shelf life (6–8 days at room temperature) and improved quality with delayed staling. This bread is consumed in local communities of the Iraqi marshes (known as the Mesopotamian marshes) in southern Iraq.