Historical, Technological, Biochemical, and Microbiological Aspects of Pastırma, an Ethnic Meat Product from Asia to Anatolia

1. Introduction

Meat and meat products are economic-interest foodstuffs, constituting valuable livestock products. From a nutritional perspective, meat's importance derives from its high biological value as a protein, which contains all the essential amino acids as well as highly bioavailable minerals, vitamins, and micronutrients like iron, selenium, and zinc. The consumption of meat has been of paramount importance in the development and sustenance of the human species, as it provides a wide array of essential nutrients that are vital for maintaining a healthy and balanced diet (Gagaoua & Boudechicha, 2018; Ledesma et al., 2016).

Traditionally, culturally, and commercially, ethnic meat products are precious foods in different nations worldwide. The meat products prepared by Eastern Mediterranean and Middle Easterners are typically cured or cooked and occasionally smoked or sun-dried (Gagaoua & Boudechicha, 2018). Many ethnic food products with animal origins are still in demand today and sold under various brands due to their customary, nutritional, and sensory properties. One example of these products is pastırma, which is commonly consumed in the Anatolian region. Also, it is consumed in the Middle East, Central Asia, the Mediterranean, and Europe (Aksu et al., 2020a; Ceylan & Aksu, 2011). At the same time, pastırma is a meat product produced without heating or smoking and consumed without cooking. So it is an ethnic meat product produced by dry-curing, drying, pressing the whole muscles of cattle and buffalo, and coating them with a paste called “Cemen” made with special spices (Aksu et al., 2020b; Kaban, 2013). Fenugreek (Trigonella foenum-graecum L.) seed flour, garlic (Allium sativum L.), milled red capia pepper (Capsicum annuum L.), and water are the primary ingredients used in the preparation of cemen (Figure 1).

Scientific research on ethnic food products is essential not only for those who create scientific knowledge but also for the sector, producers, and consumers. Although there have been a lot of research on pastırma, there needs to be literature in which all the aspects of pastırma are collected. In addition, researchers need to be shown new opinions, suggestions, and missing pieces. To this end, this comprehensive review aimed to address the definition of pastırma and its historical, technological, biochemical, and microbiological properties in all its parts.

2. Historical Aspects

Food consumption patterns are seen as a cultural attribute and, as such, vary in accordance with the societal culture. As it is known, food culture is a result of the accumulation of years of knowledge transferred from generation to generation. Nomads, who mostly salted, pressed, and dried their meat, tried alternative methods to make their food be consumed for a longer time in history. According to historians and archaeologists (Oboturova et al., 2022; Turner& Merwin, 2016; Merwin, 2015), Hun and Oghuz Turks, who led a nomadic and militant life in Central Asia, used to carry out their alimentation activities with salted meat and meat pieces of animals they hunted in order to advance on horseback without wasting time. They carried these pieces of meat in their saddles or saddlebags, which they placed on their mounts, and during the journeys that often lasted for weeks, the pieces of meat turned into pastırma by being stuck and pressed between horse and saddle (Çilginoğlu & Mutlu, 2022; Merwin, 2015). Pastırma, a Turkish name, is derived from the verb "bastırmak" which means to pressed (Özkan, 2013). The primary ancestral territory of Hun and Oghuz Turks was in Central Asia, with the Khingan Mountains in the east, the Caspian Sea in the west, Siberia in the north, and the Himalayas in the south. Hun and Oghuz Turks have been migrating for thousands of years and have spread out from the mainland to various parts of the world (Batu, 2018). Thus, pastırma culture has reshaped as a consequence of migration to different geographical areas and interaction with different cultures (Figure 2).

The fact that the cultural interaction of nomads with agricultural societies has affected pastırma to take its current form in time. To prevent the surface of the pastırma from becoming mouldy, ancient people covered meat with a thin spice paste called cemen, the main ingredient of which is fenugreek (Trigonella foenum-graecum L.). Greek hayseed, commonly known as fenugreek, was considered the best stabilizer and preservative by ancient people due to its easily obtainable and fibrous, sticky texture (Batu, 2018; Kaban, 2013; Visuvanathan et al., 2022).

Pastırma entered Anatolia from Central Asia during the Seljuk era in the 11-12^th centuries. In the Seljuk era, “Divanü Lugati-t Türk” (1073): In a work that was prepared as a dictionary by Mahmut of Kashgar in order to teach the Turkish language to Arabs, we can find pastırma and a lot of ethnic product descriptions that still exist (Batu, 2018; Kaban, 2013).

In the era of the Ottoman Empire, pastırma had spread from Anatolia to North Africa (Egypt, Algeria, Libya, Tunisia), Rumelia, and the Balkans (Gagaoua & Boudechicha, 2018; Güney, 2023). The manuscripts that described social functions in the 16^th century’s Ottoman Empire mentioned that pastırma served as an appetizer in private bars at a point in time. On the other hand, it's estimated that commercial production of pastırma started in the 17^th century (Türker et al., 2019).

Today, pastırma, known as pasterma or basṭarma in Egypt and consumed in great demand, especially by the Egyptians, is no different from Turkish-type pastırma. Unfortunately, pastırma is called pastrami in some publications from Turkey and Egypt (Abd-Elghany et al., 2020; El-Mougy et al., 2023; Yildirim et al., 2017; Akçay et al., 2015; Özkan, 2013). However, pastrami, which is considered a word of Jewish origin in America, refers to a different delicatessen product made by heat treatment, brining and smoking. The words pastırma and pastrami is cause conceptual confusion in some publication. This may perhaps be a straightforward case of a translation mistake into English.

The name seems to originate from closely related words in Romanian, Russian, Turkish, greek, and Armenian, namely pastram, pastromá, pastırma, pastramás and basturma, which all convey the meaning of "pressed." Also, an etymologist, identified a more extended version of the term, pastramagiu, in the Romanian language, which described meat that is salty, smoky, and reddish in color. Although it is basically a pressing process, it is understood that different cultures create different delicatessen products (Özkan, 2013; Cardoso et al., 2020; Merwin, 2015).

Traditional products mirroring the culture of a region are shaped according to the geographical and climatic circumstances of the area. Nowadays, pastırma manufacturing, mainly industrial production, is widely centralized in the province of Kayseri, located in the middle of the Anatolia region. Although it is not well known, Kastamonu, in the Black Sea region to the north of Turkey, is a unique and important place for consumers of traditional pastırma (Figure 2). The essential factor characterizing Kastamonu pastırma from other pastırma is that it is produced in small enterprises under natural conditions using traditional methods based on the experience and talents of the master chefs. Generally, conventional production occurs under natural conditions, depending on annual climate and weather conditions, in late September, October, and November. Also, these months are called pastırma summer by the local community in Anatolia (Kaban, 2013). The common eating practices of pastırma and the related sociocultural and historical aspects are still being investigated.

3. Definition and Classification

Dry-cured, pressed, washed, dried, coated with cemen paste, and re-dried beef or buffalo whole muscles are classified as a ready-to-eat (RTE) product without heat treatment, known as pastırma (Anar, 2017). The different parts of the carcass produce different grades of pastırma, and nearly 20 different types of pastırma may be made from a mature cattle or buffalo carcass. Pastırma can be divided into three grades according to quality (Figure 3). Grade 1 pastırma types have a highly marbled, low-fat, soft texture and pinky-red color. Again, grade 2 pastırma types have medium marbled, medium-fat, moderate texture, and red color. On the other hand, grade 3 pastırma types have a non-marbled, rich-fat, hard texture and a dark red color (Turkish Standards, 2002).

4. Manufacture of Pastırma

4.1. Animal Selection

Although horse, chicken and fish pastırma have been experimentally made, consumers are unfamiliar with it (Ren et al., 2015; Kök & Arslan, 2003; Anar, 2017). The animal chosen to produce pastırma is usually a cow, bull, or male buffalo between 3-6 years of age. The young animals' meat cannot be preferred because of its high juiciness. If the meat is too juicy, it causes problems with the drying and salting processes. In addition, heifers, oxen, and female buffaloes are not well preferred because of their meat quality (Anar, 2017).

4.2. Definition and Preparation of Cemen Paste (Fenugreek Paste)

Cemen, the edible covering used for paste seasoning and cementing, is a tremendous source of nutrients, antioxidants, and flavors that are very important to the pastırma industry (Ahhmed et al., 2017). Fenugreek seeds are the main ingredient in cemen paste. Crude fenugreek seeds are brownish-yellow in color and rectangular-shaped, hard, pleasantly bitter, and have a maple flavour (Visuvanathan et al., 2022). Seeds are composed of carbohydrates, accounting for approximately 45 to 60% of their composition. These carbohydrates include mucilaginous fiber, specifically galactomannans. These galactomannans play an important role in making fenugreek paste an excellent coating material. The seeds also contain proteins, making up around 20 to 30% of their composition, which are notably high in tryptophan and lysine. Various flavonoids such as apigenin, orientin, luteolin, quercetin, vitexin, and isovitexin are present, as well as free amino acids including 4-hydroxyisoleucine (0.09%), arginine, lysine, and histidine (Singh & Garg, 2006; Visuvanathan et al., 2022; Wani & Kumar, 2018). In addition to consumption as food, T. foenum-graecum has a wide range of pharmacological uses and therapeutic effects. T.foenum-graecum, was used as a medicine in ancient Egypt. The Ebers papyrus, one of the earliest therapeutic manuscripts, contains reports on the advantages and medicinal applications that have been discovered (Visuvanathan et al., 2022). The effects of T.foenum-graecum on dealing with many health issues have been demonstrated by a multitude of in vitro, in vivo, and clinical research. T.foenum-graecum has been shown to have anti-hyperglycemic, hypocholesterolemic, immunomodulator, anticancer, anti-obesity, phytoestrogenic, neuroprotective, antimicrobial, and antioxidant effects (Achari & Jain, 2017; Akbari et al., 2019; Almalki & Naguib, 2022; Geberemeskel et al., 2019; Abdelwahab et al., 2021; Sevrin et al., 2019; Shesharao et al., 2020; N. Singh et al., 2022).

Fenugreek (Trigonella foenum-graecum L.) seed flour, garlic (Allium sativum L.), milled red capia pepper (Capsicum annuum L.) are used to produce a semi-solid paste that consists of some natural flavors known as cemen or fenugreek paste. Cemen is an ethnic food product in and of itself. And, it is used not only in the production of pastırma. It can also be consumed on toast for breakfast or as a fresh snack (Aksu et al., 2020b). There is no standard for the composition of cemen paste. Manufacturers use various formulations of paste provided with the main ingredients. The typical composition of cemen paste used for pastırma production is 22.5% fenugreek seed flour, 15% garlic, 3.75% paprika, 3.75% red pepper powder, and 55% water (Aksu et al., 2020b; Anar, 2017; Hastaoglu & Vural, 2018).

Applying a layer of cemen paste over the pastırma results in a distinctive appearance, color, flavor, and aroma. Also, it prevents oxidation, microbial contamination, and supports the prevention of over-drying of the pastırma. Despite their benefits, many customers enjoy the unique and strong odor of cemen paste, as well as those who don't. In pastirma, the activity of organosulphur compounds, mainly solotone in fenugreek and allicin in garlic, causes an unpleasant odor in human sweat, breath, and urine (Ahhmed et al., 2017; Mebazaa et al., 2009). Notwithstanding this unpleasant odor, pastırma continues to be enjoyed with great satisfaction, particularly among those residing in the Anatolian region. For customers bothered by the odor, cemen paste scraped pastırma has also been sold in recent years.

4.3. Production Steps

Pastırma masters have their own terminology. The terminology used for production pastırma has been passed down from masters to apprentices from past to present. Even customers or suppliers may never have heard of the terms used in production. Production can use a different range of temperature and time combinations. Below is an example.

Selecting and slaughtering the animals used for processing is the first step in the production of pastırma. After rigor mortis and carcass aging occur, meat is unboned and cut off as muscle blocks. This process is called "söküm," which means dissection (Anar, 2017). Chuck and neck (Mehle, omuz, ortabez, kanlıbez), shank (bacak, kürek), rib, short plate, short loin, sirloin and flank (sırt, kuşgömü, ortaetek, kenaretek, arkabaş, döş, kavram), round and part of sirloin (şekerpare, dilme, bohça, bohçagömü, kapak, kenar) prepared to make different kinds of pastırma (Figure 3). After that, excess parts are trimmed, like lymph nodes, fascia, tendons, and ligaments. Furthermore, muscles are given a rectangular shape. This process is called "açım,” which means trimming. Then, a rope is tied to one end of the meat blocks and prepared for salting. For this purpose, a process called “şaklama”, which means gashing, is performed (Anar, 2017; Arslan, 2013). Sometimes, punctures are created in meat using the sharp point of a knife, while at other times, slices are formed. The meat is sliced into sections from its vast surface, often ranging from 5 to 8 sections. These sections are cut at an angle of 45 degrees, ensuring that they do not exceed half of the overall thickness of the meat itself (Arslan, 2013). Each section is called "şak." After şaklama, the first salting process is performed at 6±1°C for 20–24 hours. Generally, rock salt with sodium nitrite (NaNO₂) or rock salt with potassium nitrate (KNO₃) are used. Rock salt with a size of 2.0–2.8 mm is used for dry salting. The large particle size of rock salt leads to salt burns in meat. On the contrary, tiny salt particles can cause oxidation, darkening, and overly salty products. Relatively cold environments that do not receive sunlight are preferred in the salting process. Dry-salted meat blocks are stacked to a height of 20–25 cm. After the first salting, the second salting process is performed at 6±1°C for 6–12 hours. At this stage, parts of the meat that have yet to be treated are salted and turned over. Meat stacked on top of each other is turned upside down. The recommended quantity of salt to be used in the first and second salting processes should be between 5 and 10% of the total meat weight. When the salt concentration exceeds 10%, it leads to yield loss in the final product. Then, salted meat is washed and rinsed to remove excess salt. This washing and rinsing process takes 1–3 minutes. The washed meat is taken to the first drying process called "sergileme,” which means exhibition. Meats are hung on special hangers, so avoid touching something. This drying process can be performed in natural conditions or in air-conditioned rooms. The conventional method of natural drying takes place in late September, October, and November for 3-5 days on windy and sunny days when the weather is not too hot or 12–15 days in cloudy and mildly cold weather. On the other hand, the commercial drying method is carried out in climate rooms with 80–85% relative humidity at 15±1°C and 15–30 m/min airflow for 5 days. After that, the first pressure, called the "soğuk denkleme," which means cold pressure, is performed. At this stage, 0.9–1 kg/cm² pressure is applied to the dried meats at 7-8°C for 10–17 hours (Arslan, 2013). Meats that lose a little water at this time and show a flat form. Also, the sections called "şak" are closed. The next step is second drying. The surfaces of the pressed meats are moist. Therefore, a drying process is applied to the meats for 3 to 5 days, depending on the temperature and relative humidity. At the end of this process, the moisture in the meat can be below 34%. In addition, the fat on the surface of the meat melts and gives it a white appearance. This is referred to as "ağarma," which means bleaching, among manufacturers. After that, the second pressure, called "sıcak denkleme," which means hot pressure, is performed. Hot pressure is applied to 0.9–1 kg/cm² at 20–25 °C for 1–7 hours (Arslan, 2013). Finally, the meat coming out of the hot pressure process is covered with cemen paste and hung for 4 to 7 days to dry. Actually, the meats are kept in the cemen paste for 16–36 hours, and then the meats are covered with cemen paste with a maximum thickness of 4 mm and left to dry for 7–11 days (Aksu et al., 2022a; Aksu et al., 2023; Anar, 2017; Arslan, 2013; Kaya et al., 2022). It's crucial to remember that the cemen paste dough does not contain salt, and salt adsorbs from the meat into the cemen paste during the cemen paste process. Flow-sheet example for manufacture of pastırma is demonstrated in Figure 4.