Innovations in Development of Fermented Poultry Meat Products
Anita Chappalwar1 and Meena Goswami2
Assistant Professor, Dept of Livestock Products Technology
1College of Veterinary and Animal Sciences, Parbhani MAFSU Nagpur, (M.S.)
2College of Veterinary and Animal Sciences, DUVASU, Mathura, (U.P.)
Abstract
Meat industry is one of the fastest growing sectors in India, which play an important role in providing livelihood to rural people. Meat is the most pertinent livestock product which is obtained from food animal viz., cattle, buffalo, sheep, goat and poultry generally. Poultry meat and eggs has a prominent place in consumers mind and they prefer it as a less of a luxury item and more of a daily staple food due to its taste, health benefits, easily availability of biological high value protein and polyunsaturated fatty acids at affordable price to low-income people. It is composed of amino acids, minerals, fats and fatty acids, vitamins and other bioactive components. Employing of friendly microorganisms in the food fermentation is one of the ancient methods for producing and preserving food. Meat fermentation is a low energy preservation method which furnish distinctive flavor, augmented palatability, soothing color, tender and safe to the meat. Nowadays, there has been ever increasing demand of fermented meat products worldwide as an impact of series of research and development. Product quality and safety is probably the most important aspect of making fermented meat/poultry products because consumer acceptance and public health safety is the basic measures of any processing industry.
Key words: Fermentation, Poultry, Starter culture, Spoilage, Meat
“Fermentation and drying are probably the oldest ways of meat preservation. Historical event of fermentation are employed as a traditional method of meat preservation worldwide followed by a series of research and development. Meat product sausages were invented by the Sumerians, in what is Iraq today, around 3000 BC, which were produced with longer history and tradition.
Introduction
Poultry is the fastest growing section of the livestock industry, accounting 50% of total meat output in financial year 2019 (FAO 2020). The history of poultry in India is about 5000 years old. Poultry industry has registered Dynamic expansion as compared with other meat, which might upshot due to combination of factors – growth in per capita income, a growing urban population and falling real poultry prices. The poultry industry can be classified into broiler industry and layer industry, however broiler industry is concerned with poultry meat and layer industry is concerned with egg production. Late Dr.B.V.Rao, called “Father of Modern Poultry in India”. In 1982, Dr.B.V.Rao established the National Egg Coordination Committee, it is a charitable trust with 24 zones and 118 local committees has about 25,000 farmers as its members spread out all over India helping the layer farmers obtain reasonable, remunerative, viable price for eggs.. BROMARK (Broiler marketing Cooperative Society): Bromark, also a brainchild of late Dr.B.V.Rao is an all India Broiler Farmers’ Body registered under the Multi State Cooperative Societies Act in 1994. The objective of the Bromark is to ensure the gap between producer’s price and consumer price is reduced and promote the consumption of chicken meat by advertising on its nutritive value. In the domestic market the consumption of poultry meat is low due to the low purchasing power of people. Consumption of poultry meat steadily increasing over the world in both developed as well as developing countries. In India meat consumption reached to approximately 3.9 MMT during 2020. Broilers and eggs conquered 1,988 billion INR in Indian poultry market with export of 3,50,817.80 MT poultry products worth Rs 830.34 USD million during year 2019-2020 (APEDA, 2020).
Fermentation is an argot first used for the foam that occurs during wine and beer manufacture at least 6,000 B.C., when the Egyptians made wine and beer by fermentation. Later, fermentation processes have been developed to in food industry to yield a more acceptable food, to add flavor, to prevent the growth of pathogenic and spoilage microorganisms and to preserve food without refrigeration (Hesseltine & Wang, 1980).
Microorganism used in meat fermentation
Meat is mostly subjected to deterioration by the growth of several microorganisms. While these spoiling microorganisms are not acceptable in raw meat and meat products, certain types of fermentative microorganisms, especially the LAB, either exist in raw meat naturally (natural micro flora) or added by producers, are used for the production of fermented meat products. (Yilmaz & Velioglu, 2009). These desirable microorganisms added to the meat dough are called as starter cultures and they can be single species or the mix of certain microorganisms. The microorganisms of importance during fermentation and maturation of fermented products are Gram positive and rod shaped, belonging to the genera Lactobacillus, Micrococcus and Staphylococcus (Bozkurt and Erkmen, 2002). The surface flora of many air-dried fermented products consists mainly of moulds of the genus Penicillum and protects the products and gives them typical aromas (Bozkurt and Erkmen, 2002). Most fermented foods, including the major products that are common in the western world, as well as many of those from other sources that are less well characterized, are dependent on LAB to mediate the fermentation process (Caplice and Fitzgerald,1999). LAB enhances the physico-chemical properties of sausages and restricts the growth of some undesirable microorganisms. However, LAB has also been reported as major spoilage microorganisms in meat products. These types of microorganisms may cause slime and sour odour formation in sausages (Bozkurt and Erkmen, 2007). All LAB produce lactic acid from hexose and since they lack functional heme linked electron transport chains and a functional Krebs cycle, they obtain energy via substrate level phosphorylation. The lactic acid produced may be L(+) or, less frequently, D(-) or a mixture of both. LAB are generally mesophilic but can grow at temperatures as low as 5ºC or as high as 45ºC. Similarly, while the majority of strains grow at pH 4.0-4.5, some are active at pH 9.6 and others at pH 3.2. Micrococcaceae species are used to enrich fermentative microorganisms during aging of the fermented meat products in order to enhance the colour stability of the cured-meat and prevent rancidity. The activity of this microbial group prevents the growth of spoiling microorganisms, decreases processing time and contributes to flavor development (Papamanoli et al.,2002). Aroma is another important quality feature of fermented meat products. It is directly affected by the starter cultures. The textural or structural stability in market is also one of the main quality indicators for fermented meat products. It’s important that the product can keep its quality characteristics stable until consumption. Drop in pH, nitrate reduction and prevention of spoilage microorganisms in product are the main effects of LAB and Micrococaceae on the market stability of product. Finally, nitrite decomposition effects of LAB and Micrococaceae are helpful for decreasing the level of chemical residues in the product.
Meat fermentation
Meat fermentation is a fundamental preservation method with natural acidulation, which results in unique and distinctive meat. It changes raw meat into to a fermented meat product by lowering the pH with the help of starter microorganisms. It is biological process influenced by many environmental factors that need to be controlled to produce a consistent product. Some of these factors would include a fresh, low-contaminated, consistent raw material as well inoculum, strict sanitation, control of time, temperature and humidity during production, smoke, and appropriate additives (Ockerman & Basu, 2010). Lactic acid which accounts for the antimicrobial properties of fermented meats originating from the muscle glycogen and added sugar during product fermentation. Natural acidulation caused by lactic acid production and lowering the water activity (aw) due to addition of salt (curing) and drying is a. Both natural and controlled fermentations involve lactic-acid bacteria (LAB). Therefore most commercially available starter cultures consist of lactic acid bacteria and/or micrococci selected for their metabolic activity which often improves flavour development (Arslan et al., 2001). A desirable characteristic of fermented meat product is reduction of pH and lowering of water activity (aw), both are microbial hurdles that aid in producing a safe product.
Types of Fermented Meats
Fermented meats (e.g. beef, pork, chicken) products that have been subjected to the action of specific microorganisms (mainly lactic acid bacteria (LAB) and staphylococci) or tissue enzymes that results in unique and distinctive meat properties such as flavor, palatability, colour, microbiological safety, and tenderness. Generally, fermented meats are further classified into:
(i) Fermented sausages – products made from comminuted meat stuffed into casings, and
(ii) Unground fermented meats – products made from entire meat cuts (i.e. ham).
The microbiological stability and organoleptic properties of fermented meat products are mainly due to fermentation carried out by microorganisms, whereas the characteristic sensory properties of unground meats are due to the action of salt, curing agents and proteolytic muscle enzymes only (Yilmaz and Velioglu, 2009).
Starter cultures
Starter cultures are defined as preparations containing live microorganisms capable of developing desirable metabolic activity in meat. They are used to increase the microbiological safety, to maintain stability by inhibiting the growth of undesirable microorganisms and to improve the sensory characteristics of fermented sausages. Starter cultures are formed by mixing different types of microorganisms, where each one has specific function.
Traditionally, meat fermentation was based on the selective development of the natural microflora of raw materials, sometimes enriched with ‘back-slopping’ (i.e. the use of a fermented meat from the previous batch to inoculate the following batch); such practices resulted in products with heterogeneous quality. Thus, in the mid 1950s, standardized processing and safety assurance measures were enforced, and the commercial use of microbial starter cultures in industrial sausage fermentations was implemented. Suitable starter cultures must be able to grow at fermentation temperatures and to be sufficiently active under low aw conditions (0.93 – 0.96). Starter cultures also must have a good enzyme profile for the generation of the desired products (e.g. lactic acid for acidification, volatile compounds for aroma development, and nitrate reduction for colour development). Now a days, most commercial preparations contain a combination of LAB strains, mainly of Lactobacillus or Pediococcus genus, with coagulase-negative staphylococci and members of Micrococcaceae. The major role of LAB is to metabolise glucose or other carbohydrates through either homo- (e.g. Pediococcus pentosaceus, Pediococcus acidilactici) or hetero-(e.g. L. sakei, L. curvatus, Lactobacillus plantarum) – fermentative pathways and generate lactic acid (Essid and Hassouna, 2013). Acidification rates are highly dependent on the species used as well as on the processing conditions; e.g. strains of L. sakei tend to have faster rates than other lactobacilli and are thus commonly used at lower fermentation temperatures (18-25 °C), whereas strains of P. acidilactici better adapt at higher temperatures (35-40 °C) (Laranjo et al., 2016). Members of the genera Staphylococcus and Kocuria (formerly Micrococcus) are often used as starter cultures because of their ability to reduce nitrate and produce catalase (Mendonc et al., 2013). Specifically, strains of Staphylococcus carnosus, Staphylococcus xylosus and Kocuria varians are commercially available. Addition of sufficiently high levels (106-107/g) of these microrganisms is recommended as their population levels are reduced during fermentation, due to acidification (Wright and Axelsson, 2012). The presence of moulds on the outer surface of sausages is typical in certain types of Mediterranean dry fermented sausages. Strains of Penicillium nalgiovense and Penicillium chrysogenum are used as starter cultures to prevent the growth of other mycotoxin producing moulds and to give the characteristic white coating on the surface.
Microorganisms as starter cultures for Fermented Meat products
| Microorganisms contained in starter cultures | Type of metabolism | Favourable technological action |
| Lactic acid bacteria
Lactobacillus plantarum Lactobacillus sake Lactobacillus pentosus Lactobacillus casei Lactobacillus curvatus Lactobacillus alimentarius Pediococcus acidilacti Pediococcus pentosaceus |
Producing lactic acid | Inhibiting development of undesired bacteria
acceleration of food colors reaction (completion of the curing process) drying process acceleration |
| Gram-positive cocci
Staphylococcus carnosus Staphylococcus xylosus Micrococcus varians |
Nitrates reduction
using up the oxygen Decomposition of peroxides lipolysis |
Curing process completion
curing color stabilization Delaying rancidity flavor and aroma bouquet |
| Yeasts
Debaryomyces hansenii Candida famata |
Using up the oxygen
decomposition of peroxides |
Curing color stabilization
delaying rancidity |
| Moulds
Penicillium nalgiovense Penicillium camambertii/ Candicum |
Using up the oxygen decomposition of peroxides
lactic acid decomposition proteolysis lipolysis |
Flavor and aroma bouquet |
Source: Kołożyn-Krajewska & Dolatowski (2009).
Production of fermented poultry products
Poultry Industry emerges as the most efficient sub-sector in its use of natural resources and in providing protein to supply a global growing demand. Poultry sector play an important role in providing livelihood to for small holders and poor rural and urban population. While most of the sector’s growth has been driven by private investments, public concerns about the sector’s impact on the environment and human health, its contribution to climate change and local and global economy is triggering governments ‘response and the development of public policies. Raw poultry-meat-based production (i.e., salted, dried, smoked, etc,) is fairly recent (20 years old) and, in today’s world market, remains very marginal compared to pork or beef delicatessen meat. This explains the poor indexing of these products. As a matter of fact, traditionally, poultry animals are consumed just after slaughtering. This is due to the family size of the animals, which allowed total consumption of the animal without the need to preserve parts of its carcass. In contrast, other farm animals (pig, cattle), once slaughtered, could not be eaten at once and a large proportion of the carcass needed to be preserved for later use. In this way, people started to salt, dry, and, unknowingly, ferment pork or beef portions. Nevertheless, a narrow range of poultry delicatessen meats have appeared on the market, chiefly cooked products such as cured thigh meat, patties, sausages, and raw products to be cooked, e.g. bacon. More recently, there has been a renewed interest in poultry and poultry products, especially 100% pure poultry products including sausages. This can be explained by several factors. First, the increasing price of red meat and the facility to set up poultry production (compared with cattle or pigs), particularly in developing countries, have played a determining role in the worldwide spread of the poultry industry. Poultry meat also benefits from a healthier image than red meats and, as such, appeals to the ever-increasing healthconscious consumers. Last but not least, poultry and its derived products are not snubbed by any religious or cultural group (Kubberod et al., 2002), contrary to pork and beef. In fact, it is highly appreciated by Muslims, Hindus, and Tamils. Moreover, halal practice is commonly implemented in poultry processing plants in countries where a Muslim community forms a nonegligible part of the population demographics. Demand from these groups for new poultry products has led to the development of poultry bologna, franks, burgers, nuggets, and sausages. In the particular case of fermented poultry products, there is no real tradition of consumption as with red meat. Nevertheless, some raw cured poultry based products have been developed, and a few are even available on the market, such as smoked or dried duck fillet, poultry jerky), and dry sausage with partial or complete poultry meat content. These fermented delicatessen products and, in particular, fermented sausages do not yet have a broad market distribution. This may be explained by problems associated with the raw material characteristics. Indeed, the first development of fermented poultry sausages, dating back to the 1970s, met with two main obstacles.
Fermented Sausages
The drying by salting of a highly valued food, meat, has occurred for many centuries to prevent spoilage. Under favorable conditions, primarily the inclusion of salt and the subsequent addition of sugar to overcome the harshness of the salt, these comminuted products were often found to have a distinctive and enticing aroma, flavor, and “bite.” Sausage terminology is, at best, a confusion of historic, regional, seasonal and supporting nomenclature. Thus, what is known in some parts of the world as a Keilbasa is known elsewhere as Salami (or even Salame). By modern practices Fermented Sausages can be defined as a class of chopped or ground meat products that, as a result of microbial fermentation of a sugar, have reached a pH of 5.3 (although 4.6-5.0 is more typical) and have undergone a drying/aging process to remove 15-25% of the moisture. Fermented sausages often have a long storage life due to added salt, nitrite, and/or nitrate, low pH due to lactic acid production by LAB organisms in the early stages of storage, and later drying which reduces the water activity (aw) (Tjener et al., 2004) These products are typically cured, but not necessarily cooked/smoked. Although the USDA does not formally define a Semi-Dry or Dry sausage, they do regulate the “moisture to protein ratio” (MPR) of each as follows:
Semi-Dry Sausages – (MPR max. range of 2.25-3.7: 1) Undergo a moisture loss of up to 15% of the total. Final water activities (aw) range from 0.90-0.94. These sausages are generally cooked/smoked prior to sale or consumption. These sausages should be refrigerated. Examples: Summer sausage, Thuringer, Cervelat, Landjaegar.
Dry Sausages – (MPR max. range of 1.6-2.3: 1) Undergo a moisture loss of up to 25% of the total. Final aw ranges from 0.85-0.91. Typical pH ranges are 4.7-5.0, slightly higher than Semidries. Many of these products are considered shelf stable due to low aw, and may be sold and consumed without heat treatment. Examples: Pepperoni, Salami(s).
Sausage products must have a water activity reading below 0.85 and a pH under 5.3 to be shelf stable. In light of foodborne outbreaks of E.coli 0157:H7 linked to dry fermented ready-to-eat sausage products, all procedures for dry and semi-dry fermented sausages must be validated to show products achieve a 5-log reduction of E.coli 0157:H7.
Fermented poultry sausage specific characteristics of raw poultry meat and fat in relation to process and quality
The quality of poultry meat and fat, together with those of other meats and fats, are having various advantages likeas poultry meat is generally lower in fat than pork or beef, it is also less fibrous and tenderer. Moreover, its ultimate pH tends to be higher than that of pork and beef, with high activity muscles (thigh and leg) generally showing a higher ultimate pH than low-activity muscles (breast, wing). In addition, poultry meat has on average, lower myoglobin content than beef. This explains the lighter color of poultry compared to beef. Furthermore, color varies with the type of muscle within a carcass: in poultry, thigh meat is darker than breast meat. The composition of poultry fat (abdominal and skin) is significantly different from that of beef and pork fats. First, its water content is higher and fat content lower, with chicken skin showing more marked differences. Like beef and pork fat, chicken abdominal fat is an association of fat cells held in a loose framework of connective tissue. However, it contains more water and less collagen, accounting for its lower protein content and very weak structure. In contrast, chicken skin is composed of cellular layers (superficial epidermal and inner dermal layers) that hold the subcutaneous adipose tissue. Hence its higher protein content and greater level of structure compared to pork or beef fat. Poultry fat also contains less saturated fatty acids and more monounsaturated and polyunsaturated fatty acids than pork or beef fat. This justifies the lower melting point of chicken fat and its semiliquid consistency at ambient temperature (Arnaud et al. 2004). The distinctive features of poultry lean and fat have a direct bearing on formulations, processes, and end product organoleptic quality. Indeed, from a nutritional standpoint, poultry meat is leaner than red meats and thus constitutes an excellent source of high-quality proteins for weight control diets (Mountney and Parkhurst 1995). Furthermore, compared to pork and beef fat, poultry fat contains higher levels of mono- (MUFA) and polyunsaturated (PUFA) fatty acids and lower levels of saturated fatty acids (SFA).
Other fermented products
Although dry sausage is the most common fermented poultry meat, a few other fermented poultry products may also be found. Among these, the French dry-cured magret is probably the most famous. It is made with the breast of Moulard duck, a breed used for foie gras (fattened duck liver). The magret refers specifically to the lobe, or half breast of the Moulard duck, well known for its excellent quality. In particular, the flavor of this processed fillet is related to exogenous and endogenous compounds and their distribution between the fatty panicle and the lean. The dry-cured fillets are commercialized either entire or thinly sliced. Often vacuum-packed, they keep for 2 months under refrigeration. Dry magret makes a great appetizer. It may be served with fruit slices (pear, melon, or fig depending on the season) as part of an antipasto platter, or sliced thinly on top of a green salad. Other dried and cured duck meats that are encountered may be classified as fermented products. It is the case of NAN-AN, a traditional dried duck meat (more than 100 years old) from China (Jiangxi province) processed from Big Gunny ducks. The process mainly includes cutting of the carcass into five pieces, salting in brine and sun drying. Prosciutto is originally a traditional Italian cured pork meat which is cured and further matured by air drying. However, it can also be made with magret, Moulard duck breast (Smith 2005). In the particular case of Moulard magret prosciutto, a mixture of salt and spices (juniper berries, bay leaf, coriander, peppercorns, and garlic) is used for curing under refrigeration (4°C) for 24 hours. Without rinsing, the magret is then hung in a dry chamber at 10°C for 2 weeks. For many years, jerky and biltong meats have been favorite snack foods for Americans and southern Africans, respectively. They are produced by using a combination of curing, drying, and sometimes smoking procedures. People generally associate jerky and biltong with beef. However, the meat sources are unlimited and it is not uncommon to use meat from turkey, ostrich, and emu.
Factor affecting the quality of fermented poultry products
There are numerous factors that influence fermented meat products. They may be grouped as follows:
- Internal factors: Types of microorganisms comprising the starter culture, the recipe, quality of components and additives, salt content, saccharides content, and meat size reduction degree
- External factors: Temperature, relative air humidity, smoke and oxygen availability
- Quality factors: acidity degree, water activity, redox potential and mass decrement.
The fermentation process is more complex than most other processes in meat technology. The fermentation, the energy-producing metabolism in microorganisms, although taking place inside the microbial cell, is not an isolated procedure, but is closely related to intrinsic and extrinsic factors and their interactions in the fermented products. There is no decisive factor ruling the fermentation/ripening (unlike in cooked products where cooking stabilizes the gel and destroys most microorganisms in a very consistent way). The natural laws provide the limits of the activities, and each individual aspect will follow these. The complexity is, however, a result of so many independent and dependent factors functioning at the same time. The main influencing factors are intrinsic, and only little can be done after the preparation of the fermented product, except extrinsically varying the temperature-humidity-air velocity programming and smoking. Individual, and more or less interrelated, factors such as meat enzymes, the dynamic microbial flora, salt, nitrate/nitrite, temperature, drying, carbohydrates, smoke, etc., have an influence on the fermentation/ripening. The process is characterized by lactate production resulting in a decrease in pH, an increase in salt content, nitrate/nitrite reduction, and changes in color, firmness, taste, aroma, weight loss, etc. The process can be controlled by careful selection of various ingredients, including meat raw materials, with special attention paid to their natural microbial flora, sugar, food additives, and spices. Reliable control of the atmosphere and air circulation, as well as temperature in the ripening chamber, suitable casings, and smoking conditions are necessary for successful and safe production. These aspects are exceptionally difficult to control theoretically, but long experience makes possible the fine-tuning of the process for good results. Finally, the utilization of bacterial pure cultures and surface yeasts and molds provides the final technological security and also safety concerning health hazards. There will, always remain large uncontrolled areas. A large part of the process remains more or less uncontrolled, but the processors try to keep the uncontrolled part as small as possible. Starter cultures are not used only for safety reasons, but they also provide significantly added value. The process is accelerated compared to the case where only natural (accidental) flora is responsible for fermentation. Starter cultures create faster fermentation and nitrate/nitrite reduction, and usually better aroma and color will be the result. For successful fermentation, suitable raw materials should be selected, especially microbial flora and pH (no meat with high pH). Sugar content (natural carbohydrates and added glucose with derivates) and other nutrients, like amino acids, fatty acids, minerals, vitamins, etc., create the driving forces that cause the fermentation. Starter cultures (and natural flora) and meat enzymes start the fermentation, the rate of which is controlled by external factors such as temperature and, to a lesser extent, by humidity, air circulation, and smoking.
Conclusion
The fermented meat and poultry products have a intense potential in the development of novel meat products with improved nutritive value, keeping quality, sensory attributes, and functionality intact. The demand for fermented meat and meat products has been increasing rapidly over the past few decades and the meat industry is looking for functional starter cultures with improved sensory attributes, nutritional quality, and health and microbial safety of meat products. Product quality and safety is probably the most important aspect of making fermented meat and poultry because it addresses the question of consumer acceptance and public health safety.
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