What is Mechanically Recovered Chicken? A Complete Guide

Mechanically separated meat (MSM) is used a lot in the food industry, but not many studies have been done on how people eat it. The objective of this study was to identify the frequency and amount of MSM consumption, factors associated with MSM consumption, nutrient intake and preferential choice of food groups among MSM consumers. This was an observational, cross-sectional prospective study based on a probability sample of manufacturing workers, conducted in Brazil. Logistic and linear multiple regression with robust standard errors were used. 921 workers from 33 manufacturing companies were studied, with an average age of 38. 2 ± 10. 7 years, 55. 9% males. MSM products are consumed by 28. 8% and represent in average 10% of total daily caloric intake, and 47. 3% of the daily kcal from ultra-processed products. Younger age and greater waist circumference are associated with MSM consumption. Younger age and lesser educational level are associated with increased contribution of MSM to total daily kcal intake. MSM consumers have greater consumption of energy, fats, carbohydrates and sodium. Their dietary patterns are characterized by lower consumption of in natura and minimally processed foods, such as tubers and roots, fruits, white and red meat, and eggs and greater consumption of ultra-processed foods and beverages.

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Mechanically separated meat (MSM) is a raw, paste-like material, obtained by mechanical separation of soft tissue residues from bones, which remain after cutting and puncture of carcasses of poultry, mutton, pork and bovine origin. MSM is used as an ingredient in a variety of meat products and may have a significant impact on their quality, as well as on consumer satisfaction and safety1. Due to its low cost, MSM is widely used in the food industry2 and is commonly used in meat processing around the world, mainly in cooked or roasted meat products, canned meat, homogenized sausages, frankfurters, bologna, nuggets, patties and many other ready-to-eat ultra-processed food products3,4.

Identifying and differentiating MSM from fresh meats, minced meats and meat preparations is important because they are food products with different characteristics, properties and processing levels. For the European Commission, MSM is “the product obtained by removing meat from fleshy bones after deboning or from poultry carcasses, using means that result in the loss or modification of the structure of the muscle fiber”5. In the United States, mechanically separated meat is a paste-like and batter-like meat product produced by forcing bones with attached edible meat under high pressure through a sieve or similar device to separate the bone from the edible meat tissue. Due to FSIS (Food Safety and Inspection Service) regulations enacted in 2004 to protect consumers against Bovine Spongiform Encephalopathy, mechanically separated beef was considered inedible and was prohibited for use as human food6. In Brazil, MSM is defined as meat obtained by a mechanical grinding and separation process of bones from butchered animals (poultry, bovine and pork), intended for the production of specific meat products. Plus, you can only use animal bones, carcasses, or parts of carcasses that have been approved by the Federal Inspection Service to be safe for humans to eat7. Some parts about keeping things fresh when they’re frozen, physical and chemical criteria (like the amount of protein, fat, calcium, and bone diameter), and microbiological criteria were added to this set of rules in 20208. According to this regulation, in Brazil, MSM must have at least 12% protein and a maximum of 30% fat and 1. 5% calcium content (dry basis).

In the production of MSM, after the primal meat cuts are extracted, the remaining traces of meat are removed to obtain as much meat as possible. When mechanical methods are used for separating the meat from bones, the carcasses are forced, under high pressure, through a sieve that separates bone fragments from the meat tissue and some bone particles inevitably pass into the final product9. Getting this raw material in the right way is very important for both its quality and its usefulness in processing10 Two mechanical methods of boning processing are recognized, high pressure or low pressure. High pressure MSM, the most frequently used type, is characterized by a greater degree of destruction of muscle fibers, which makes it more perishable, of poorer technological quality and less stability compared to manually boned meat, i. e. in the traditional way11,12.

Being a cheaper product than hand-boned meat, the noticeable increase over time in the manufacturing and marketing of this type of food product is readily understandable. Consumer tastes have been changing, from a preference for whole animal carcasses to cut parts and processed products, mainly chicken meat (which has the largest share in the meat production industry). This has led to an increase in the availability of bones and poultry trimmings that remain after the larger muscles (breasts and thighs) are separated. These parts still contain portions of muscle tissue, most of which can be recovered through the production of MSM10,13,14,15. Thus, MSM emerged in the food industry as an alternative to the disposal of those materials and an opportunity to use them for the production of by-products, resulting in semi-finished or ready-made products with good commercial properties, long shelf life and an acceptable price16.

However, the composition of these reconstituted meat products using mechanical deboning include a high fat content, propensity to lipid oxidation and a series of spices and additives used in the food industry with the intention of stabilizing and increasing the shelf life of these products that have a non-standard composition and who are prone to microbiological risks13,17,18. It is known that during meat processing, more meat and animal fat are added along with a wide range of non-meat substances and additives, leading to more complex products. Although the differences between types of meat (red, white, different cuts, processed meats, etc.) may not be clear to many consumers, the differential benefits and risks of developing chronic diseases due to its consumption are significant18. In the processing, there is extreme mechanical stress, extraction of a high proportion of fat and heme components (hemoglobin and myoglobin) from the bone marrow, resulting in a pasty consistency and conditions that may lead to lipid oxidation problems and color instability of the final product13. In addition, the bones used for the production of MSM may contain a high number of microorganisms3,19,20. Thus, several methods are used to stabilize these food products, among them is sodium nitrite which is used in industrial practice for the curing process, which plays a role in color formation and also contributes to the flavor of products containing MSM21.

This food transformation process aims to stabilize food products as safe and suitable for consumption, extend the shelf life, enhance less attractive and/or less sought after-cuts, diversify the market offer, and propose products that are easy to cook and store, tasty, or even ready-to-eat foods22. Thus, the production of MSM made it possible to use considerable quantities of parts that have lower commercial value (bones, carcasses…), transforming them into products with greater added value and high sales potential, attractive prices in relation to other types of meat, and lower processing costs23. All these characteristics have been driving its growth and increased sales throughout the world, represented by numerous types of products and brands, such as the sausages and frankfurters that are the preference of MSM consumers as seen in this study, used in preparations as hot dogs, hamburgers, feijoada, industrialized pâtés, mortadella, nuggets, regional corn-based foods, frozen ready meals, among others, which are widely sold in retail chains in Brazil.

In recent years, research related to the consumption of ultra-processed foods in general has been explored in the literature, but little has been studied specifically about MSM. Existing studies have focused on microbiological aspects, methods of identification, technological applications, and rarely if ever have highlighted their nutritional aspects and characteristics related to their food consumption by the population. Therefore, the aim of the present study was to quantify the frequency and amount of MSM consumption, to identify indicators and determinants of MSM consumption, the association between MSM consumption and nutrient intake, and the relationship with food groups and food classes according to the level of processing. The focus of our research is on manufacturing workers, who are an important segment of the population, in most countries representing more than 10% of the working force and accounting for more than 10% of the Gross National Product24, in whom nutrition directly influences their health and productivity, but who may be in a position of vulnerability to potential lack of access to healthy food in the workplace, as studies have shown25.

Study design and population

This was an observational, cross-sectional study based on a representative, probability sample of manufacturing workers in the state of Rio Grande do Norte, Brazil. The sampling plan consisted of a combined stratified proportional and two-stage survey. The strata were company size, with three levels (small, less than 50 workers; medium, 50 to 500 workers; and large, more than 500 workers), and sector of activity, also with three levels (food and beverages, non-metallic minerals, and textiles) corresponding to the industries with greater representation in the state.

For the first sampling stage, manufacturing companies were selected in each combination of strata levels, in a number proportional to the total number of companies in the state in that combination of strata, by simple random sampling from a sampling grid provided by the federation of state industries (FIERN). In the second sampling stage, a fixed number of workers from each company recruited in the first stage was selected by simple random sampling, using a computer random number generator, from listings of workers provided by the human resources departments of each company.

All companies in the state from the three mentioned sectors of activity that agreed in written to participate in the research were eligible for the study. The inclusion criteria for workers were: over 18 years old with an effective employment relationship with the company. Pregnant women, temporary employees, interns and employees on probationary periods were excluded from the research.

The research was approved by the Research Ethics Committee of the Hospital Universitário Onofre Lopes (authorization number 2.198.545/2017) and carried out in accordance with the Declaration of Helsinki. All participants gave informed consent in writing.

In the preparation of the field survey, each visit of the research team was scheduled with each company to occur between Tuesdays and Saturdays. The workers that were previously selected were approached during lunch time and invited to participate in the research. After signing the informed consent form, biodemographic data (age, sex, marital status, education, income, participation in in-house training programs) were recorded and food consumption was assessed using the 24 h dietary recall method (24HR). For the application of the 24HR, the interviewers used the Multiple Pass Methods—MPM, which helps the interviewee to remember the foods consumed the day before the interview and, therefore, minimizes errors in food consumption measurements. This Method is divided into stages, which include a list of the foods consumed, time and place of the meal, detailed description of the quantities of the food (in household measurements), preparation and cooking methods, among other aspects26.

Body mass index (BMI), defined by weight in kg divided by squared height in meters, was measured with a digital scale (Inner Scan, Tanita Corp., Tokyo, Japan) and a body height meter (Sanny, São Bernardo do Campo, SP, Brazil). Waist circumference (WC), measured at the midpoint between the lower edge of the last rib and the iliac crest, was measured with a tape meter (Cescorf, Ltda, Porto Alegre, RS, Brazil). The measurements were performed according to the guidelines of the Brazilian Alimentary and Nutritional Surveillance System (SISVAN)27.

The infamous Mechanically separated meat

FAQ

Is it safe to eat mechanically separated chicken?

Mechanically separated poultry still has calcium content and bone size limits, but no longer any limits on fat and protein levels. It is now considered safe to use without restriction on proportion, but still needs to be labeled clearly. The rule took effect in 1996.

Does McDonald’s still use mechanically separated chicken?

McDonald’s chicken nuggets do not use mechanically separated chicken. In fact, they have ground up breast meat from breasts that have been bruised (because most people don’t buy bruised breasts because they don’t look as good).

Are there bones in mechanically separated chicken?

(a) “Mechanically Separated (Kind of Poultry)” is any product resulting from the mechanical separation and removal of most of the bone from attached skeletal muscle and other tissue of poultry carcasses and parts of carcasses that has a paste-like form and consistency, that may or may not contain skin with attached fat .

Why do ingredients say mechanically separated chicken?

When machines are used to take out every edible part of a chicken carcass, the result is mechanically separated chicken.