Problem statement: Extremely perishable meat provides favorable growth condition for various microorganisms. Meat is also very much susceptible to spoilage due to chemical and enzymatic activities. The breakdown of fat, protein and carbohydrates of meat results in the development of off-odors, off-flavor and slim formation which make the meat objectionable for human consumption. It is, therefore, necessary to control meat spoilage in order to increase its shelf life and maintain its nutritional value, texture and flavor. Approach: A comprehensive literature review was performed on the spoliage mechanisms of meat and meat products and preservation techniques. Results: Historical data reveals that salting, drying, smoking, fermentation and canning were the traditional methods used to prevent meat spoilage and extend its shelf life. However, in order to prevent wholesomeness, appearance, composition, tenderness, flavor, juiciness and nutritive value, new methods were developed. These included: cooling, freezing and chemical preservation. Wide range of physical and chemical reactions and actions of microorganisms or enzymes are responsible for the meat spoilage. Microbial growth, oxidation and enzymatic autolysis are three basic mechanisms responsible for spoilage of meat. Microbial growth and metabolism depends on various factors including: pre-slaughter husbandry practices, age of the animal at the time of slaughtering, handling during slaughtering, evisceration and processing, temperature controls during slaughtering, processing and distribution, preservation methods, type of packaging and handling and storage by consumer. Microbial spoilage causes pH change, slime formation, structural components degradation, off odors and appearance change. Autoxidation of lipids and the production of free radicals are natural processes which affect fatty acids and lead to oxidative deterioration of meat and off-flavour development. Lipid hydrolysis can take place enzymatically or non-enzymatically in meat. In muscle cells of slaughtered animals, enzymatic actions are taken place naturally and they act as catalysts for chemical reactions that finally end up in meat self deterioration. Softening and greenish discoloration of the meat results due to tissues degradation of the complex compounds (carbohydrates, fats and protein) in the autolysis process. Conclusion: Microbial, chemical and enzymatic activities can be controlled by low temperature storage and chemical techniques in the industry. Proper handling, pretreatment and preservation techniques can improve the quality of meat and meat products and increase their shelf life. Combination of chemical additives (TBHQ and ascorbic acid) and low temperature storage (5°C) in darkness are well recognized techniques for controlling the spoilage (microbial, enzymatic and oxidative) of meat and meat products. Understanding of the intrinsic factors and extrinsic factors at every meat processing stage (from preslaughtering to meat product development) is necessary before developing proper handling, pretreatment and preservation techniques for meat.

/pdf/meat-spoilage-mechanisms-and-preservation-techniques-a-2l1peh6rt5.pdf

Meat Spoilage Mechanisms and Preservation Techniques: A Critical Review

Considerable research has been done to better understand the basis for gel formation by myofibrillar proteins (MPs) in effort to manufacture acceptable processed meats with lower cost and more desirable nutritional characteristics. Results from research available indicate that there is no substitute for the myofibrillar protein myosin in gel formation by proteins from a wide variety of animal and fish species. This report consolidates information on determinants of protein gel formation, examining types of muscles and fibers, the species influence, and interactions of the MPs actin and myosin with each other and with fat, gelatin, starch, hydrocolloids, some protein soy, whey, and nonprotein additives such as phosphates and acidifiers, and the influences of pH, ionic strength, rates of heating, and its absence, protein oxidation, as well as the use of transglutaminase and high hydrostatic pressure. It is of interest that myosin alone will form acceptable gels. Gel formation by MPs is optimized at pH 6, an ionic strength of 0.6 M, and at 60 to 70 °C. The observations that collagen-derived gelatin can reduce the rubbery texture of low-fat products and that solubilization of MPs is not always essential for gel formation, and the observation that good gels can be formed in the absence of salt, are exciting developments that should be considered as pressure mounts to continue to reduce fat and salt in the diet.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1541-4337.2010.00137.x

Factors Influencing Gel Formation by Myofibrillar Proteins in Muscle Foods

During the last two decades, a number of methods have been developed to objectively measure meat quality attributes. Hyperspectral imaging technique as one of these methods has been regarded as a smart and promising analytical tool for analyses conducted in research and industries. Recently there has been a renewed interest in using hyperspectral imaging in quality evaluation of different food products. The main inducement for developing the hyperspectral imaging system is to integrate both spectroscopy and imaging techniques in one system to make direct identification of different components and their spatial distribution in the tested product. By combining spatial and spectral details together, hyperspectral imaging has proved to be a promising technology for objective meat quality evaluation. The literature presented in this paper clearly reveals that hyperspectral imaging approaches have a huge potential for gaining rapid information about the chemical structure and related physical properties of all types of meat. In addition to its ability for effectively quantifying and characterizing quality attributes of some important visual features of meat such as color, quality grade, marbling, maturity, and texture, it is able to measure multiple chemical constituents simultaneously without monotonous sample preparation. Although this technology has not yet been sufficiently exploited in meat process and quality assessment, its potential is promising. Developing a quality evaluation system based on hyperspectral imaging technology to assess the meat quality parameters and to ensure its authentication would bring economical benefits to the meat industry by increasing consumer confidence in the quality of the meat products. This paper provides a detailed overview of the recently developed approaches and latest research efforts exerted in hyperspectral imaging technology developed for evaluating the quality of different meat products and the possibility of its widespread deployment.

Meat Quality Evaluation by Hyperspectral Imaging Technique: An Overview

Colour calibration of a laboratory computer vision system for quality evaluation of pre-sliced hams.

Various types of functional ingredients in the forms of inorganic salts (i.e. sodium chloride, phosphates, bicarbonate) and organic compounds mainly from plant and animal origins have been introduced to meet wide sensory and technological requirements of processed meat producers and consumers. This review deals with functional ingredients that are commonly used in processed poultry meat products, their mechanisms of action, scope of applications and current market trends. Functional ingredients could be effectively used by adopting integrated approaches which manage the use of these ingredients in way allow to produce cleaner label, accepted products and at the same time optimize the cost formulations.

/pdf/functional-ingredients-for-poultry-meat-products-16ke993s9p.pdf

Functional ingredients for poultry meat products

Part 1 Meat composition and additives: The protein and fat content of meat The biochemistry of meat The tenderness of fresh meat Definitions of terms used in meat science and technology and meat conductivity Additives: phosphates, salt-sodium chloride, hydrocolloids, salts of organic acids and lactate Additives: proteins, carbohydrates, fillers and other additives Colour in fresh meat and cured meat products. Part 2 Technologies for particular meat products: Cooked ham: whole muscle, brine-injected products Typical whole muscle, brine-injected cooked ham products from around the world Cooked ham: non-injection methods for adding brine Typical cooked ham products from around the world using non-injection methods for adding brine Cooked sausages Typical cooked sausage products from around the world Fresh sausages Typical fresh sausage products from around the world Raw fermented salami Typical raw fermented salami products from around the world Semi and fully-cooked fermented salami Non-fermented salami Typical non-fermented salami products from around the world Spreadable raw fermented sausage Typical raw fermented sausage products from around the world Cured air-dried meat products Typical cured air-dried meat products from around the world Spreadable liver sausage and liver-pate Typical liver sausage and liver-pi? ti? products made around the world Burger, patties and crumbed products Typical patty and nugget products from around the world Sliceable and non-sliceable blood sausage Typical blood sausage products from around the world Brawn and meat jelly Typical brawn and meat products from around the world Canned retorted corned beef Moisture-enhanced (case-ready) and marinated meat Casings and packaging material. Part 3 Quality and safety issues: Sensory evaluation of meat products HACCP in meat processing companies Introduction to the microbiology of meat and meat products The microbiology of specific bacteria Predictive microbiology for meat products.

Gerhard Feiner

Papers

Meat Products Handbook: Practical Science and Technology