Protein Oxidation in Muscle Foods: A Comprehensive Review

Muscle foods and their products are a fundamental part of the human diet. The high protein content found in muscle foods, as well as the high content of essential amino acids, provides an appropriate composition to complete the nutritional requirements of humans. However, due to their special composition, they are susceptible to oxidative degradation. In this sense, proteins are highly susceptible to oxidative reactions. However, in contrast to lipid oxidation, which has been studied in depth for decades, protein oxidation of muscle foods has been investigated much less. Moreover, these reactions have an important influence on the quality of muscle foods, from physico-chemical, techno-functional, and nutritional perspectives. In this regard, the loss of essential nutrients, the impairment of texture, water-holding capacity, color and flavor, and the formation of toxic substances are some of the direct consequences of protein oxidation. The loss of quality for muscle foods results in consumer rejection and substantial levels of economic losses, and thus the control of oxidative processes is of vital importance for the food industry. Nonetheless, the complexity of the reactions involved in protein oxidation and the many different factors that influence these reactions make the mechanisms of protein oxidation difficult to fully understand. Therefore, the present manuscript reviews the fundamental mechanisms of protein oxidation, the most important oxidative reactions, the main factors that influence protein oxidation, and the currently available analytical methods to quantify compounds derived from protein oxidation reactions. Finally, the main effects of protein oxidation on the quality of muscle foods, both from physico-chemical and nutritional points of view, are also discussed.

Preservation of meat products with natural antioxidants from rosemary

Oxidative reactions can reduce the quality of meat products. Synthetic antioxidants can delay the formation of oxidation products but their use in muscle foods has been reconsidered among modern consumers willing to purchase clean label products. Rosemary is a relevant source of antioxidants that can be explored as natural additive in muscle foods. This review aims to provide an overview of the protective effect of rosemary active against the oxidative decay in meat products. The use of rosemary essential oil or extract can slow the progression of oxidative reactions and preserve redness, reduce the accumulation of primary and secondary lipid oxidation and protein oxidation products, and slow the increase of perceived rancidity in sensory analysis. These effects were reported during the storage of patties, burgers, meatballs, sausages, and nuggets. In this sense, rosemary extracts and essential oil can be explored as natural antioxidant in meat products.

Can Tumbling without Brine Improve Tenderness and Proteolysis of Beef Loin Muscles?

Tumbling of intact muscle foods has been widely applied toprocessed meats using brine solution. However, the use of tumbling withoutbrine on fresh beef muscles has not been fully examined. Therefore, this studyaimed to evaluate fresh beef tumbling on meat quality and proteolytic featuresof loin (longissimus lumborum)muscles. Moreover, interactions with the duration of postmortem aging wereinvestigated. Loins (n=9) at 7d postmortem were sectioned and allocated among twotumbling (T) treatment groups at 60 (T60) or 90 (T90) minutes, as well as a non-tumbledcontrol (T0) group. After treatment, sub-sections were made and divided among0d, 7d, or 14d of further aging. Meat quality was assessed by shear forcevalues, water-holding ability, and color attributes. The extent of proteolysiswas determined by quantification of desmin and troponin-T, myofibrilfragmentation index (MFI), and transmission electron microscopy. An interactionbetween fresh beef tumbling and aging duration was observed in shear forcevalues (P=0.032). At 0d, muscles fromT90 exhibited lower shear force (21.6 N) compared to T0 (34.8 N) and T60 (24.7N) groups. Muscles from T60 and T90 groups maintained lower shear force than T0controls at each respective aging duration.Higher cooking loss (P=0.011) but notpurge loss (P=0.412) was observed in theT60 and T90 groups compared to T0. Shear force results were supported by higherMFI in T60 and T90 groups than T0 controls (P<0.001), as well as the disappearance of intact troponin-T withfurther aging (P=0.009). Transmissionelectron microscopy supported increased initial tenderness would owe primarily tophysical disruptions to myofibrillar structure, though fresh beef tumbling may facilitateproteolysis with further aging.

Beta vulgaris as a Natural Nitrate Source for Meat Products: A Review

Curing meat products is an ancient strategy to preserve muscle foods for long periods. Nowadays, cured meat products are widely produced using nitrate and nitrite salts. However, the growing of the clean-label movement has been pushing to replace synthetic nitrate/nitrite salts (indicated as E-numbers in food labels) with natural ingredients in the formulation of processed foods. Although no ideal synthetic nitrate/nitrite replacements have yet been found, it is known that certain vegetables contain relevant amounts of nitrate. Beta vulgaris varieties (Swiss chard/chard, beetroot, and spinach beet, for instance) are widely produced for human consumption and have relevant amounts of nitrate that could be explored as a natural ingredient in cured meat product processing. Thus, this paper provides an overview of the main nitrate sources among Beta vulgaris varieties and the strategic use of their liquid and powder extracts in the production of cured meat products.

A Comprehensive Review of Nutritional Benefits of Minerals in Meat and Meat Products

Minerals are chemical elements that organisms require as a necessary nutrient to sustain good health at various stages of life. To support human biochemical processes, including structural and functional activity in the body, at least twenty mineral elements are required. However, inadequate consumption of these essential minerals in the human diet can result in metabolic problems, organ damage, chronic diseases, and death. Mineral deficiency affects roughly two billion people globally, the bulk of whom live in third-world nations. Among those, infants and pregnant women are more susceptible to the mineral shortage in the body. To avoid these deficiencies, humans need to consume muscle foods, which are superior sources of essential minerals, particularly zinc, selenium, phosphorus, iron, etc. compared to plant-based foods. Minerals derived from muscle foods are easier to absorb in the body than minerals derived from plant foods. However, the amount of essential minerals in muscle foods varies widely and depends on several factors, including nutrition, species, breed, sex, age at slaughter, muscle types, physiological status, production system, and post-mortem factors such as processing and analytical methods. The present study discusses the mineral composition of different muscle foods, factors affecting the mineral contents in different muscle foods and the beneficial and important roles that minerals play in human health.

Edible Mushrooms as Functional Ingredients for Development of Healthier and More Sustainable Muscle Foods: A Flexitarian Approach

Consumers are increasingly interested in nutritious, safe and healthy muscle food products with reduced salt and fat that benefit their well-being. Hence, food processors are constantly in search of natural bioactive ingredients that offer health benefits beyond their nutritive values without affecting the quality of the products. Mushrooms are considered as next-generation healthy food components. Owing to their low content of fat, high-quality proteins, dietary fibre and the presence of nutraceuticals, they are ideally preferred in formulation of low-caloric functional foods. There is a growing trend to fortify muscle food with edible mushrooms to harness their goodness in terms of nutritive, bioactive and therapeutic values. The incorporation of mushrooms in muscle foods assumes significance, as it is favourably accepted by consumers because of its fibrous structure that mimics the texture with meat analogues offering unique taste and umami flavour. This review outlines the current knowledge in the literature about the nutritional richness, functional bioactive compounds and medicinal values of mushrooms offering various health benefits. Furthermore, the effects of functional ingredients of mushrooms in improving the quality and sensory attributes of nutritionally superior and next-generation healthier muscle food products are also highlighted in this paper.

Application of Pomegranate by-Products in Muscle Foods: Oxidative Indices, Colour Stability, Shelf Life and Health Benefits

In recent years, considerable importance is given to the use of agrifood wastes as they contain several groups of substances that are useful for development of functional foods. As muscle foods are prone to lipid and protein oxidation and perishable in nature, the industry is in constant search of synthetic free additives that help in retarding the oxidation process, leading to the development of healthier and shelf stable products. The by-products or residues of pomegranate fruit (seeds, pomace, and peel) are reported to contain bioactive compounds, including phenolic and polyphenolic compounds, dietary fibre, complex polysaccharides, minerals, vitamins, etc. Such compounds extracted from the by-products of pomegranate can be used as functional ingredients or food additives to harness the antioxidant, antimicrobial potential, or as substitutes for fat, and protein in various muscle food products. Besides, these natural additives are reported to improve the quality, safety, and extend the shelf life of different types of food products, including meat and fish. Although studies on application of pomegranate by-products on various foods are available, their effect on the physicochemical, oxidative changes, microbial, colour stabilizing, sensory acceptability, and shelf life of muscle foods are not comprehensively discussed previously. In this review, we vividly discuss these issues, and highlight the benefits of pomegranate by-products and their phenolic composition on human health.

Emerging Techniques for Differentiation of Fresh and Frozen–Thawed Seafoods: Highlighting the Potential of Spectroscopic Techniques

Fish and other seafood products have a limited shelf life due to favorable conditions for microbial growth and enzymatic alterations. Various preservation and/or processing methods have been developed for shelf-life extension and for maintaining the quality of such highly perishable products. Freezing and frozen storage are among the most commonly applied techniques for this purpose. However, frozen–thawed fish or meat are less preferred by consumers; thus, labeling thawed products as fresh is considered a fraudulent practice. To detect this kind of fraud, several techniques and approaches (e.g., enzymatic, histological) have been commonly employed. While these methods have proven successful, they are not without limitations. In recent years, different emerging methods have been investigated to be used in place of other traditional detection methods of thawed products. In this context, spectroscopic techniques have received considerable attention due to their potential as being rapid and non-destructive analytical tools. This review paper aims to summarize studies that investigated the potential of emerging techniques, particularly those based on spectroscopy in combination with chemometric tools, to detect frozen–thawed muscle foods.