Natural additives and their extracts have the ability to protect fresh meat from protein and lipid oxidation. They have antibacterial activities and can extend the shelf life of meat products. In fact, in response to the increasing consumers’ mistrust in synthetic additives, the meat industry is focused on searching sources of natural antioxidants, which is expected to dominate the market through 2025.
Food additives are broadly categorized as acidulents, acidity regulator, antioxidants, antifoaming & foaming agents, emulsifiers, flavor enhancers, color retention agents, stabilizer, and sweeteners. However, a growing demand for convenience and organic food in North America and Europe is increasing consumer inclination towards natural food ingredients such as natural flavoring agents, organic preservatives, natural coloring, and stevia-based sweeteners. Of all of these, organic preservatives and antioxidants are the ones that are experiencing more growing in the food market.
Fresh sausage is one of the most popular meat products all over the world that are cheap, delicious, easily prepared and can solve the problems of shortage in fresh meat. On the other hand, they are mostly processed from meat trimmings which are relatively cheap as a raw material and are basically characterized by a high fat content and connective tissue with low functionality. Therefore, sausage manufacture is considered a mean of adding value to these low value cuts and increasing the utilization of carcass meat.
There are more than 250 type of sausage sold around the world, which are named after the country of origin. Fresh sausages are coarsely comminuted, not heat treated products that are sold as uncooked, fresh (chilled) or frozen. It is composed of a mixture of meat, fat and spices stuffed into natural casing of animal small intestine. The lean portion can be made from edible red meat, poultry or both of them, while the fat portion is made from animal fat tissue to give a distinctive marbling appearance to the product.
Fat is one of the most important raw materials in sausage products, as it represents a large percentage of sausage composition which may reach up to 30% and is important in the processing, textural, juiciness and sensory criteria of sausage products. The high lipid contents of fresh sausage make the product more susceptible to lipid oxidation with subsequent changes in the organoleptic characteristics of the product.
Lipid oxidation, protein degradation, the rise of the pH and reproduction of bacteria are some of the main causes of food degradation. Let´s take a view on them.
Lipid oxidation. It consist in the oxidative deterioration of the polyunsaturated lipids of food, leads to formation of hydroperoxides and short-chain aldehydes, ketones, and other oxidized compounds, which are considered to be responsible for causing flavor, texture, color and nutritional deterioration of meat and meat products. Several adverse health effects, due to the presence of free reactive oxygen species (ROS), such as superoxide radical, hydroxyl radical, peroxyl radical, during lipid oxidation, have been reported.
Moreover, lipid oxidation is known to promote the occurrence of protein degradation, resulting in loss of essential amino acids and detrimental effects on meat quality. It is well known that the addition of antioxidants could effectively delay lipid oxidation of meat products.
Synthetic antioxidants as butylated hydroxytoluene (BHT) and butylated hydro-xyanisole (BHA) are commonly used to retard lipid oxidation during the industrial production of meat products, are thus consumed in appreciable quantities by humans; however, use of such compounds has been related to health risks in some animals resulting in strict regulations over their use in foods.
For example, BHA has been shown to cause lesion formation in the rat forestomach. Moreover, several studies have shown that BHT may cause internal and external haemorrhaging at high doses that is severe enough to cause death in some strains of mice and guinea pig. Accordingly, there is a strong argument for the effective isolation of organic anti-oxidants from natural sources as alternatives to prevent deterioration of foods.
As a result, natural antioxidants have been used instead of synthetic antioxidants and have been reported to be an effective method of controlling and retarding lipid oxidation. For example, a mixture of garlic, cinnamon, cloves and rosemary essential oils and a Rosa canina L. extract, were compared with a commercial antioxidant additive (Artinox®) for their ability to control protein and lipid oxidation in cooked hams after a settling period of 30 days and at the end of a chilled storage (150 days). The mixture of essential oils was the most effective against lipid oxidation while R. canina L. extracts were the most effective in controlling protein carbonylation at day 150.
Regard natural antioxidants, they are primarily plant phenolic that may occur in all parts of plants, such as fruits, nuts, seeds, leaves, roots and barks.
In the recent years many studies have been evaluating these natural substances as antioxidative additives in meat products leading to the development of novel food products and their effectiveness in extending shelf-life of the products has been widely documented.
From these natural additives green tea, clove and garlic have gained more interest from the public and scientific point of view due to their health promoting properties.
Green tea, clove and their extracts as well as fresh garlic and garlic powder have been used extensively as antioxidants in meat, however, their use during processing of fresh sausage still limited.
On the other hand, meat processors are concerned about the quality characteristics of processed products during storage, and the latest studies about the use of natural preservatives in food may encourage meat processors to use these natural antioxidants during processing of fresh sausages for production of high quality products.
Which are the activities that natural additives develop regard to food preservation?
pH. Maintain lower pH during storage. An increase in pH is attributed to an increase in the counts of psychrotrophic microorganisms during storage, which produce protease. Once protease production is started, the bacteria use amino acids as growth substrate instead of using glucose. The consumption of amino acids leads to elevation of pH due to the formation of ammonia and amines.
Protein degradation. The effectiveness of natural additives and their extracts on protein degradation may be attributed to the phenolic compounds offered by these plants. The antioxidant activities of plant phenolics against protein degradation have previously been described in meat and meat products. It has been reported that phenolic compounds can inhibit protein degradation by chelating metal ions, scavenging free radicals, blocking lipid oxidation and combining with proteins to prevent protein carbonylation.
Antioxidant activity. The antioxidant activity of natural additives have been attributed to their phenolic compounds which act by terminating the free radical chain reaction by donating hydrogen or electrons to free radicals and converting them to more stable products.The lower antioxidant activities of green tea extract or clove extract when compared with those of green tea powder or clove powder have been explained by the losses of volatile sulfur compounds during boiling or steam distillation. It has been recorded that garlic oil or steam-distilled garlic did not contain large amount of allicin, but contain various products of allicin transformation, none of which appears to have much biologic activity as either fresh garlic or garlic powder.
Now that you know, you can take action and consume accordingly, taking into account their characteristics and selecting from them the ones that fit you better.
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