The quality attributes of meat products deteriorate due to the lipid oxidation during processing and storage. Lipid oxidation is responsible for development of primary and secondary oxidation products, reduction in nutritional quality, as well as changes in flavor, which can precipitate health hazards and economic losses in terms of inferior product quality. Lipid oxidation is a rather complex process whereby the unsaturated fatty acid fraction of membrane phospholipids is oxidized, and hydroperoxides are formed which are further susceptible to oxidation or decomposition to secondary oxidation products, such as short-chain aldehydes, ketones, and other oxidized compounds that may adversely affect the overall quality and acceptability of meat and meat products.
Antioxidants are compounds that are capable of donating hydrogen (H·) radicals for pairing with other available free radicals to prevent the propagation reaction during the oxidation process. This effectively minimizes rancidity, retards lipid oxidation, without any damage to the sensory or nutritional properties, resulting in maintaining quality and shelf-life of meat products. However, intrinsic factors are available in live muscle to prevent lipid oxidation. These factors are often lost after slaughtering during conversion of muscle to meat, primary/secondary processing, handling, or storage of meat products, necessitating further supplementation with extrinsic antioxidants.
For this reason, synthetic antioxidants, such as butylated hydroxytoluene (BHT), were extensively used to delay, retard, or prevent the lipid oxidation by scavenging chain-carrying peroxyl radicals or suppressing the formation of free radicals. However, because of the concern over the safety of these synthetic compounds, extensive work is being carried out to find novel and naturally occurring compounds to delay the oxidative degradation of lipids, improve quality, and maintain the nutritional value of foods. Thus, natural antioxidants have greater application potential in the meat industry because of the consumers’ acceptability over the synthetic antioxidants. However, the application of plant extracts, herbs, spices, and essential oils with antioxidant effects is still distant for the major reasons of limited data about their effects in different meat products.
The meat industry is demanding antioxidants from natural sources to replace synthetic antioxidants because of the negative health consequences or beliefs regarding some synthetic antioxidants. Fruits, vegetables, byproducts, and other plant materials provide good alternatives. Some of these antioxidants, apart from oxidation inhibition, may also affect other quality attributes positively or negatively, and ultimately affect consumer acceptability of the product. It has been shown that treatment with some natural sources can cause changes in the color of meat or meat products. Spices have shown to affect the flavor profile of treated meat and poultry products. Depending on the product, these flavors may be viewed as negatively or as positively by sensory panels. Some ingredients negatively affect the technological properties of meat and meat products, such as texture and emulsion properties. The safe edible use of these natural sources also depends on their health-related issues because some of these may also contain antinutritional or even toxicological factoRs. Thus, while establishing a new source of natural antioxidant for use in the meat and meat product at small, medium, or commercial level, following should be considered:
- The in vitro antioxidant activity should be based on various different analytical techniques. The activity should also be confirmed in targeted products during various processing conditions; thus, the effects of cooking, pressure, product ingredients, and so on, on antioxidant potential should be confirmed.
- The active ingredients/molecules of crude, concentrated or/and raw material should also be identified, and efficient conditions for extraction/separation of that particular molecule possessing potent antioxidant activity should be studied.
- Apart from oxidation inhibition, other product attributes should also be considered. Thus, the overall cumulative effect of identified antioxidants should be evaluated in different products before reaching to a conclusion. For example, if one source is a very potent antioxidant, it can also affect the color and sensory properties negatively and lower the acceptability of the final product; then a proper conclusion should be drawn to establish these negative implications. Some natural antioxidants are also sensitive to light, temperature, and pH which results in reduction of antioxidant potential. Thus, future studies should also be directed towards exploring the storage and processing environment effects on the antioxidative potential of natural antioxidants.
- Economics is the other main factor on which sustainability of any industry depends. Thus, economical extraction conditions should be well addressed relative to yield, time, infrastructure requirements, treatment materials, as well as the availability of natural sources. The correlation between economics of antioxidant use and economics of oxidation spoilage should also be considered before making any conclusion for the meat industry.
- Mere conclusions based on in vitro, in vivo, or in producto antioxidant activity is not suitable when new unconventional antioxidant sources are discovered. Thus, nutritional and toxicological studies (in vitro/in vivo) must be done to ascertain the safe edible use of these natural sources. This is the most important point because the meat industry is rejecting synthetic antioxidants on the basis of negative health-related issues; thus, while accepting new natural antioxidants, these must be analyzed for the same health-related consequences.