Meat contains a large amount of protein and trace elements needed by human beings, but due to the high moisture content, the shelf life of fresh meat is short. Therefore, people are increasingly concerned about the preservation technology of meat products during processing. When adding additives, natural green additives have also become the first choice.
At present, the main technologies for extending the shelf life include irradiation treatment, fence technology, microwave treatment, modified atmosphere preservation treatment, biological preservatives, and food additives. This article mainly reviews the effect of some natural preservatives on the preservation of meat products.
Commonly used chemical preservatives are benzoic acid, sorbic acid, dehydroacetic acid, ethylparaben, and propylparaben. The synthetic process of chemical additives is complicated, and the number of additional needs to be strictly controlled. Although the addition amount within the national standard will not be harmful to the human body, the general public still needs a more green and healthy addition method. Therefore, considering some natural additives, it can not only prolong the shelf life of meat products but also meet the green health requirements of ordinary people. Natural preservatives can be divided into plant-derived substances, animal-derived substances, microorganisms, and their metabolites according to their sources.
1. Substances of Plant Origin
Plant-derived preservatives refer to ingredients with a fresh-keeping effect extracted and refined from plants. It can be applied to food to keep food fresh. In recent years, research on plant-derived preservatives can be divided into two categories: spice preservatives and Chinese herbal preservatives.
1.1. Spice Preservative
Spices not only give food a richer flavor but also have antioxidant properties. It can be used to cook many delicious dishes, and it is safer to use. So some people considered using some of the ingredients in the spice to make it a preservative. This can make food more delicious and can replace chemical preservatives to make food greener and healthier.
The extract of spices is usually used as a preservative. Li Jin et al. measured the relationship between antioxidant capacity and inhibitory capacity by using dried ginger, green peppercorns, red peppercorns, cinnamon, black pepper, and dried tangerine peel. The results showed that the inhibitory ability of spices was related to the scavenging ability of hydroxyl radicals, which provided clues for studying the inhibitory mechanism. Zhu Mingtao et al. studied the fresh-keeping effect of clove, star anise, and angelica extracts on chilled beef. The results showed that the fresh-keeping effect of Angelica dahurica extract was the best. Chen Jiali et al. found that some strains, mainly Bacillus cereus and Penicillium chrysogenum, can lead to spoilage of roasted chicken. The spices with better bacteriostatic effect on Penicillium chrysogenum are rosemary, cumin, and garlic. The spices with better antibacterial effect on Bacillus are star anise and rosemary. Caroline et al. used lemongrass extract as a natural additive for chicken, and the results showed that the extract reduced lipid oxidation compared with synthetic additives and also retained the aroma characteristics of meat products.
The combined use of a single spice has a better antibacterial effect on meat products. Wu Danfeng and others used compound spices to study the antibacterial effect of donkey meat products. The results showed that the combination of ginger alcohol extract, clove alcohol extract, and nisin had a better preservation effect on donkey meat products. Hong Jun et al. studied the preservation effect of pomegranate peel on chicken products. After further research, it was concluded that the fresh-keeping effect of chitosan and rosemary extract and pomegranate peel crude extract was significantly higher than that of a single pomegranate peel preservative, which could achieve the preservation of chilled chicken. Huang et al. made a composite emulsion of gelatin, chitosan, rosemary nano-extract, and ε-poly-L-lysine coated on the surface of roast chicken, and found a new nano-emulsion-based antibacterial and antioxidant material. It effectively releases active compounds to the meat surface and is a promising technology for improving the safety and quality of meat-eating products.
1.2. Chinese Herbal Preservatives
Chinese herbal medicine can not only treat diseases but also nourish the body. Many scholars at home and abroad have studied its efficacy.
Zhong Li et al studied the bacteriostatic effect and antioxidant capacity of 15 common Chinese herbal extracts on chilled pork. The results showed that the loquat leaf extract could be used as a preservative for chilled pork, and the extracts from Tinglizi and Salvia miltiorrhiza could be developed and utilized as short-term preservatives. Staphylococcus aureus can cause spoilage in meat products. Cui HY et al. studied the antibacterial mechanism of oregano essential oil and further studied the effect of oregano essential oil on the relative expression of Staphylococcus aureus from the genetic level. The results show that oregano essential oil can cause irreversible damage to the cell membrane of S. aureus, resulting in the leakage of intracellular biomacromolecules. Liu Chengxin and others studied the inhibitory effect of several Chinese herbal medicines on Staphylococcus aureus. The results showed that the extracts of Magnolia Officinalis, Atractylodes Rhizoma, and Yinchen had strong antibacterial activity against Staphylococcus aureus. In particular, the fine-grained Magnolia Officinalis extract had a better bacteriostatic effect on Staphylococcus aureus than the coarse-grained Magnolia Officinalis extract.
At present, the antibacterial effect of Chinese herbal medicine has not been widely used. However, as a treasure of China, it will definitely be more fully developed and utilized in the future.
2. Substances of Animal Origin
Animal-derived preservatives refer to the preservatives extracted from animals for preservation, and the effect is better. Mass production can be carried out after studying the freshness-preserving effects of these ingredients.
The operation of compounding essential oils to make a composite film to impregnate meat products greatly improves the preservation effect. Tooraj Mehdizadeh et al. studied the effect of propolis extract and chitosan composite coating film impregnation on chicken breast. Studies have shown that the combination of chitosan and polyethylene can prolong the shelf life of chicken breast by about 16 days. This blend of essential oils has strong antibacterial and antioxidant effects against certain bacteria, showing good antibacterial and antioxidant properties. Zeng Liping et al. studied the preservation effect of chitosan, whey protein, and potassium sorbate composite membrane liquid on chilled meat. The results showed that the composite membrane solution with 3% potassium sorbate added had the best fresh-keeping effect. Wang Zhengrong et al. studied the preservation effect of chitosan and ginger extract composite film on pork. The results showed that they could effectively inhibit the increase of total bacterial count and pH of chilled pork, inhibit lipid peroxidation, and the shelf life of chilled pork was more than 15 days.
3. Microorganisms and Their Metabolites
Microorganisms and their metabolites preservatives refer to the use of certain microorganisms or certain metabolites of microorganisms as preservatives. Its antiseptic effect is better, but it is difficult to extract. With the continuous development of science and technology, the use of microbial preservatives will certainly be more extensive. Terpenes and polyphenols are high-value plant secondary metabolites. Their high antibacterial activity shows their great potential as natural preservatives in the food industry. With the rapid development of metabolic engineering, it has become possible to achieve large-scale production of unnatural terpenes and polyphenols using a recognized safe strain of Saccharomyces cerevisiae as a cell factory.
analyzed the antibacterial and antioxidant activities of phenolic metabolites secreted by a naringenin-producing strain of Saccharomyces cerevisiae against pure flavonoid naringenin and its derivatives to evaluate their potential as natural food preservatives. The results showed that the engineered yeast metabolites had strong antibacterial activity. Phenolic metabolites secreted by naringenin-producing yeast are a sustainable source of natural food preservatives. Duan et al. isolated Lactobacillus paracasei FX- from kefir and identified antibacterial activity from its fermentation process. The results showed that the shelf life of chicken breast meat was prolonged by 4 days after treatment with 100 mg·mL -1 antibacterial agent. This microbial preservative effectively extends the shelf life of meat products.
Later, not only did some people use a variety of natural preservatives in combination, but they also used the preservatives after compounding in food coatings. Yousef Khaledian et al. applied cellulose nanofibers, edible coating, ginger essential oil, and citric acid to the surface of roast chicken, and the result could extend the shelf life of the meat to 6d. Liu Shaopeng et al. studied the effect of compound biological preservatives containing phenyllactic acid in the preservation of chicken. The results showed that when the garlic and ginger essential oils and phenyllactic acid were combined in the coating, the preservation effect was the best. The effects of carvacrol and thymol on marinated fresh chicken were studied by Layal Karam et al. The results showed that the shelf life was significantly prolonged by 15d and 21d. Giuseppe et al. encapsulated essential oils in polymer nanocapsules and prepared nanocapsules by nanoprecipitation. The results showed that bactericidal activity was exhibited even at the minimum inhibitory concentration.
4. Conclusion and Outlook
At present, natural meat preservatives are mainly plant-derived, animal-derived, and microbial preservatives, especially plant-derived preservatives account for a large proportion. The main principle of research on preservatives is to study the antioxidant and bacteriostatic effects of substances, so as to improve or develop preservatives. The research results are very impressive, but they have not been widely used. With the development of biotechnology and people paying more and more attention to food health, natural food preservatives will definitely occupy the main position of preservatives in the future. At the same time, researchers should strengthen research on natural food preservatives. Combine existing research results, develop more new products, and make the use of natural food preservatives mainstream.
