The development potential of natural antiseptic raw materials is gradually emerging

With the improvement of people's living standards, consumers are increasingly pursuing nutritious, green and safe food
.
Although the addition of preservatives in regulations and standards will not affect the human body, compared with synthesis, natural preservatives have safe, green and efficient anti-corrosion characteristics due to natural resources, so they are more widely used in food than synthetic preservatives and are more favored
by people.
At present, many companies around the world are rushing to research natural food preservatives
.

Resources are natural and extensive

Natural food preservatives can be divided into plant preservatives, animal preservatives and microbial preservatives
according to the source.
Due to different sources, different compositions and structural characteristics, its application in food is also different
.

Plant preservatives are mostly derived from plant extracts, such as certain natural herbs and fragrances and plant essential oils
.
Plant extracts and essential oils have long been used as food preservatives, seasonings and medical preparations
due to their unique flavor and bacteriostatic effects.

Studies have shown that plant extracts are rich in natural antioxidants, which are very effective in controlling the growth of foodborne pathogenic bacteria, can delay or prevent rancidity of food due to oxidation, and extend the shelf life
of food.
Plant-based antioxidants mostly exhibit protective effects similar to butylhydroxyanisole and butylated hydroxytoluene, and a variety of vegetables and fruits are important sources
of natural antioxidants used to fortify and stabilize food quality.

Essential oils are aromatic and volatile liquids obtained from natural herbs and spices, containing a large number of secondary metabolites that have the effect of delaying or inhibiting the
growth of bacteria, yeast and mold.
In the food industry, essential oils are mainly used as flavoring agents
.
Due to the mature extraction process of most essential oils, strong antibacterial effect, non-toxic and harmless, it is more commonly used
in food preservation as a natural antibacterial agent.

Animal preservatives refer to biologically active substances with antiseptic effects extracted from certain animals or their metabolites, mainly classified according to their functions: antibacterial enzymes, antibacterial peptides and antioxidant peptides
.

Enzymes exert antimicrobial activity
through many different mechanisms.
For example, lysozyme and other antimicrobial enzymes have antimicrobial activity mainly by catalyzing the lysis of cell surface polymers or cell walls, inducing bacterial decomposition; Lactoperoxidase (LPO) and other peroxidase systems act as antimicrobial by
catalytic oxidation.
LPO has an inhibitory effect
on the growth of both gram-positive and gram-negative bacteria.

Antimicrobial peptides have broad-spectrum antimicrobial activity against bacteria, fungi, protozoa, and certain viruses, and can be isolated from organisms such as plants, insects, crustaceans and marine
organisms.
Antimicrobial peptides of animal origin are mainly derived from mammals, amphibians, fish, etc
.

Antioxidant peptides mainly include proteins and their hydrolysates, peptides and amino acids
.
The researchers added fish and chicken enzymatic hydrolysates to beef mince and found that the enzymatic hydrolysates had antioxidant effects and prevented lipid oxidation in beef, with inhibition rates of 93% and 80%,
respectively.

Lactic acid bacteria (LAB) in microorganisms have the ability to inhibit microbial growth and are considered good candidates
.
In the production of fermented foods, lactic acid bacteria are used to improve the taste, flavor and texture of food and prevent the growth of pathogenic microorganisms, and LAB is not harmful
when consumed.
The antibacterial components of LAB mainly include bacteriocins, organic acids, hydrogen peroxide, carbon dioxide and diacetyl
.
Among them, bacteriocin is a natural preservative or biological preservative synthesized by LAB and other strains, which has a good bactericidal or bacteriostatic effect on foodborne pathogenic bacteria such as Staphylococcus aureus, Listeria monocytogenes, and botulinum toxin, and also has good antibacterial activity against gram-positive bacteria, and bacteriocin has stronger
antibacterial activity at lower pH.

The market is showing its potential

In recent years, finding active substances from natural resources to replace chemical substances has become an important direction
for international research and development.

For example, the antiseptic clean label solution consisting of rosemary and green tea extracts developed by the American ingredient manufacturer Kemin Group is very effective
in sauces, spices and condiments, as well as meat and poultry products.

In addition to the combination with green tea extract, rosemary has many "+ alternative antiseptic" products
.
For example, in 2021, Kalsec, a provider of natural antioxidant solutions in the United States, launched a blend that combines traditional antioxidant products such as rosemary and acerola cherry extracts with natural antimicrobial solutions such as cultured glucose and buffered vinegar to protect against spoilage, odors and common foodborne pathogens
caused by microbial growth.
The product can be applied to meat, poultry, deli salads, dips, etc
.

Compared with the common "rosemary +", postbiotic embalming can be said to be a new concept
.

China's Qingdao Yuanda Biotechnology Co.
, Ltd
.
is a typical representative of it.
The postbiotic preservative raw materials produced by it do not affect the original sensory of food, and have high acid and alkali tolerance, a wide range of application scenarios, and can be added to different types of
food.

Israeli startup Resorcix has introduced a plant-based ingredient based on natural pine resin that prevents thermophilic acidophilus (TAB) spoilage
in transparent fruit drinks.
The ingredient has a slight herbal flavor and requires only a very small amount to preserve the organoleptic flavor of the beverage while ensuring that the product retains its original flavor
during its shelf life.

TAB is a non-pathogenic microorganism that is very susceptible to the appearance of beverages, derived from certain ingredients often used in beverage preparation, such as sugar, pectin, fruit juice concentrates, etc.
, and more importantly, it is almost impossible to eradicate and often requires regular batch testing and isolation to prevent
.
The plant component of the above-mentioned natural pine resin has been shown to have an antibacterial effect by breaking down TAB cells at the germination stage, thus preventing bacteria from producing odorous and unpleasant metabolites, and this component allows pasteurization at lower temperatures
.
Currently, the U.
S.
FDA, European Food Safety Authority, Japan and Israel officially regulate that this new ingredient can be labeled on
the label.

Mushrooms can also be developed
as preservatives.
Chinova Bioworks' natural mushroom fiber products have been recognized as generally recognized as safe (GRAS)
by the FDA.
It is reported that the product is a natural mushroom fiber derived from the upcycled stem of white mushrooms, which can be used as a natural preservative in food and beverages and meet clean label needs
.

Synthetic biology technology has also penetrated into the field of natural preservatives
.

In August 2021, American biotech company Conagen launched a natural preservative, coumaric acid (PCA),
made from synthetic biotechnology fermentation.
PCA is a natural antioxidant and antimicrobial compound found in
many plants.
The product can be used as a potential alternative
to benzoic acid and sorbic acid, among others.

At the same time, scientists have also unearthed more potential natural preservative raw materials
.

Such as moringa flower extract
.
An Indian study found that moringa flower extract could increase the antimicrobial properties of
a product.
Its mechanism of action is due to the antibacterial effect
exerted by the rich polyphenolic compounds of Moringa flower extract.
Studies have confirmed that meat products with natural antioxidants added to moringa flower extract have a high flavor and overall acceptability
by inhibiting lipid and protein oxidation during storage.

Another example is fig peel
.
The study found that fig peels contained high concentrations of total polyphenols, flavonoids and antioxidant active substances, which were added to handmade pasta in powder form in 10%, 13% and 16% proportions, respectively, and stored in a refrigerated environment
at 4°C.
The results showed that products without added fig peel powder had a lot of bacteria within 1 day, and the shelf life of the added products corresponded to 2 days, 8 days and 7 days
, respectively.
This means that fig peels have the potential to become a potential ingredient
to extend the shelf life of pasta.

In addition, researchers from the College of Life Sciences of Northwest Normal University found that olive leaf extract has strong bacteriostatic activity and can be used as a green and safe bacteriostatic preparation
.
Olive leaf extract contains a large number of antioxidant polyphenols, including hydroxytyrosol, oleuropein, verbascoside, etc.
, among which, oliveside and caffeic acid both show inhibitory effect on microorganisms, and the antibacterial effect of combined phenolic compounds is significantly higher than that of phenolic compound monomers
.

According to relevant data, the global food preservatives market is expected to grow from $3.
3 billion in 2021 to $4 billion in 2026, with a compound annual growth rate of 4.
1%
during the period.
With the preference for natural ingredients at the consumer end, the iteration of the food preservative market is accelerating
.

(Yang Xiaojing, integrated and sorted)

China Food News (December 05, 2022, version 06).

(Responsible editor: Yang Xiaojing)