Worldwide, due to increasing consumer awareness of the impact of food on health,
The demand for functional foods is growing rapidly.
Probiotic foods are also known as “medicinal foods” or “nutrients”.
Probiotic foods contain ingredients to treat or prevent diseases.
Today, there is a sharp increase in the consumption of probiotic bacteria in food products.
Including probiotics:
Fermented milks
Ice cream
Types of cheese
Milk powder for baby food
Frozen dairy desserts
Drinks containing whey
The following products are popular among probiotic dairy products:
Sour cream
Dough
Liquid and flavored milk and condensed milk as well as ice cream
Probiotic ice cream can be kept unchanged for a long time.
Compared to matrix fermented dairy products, ice cream is an excellent idea for delivering probiotic organisms to the human body.
Probiotics can be defined as live microorganisms that can provide health benefits to the human body or animals.
Usually Lactobacillus and Bifidobacterium are the most common types of bacteria and they are effective in maintaining and improving the microbial balance of the intestinal environment.
Probiotics are used to produce fermented milk and other dairy products.
Among the benefits of probiotics for health, we mention the following:
Anti-mutagenic effects
Anticancer
Stimulation of the immune system
Anti-infective properties
Reduction of serum cholesterol
Reducing the symptoms of lactose intolerance
Increase nutrition
Maintaining the shelf life of probiotic cultures in food until the end of shelf life is an important criterion for providing probiotic food products.
Most of the studies on the viability of probiotic bacteria in ice cream have been related to their survival rate in products obtained by different techniques such as mixed ice cream culture.
Using unfermented ice cream mix or adding fermented milk to regular ice cream mix. The figure shows the flow diagram of the production process of fermented and unfermented ice creams.
Various researches have shown that probiotic cultures can better maintain their stability in frozen food products at an appropriate level compared to probiotic fermented milks.
Loss of probiotic organisms in ice cream occurs either during production or during frozen storage.
Thawing the product at the moment of consumption can be harmful to the probiotic cells.
At each stage, probiotic cells are exposed to various stressors.
Among the side effects of stress, the following can be mentioned:
Harmful chemical compounds in the product formula,
freeze damage,
Oxygen toxicity and
Mechanical stresses.
Therefore, during cold storage, temperature fluctuations that lead to periodic relative melting and refreezing should be avoided.
Effects of formulation
Sugars, which are used as main ingredients in dairy desserts and ice cream,
have complex effects on the viability of probiotics in frozen products.
While they may reduce probiotic survival
Because osmotic stress can affect cell viability,
At the same time, they may increase the viability of a probiotic by acting as a cryoprotectant.
The final effect may depend on the type and concentration of sugars, the type of probiotic organism, freezing temperature and speed, as well as freezing technology and storage time.
Short-chain polysaccharides have been shown to be more protective against cold than long-chain polysaccharides.
Short chain polysaccharides, which are considered “prebiotic compounds”, have the most beneficial effects on probiotic stability.
However, the effect of these carbohydrates on the texture of the product when they are used as a cold protectant or prebiotic should not be ignored.
Consumer positive opinion tests are a must in the formulation of a food product.
Consumer testing, which is valuable in determining the sensory characteristics of a product, is in the following two ways:
diagnostic
Descriptive
These tests show what sensory characteristics and levels of these characteristics a product must show in order to be successful in the market.
Some studies have shown that taste is the first time indicator
that consumers choose a food and look for its health benefits.
These studies also showed that consumers are not interested in consuming a functional food.
If the added material gives unpleasant flavors to the product,
Even if this leads to health benefits.
In general, the composition of prebiotics in ice cream has a greater effect on taste and texture.
While the addition of probiotics mainly affects the taste.
The metabolism of probiotic cultures can lead to the production of components that may contribute to product flavor and aroma.
During fermentation and storage, the Bifidobacterium fermentation pathway results in 3 moles of acetic acid and 2 moles of lactic acid for every 2 moles of glucose in an ideal synthetic medium.
which creates a theoretical molar ratio of acetic acid to lactic acid of 3:2.
If the concentration of acetic acid is high enough, it causes “vinegar stain”.
Davidson et al reported that, in general, ice creams fermented with probiotic cultures,
They have a weaker flavor compared to ice creams fermented with traditional yogurts.
Therefore, producing probiotic ice creams with high sensory acceptance is a difficult task.
However, it is possible to produce probiotic ice cream with good sensory quality.
The combination of probiotic bacteria in different types of ice cream is very beneficial.
In addition to creating a food rich in health benefits, Setni itself contains raw dairy ingredients, vitamins and minerals and is consumed by the general public.
Therefore, ice cream can serve as an excellent medium for delivering probiotics to the human gut.
Frozen production and storage of ice cream has relatively little effect on probiotic survival compared to fermented milk products.
And studies have shown that bacterial cultures remain at levels sufficient to provide the proposed therapeutic effects.
However, loss of viability of probiotics in ice cream inevitably occurs during processing and storage.
Occurs due to exposure of cells to various stress factors associated with formulation, freezing, overdrying, storage and thawing.
The stability of probiotics in ice cream can be increased by several methods, including selection of strong bacterial strains, removal of molecular oxygen, use of microencapsulation techniques, and adjustment of product formulation.
Efforts are being made to increase the shelf life of probiotic ice cream and maintain the therapeutic benefits of this product.
Supplementing ice cream with probiotic bacteria has been found to have little effect on its flavor, texture, or compositional characteristics.
There are also many ways to improve the sensory properties of the product.
Ice cream can be supplemented with prebiotics to improve probiotic stability as well as sensory and physicochemical properties of synbiotic ice cream.
