pre bio tics and pro bio tics

8/3/2019 Pre Bio Tics and Pro Bio Tics

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PREBIOTICS AND PROBIOTICS

Probiotics

Living bacteria that can be intended to benefit Killed by heat, acid or simply the passage of time. Contain from one to a few species of bacteria which are added to the colon when they are

ingested (eaten).

Found in fermented foods like sauerkraut and yoghurt Bacteria that you can ingest. Past through the digestive tract to the intestine. Found naturally in your digestive system. Functionsdigestion Absorption of nutrients & minerals Boost the immune system

Prebiotics

Form of dietary fiber Not affected by heat, cold, acid or time. Nourish the thousands of good bacterial species already living in the colon. Found in thousands of plant spices They are not bacteria, they are specific nutrients, usually non-absorbable CHO like

fructo- and oligo-saccharides,

Found naturally in whole grains, fruits and legumes.

Benefit- by stimulating the bacteria in the digestive tract, to either grow or become moreactive, thereby increasing digestive health.

PREBIOTICS

A number of different strategies can be applied to modify microbial intestinalpopulations. Prebiotics represent a third strategy to manipulate the intestinal microbiota.


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Prebiotics are non-digestible food ingredients that selectively stimulate the proliferationand/or activity of desirable bacterial populations already resident in the consumers

intestinal tract.

Intestinal populations of bifidobacteria, in particular, are stimulated to proliferate uponconsumption of a range of prebiotics, increasing in numbers by as much as 10100-foldin feces

Advantages over probiotics

Stable in long shelf life foods and beverages; Heat and pH stable and can be used in a wide range of processed foods and beverages; Have physicochemical properties useful to food taste and texture; Resistant to acid, protease, and bile during intestinal passage; Stimulate organisms already resident in the host, and so avoid host/strain compatibilities,

and the need to compete with an already established microbiota;

Stimulate fermentative activity of the microbiota and health benefits from SCFA (shortchain fatty acids);

Lower intestinal pH and provide osmotic water retention in the gut.Advantages over antibiotics

Safe for long-term consumption and prophylactic approaches; Do not stimulate side effects such as antibiotic-associated diarrhea, sensitivity to UV

radiation, or liver damage;

Do not stimulate antimicrobial resistance genes; Not allergenic.Disadvantages of prebiotics

Unlike probiotics, overdose can cause intestinal bloating, pain, flatulence, or diarrhea. Not as potent as antibiotics in eliminating specific pathogens. May exacerbate side effects of simple sugar malabsorption during active diarrhea.TYPES OF PREBIOTICS

Most identified prebiotics are carbohydrates.


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These carbohydrates share a number of physiological traits important to their beneficialeffects.

They are:

Non-digestible (or only partially digested);

Non-absorbable in the small intestine; Poorly fermented by bacteria in the mouth; Well fermented by purportedly beneficial bacteria in the gut; Poorly fermented by potentially pathogenic bacteria in the gut. To date, the largest number of reported studies and the most consistent evidence

accumulated for prebiotic effects have been for several non-digestible oligosaccharides

(NDOs).

These include fructooligosaccharides (FOS), and the polyfructan inulin,galactooligosaccharides (GOS) and lactulose.

Indeed, it appears that a wide range of NDOs can stimulate the growth of bifidobacteriaand new potential prebiotics continue to emerge.

The evidence that some polysaccharide dietary fibers, such as resistant starches,arabinoxylan, and plant gums have prebiotic potential is accumulating, but to date

remains limited largely to in vitro and animal studies.

PROBIOTICS

DEFINITIONS

Probiotics is derived from Greek and means prolife. Tannock in 2000 Microbial cells which transit the GI tract and which, in doing so,

benefit the health of consumer.

FAO/WHO (2001) and Reidet al.(2003) concentrated exclusively on its health purpose:Live microorganisms which when administered in adequate amounts confer a healthbenefit on the host.

Schrezenmeir and de Vrese in 2001A preparation of a product containing viable, definedmicroorganisms in sufficient numbers, which alter the microflora (by implantation or

colonization) in a compartment of the host and by that exert beneficial health effects in

this host.


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INCORPORATING PROBIOTICS IN FOODS

Probiotics have for decades been used in fermented dairy products such as yogurts andfermented milks.

The techniques and technologies to incorporate these organisms into fresh, refrigerateddairy products are now relatively mature.

The continuing emergence of clinical evidence for benefits to consumers and thesubsequent marketing power these ingredients bring have now seen probiotics become

the fastest growing category of functional food ingredients.

Probiotics remain defined as live microorganisms that when administered in adequateamounts confer a health benefit on the host

Health benefits have usually been attributed in clinical studies to doses of probiotics inexcess of 10

8

09

viable cells per day

Therefore, food regulatory/advisory bodies generally stipulate that foods containingprobiotic organisms need to have >10

610

7 cfu/g at the time of consumption

An acceptable viable count can sometimes be achieved by introducing higher numbers ofprobiotics during manufacture (called overage). The consumption of probiotic organisms

at high doses is safe and so oversupplying consumers does not appear to pose a health

risk.

However, in practice the addition of considerable overage can be an expensiveproposition given the relatively high cost per weight of probiotic cultures as ingredients.

Overall, there are five main points to address when incorporating probiotics into foods:

1. Select a compatible probiotic strain/food type combination.

2. Use food-processing conditions that are compatible with probiotic survival.

3. If fermentation is required, ensure that the food matrix will support probiotic growth.

4. Select a product matrix, packaging, and environmental conditions to ensure adequate

probiotic survival over the products supply chain and during shelfstorage.

5. Ensure that addition of the probiotic does not adversely impact on the taste and texture of

the product.


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Probiotic Ingredients

Probiotic organisms are predominantly bacteria selected from the genera Lactobacillusand Bifidobacterium, which are normal constituents of the human intestinal microbiota.

Probiotics organisms are usually supplied by manufacturers of these ingredients as eitherdry powders (freeze-dried or spray-dried) at 10101012cfu/g or as frozen direct vat set

concentrates at 10910

10cfu/g. When received as ingredients, it is important that the

probiotic be correctly stored as per the manufacturer instructions in order to avoid rapid

losses in probiotic viable counts.

Dry blended into foods and powders such as infant formulas. Dispersed into liquid or semi-liquid products such as juice or ice-cream. Inoculated into fermented products such as yogurts and fermented milks. In the first two cases, the probiotics do not multiply in the product and are generally

added at doses in the order of 10710

8cfu/g.

For a standard probiotic freeze-dried powder at 1011 cfu/g, this represents addition of theprobiotic at 0.010.1% (w/w) of the final product.

In fermented products there may be some growth and increase in probiotic numbersduring fermentation, allowing a lower number of organisms to be initially added (for

example 106

cfu/g).

Factors Affecting the Viability of Probiotics in Foods

The main factors to be considered that may influence the ability of the probiotics tosurvive in food products include:

1. The physiological state of the added probiotic;

2. The physical and chemical conditions of food processing;

3. The physical conditions of product storage (e.g. temperature);

4. The chemical composition of the product (acidity, nutrients, moisture, oxygen);

5. Interactions with other product components (inhibitory or protective).

Synbiotics

Ingredients and foods that contain both prebiotics and probiotic are called synbiotics.


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A range of non-digestible sugars, oligosaccharides, and polysaccharides can act asprebiotics, and possess a range of physiological and physicochemical properties that

make them attractive food ingredients.

Delivery Systems

Microencapsulation Delivery DevicesMicroencapsulation

Microencapsulation is described as a process of enclosing micron sized particles of solidsor droplets of liquids or gasses in an inert shell, which in turn isolates and protects them

from the external environment.

The product obtained by this process is called as micro particles, microcapsules,microspheres.

When the particle size is below 1m are known as nanoparticles, nanocapsules,nanospheres.

Particles having diameter between 3 - 800m are known as micro particles ormicrocapsules or microspheres.

Particles larger than 1000m are known as macroparticles3. Micro particles or microcapsules consist of two components namely core material and

coat or shell material. Core material contains active ingredient while coat or shell

material covers or protects the core material.

Demands for a successful probiotic microencapsulant: The materials have to be food grade, inexpensive, and compatible with the food into

which the probiotic will be encapsulated.

The microencapsulation process must be simple, inexpensive and must not reduceprobiotic viability.

The encapsulation efficiency must be high (i.e. close to 100% of the bacteria in asuspension should be encapsulated).

The microcapsules must contain a high loading (%v/v) of probiotics. The microcapsules must not adversely impact on the taste and texture of food and

beverages (small capsules


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The microcapsules must protect the probiotics against a range of environmental stressesduring manufacture and storage.

Protection against moisture and low pH are two of the most common stresses to protectagainst.

It is also an advantage for the microcapsules to protect the probiotics duringgastrointestinal transit.

The microcapsule must be able to release the probiotic bacteria in the gut at the requiredsite of action.

There are various techniques are available for the encapsulation of core materials.Broadly the methods are divided into

Chemical methods Physico-chemical methods Physico-mechanical methods

Schematic representation of the coacervation process. (a) Core material dispersion in

solution of shell polymer; (b) separation of coacervate from solution; (c) coating of core

material by microdroplets of coacervate; (d) coalescence of

coacervate to form continuous shell around core particles.


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Microencapsulation by rapid expansion of supercritical solutions

(RESS).

Schematic illustrating the process of micro-encapsulation by spraydrying.

Delivery Devices

Another approach to maintaining the viability of probiotics for long periods at ambienttemperatures is to physically separate the probiotics from the food and atmosphere.

This can most simply be achieved by keeping dried probiotics in sealed sachets with thefood or beverage to be mixed immediately prior to consumption.

More innovative packaging and delivery systems have been developed to deliver driedprobiotic ingredients into beverages.

These include drinking straws that contain dried probiotics, which are released into thebeverage as it passes through the straw and a drink cap that contains the dried probiotics,

which are released into the drink as the cap is opened.

pre bio tics and pro bio tics

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