Winter 2001 Issue — Health and Wellness with Probiotics

	Patricia Siuta-Cruce, Ph. D. Vice-president, Technology for Balchem Corporation, New York
	Jacques Goulet, agr, Ph. D. Scientific Director, Institute Rosell, Montreal Canada

 

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Introduction

Today's consumers worldwide are demanding much more from the foods they eat everyday. They are looking for foods that will provide added health benefits. probiotics are beneficial bacteria, further defined as "living micro organisms, which upon ingestion in certain numbers, exert health benefits beyond inherent basic nutrition". (1)

The study of probiotics started at the beginning of the 20th century when Nobel laureate Dr. Elie Metchnikoff studied peasants that seemed to live longer.(2) He noted that their diets included fermented dairy products and proposed a link between longer lives and ingested bacteria in yoghurt.

Gastrointestinal (GI) Tract Function

Gastrointestinal disturbances can range from just being annoying, to in some cases, life threatening. Probiotic bacteria have been shown to improve the clinical outcome of many such conditions, including antibiotic-associated diarrhoea,(3) inflammatory bowel syndrome,(4) as well as lactose intolerance(5) symptoms. The general concept of probiotics is to reintroduce the beneficial bacteria to the gut via ingestion in order to help maintain and restore the healthy ecosystem against harmful pathogenic bacteria. The scientific evidence suggests that probiotic bacteria consumed at high levels (i.e., 109 - 1011/day) could decrease the incidence, duration and severity of some GIT illnesses. The probiotic bacteria most commonly studied include members of the generalLactobacillus and Bifidobacterium for human consumption andEnterococcus and Pediococcus strains for animal consumption.(6)

Global Consumption

The value and use of probiotics is widespread in Europe and Japan and is becoming quite popular in the US. These probiotics are available as supplements or as food forms. Most of the foods containing probiotics are dairy-based and include yoghurt, kefir (fermented milk) and Bio Milks (milk with probiotics added). The passage of the Dietary Supplement health and Education Act in 1994, in the US, helped the popularity of products containing probiotics.

Obstacles Affecting Probiotics

Probiotics offer great market potential for food manufacturers and have certainly gained momentum recently. However, there are complex processing challenges when one is formulating products with probiotics. They, in fact, are very susceptible to the environment encountered during processing and storage, i.e., moisture, oxygen, temperature and acidity. Most critically, the probiotics must remain alive in order to provide the health benefits to the consumer. The next issue following processing and storage is survival from the mouth through the stomach into the intestines. In the intestines is where they work to maintain a healthy ecosystem.

Increasing Probiotic Survival Rates

Enteric coating of tablets or capsules is one approach of protecting these sensitive microbial cells against the low pH of the stomach. Coating these tablets or capsules, however, does not allow probiotics to be incorporated into food probiotics via this route, but only to guarantee a protection against stomach acids on an empty stomach. Most importantly, there have been other breakthroughs in the area of probiotic stability, most specifically; microencapsulation protects the probiotics against stress during processing and storage as well as against the acidic conditions of the stomach. Also, microencapsulation is much better adapted to the protection of fine particles such as those resulting from freeze-drying and milling of probiotic bacteria. Ultimately, these microencapsulated beneficial bacteria can be used in many food systems.

Microencapsulation Technology

In order to overcome the hurdles facing probiotics, Institut Rosell partnered with Balchem Corporation to coat these beneficial bacteria with proprietary microencapsulation (m-e) technology (see Fig 1) in order to extend shelf life at room temperature, increase resistance against heat, improve compression and enhance acid resistance. This encapsulation technology has been applied to several probiotic strains for use in food applications, includingLactobacillus Acidophilus, Lactobacillus rhamnosus andBifidobacterium longum. The microencapsulation technology has also been applied to two strains geared towards animals, namelyPediococcus acidilactici and Enterococcus Faecium.

The m-e technology allows the active core ingredient to be separated from its potentially stressful environment by a protective coating. Such a separation occurs until a time when the release of this functional ingredient is desired, which, for probiotics, is in the intestines, directly after exposure to the low pH of the stomach.

Protective coatings that are preferably used are lipid materials, such as mono, di-, and triacylglycerols and waxes. Examples include soybean oil, cottonseed oil, palm kernel oil, and esters of long chain fatty acids and alcohols.

The lipid coating material applied to fine particles of highly concentrated probiotic cultures is an effective barrier against deleterious factors such as moisture, oxygen and acids (see Fig 2). Also, it is a good protector against exposure to high pressures and high temperatures (see Fig 3, 4 and 5).Balchem's patent describes an encapsulation of sensitive substances such as probiotics. (6)

Institut Rosell teamed up with Balchem Corporation to incorporate encapsulated probiotics into a number of food applications with very exciting results. These include yoghurt-covered raisins, nutrient bars, chocolate bars and tablets. In stability testing, the company has found that compressed tablets with encapsulated probiotics revealed a 100% delivery rate. In the industry, normal survival is only 25-50%. The testing in nutrient bars and chocolate bars have also showed a good recovery rate. Studies are underway to determine the stability of yoghurt-covered raisins.

One other important issue relating to the use of probiotics in functional foods is the dosage of live cells to be delivered. Mortality rates as high as 90 to 99% are usually reported for unprotected probiotics exposed to the low pH of the stomach and the duodenum. Thus it is not unusual in the field of food supplements to recommend the intake of 1 to 10 billion live cells. This will ensure a delivery of at least 100 million (108) live cells per dose in the intestinal tract. Microencapsulated probiotic products can overcome the major hurdles of the GI tract and offer much better efficacy than unprotected products.

Microencapsulation is the best available technology to preserve the potency of probiotics for delivery into the intestines through different food systems. Such technology will not only allow these beneficial bacteria to be formulated into numerous food systems more readily but also allow food manufacturers the capability of including viable probiotics in finished products at an efficacious dosage level.

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