Progress 10/01/05 to 09/30/08
Outputs
OUTPUTS: The overall goal of this project is to develop a new technology that could be applied in the food industry to ensure the survival of probiotic cultures during processing steps. The major outputs of this project could be summarized in three areas: 1. Research accomplishments, 2. education and training of students, and 3. Presentations at local, regional and national conferences. 1. Research accomplishments: In this project, we had two objectives. Objective 1 was to screen different probiotic supplements available in the market for viable and active probiotic cells. Objective 2 was to examine the ability of different antioxidants agents (reducing agents) to promote the survival and growth of probiotics under different processing conditions. In the first objective, several experiments were conducted to determine the viability of probiotic in the local market. Over 25 different products were located in local stores and analyzed for the viable probiotics. Our results showed that
at least 75% of the products did not meet the standard for active and live cultures: the bacterial populations were below 100,000 CFU/g. Only three products contained cultures within 100,000 CFU/g. In the second objective, we tested the effect of four different antioxidants on the survival and stability of probiotics. These are natural ingredients including ascorbic acid, blue berries, cysteine and Lycopin. Our results showed that the presence of antioxidants enhanced the survival of probiotic cultures in refrigerated storage. Both ascorbic acid and blue berries were able to provide high protection for bacterial cells during storage. 2. Student education and training: Several undergraduate and graduate students were able to work on this project and learn new techniques related to probiotic cultures and methods of bacterial growth and survival. 3. Presentations at local, regional and national conferences: These students were able to attend several local, regional and national
conferences including the Institute of Food Technologists (IFT), American Dairy Science Association (ADSA) and American Chemical Society (ACS).
PARTICIPANTS: Scientists, post-doc and undergraduate and graduate students were the major participants in this project. In addition we had a visiting scientist from Egypt, Dr. M.M. Eid who was interested in probiotic cultures and fermentation process.
TARGET AUDIENCES: The major target for this type of research project would be the food industry and federal government agencies who are interested in using probiotic cultures to improve food quality and safety of products. Probiotics are now allowed to be used in several products including infant foods, therefore the knowledge learned from this project could be applied to benefit such industry.
Impacts
Our study has demonstrated that many commercial products available in the market do not meet the standard for human health promotion. This simply means that most consumers are paying high prices for low quality products. Our results are strong evidence that the industry needs to pay extra attention to processing conditions to improve the viability of probiotic cultures. In this project, we were able to test natural antioxidants that have health benefits. These antioxidants could also provide protection for the probitoc cultures not only during processing conditions, such as fermentation and drying but also protect the bacterial cells during storage at refrigerated temperatures. Our approach to improve stability and viability of probiotic cultures is a very practical and could be easily adapted by the industry. The addition of antioxidants would provide extra health benefits to the commercial products and ensure the viability of probiotic cultures.
Publications
- Platt, S., S. A Ibrahim, M. Holmes-McNary, M. Smith, and C. Kim. 2007. Development of enriched medium for routine enumeration of Bifidobacterium sp. in probiotic supplements. IFT Annual Meeting Program and Abstracts. Abstract # 058-20
- Ibrahim, S.A., J. W. Allen, A. R. Byers. 2006. Effect of calcium on autoaggregation behavior of Lactobacillus reuteri. American Chemical Society Annual meetings (Abstract # AGFD 107).
- Awaisheh, S., S. A. Ibrahim, A. Shahbazi. 2006. Effect of thyme on the viability of probiotics, and overall acceptability of probiotic soft white cheese. American Chemical Society Annual meetings (Abstract # AGFD 105).
- AbuGhazaleh, A.A. Y. M. Murad, A. Shahbazi, and S. A. Ibrahim. 2006. Isolation of food grade Beta-galactosidase overproducing mutants of Lactobacillus reuteri using chemical mutagenesis approach. American Chemical Society Annual meetings (Abstract # AGFD 103).
- Ibrahim, S.A. H. Yang and C. W. Seo. 2008. Effect of lactic acid alone or in combination with copper on the survival and growth of E. coli O157:H7 and salmonella in carrot Juice. Food Chemistry (Accepted).
- Ibrahim, S.A. 2008. Enhancement of bile tolerance in lactobacillus by Tween 80. Milchwissenschaft - Milk Science International. (Accepted).
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Progress 01/01/06 to 12/31/06
Outputs
Probiotic cultures including bifidobacteria play a vital role in the maintenance of good human health. These supplements have become popular consumer products in recent years. There are many commercial supplements that claim to contain high viable amounts of bifidobacteria. Maintaining high viability throughout processing and storage period has been a challenge to the supplement industry. Little work has been done on testing these commercial products for viable bacterial cells. In addition, most of the available laboratory media have failed to detect the total amount of viable bacterial cells in these supplements. Therefore, the purpose of this research was to develop a comprehensive laboratory medium for the routine enumeration of Bifidobacterium in probiotic supplements. A comprehensive medium consisting of the following chemical ingredients (g/l) was prepared: 10g/L pancreatic digest of casein, 14g/L agar, 5g/L yeast extract, 4g/L dextrose, 8 g/L beef extract, 10
g/L proteose peptone #3, 5g/L sodium chloride, 1g/L corn starch, 3 g/L lithium chloride, 2 g/L sodium acetate, 0.5 g/L cysteine, 0.5 g/L magnesium chloride, 0.25 g/L manganous sulfate, 0.10 g/L calcium choride, 2.0 g/L ammonium phosphate, 2.0 g/L dibasic potassium phosphate and 0.25 g/L Zinc sulfate . A mixture of 4 sugar solution (100ml) was prepared, consisting of 0.4g dextrose, 0.3g lactose, 0.3g fructose, 0.1g corn starch. To enhance the selectivity of this medium two selective agents (dicloxicillin, 0.2 g/100mL and propionic acid ,5 mL/L) were added after the medium was autoclaved at 121C for 15 min. The dietary probiotic supplements were diluted and appropriate dilutions were surface plated on the developed enriched medium. A total of seven dietary supplements were tested. Inoculated plates were then incubated for 5 days in anaerobic jars at 37 degrees C and colonies were counted. Our results show that the new enriched medium was able to detect viable cells in all tested
supplements. The bacterial population ranged between 105 - 107 using the developed enriched medium, whereas, in the standard media (mBIM25 and DP) the microbial population ranged between 0 -103. In conclusion, the medium developed in this project has shown great potential for use in detection of viable strains in dietary supplements. The use of this medium will serve as a tool for quality control and evaluation of probiotic dietary supplement of bifidobacteria.
Impacts
The new medium developed in this project has great potential for use in detection and evaluation of viable strains of bacteria in probiotic dietary supplements. The medium will allow probiotic supplements manufacturers a tool to improve how they evaluate and control the quality of their bifidobacteria supplements.
Publications
- No publications reported this period
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Progress 01/01/05 to 12/31/05
Outputs
Dietary supplements have had resurgence due to the increased consumer demand for these products. These supplements include probiotics, antioxidants, herbs, extracts and other various nutraceuticals. Most of these products come in the form of capsules, tablets, powder or liquids. A key challenge for the industry today is to make ingredients more functional and beneficial for consumer health. One approach for achieving this goal is to determine optical combinations of supplemental compounds that produce synergistic and holistic effects. Currently, most information on the interaction between various supplements is largely anecdotal. Therefore, the food industry could benefit greatly if more research would be conducted in this area. The objectives of this project are: Screening different supplement available in the market for viable and active probiotic cultures; and testing different antioxidant agents for their ability to promote the survival and growth of probiotic
cultures under different processing conditions.
Impacts
This project will develop a new technology that improves the quality and shelf life of many dietary supplements available in the market. This project will determine which compounds that could be added to these supplements to enhance the nutritional value and to enhance the microbiological quality of many supplements.
Publications
- No publications reported this period
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