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Effect of Drying Processes on Viability and Selected Functional Properties of Probiotic Lactic Acid Bacteria

Praveen Kumar, Reddy K. B. (2007) Effect of Drying Processes on Viability and Selected Functional Properties of Probiotic Lactic Acid Bacteria. UNSPECIFIED thesis, University of Mysore.

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Abstract

Lactic acid bacteria (LAB) are a large group of beneficial bacteria that have similar properties and produce lactic acid, as an end product of the fermentation process and are used in the preparation of traditional fermented foods since many centuries. They are used extensively in fermented milk products like yoghurt, cheese, butter, buttermilk, and kefir all over the world. The present research investigation focuses on the isolation of LAB from Kanjika, an Ayruvedic lactic acid fermented product prepared in our laboratory. Some of the important probiotic properties such as tolerance to low pH, high bile salt concentration up to 1%, antimicrobial activity against food-borne pathogens, β-galactosidase and phytase activity, antibiotic susceptibility and cholesterol lowering capacity were evaluated. Out of the 17 isolates, 6 were found to be potent probiotics and further characterized by 16S rDNA gene sequencing. Total DNA isolation, optimization of PCR conditions for the amplification of the 16S rDNA gene and cloning of PCR product for the sequencing was carried out followed by BLAST analysis and phylogenic study. Three potent probiotic isolates; K3a, K7b and K23c were identified as Lactobacillus plantarum CFR 2191, Lactobacillus fermentum CFR 2192 and Pediococcus acidilactici CFR 2193, respectively. 13 LAB cultures from department culture collection were also evaluated for functional probiotic properties, out of which L. plantarum B-4496 and L. salivarius CFR-2158 exhibited potent probiotic properties. All these five cultures showed good antibacterial activity against Enterotoxigenic E. coli (ETEC), a deadly pathogen which causes traveller's diarrhea. The effect of spray drying and freeze drying on the viability and retention of key probiotic properties of Lactobacillus plantarum CFR 2191, Pediococcus acidilactici CFR 2193, L. salivarius CFR-2158 were studied. Maltodextrin (MDX) and Non Fat Skimmed Milk (NFSM) were used as carriers in spray drying studies. No significant improvement in viability and retention of probiotic properties were noticed in case of cultures subjected to heat shock treatment. The results highlight that spray drying of LAB cultures with MDX as a carrier is a cost effective way of producing large quantities of probiotic cultures with functional properties for neutraceutical application. Lactose, skimmed milk and maltodextrin were found to be potent cryoprotectants in freeze drying studies. An increase of 6-8% both in viability and probiotic properties was observed when LAB were subjected to cold shock treatment and freeze dried in comparison with that of those freeze dried without cold shock treatment. . In depth ‘in vivo’ studies to evaluate the probiotic properties of the isolated and characterized cultures are further recommended .It is hoped that the work carried out sets the base for future research investigations and would further help in assessing the probiotic properties in animal models This would widen the scope for varied applications on a commercial scale.

Item Type: Thesis (UNSPECIFIED)
Uncontrolled Keywords: Lactic acid bacteria (LAB) traditional fermented foods spray drying freeze drying probiotic properties
Subjects: 500 Natural Sciences and Mathematics > 07 Life Sciences > 04 Microbiology
600 Technology > 08 Food technology > 18 Processed foods > 04 Functional foods
Divisions: Fermentation Technology and Bioengineering
Depositing User: Food Sci. & Technol. Information Services
Date Deposited: 07 May 2009 11:09
Last Modified: 24 Sep 2018 10:57
URI: http://ir.cftri.com/id/eprint/8934

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