Influence of sub-lethal stresses on the survival of lactic acid bacteria after spray-drying in orange juice.
The demand for new functional non-dairy based products makes the production of a probiotic orange juice powder an encouraging challenge. However, during drying process and storage, loss of viability of the dried probiotic cultures can occur, since the cells are exposed to various stresses. The influence of sub-lethal conditions of temperature, acidic pH and hydrogen peroxide on the viability of Pediococcus acidilactici HA-6111-2 and Lactobacillus plantarum 299v during spray drying in orange juice and subsequent storage under different conditions was investigated. At the end of storage, the survival of both microorganisms through simulated gastro-intestinal tract (GIT) conditions was also determined. The viability of cells previously exposed to each stress was not affected by the drying process. However, during 180 days of storage at room temperature, unlike P. acidilactici HA-6111-2, survival of L. plantarum 299v was enhanced by prior exposure to sub-lethal conditions. Previous exposure to sub-lethal stresses of each microorganism did not improve their viability after passage through simulated GIT. Nevertheless, as cellular inactivation during 180 days of storage was low, both microorganisms were present in numbers of ca. 10(7) cfu/mL at the end of GIT. This is an indication that both bacteria are good candidates for use in the development of an orange juice powder with functional characteristics.
CBQF-Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Porto, Portugal.
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J
Barbosa
CBQF-Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Porto, Portugal.
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Borges
CBQF-Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Porto, Portugal. Electronic address: pcteixeira@porto.ucp.pt.
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Teixeira
D001628:Beverages / Q000032:analysis / Q000382:microbiology*; D032084:Citrus sinensis / Q000737:chemistry / Q000382:microbiology*; D015169:Colony Count, Microbial; D005511:Food Handling; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000378:metabolism; D007777:Lactobacillaceae / Q000737:chemistry / Q000145:classification / Q000254:growth & development* / Q000302:isolation & purification; D050296:Microbial Viability; D019936:Probiotics / Q000737:chemistry*; D013696:Temperature
D019344:Lactic Acid
Acidic stress; Gastro-intestinal tract; Heat shock; Lactobacillus plantarum 299v; Oxidative stress; Pediococcus acidilactici HA-6111-2