Applications of biopreservative methods

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Applications of biopreservative methods

  1. 1. Applications of Biopreservative Methods P. H. Laksara De Silva
  2. 2. Food preservation • A continuous fight against microorganisms spoiling or making food unsafe • Extend the shelf life of food items
  3. 3. What is biopreservation ? • can be defined as the extension of shelf life and food safety by the use of natural or controlled microbiota and/or their antimicrobial compounds . • the most common forms is fermentation • The Lactic Acid Bacteria (LAB), generally considered food-grade organisms
  4. 4. Factors contributing to antimicrobial activity by Microbiota • Organic Acids Lactic acid, acitic acid, propionic acid • Bacteriocins -ribosomally synthesized, extracellularly released bioactive peptides or peptide complexes, -primarily active against closely related organisms, -have a bactericidal or bacteriostatic effect, -widespread bacteriocin is Nisin
  5. 5. • Diacetyl and acetaldehyde have an antimicrobial effect, imparting aroma and flavor to cultured dairy products Reuterin by Lactobacillus reuteri • Enzymes lacto peroxidase system, lysozyme • CO2 • hydrogen peroxide
  6. 6. Fermentation • most common forms of food biopreservation • a process based on the growth of microorganisms in foods, whether natural or added
  7. 7. Fermentation-Effects on Food • Break down of complex compounds • Production of acids & alcohols • Synthesis of Vit-B12, Riboflavin, Vit-C precursor • Improve organoleptic qualities Production of flavour, aroma compounds • Add variety to raw food items • Extend shelf life • Antifungal activity
  8. 8. Applications of biopreservation in different food products • Dairy products - Curd ,yogurt , cheese • Fermented meat products- Sausages, • Vegetable products- Pickles, Sauerkraut, Kimchi,
  9. 9. • Fruit based products- Wine, cider • Fresh sea foods • Cereal products- beer
  10. 10. Other Applications • Control of mycotoxin contamination Ability to prevent or limit mycotoxinogenic mould growth, The inhibition of aflatoxin accumulation by occurrence of a low-molecular-weight metabolite produced by the LAB • Control of postharvest diseases in fruits & vegetables Microbial antagonists are used to control the growth of disease causal organism, Characteristics of antagonist, • Genetically stable. • Effective at low concentrations.
  11. 11. • Ability to survive adverse environmental conditions • Effective against a wide range of pathogens • Amenable to production on an inexpensive growth medium. • Amenable to a formulation with a long shelf life. Easy to dispense. • Does not produce metabolites that are harmful to human health. • Resistant to pesticides. • Nonpathogenic to host commodity.
  12. 12. • Apple Blue mold Pseudomonas syringae Pseudomonas cepacia Cryptococcus spp Gray mold Pichia guilliermondii Pseudomonas cepacia C. laurentii Mucor rot Pseudomonas cepacia • Cirus Green mold Pichia guilliermondii Bacillus subtilis Blue mold Pichia guilliennondii Stem end rot B. subtilis Few currently used microorganisms
  13. 13. • Application of hurdle concept with biopreservation Chemical preservatives, physical treatments (heat), or mild heat, non-thermal physical methods, increase the permeability of cell membranes, Positively affects the activity of many bacteriocins Low intensity of preservation method is required
  14. 14. Health benefits • Probiotic cultures- -stabilizing or normalizing the gastrointestinal tract -increase function of immune system • Production of Vitamins & precursors Vit-B12, Riboflavin, Vit-C precursor
  15. 15. Requirements and regulatory status for bacteriocins In general, when selecting bacteriocin-producing strains for food applications • The producing strain should have GRAS status • bacteriocin with broad spectrum of inhibition that includes pathogens, spoilage microbs • Thermostability • Improved safety • No adverse effect on quality and flavour
  16. 16. Requirements and regulatory status for bacteriocins • Microorganism should be in GRAS status • Purified bacteriocin must be approved as GRAS • Distinguish bacteriocins from antibiotics • Bacteriocin must be genetically and chemically identified, and its use and efficacy must be shown • Toxicological data and the fate of the molecule after ingestion are also required
  17. 17. Thank You

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