Applications of Biopreservative

Methods P. H. Laksara De

Silva

Food preservation

• A continuous fight against microorganisms spoiling or making food unsafe

• Extend the shelf life of food items

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

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

• 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

Fermentation

• most common forms of food biopreservation

• a process based on the growth of microorganisms in foods, whether natural or added

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

Applications of biopreservation in different food products

• Dairy products - Curd ,yogurt , cheese

• Fermented meat products- Sausages,

• Vegetable products- Pickles, Sauerkraut, Kimchi,

• Fruit based products- Wine, cider

• Fresh sea foods

• Cereal products- beer

Other Applications

• Control of mycotoxin contaminationAbility 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.

• 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.

• 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

• 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

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

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

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

Thank You