Food Microbes and Fermentation

• Beneficial microorganisms are present in foods and can be probiotics
• Fermented foods utilize lactic acid and fungal fermentation
• Safety must be considered alongside emerging trends
• Food is not sterile

Food Microbes

• About 3% of microbe species in adults' guts are found in fermented food
• The gut microbiome includes:
  • Bifidobacterium longum
  • Escherichia coli
  • Streptococcus Salivarius
  • Streptococcus thermophilus
  • Bifidobacterium bifidum
  • Bifidobacterium breve
• Beneficial microorganisms can be probiotics or starters
• Starters inhibit spoilage or pathogenic microbes as a result of enzymatic activity
• Specific compounds produced by microorganisms
  • Bioactive compounds include vitamins, biopeptides, and antioxidants
  • Enzymes catalyze reactions
• Microbes can cause spoilage
• Microbes can be pathogenic

Traditional Fermentation

• Alcohol production
• Food preservation
• Taste and texture development

Enhanced Fermentation

• Strains chosen, bred, or engineered to improve aspects of a food
  • Taste & texture
  • Health benefits

Animal Feed

• Nutritional Supplement
• Primary food source
• Nutraceutical and/or therapeutic Platform

Ingredient Production

• Production and purification of native/recombinant food additives
  • Nutrition
  • Taste/odour
  • Processing

Meat & Dairy alternatives

• Microbial meat analogues recreate nutrition, taste, and texture
• Animal product components produced in cell factories

Single Cell Protein

• Microbial food product as a:
  • Primary source of protein
  • Complete food source
  • Health supplement

Health Benefits of Microbes

• Live dietary microbes have been hypothesized to contribute to health improvement
• Positive Health Outcomes Associated with Live Microbe Intake from Foods, Assessed using the NHANES Database

Health Effect of Microbes

• Early human diets lead to a high level of interaction with our immune system
• Industrialized human diets lead to a low level of interaction with our immune system
• Supplements attempt to correct for industrialized diets

Postbiotics, Prebiotics, Synbiotics, Probiotics

• Probiotics are live
• Prebiotics are food for bacteria
• Synbiotics are a combination of both
• Advanced microbiome therapeutics exist

Probiotics Defined

• Live microorganisms administered in adequate amounts confer a health benefit on the host
• Examples of microorganisms
  • Lactobacillus
  • Bifidobacterium
  • Saccharomyces boulardii
  • Saccharomyces cerevisiae
• 1 × 109 CFU is administered per serving/day
• at least 107-109 live cells of a strain/day
• Probiotics impact gut microbiota

Documented Benefits

• A 2012 meta-analysis showed that probiotics help with gastrointestinal diseases
  • A total of 74 studies were done, testing 84 assays with 10,351 volunteers
• Study showed 7 prebiotics and 29 probiotics
• One study tested 20 participants
• Positive effects observed for a widespread effect

Short-Chain Fatty Acids

• Butyrate

  • Fermicutes: Lachnospiraceae & Faecalibacterium prausnitzii
  • Primary energy source and anticancer agent
  • Modulates gene expression

• Propionate

  • Bacteroides: Negativicutes & Clostridium
  • Energy source for colonocytes and modulates liver gluconeogenesis
  • Modulates satiety

• Acetate

  • Cholestoral Metabolism, regulates appetite and induces Lipogenesis
  • Bacteroidetes: Blautia hydrogenotrophica & Methanobrevibacter smithii
  • Ruminococcus gnavus, Eubacterium hallii, Eubacterium cylindroides, Faecalibacterium prausnitzii

Carbohydrates and Microbiota

• Non-digestible carbohydrates can also impact health positively
• Gut microbiota create SCFAs, increasing BBB integrity by passing through to the brain

Fermented Foods Defined

• Fermented foods and beverages undergo microbial growth and enzymatic conversion of major and minor food components

Global Fermented Foods

• Various fermented foods around the world, such as:
  • Kombucha
  • Kimchi
  • Miso
  • Soy Sauce
  • Wine
  • Sauerkraut

Fermented Foods

• Alcoholic fermentation is fueled using Ethanol and gas yeast
• Acetic is fueled using Acetobacter
• Lactic is fueled using LAB
• Butiric is fueled by Clostridium
• Propionic is fueled by Propionibacterium
• Alkaline is fueled Bacillus, mold

Reasons for Fermenting Foods

• Enrichment of the diet through the development of a variety of flavors, aromas, and textures
• Preservation of food through lactic acid, alcoholic, acetic acid, alkaline fermentations, and antimicrobial compounds
• Biological enrichment of food substrates with proteins, essential amino acids, essential fatty acids, and vitamins
• Detoxification during food fermentation processing
• Decrease in cooking times and fuel requirements
• Controlled and efficient fermentation could decrease production costs and loss due to food spoilage and can increase nutrient content

Lactic Acid Fermentation

• Homofermentative fermentation forms lactic acid
• Heterofermentative fermentation involves lactic acid, ethanol and other compounds

LAB

• Gram-positive bacteria that use carbs as a carbon source
• LAB include - Lactobacillus - Lactococcus - Leuconostoc - Pediococcus - Streptococcus - Enterococcus - Weissella - Bifidobacterium
  • Lactic acid in foods includes yogurt and yogurt bacterias
    • Lactobacillus plantarum and Lactobacillus helveticus
    • Streptococcus thermophilus and Lactobacillus delbrueckii subsp --Lactobacillus and Leuconostoc are used in lactic acid

Probiotic Characteristics

• Probiotics may exist in yogurt, be bacterial based
• Yogurt must contain specific bacteria
• Suan tsai is fermented with Lactobacillus, Leuconostoc, and Pediococcus
• Used for soybean based fermentation
• Lactobacillus, Leuconostoc, Weissella and Pediococcus utilized with fermentation of meats

Food Benefits

• Food improvements by lactic acid application - Lactic acid production itself - Other organic acids such as formic, acetic, propionic, butyric, and succinic acid. - Bacteriocins - Vitamins such as folic acid and riboflavin - Polysaccharides - y-aminobutyric acid - Flavor substances such as 2,3-butanedione, 2,3-pentanedione - Antioxidant substances Benefits include, - Reduction of phytic acid content - Degradation of allergenic proteins - Reduction of lactose content - Degradation of toxins - Degradation of protease inhibitors

Degradation of Macromolecules

• Some examples of this are - Lactose, Starch, Cellulose, Fructan, Hemicellulose - Mycotoxin: Aspergillus flavus converted either into Aflatoxin B1, or Lentilactobacillus kefiri FR7 or Aflatoxin B2

Protein Degradation

• This has an application as well to benefit protein use through reducing allergenicity and increased digestibility and flavor

Synthesis Of Specific Molecules

• Creates substances containing a lanthionine through the compounds bacteriocins which both prolongs food preservation for a more natural and safe result.
• Vitamins can be synthesized by LAB

LAB in Food Industry

• Through metabolic engineering, LAB are used to produce therapeutic products
• Fungi is used to ferment many food types
• Bioactive compounds for fungal fermentation include
  • Bioactive peptides
  • Gamma-aminobutyric acid
  • L-carnitine - Ergosterol
    • Chitin, chitosan
    • β-glucan
    • Fructooligosaccharides

Antimicrobial Resistance

• Antimicrobial resistance poses a risk
• Microoganisms develop decarboxylase activity and BAs can degrade as well
• Microorganisms produce mycotoxins
• Regulatory and safety standards govern the use of microorganisms

Microbial Foods

• Microbial foods can come from multiple ingredients with different characteristics - Cell Factories for Waste/Gas with genetic engineering with byproducts for purified protein. - Improved Gut Microbiome to increase nutritional value and hunger reduction.

Solar Foods

• Solar foods through typical values of Solein is composed of - Average values consisting of 78% dry proteins, 6% fats, 2% carbohydrates, 10% dietary fibres These foods impact the organism

• High protein microorganisms create - Algae