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Microbial flavours
- 1. Microbial metabolites as flavouringagents Lasina .J
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- 4. (-OH) (-CHO) (-CO-) ( -COOR) Alcohols Aldehydes Dicarbonyls Esters Lactones ( ) Methyl ketones(-COCH3) Phenolic compounds Short to medium chain free fatty acids Sulphur compounds Compounds responsible for the aroma of the food products
- 5. Classification of flavourson the basis of sources NATURAL FLAVOURS MICROBIAL FLAVOURS SYNTHETIC FLAVOURS ENZYMATIC FLAVOURS •Vanilla •Cinnnamic acid •Limonene •Menthol •Camphor •Eucalyptol •Cinnamaldehyde •Eugenol •Isoamyl acetate Flavours •Diacetyl •Lactones •Esters •Alcohols •Methyl ketones •Benzeldehydes •Ester •Terpenes •Vanilla • Allylpyrazine •Methoxypyrazines •2-Isobutyl-3- methoxypyrazine • Acetyl-L-pyrazines •2-Acetoxy pyrazine • Aldehydes
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- 7. I. Natural flavours •Natural flavors contains the flavoring constituents derived from aspice, fruits, vegetables, similar plant material, edible yeast, meat, seafood, poultry, eggs, dairy products. (i) In plants- • Plants can synthesize, accumulate and emit volatiles that act as aroma and flavor molecules due to interactions with human receptors. • Natural flavours present in different parts of plants- i. Bark- Cinnamon, ii. Bud- Onion, garlic, iii. Root-Carrot, iv. Leaf - Coriander, Curry leaf • They are commercially important for the food, pharmaceutical, agricultural and chemical industries as flavorants, drugs, pesticides and industrial feedstocks.
- 8. ii. Animal basedflavours- such as meat • Raw meat - salty, metallic with slightly sweet aroma • Cooked meat- meaty flavor notes due to bis-(2- methyl-3-furan) disulfide, formed by interactions between Maillard reaction products and lipid oxidation products Plant species Compounds Products Oryza sativa (Rice) 2-acetyl -1-pyruvate Basmati flavour Allium sativum (Garlic) Thiols Garlic Allium cepa (Onion) Phenolics Onion Vanilla planifolia (Vanilla beans) Vanilla(4-Hydroxy-3- methoxybenzaldehyde) Vanillin
- 9. Biosynthetic pathway ofnatural flavours
- 10. Limitations of naturalflavours • Low abundance of the volatiles • Flavours are affected by plant type, geographical location, seasonal restriction • High cost
- 11. Synthetic flavours • Synthetic(or artificial) flavors are complex mixtures of naturally occurring flavor compounds to either imitate or enhance a natural flavor. • In the 1800s, a German chemist was the first to develop synthetic aromatic chemicals of fruity odour. • In 1858, Vanillin was first crystallized from an alcoholic extract ofvanilla beans by Gobley • By the end of the 19th century, production of synthetic flavors shares a global market. • These mixtures are formulated by flavorists to give a food product a unique flavor and to maintain flavor consistency between different product batches. • Produced by fractional distillation and additional chemical manipulation of naturally sourced chemicals, crude oil or coal.
- 12. Chemical flavours usedfor food flavouring • Chemicals : • Allylpyrazine • Methoxypyrazines • 2-Isobutyl-3-methoxypyrazine • Acetyl-L-pyrazines • 2-Acetoxy pyrazine • Aldehydes • Alcohols • Esters • Ketones • Pyrazines • Phenolics Flavours Roasted nut Earthy vegetables Green pepper Popcorn Toasted flavours Fruity Bitter Fruity Butter, caramel Caramel Smokey
- 13. Health Risks ofSynthetic Flavours • Brain tumors, cancer, depression, DNA damage, allergies, kidney problems, high blood pressure. • Nowadays, the consumer has developed a ‘chemophobia’- attitude towards synthetic compounds, especially when related to food and its products.
- 14. • Since timeimmemorial, man has unwittingly used microorganisms to produce flavours while preparing fermented foods and drinks. • Around the turn of 20th century that the relationship between the typical desirable flavour of fermented foods and beverages, and the microorganisms involvement became recognised. • A wide range of microorganisms is known to produce flavourcompounds from simple nutrients via de novo synthesis, e.g. sugars, alcohols,etc. • Provide characteristic flavour to fermented products such as in wine,beer, yogurt, butter ,bread, fruity and nutty flavour. • In most cases the de novo fermentation processes can be boosted by supplying a limiting intermediate or precursor molecule, which is otherwise limiting the yield, to the culture. Microbial flavours
- 15. Microbial flavours MicroorganismsCompounds Butter flavour Lactococcus lactis Diacetyl Cocconut like, buttery, creamy, sweet and nutty Candida tropicalis, Trichoderma viridae Lactones Fruity flavour Pichia anomola Esters Nutty and roasted flavour Corynebacterium glutamicium Pyrazines Organoleptic properties Saccharomyces cereviase Alcohols Vanillin Vanilla planifolia Vanilla Natural fruit flavour Phanerochaete chrysosporium Benaldehydes Microbial flavours
- 16. Biosynthetic pathway ofMicrobial flavours
- 17. Diacetyl (Butane-2,3-dione) • Diacetylis a byproduct formed in the curd, butter, cheese , milk , bread, coffee, brandy, rum. • It also is manufactured as a component of artificial butter flavoring that is used in butter-flavored microwave popcorn, candy, baked goods and cake mixes • The FDA currently classifies diacetyl as “Generally Recognized as Safe” (GRAS) for consumption.
- 18. Biosynthetic pathway ofDiacetyl production • Substrate : Whey media, lactose peptone medium, with 1% citrate as inducer • Organisms : Lactococcus lactis , Lactobacillus sp., Streptococcus thermophilus and Leuconostoc mesenteroids Biosynthetic pathway
- 19. Lactones( D-glucono-1,5-lactone lactonohydrolase) • The microbial bioprocess of lactone synthesis was first established in the early 1980s. • Microbial lactones are produced by the β-oxidation of hydroxy fatty acids. • They contribute to the aroma of butter, cheese and various foods and fruits. e.g.- i. Cyclopentadecanolide is responsible for the musk like odor of angelica root oil. ii. Phthalides are responsible for the odors of celery and lovage oils. iii. Raw milk does not contain free lactones, appear after heating.
- 20. Biosynthetic pathway oflactones production • Organisms: Trichoderma viridae, Cladosporium suaveolens Candida tropicalis Yarrowia lipolytica. • Fruity , coconut like , buttery, creamy, sweet and nutty.
- 21. ESTERS (-COOR) iii. • Volatileesters are responsible for the fruity character of fermented beverages and constitute a vital group of aromatic compounds in beer and wine. • Maarse and Visscher (1989) listed 94 esters formed in beer during primary fermentation. • A study conducted by Saerens et al. (2007) to evaluate the fermentation parameters with ethyl ester production using yeast strain. • Observations- i. Higher level of unsaturated fatty acids - decrease in ethyl ester production ii. Higher carbon or nitrogen content - moderate levels in ethyl ester production. Limited level of medium chain fatty acids – leads to increase in ethyl ester production Conclusion- The precursor availability is the major limiting factor in ethyl ester production. So, the expression level and activity of the fatty acid biosynthetic enzymes therefore appear to be prime targets for flavour modification by alteration of process parameters
- 22. Biosynthetic pathway ofEster production • Substrate : Barley malt • Organisms: Saccharomyces , Henseniaspora guilliermondii and Pichia anomola Biosynthetic pathway
- 23. Ester products • Ethylbutyrate ester has large market demand • Fruit-flavoured products: • Beverages • Candies • Jellies, jams • Baked good • Wines • Dairy products : • Cultured butter, • Sour cream • Yogurt and chesse.
- 24. Pyrazine((7R)-7-methyl-6,7-dihydro-5H- cyclopenta) • Constituents ofpeas, coffee, c apsicum peppers and wines at concentration as low as 0.00001 ppm. • The synthesis of pyrazine was first recorded by Laurent in 1844, the compound was proved to be tetraphenylpyrazine • In 1912 – 1916 Louis-Camille Maillard observe the colour changes on mixing amino acids and sugars • Pyrazines is a heterocyclic, N2 containing compound formed during roasting of food through Maillard reaction. • Modern cooking do not favour pyrazine formation, so need to supply natural pyrazine with roastyflavour • Has interesting anticancer as well as antituberculosis activities.
- 25. BROWNING IN THERMALLYPROCESSED FOODS: THE MAILLARD REACTION
- 26. Flavour and Colourin the Maillard Reaction H2O rearrangement H OH OH NHR OH OH O Amadori intermediate carbonyl compounds H2O RNH2 O O H O O CHO HO O O OH O O O CHO O OH OH O O FLAVOUR COMPOUNDS MELANOIDIN PIGMENTS H OH OH O R NH2+ OH OH OH reducing sugar amino compound Aammiinnooaacciidds or proteins
- 27. Biosynthetic pathway ofPyrazine((7R)-7- methyl-6,7-dihydro-5H-cyclopenta) production • Organism: Corynebacerium glutamicum.
- 28. Biosynthetic pathway ofAlcohols (-OH) production • Theses complex alcohols and derived esters has organoleptic properties. • Organisms: Saccharomyces cerevisiae , Hansenula anomala, Kluyveromyces marxianus. Methyl phenyl acetate 2-phenyl ethanol Phenylacetic acid
- 29. Alcohols products • 2-phenylethanolis most relevant aroma compounds give rose like smell.
- 30. Vanillin(4-hydroxy-3- methoxybenzaldehyde) • It isthe immature fruit of the orchid Vanilla planifolia and is cultivated as a vine . • Vanilla extract contain more than 250 chemical compounds extracted through percolation method. • It is the second most expensive spice in the world • In 1997,the H&F Florasynth began the production of vanillin identical to natural one by process consist of two steps leads to ferulic acid turns into vanillin
- 31. Biosynthetic pathway ofVanillin production • Vanillin flavour • Organisms: – Pseudomonas putida – Aspergillus niger – Corynebacterium glutamicum, – Corynebacterium sp., – Arthrobacter globiformis – Serratia marcescens . Vanilla beans
- 32. Production of Vanillinfrom Caffeic acid •A two step bioconversion by filamentous fungi to transform Ferulic acid to vanillin by Aspergillus niger. • Vanillic acid reduced to vanillin by Pycnoporous cinnabarinus.
- 33. Applications • Febrifuge: Vanillaessential oil an effectively reduce fevers by fighting infections • Anti-carcinogenic: The anticarcinogenic property of vanilla oil comes from its antioxidant properties. • Antioxidant: This property of vanilla essential oil solve many problems
- 34. Vanillin products Ice creamPerfumes Cookies 1. Used in flavouring in sweet foods • Cookies • Muffins • Cakes • Icecreams • Softdrinks • Beverage , 2. Non-food users • Perfumes, • Pharmaceuticals
- 35. Benzaldehyde • Benzaldehyde isthe second most important Flavour molecule after vanillin. • Benzaldehyde was first extracted from bitter almonds in 1803 bythe French pharmacist Martres. • In 1832 German chemists Friedrich Wohler and Justus von Liebigfirst synthesized benzaldehyde • It is mainly in the form of glycosides in cherry, laurel, peach contain significant amount of amygdalin. • Occur naturally in bitter almond oil. • Used as a flavoring and fragrance in food, cosmetics, pharmaceuticals, and soap and is "generally regarded as safe" (GRAS) by the US FDA.
- 36. Biosynthetic pathway ofBenzaldehyde production • Made up of benzene ring with a formyl substituent. almond• Bitter Flavour • Organisms : – Pseudomonas putida – Trametes suaveolens – Polyporous tuberaster – Bjerkandera adusta – Phanerochaete chrysosporium . Metabolism of L-phenylalanine by Trametes suaveolens
- 37. Benzaldehyde Product • Consumptionof Benzaldehyde approximately 7000 tones per year as product of almond and cherry
- 38. Methyl ketones • Methylketones are important flavor components, especially of blue cheeses • Penicillium roqueforti produces 2-pentanone, 2-heptanone and 2-nonanone • Contributing to the flavor of fresh butter. • They also have applications as biofuels, owing to their reduced, aliphatic carbon chains • Methyl ketones can be produced from the fatty acid β- oxidation pathway
- 39. Methyl ketones • Organisms: – Agaricus bisporus, – Aspergillus niger – Penicillium roqueforti – Trichoderma viridae
- 40. Methyl ketone products •Application: • blue cheese and fruit flavours
- 41. Solid state fermentation •Solid state fermentation process occuring in the absence or near-absence of free water. • SSF employ natural raw material as carbon source such as cassava,barley,wheat bran, rice bran,sugarcane bagasse, various oil cakes,fruit pulp,corn cobs,seeds, coffee husk,
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- 43. Flavours produced bymicrobial bioconversion of the precursor
- 44. Advantages of SSF •Processis simple •Cost effective •Less Effluent release,reduce pollution •Aeration process is easy •Easier downstream processing