OFF FLAVOR FORMATION IN FOODSTUFFS OBJECTIVES 1. Formation of aroma compounds via enzymatic mechanism; 2. Transformation of carbohydrates, lipids and amino acids; 3. Transformation of other compounds.

OFF FLAVOR FORMATION IN FOODSTUFFS 1 Off-flavor – a flavor that is not natural or up to standard owing to deterioration or contamination

OFF FLAVOR FORMATION IN FOODSTUFFS 2 Off-flavor

OFF FLAVOR FORMATION IN FOODSTUFFS 4 Off-flavor 1. As a result of chemical and biochemical processes 1.1. Fishy / mushroom smell in butter (octa-1-en-3-on) – degradation of phospholipids; otherwise – smell of mushrooms, found in Camembert cheese

OFF FLAVOR FORMATION IN FOODSTUFFS 5 Off-flavor 1. As a result of chemical and biochemical processes 1.2. Soybean oil – presence of 3-methyl-2,4-nonadion and diacetyl: bean and oily aroma; 1.3. In the dry sterilized milk – sometimes is felt pockety and stale smell; the reason is oxidation of lipids and formation of Z-nona-6-enal; Other reason might be presence of о-amino acetophenone – potato and animal odor (interestingly at higher concentrations this compound have grape odor notes!) The main factor for formation of smell of molds and stale – cork taint. 2,4,6-trichloroanisole (TCA)

OFF FLAVOR FORMATION IN FOODSTUFFS 6 Off-flavor 1. As a result of chemical and biochemical processes 1.3. Off-flavor formation during carrot treatment – sterilized or dried; reason – formation of ionones (α-, β-) having floral aroma

OFF FLAVOR FORMATION IN FOODSTUFFS 7 Off-flavor – due to degradation of carotenoids

OFF FLAVOR FORMATION IN FOODSTUFFS 8 Off-flavor 1. As a result of chemical and biochemical processes oxidative deamination Skatole Smell in the Emmental Off-flavor in processed peppers Tryptophan decarboxylation It’s formed in the mammalian digestive tract – in higher concentrations has strong fecal odor. In low concentrations has flowery smell (found in some flowers, used as fragrance and fixative in perfumes. о-aminoacetophenon (animal, potato smell); Found in tortilla, taco (in dairy products – gives off-flavor)

OFF FLAVOR FORMATION IN FOODSTUFFS 9 Off-flavor 2. As a results from external contamination of foodstuffs 2.1. Geosmin in water, vegetables (beets) and fishes – smell of soil, earth produced by gram-positive bacteria Streptomyces. 2.2. Formation of acrid taste and burnt smell in dairy products – from the milk of animals consumed Coronopus didymus (swinecress); reason – formation of benzylmethyl sulfide and benzylthiocyanate; losses for the producers. Coronopus didymus (swinecress)

OFF FLAVOR FORMATION IN FOODSTUFFS 10 Off-flavor 2. As a results from external contamination of foodstuffs 2.3. Allium ursinum – known as ramsons,  buckrams, wild garlic; Animals which has consumed it gives milk with garlic off-flavor.