Volatile compounds of fresh and processed garlic (Review)

Abstract

Garlic is used as a spice in cooking due to its unique aroma. The unique aroma of garlic has attracted considerable attention from scientists. The cloves contain large amounts of sulfur-based substances, which as a consequence of their reactive properties, are converted easily to a variety of volatile compounds during processing. The volatile profiles of processed garlic are influenced by processing conditions, such as temperature, pH and solvent. Numerous studies on these changes in volatile compounds that occur during processing have been reported, with a number of types of sulfur-containing volatile compounds being identified in fresh and processed garlic. This review summarizes the volatile components of fresh and processed garlic, particularly those produced by heating and aging. The pungent odor of fresh garlic is contributed mainly to thiosulfinates and their degradation products. During the heating process of garlic, thiosulfinates are mainly decomposed, and nitrogen-containing volatile compounds, such as pyridines and pyrazines are generated. Aldehydes are dominant compounds in black garlic, while esters and phenols are key aroma compounds in aged garlic extract. The slight variations in chemical reactions during the aging process may lead to differences in the aroma of the two types of garlic. Contents 1. Introduction 2. Volatile components of raw garlic cloves 3. Nature of volatile compounds in garlic cloves during heating 4. Comparison of volatile components between black garlic and aged garlic extract 5. Conclusion

Variability in Bulb Organosulfur Compounds, Sugars, Phenolics, and Pyruvate among Greek Garlic Genotypes: Association with Antioxidant Properties

“…Other common acyclic disulfides and trisulfides are methyl allyl disulfide (MADS; peak 5), diallyl disulfide (DDS; peak 9), 1-propenyl allyl disulfide (peak 11), allyl methyl trisulfide (MATS; peak 12), and diallyl trisulfide (DATS; peak 19) [ 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ]. We also identified the following cyclic disulfides: 3-vinyl-4H-1,2-dithiin (3-VDT; peak 14) (a common one [ 6 ]), 3H-1,2-dithiole (peak 6) [ 25 , 27 ], and 3-dithiane (or 3,4-dihydro-1,2-dithiin) (peak 10). The latter has been earlier wrongly ascribed as trithiacyclohexene, whereas we identified only one cyclic trisulfide (4H-1,2,3-trithiine; peak 15) [ 25 ].…”

“…Recent studies reported that organosulfur compounds are also formed nonenzymatically in the aqueous environment of raw garlic at room temperature and thus are naturally occurring and are responsible for its distinct aroma [ 33 ]. In particular, 2-VDT has the highest flavor dilution factor among other volatiles and thus determines aroma of fresh garlic samples [ 6 ]. Therefore, GC profiling gives information not only on the different quantities of alliin and other γ-glutamylalk(en)ylcysteine precursors, but also on the aroma-responsible transformation products which are naturally occurring in the untreated (raw) plant material, while any observed differences are also genotype-dependent.…”

“…This compound is metabolized to allicin by the enzyme alliinase, when the bulb is crushed, also producing ammonia and pyruvic acid. Allicin and other sulfoxides may undergo many transformations both in vitro and in vivo, resulting in a wide variety of organosulfur volatiles, which are responsible for the flavor and aroma, as well as for most of the beneficial health effects of garlic [ 6 , 7 ]. Although many differences in the bioaccessibility and bioactivity of those compounds have been recorded so far, phenolics and saponins may also contribute to the antioxidant and anti-inflammatory properties of garlic, whereas polysaccharides (>85% fructose) have exhibited immunomodulatory effects [ 3 , 7 ].…”

Portuguese cacholeira blood sausage: A first taste of its microbiota and volatile organic compounds

“…Finally, other minor compounds were also found, including: allylsulfide, a sulphur compound dominating in black garlic (Abe, Hori & Myoda, 2020); gamma and butyrolactones, two lactones probably originating from lipid oxidation; and benzonitrile, a nitrogen compound.…”

Evaluation of Garlic Landraces from Foggia Province (Puglia Region; Italy)

“…The volatile S-containing compounds include thiosulphinates, which are very unstable and are transformed into compounds belonging to Sulphides-di-allyl-sulphide (DAS), di-allyl-disulphide (DADS), di-allyl-trisulphide (DATS) or into compounds belonging to 'Vinyldithiins' (cyclic sulfur-containing compounds) or into others [31]. All of them are responsible for the typical flavour of garlic and the protective effects against cardiovascular diseases [1,2,32].…”