Role of Lipids in Food Flavor Generation

Abstract

Lipids in food are a source of essential fatty acids and also play a crucial role in flavor and off-flavor development. Lipids contribute to food flavor generation due to their degradation to volatile compounds during food processing, heating/cooking, and storage and/or interactions with other constituents developed from the Maillard reaction and Strecker degradation, among others. The degradation of lipids mainly occurs via autoxidation, photooxidation, and enzymatic oxidation, which produce a myriad of volatile compounds. The oxidation of unsaturated fatty acids generates hydroperoxides that then further break down to odor-active volatile secondary lipid oxidation products including aldehydes, alcohols, and ketones. In this contribution, a summary of the most relevant and recent findings on the production of volatile compounds from lipid degradation and Maillard reactions and their interaction has been compiled and discussed. In particular, the effects of processing such as cooking, drying, and fermentation as well as the storage of lipid-based foods on flavor generation are briefly discussed.

Formation and Analysis of Volatile and Odor Compounds in Meat—A Review

“…The course of the Maillard reaction depends on the nature of the food product in question, i.e., moisture content, pH, reactants involved, and cooking temperature. The rate of the Maillard reaction increases with increasing temperature and decreasing moisture levels, meaning that the formation of the Maillard reaction compounds primarily takes place in the areas of the food that have been dehydrated by the cooking process [ 77 ].…”

Influence of Peanut Varieties on the Sensory Quality of Peanut Butter

“…The gustatory system is involved with the taste (sweet, bitter, salty, sour, and umami) sensation that is stimulated by mastication of the non-volatile high-molecular-weight components. Somatosensory perception (astringency, pungency, and acridness) is interpreted by the trigeminal nerves [ 71 , 72 ]. Peanut butter flavor is generated during roasting, when the high temperatures of the roasting process initiate a series physical changes and chemical reactions involving the peanuts’ chemical constituents and metabolites.…”

“…Discussion on lipids’ contribution to peanut butter flavor usually centers on lipid oxidation and the generation of undesirable flavor notes. However, given that almost half of the weight of peanut butter is lipids, the influence of lipids on taste during mastication, and the possibility generating lipoxygenase-derived lipid-based volatile compounds that are responsible for desirable flavors in peanuts, lipids might require further consideration [ 72 ]. Twelve different fatty acids have been reported in peanut oil; of these twelve, only oleic, linoleic, and palmitic fatty acids exist in concentrations above 5%.…”

“…Lipid oxidation affects the flavor of peanut butter in two ways. First, during roasting, the lipids in peanuts can undergo degradation, producing some volatile compounds that can directly alter the flavor profile of peanut butter or indirectly influence the flavor of peanut butter by possibly interacting with other constituents developed from the Maillard reaction and Strecker degradation [ 72 ]. Second, during storage, lipid oxidation can lead to a fading out of the desirable peanut butter flavor with time.…”

“…In both cases, lipid degradation in peanut butter could be initiated by autoxidation, photooxidation, or the presence of metallic ions and, in some cases, a combination of all three. Oxidation proceeds with the generation of aliphatic aldehydes, ketones, and alcohols that are highly associated with undesirable flavors, and which can compromises the nutritional quality of fats, possibly leading to the production of toxic compounds [ 20 , 72 , 80 ]. Both the total lipid content and the actual oil profile have a effects on the propensity and actual rate of peanut butter deterioration by oxidation and, subsequently, on flavor [ 20 , 95 ].…”