Page 46 - FoodFocusThailand No.160 July 2019

STRATEGIC R & DD
STRATEGIC R &

What should we know about

aroma and flavor

for application purposes in foods?

In the world of food marketing, aroma and flavor of
foods are important since they are driving force of
acceptability of the products. If the aroma or flavor are
not good enough, consumer might decide not to ingest
or not to buy the product or buy it just only one time, no
second time.

Do you know that aroma and flavor are difference? In term of amino acids composition) could affect Maillard reaction products, thus the
perception, aroma and flavor are totally difference. Aroma is perceived reaction rates also depend on those type and composition of sugars and
by nose. On the other hands, flavor is perceived after the food is put in amino acids in the food system as well.
the mouth, the volatile flavor compounds are vaporized through nasal Lipids in the foods are subjected to change during food processing
cavity during exhale (aroma by mouth). Therefore, the perception of since the oxidation and lipolysis can be occurred and affect the desirable
flavor is the combination of aroma, taste, and sensation (e.g. hot, cold, aroma and flavor in foods. The example of food containing lipid is deep fat
pain, and others) in the mouth during consumption. In term of definitions fried food, such as doughnuts and French-fries potatoes. It is known that
of aroma and flavor depend on definer’s viewpoints, both terms can be the aroma and flavor characters of deep-fried products will show after using
referred as both biological perception (produced by chemicals and oil for a certain period of time because the aroma and flavor developed
perceived in the nose or mouth) and sensorial attributes of the food from lipid oxidation. The volatiles formed to represent aroma and flavor of
during smell or eating. Sometimes, intensity of the aroma and flavor is fried foods depend on temperature of the processing. The numerous
quite difference, even they are from same chemical. This phenomenon compounds have been reported as products of deep fat frying include acids,
is happening because the perception of flavor is depended upon condition alcohols, aldehydes, ketones, lactones, and esters. Some of these
in the mouth (e.g. moisture content and temperature), which related to compounds may come from degradation of lipid to by-products of free fatty
volatilization of the compounds. This can make the sensorial terms of acids, for example, hexanal and heptanal which provide green note to the
flavors are not similar to aroma perceived by nose as well. Therefore, fried food products.
food producers need to consider the changes that may be happened Fermentation can also cause various aroma and flavor in food product,
during processing or the formation of aroma or flavor during processing such as soy sauce, cheese, yogurt, bread, beer, wine, and sausages. The
and preparation. aroma and flavor of these products are formed from primary metabolism
During processing, the foods are subjected to change due to their of the microorganisms, which can be different classes of the compounds.
components and interactions occurred. The aroma and flavor formation However, fermentation sometime causes other products that producers
during processing could be from non-enzymatic browning reaction (e.g. might not want in the products. For example, the peptides or amino acids
Maillard reaction and caramelization), oxidation of fats, and fermentation. from protein degradation can cause meaty, brothy aroma and flavor in the
These reactions could form important chemical compounds generated products, and sometime also cause bitterness.
from food components and give such a characteristic of those kind of In order to solve the aroma and flavor changes during processing,
food. In contrast, the opposite direction of aroma and flavor can be incorporate of flavoring compounds to the food products could help. The
formed during processing as well. Some compounds can be off-note or main objectives of using food flavorings are increase intensity of aroma
off-flavor for consumers. In term of food companies, it is important to and flavor that loss during processing, develop new products that contain
understand what would be happened or changed during their productions special character of the food products, and mask off-notes and off-flavors
to affect aroma and flavor quality. that might occurred in the products. However, some problem can be occurred
The Maillard reaction plays the major key role in aroma and flavor as well after adding flavorings into the food system. For example, in general,
formation, which consumer usually enjoy this kind of aroma and flavor. the aroma and flavor can be faded after adding certain amount of flavorings
This reaction can be occurred in many products include bread, steak, into food containing proteins, such as milk and soymilk products. The aroma
coffee, and chocolate. In general, the Maillard reaction can be occurred and flavor fade problem can cause unacceptable to the product if consumers
because of the reaction of carbonyl groups (mainly from sugar with cannot perceive what they expect from the products. The main interaction
reducing end) and amines (from protein). Even the main products of that cause fading is colavent bonding of carbonyl containing flavor volatile
Maillard reaction are non-volatile compounds called melanoidins, but compounds that might contain in flavorings and amide side chain of amino
more than three thousand volatile compounds with very low threshold acids in the proteins containing in food. These strong interactions cause
can make a contribution to food aroma and flavor. For example, pyrazines no or less aroma and flavor release from the product during consumption,
(roasted, nutty, toasted notes) are formed during cocoa beans roasting thus the intensity perceived will be lower than what the producer expected.
process just small amount by Maillard reactions and contribute important If we understand what are happening in the food system, we can predict
aroma and flavor of chocolate. In addition, there are many factors that the phenomena and add more flavorings or choose the flavorings that
influence the Maillard reaction, including heating time and temperature, contain less carbonyl containing compounds instead to make consumers
composition in the food system, pH, and water activity. There are studies to be able to enjoy the food with small amount of flavorings adding into the
indicated that pyrazines are formed at high temperature (more than formulations.
70 ºC and rapidly increased in term of quantity when increase in In summary, food producers should understand the aroma and flavor
temperature. In term of time, the products of Maillard reaction is not perception, the changes during food processing, and also the interactions
necessary to increase in aroma and flavor intensity, but the balance of that might be occurred in the food systems that affect the aroma and flavor
aroma and flavor compounds may be changed. Moreover, the perception. So, they can plan and know how to solve the problems and
composition of the food system (e.g. different sugar composition, different can apply flavorings into the food follow the objectives of using flavorings
in the food products.
46 FOOD FOCUS THAILAND JUL 2019

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