• Journal of Dairy Science and Biotechnology
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• v.21 no.2
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• pp.88-96
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• 2003

Cheese flavor is derived from three main pathways, that are proteolysis, lipolysis and glycolysis, the extent of which varies according to the cheese variety. Proteolysis is the most complex of the three primary events during cheese ripening. The basis of EMC technology is the use of specific enzymes acting at optimum conditions to produce required cheese flavors from suitable substrates. These enzymes consist of proteinases, peptidases, lipases, esterases. The key factors in EMC production are the type of cheese flavor required, the type and specificity of enzyme or cultures used, their concentration and some processing parameters, such as pH, temperature, agitation, aeration, and incubation time. The emulsifiers, bacteriocins, flavor compounds, and precursors also effect to it importantly. The dosage of enzyme or starter culture used is dependent on the intensity of flavor required, processing time and temperature and the quality of the initial substrate. To produce a consistent EMC product it is necessary to have a highly controlled process, and a detailed knowledge of the enzymatic reactions under the conditions used must be fully understood.

• Journal of Microbiology and Biotechnology
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• v.1 no.4
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• pp.285-287
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• 1991

To produce the tetramethylpyrazine (TMP) flavor compound, Lactococcuss lactis subsp. lactis biovar. diacetilactis (L. diacetilactis) FC1 was cultivated in the TMP medium containing 3% (w/v) of Na-citrate and 6% (w/v) arginine-HC1 as substrates of acetoin and $NH_3$, respectively, which are the two precursors of the TMP. After 19-day fermentation at $34^{\circ}C$, 0.57 g/l or 4.19 mmole/l of the TMP was produced. This was the first result showing that the TMP could be produced by L. diacetilactis.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.2
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• pp.174-181
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• 2023

Volatile flavor compounds of optimal Maillard reactions (MR) derived with the addition of precursors (AP), control (without AP) and raw as anchovy Engraulis japonicus sauce residue were identified and comparatively analyzed using solid phase microextraction/gas chromatography/mass spectrometry (SPME/GC/MS). MR was produced by adding 1% (w/w) glucose and mixed amino acids (threonine 0.543%, glutamic acid 0.194%, glycine 0.382%, w/w) to raw (100 g of anchovy sauce residue and 100 mL of distilled water), and heating at 110 ℃ for 2 h. Among 65 flavor components detected, 7 compounds were produced through Maillard reaction to change in content. A total of 7 volatile flavor compounds, including 2-methylbutanal, 3-methylbutanal, dimethyl disulfide, methylpyrazine, dimethyl trisulfide, methional, and 2-furanmethanol, tended to increase in the order of raw, control, and MR, but methylpyrazine was not detected in control. Amounts of 2-methylbutanal, 3-methylbutanal, dimethyl disulfide, methylpyrazine, dimethyl trisulfide, methional, and 2-furanmethanol having positive odors (dark chocolate-, garlic-, hazelnut-, cooked potato-like) were 11.04, 50.15, 3.25, 8.38, 4.60, 9.59, and 3.08 times higher, respectively, in MR than those in raw.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.6
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• pp.350-355
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• 2007

The optimal substrates and reaction flavoring conditions were examined to develop pearl oyster extract (POE) flavor using the Maillard reaction under a model system. The sugar for the Maillard reaction was glucose, and the amino acid was cysteine, with glycine as the reaction substrate. A three-dimensional response surface method was used to monitor the dynamic changes of the substrates during the Maillard reaction. To enhance the flavor of POE, a two-step enzymatic hydrolysate (Brix $20^{\circ}$) was reacted with the precursors (1:1, v/v). A 2:1:1 mixture of 0.4 M glucose:0.4 M glycine:0.4 M cysteine (v/v) was selected as a suitable reaction system for the reappearance of baked potato odor and boiled meat odor, and masking the shellfish odor. The two-step enzymatic hydrolysate and selected precursors were reacted in a high-pressure reactor to optimize the reaction parameters. The optimum conditions were 150 minutes at $120\;^{\circ}C$ and pH 7.0. The pH was the most critical factor for the response of the baked potato odor and masking the shellfish odor, while the reaction time affected the reappearance of the boiled meat odor.

• Culinary science and hospitality research
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• v.19 no.3
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• pp.105-115
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• 2013

Maillard reaction flavors had been tried by using krill hydrolysate and precursors in order to develop Teriyaki sauce with the reaction flavors. Also, the study for applying krill to Teriyaki sauce had been tried by using krill instead of eel bones. To make boiled-type and grilled-type reaction flavors, krill hydrolysate was used with other precursors such as serine, glucose and glucosamine. In the dynamic analysis of headspace volatile compounds, 20 mL reaction flavor was analyzed by the combined system of purge & trap, automatic desorber, gas chromatography and mass selective detector. Three kinds of Teriyaki sauce were developed with reaction flavor, krill and eel bones, and their products were evaluated by 10 items of cooked vegetables, cooked potatoes, boiled shrimp, grilled shrimp, fishy smell, pungent aroma, burned smell, sweety aroma, chemical smell, mud smell and preference. In the results of headspace analysis, 35 and 33 volatile compounds were identified from grilled-type and boiled-type reaction flavors. Grilled-type had sulfur-containing, aliphatic compounds, alcohols, ketones, pyrazines, and other aromatic compounds, and grilled-type had aldehydes, furans, other nitrogen-containing compounds. In the sensory evaluation of Teriyaki sauce, the items of roasted shrimp and sweety aroma showed significant differences for grilled-type application to Teriyaki sauce. The above results show the possible application of grilled-type reaction flavor to Teriyaki sauce.

• Fisheries and Aquatic Sciences
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• v.17 no.4
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• pp.403-408
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• 2014

Antarctic krill Euphausia superba is an excellent potential source of food protein. We used enzymatic hydrolysate of Antarctic krill and 10 other precursors to seek the optimum krill reaction flavor and apply to ramen sauce. Krill concentrate and powder were compared by sensory evaluation. The krill powder performed better preference, and was added to ramen sauce, which itself performed better than a commercial shrimp flavored sauce. In total, 47 and 39 volatile compounds were identified from krill concentrate and powder, respectively. Both products contained many aldehydes and sulfur-containing compounds. The whisky flavor of aldehydes lowered the shrimp flavor of the krill concentrate. Sulfur-containing compounds were found in krill powder, confirming the results from sensory evaluation.

• Fisheries and Aquatic Sciences
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• v.26 no.6
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• pp.393-405
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• 2023

The aim of this research was to enhance the flavor of visceral extracts from skipjack tuna. Flavor precursors and the optimum condition for the Maillard reaction were determined. The flavor extract was prepared from the tuna viscera using Endo/Exo Protease controlled in 3 factors; temperature, enzyme amounts and incubation time. The optimal condition for producing tuna viscera protein hydrolysate (TVPH) was 60℃, 0.5% enzyme (w/w) and 4-hour incubation time. TVPH were further processed to tuna viscera flavor enhancer (TVFE) with Maillard reaction. The Maillard reactions of TVFE were conducted with or without supplements such as xylose, yeast extract and methionine. The Maillard volatile components were analyzed with gas chromatography-mass spectrometry. Sixteen volatiles such as 2-methylpropanal, methylpyrazine, 2,5-dimethylpyrazine, dimethyl disulfide and 2-acetylthaizone were newly formed via Maillard reaction and the similarity of volatile contents from TVPH and TVFE were virtualized using Pearson's correlation integrated with heat-map and principal component analysis. To virtualize aromagram of TVPH and TVFE, odor activity value and odor impact spectrum (OIS) techniques were applied. According to OIS results, 3-methylbutanal, 2-methylbutanal, 1-octen-3-ol 2,5-dimethylpyrazine, methional and dimethyl trisulfide were the potent odorants contributed to the meaty, creamy, and toasted aroma in TVFE.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.3
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• pp.435-446
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• 2012

The present study identified volatile flavor components of Hanwoo longissimus muscle and other Korean foods (Doenjang, Chungukjang, sesame oil) and their traits were compared in relation with flavor precursors that include fatty acids and protein degradation products. Hanwoo longissimus muscle was purchased from a commercial abattoir while the other foods were sampled from three separate households. The results showed totals of 68 ($9.94{\mu}g/g$), 60 ($15.75{\mu}g/g$), 49 ($107.61{\mu}g/ml$) and 50 ($7.20{\mu}g/g$) volatile components for Doenjang, Chungukjang, sesame oil and Hanwoo beef longissimus, respectively (p<0.05). Aldehydes were the most predominant components in beef, but alcohols, acids and esters, and pyrazines are probably the major contributors to the flavor characteristics of other foods. SDS-PAGE revealed that beef longissimus muscle and Doenjang showed higher protein degradation than other foods which could be likely related to chiller ageing and ripening process. The total polyunsaturated fatty acids were approximately 50, 60, 41 and 5% for Doenjang, Chungukjang, sesame oil and beef longissimus muscle, respectively. Based on the mechanism(s) of generation of the volatile compounds and the chemical composition of each food sample, differences and traits of volatile flavor components among the four food types are likely due to fatty acid profiles, proteolytic activity and processing conditions. Aroma intense compounds like pyrazines and sulfur-containing compounds were limited in cooked beef in the current experimental condition (i.e., relatively low heating temperature). This suggests that higher heating temperature as in the case of roasting is needed for the generation of high aroma notes in meat. Furthermore, proteolytic activity and stability of fatty acids during ageing have a great influence on the generation of flavor components in cooked beef.

• Food Science of Animal Resources
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• v.44 no.3
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• pp.662-683
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• 2024

Thai-Native×Anglo-Nubian goat meat cooked by grilling (GR), sous vide (SV), and microwave (MW), was compared to fresh meat (Raw) in terms of flavor development. Non-volatile [i.e., free amino acids, nucleotide-related compounds, taste active values (TAVs) and umami equivalency, sugars, lipid oxidation, Maillard reaction products] and volatile compounds, were investigated. Notably, inosine monophosphate and Glu/Gln were the major compounds contributing to umami taste, as indicated by the highest TAVs in all samples. Raw had higher TAVs than cooked ones, indicating that heat-cooking removes these desirable flavor and taste compounds. This could be proportionally associated with the increase in aldehyde, ketone, and nitrogen-containing volatiles in all cooked samples. GR showed the highest thiobarbituric acid reactive substances (1.46 mg malonaldehyde/kg sample) and browning intensity (0.73), indicating the greatest lipid oxidation and Maillard reaction due to the higher temperature among all cooked samples (p<0.05). In contrast, SV and Raw exhibited similar profiles, indicating that low cooking temperatures preserved natural goat meat flavor, particularly the goaty odor. The principal component analysis biplot linked volatiles and non-volatiles dominant for each cooked sample to their unique flavor and taste. Therefore, these findings shed light on cooking method selection based on desirable flavor and preferences.

• Journal of Microbiology and Biotechnology
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• v.4 no.4
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• pp.327-332
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• 1994

Optimum conditions for the production of acetoin and ammonia as the precursors of tetramethylpyrazine(TMP) were determined using Lactococcus lactis subsp. lactis biovar. diacetylactis FC1 in a modified Lactose-citrate broth containing galactose, citrate, and arginine. The cell growth and the productivity of acetoin and ammonia were remarkably increased in an aerobic culture with 10 $\mu M$ of hematin. For the optimum conditions of acetoin and ammonia production, the concentration of citrate and arginine were adjusted to 156 mM and 50 mM after 18 hr cultivation, and citrate and galactose to 156 mM and 50 mM after 36 hr cultivation, respectively. In these conditions, acetoin and ammonia were produced to the final concentration of 127 mM and 195 mM, which were the highest concentations, respectively. The optimum conditions of the TMP production were also determined as follows; 4 hours at 121, pH 8.3, and the maximal yield of TMP under these conditions was 0.81 g/l.