• Journal of the Korean Society of Food Culture
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• v.22 no.2
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• pp.246-253
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• 2007

Mineral and volatile flavor compounds of Pimpinella brochycarpa N., a perennial Korean medicinal plant of the Umbelliferae family, were analyzed by inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and simultaneous steam distillation extract (SDE)-gas chromatography mass spectrometry (GC/MS), head space solid phase micro-extraction (HS-SPME)-GC/MS. Mineral contents of the stalks and leaves were compared and the flavor patterns of the fresh and the shady air-dried samples were obtained by the electronic nose (EN) with 6 metal oxide sensors. Principal component analysis (PCA) was carried out using the data obtained from EN. The 1st principal values of the fresh samples have + values and the shady air-dried have - values. The essential oil extracted from the fresh and the shady air-dried by SDE method contain 58 and 31 flavor compounds. When HS-SPME method with CAR/PDMS fiber and PDMS fiber were used, 34 and 21 flavor compounds. The principal volatile components of Pimpinella brachycarpa N. were ${\alpha}$-selinene, germacrene D, and myrcene.

• Food Science and Preservation
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• v.30 no.2
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• pp.287-299
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• 2023

In vitro luwak coffee was produced using enzyme­microbial complexes. The coffee quality of non-fermented coffee beans (NFC) and fermented coffee beans (FC) was compared. The total free amino acid content was higher in FC than in NFC. The levels of glutamic acid and γ-amino-n-butyric acid in NFC were higher than those in FC; however, the contents of essential amino acids, such as lysine, leucine, and valine, in FC were higher than in NFC. During fermentation, the sucrose content decreased, whereas the fructose and glucose contents increased (p<0.001). The chromaticity of the coffee extract showed higher lightness (L), redness (a), and yellowness (b) values in FC than those in NFC. The caffeine content was significantly lower in FC (696.94±0.04 ㎍/mL) compared to that in NFC (1,130.22±1.55 ㎍/mL) (p<0.001). Conversely, the polyphenol and chlorogenic acid contents were significantly higher in NFC than in FC (p<0.001). Electronic nose analysis indicated considerable differences between the volatile aromatic components in NFC and FC. Sensory scores were significantly higher for FC than those for NFC. Therefore, the fermentation of coffee beans using enzyme­microbial complexes altered the chemical components, which promoted the Maillard reaction during the coffee bean roasting process. These results suggest the possibility of producing in vitro luwak coffee with better flavor and lower caffeine content.

• Food Science and Preservation
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• v.30 no.4
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• pp.683-690
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• 2023

The study was conducted to confirm the possibility of producing alcohol beverages from Dae-hong peaches. Upon examining the quality characteristics of distilled soju using Dae-hong peaches, the alcohol content was 1.12 to 1.16 times higher than that from the atmospheric distillation method. Soju with 20 % peach extract content had the highest alcohol content and the lowest volatile acid content, indicating a low possibility of causing irritating odors. Acetaldehyde was 1.3-1.94 times lower in vacuum-distilled soju, and methanol was not detected in all samples. The absorbance value of furfural, a burnt component generated during distillation is high in atmospheric distillation, which can cause irritating odors. Upon examining the volatile fragrance components, isoamylalcohol and 1-propanol were found to be the main components, both of which were the highest in the treatment group with 20 % peach extract content. The electronic nose analysis revealed that this group showed the most opposing flavor patterns to the control group, and when distilled under reduced pressure with 20 % addition of Dae-hong peaches can produce high-quality soju.

• Korean Journal of Poultry Science
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• v.40 no.1
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• pp.57-65
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• 2013

This study was conducted to evaluate the effect of dietary Weissella koreensis (Wk), a prominent kimchi lactic acid bacteria supplementation on growth performance, nutrients utilization, gut microbiota and meat characteristics in broiler chicken. Both live and killed Wk was compared to know which could be more efficacious as a feed probiotics. Three Wk supplemented groups and no Wk supplemented group were designated according to supplementation levels and cell status. Those were; Control (no Wk), 0.1 % live Wk (LWk 0.1), 0.5% live Wk (LWk 0.5) and 0.5% killed Wk (KWk 0.5). Body weight gain and feed conversion efficiency were improved (P<0.05) by dietary LWk supplementation. KWk did not exert any benefit on growth performance. Crude protein utilizability of KWk supplemented diet was lower (P<0.05) than that of other diets. However, there were no differences among treatments in other nutrients utilization. Serum IgG concentration and relative weight of bursa of Fabricius was highest (P<0.05) in broiler chicken fed KWk 0.5 diet. Cecal anaerobic lactic acid bacteria count of LWk groups were higher (P<0.05) than those of control and KWk 0.5 groups. Dietary Wk supplementation failed to lower the count of cecal and fecal E. coli. There was no effect of dietary Wk on TBARS values and fatty acids profile of broiler leg meat. However, the dietary supplementation of Wk exerted characteristic difference on electronic nose flavor of broiler meat. This study showed that dietary supplementation of LWk was able to improve body weight gain, feed conversion efficiency and cecal lactic acid bacterial count in broiler chicken. Further, the result of this study implemented that a live kimchi lactic acid bacteria, LWk, but not killed Wk, could be used as a probiotic feed supplement for broiler.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.12
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• pp.1769-1775
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• 2016

Aerial parts (leaves and stems) of radish are usually discarded due to the distinct undesirable flavors associated with inappropriate preparations, despite their many health benefits. In this study, we examined the role of extrusion process in the removal of off-flavors and elevation of antioxidant activity in radish (Raphanus sativus L.) leaves and stems. To optimize the extrusion conditions, we changed the barrel temperature (110, 120, and $130^{\circ}C$), screw speed (150, 200, 250, and 300 rpm), and moisture content (20, 25, and 30%). The polyphenol and flavonoid contents significantly increased in extruded radish leaves and stems (ER) under optimum extrusion conditions ($130^{\circ}C$, 250 rpm, and 20%). Under extrusion conditions, we compared off-flavors (as amount of sulfur-containing compound) levels between ER and non-extruded radish leaves and stems (NER) by an electronic nose. A total of six peaks (sulfur-containing compound) were similarly detected in both ER and NER, whereas the ER showed reduced off-flavors. Levels of glucosinolate (${\mu}g/g$), which can be hydrolyzed into off-flavors during mastication or processing, were significantly decreased in the ER. From these results, extrusion processing can be an effective method to increase anti-oxidant activity and removal of off-flavors in radish leaves and stems.

• Food Science of Animal Resources
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• v.32 no.3
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• pp.346-353
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• 2012

This study was carried out in order to investigate the relationship of antioxidant enzyme activity, lipid oxidation, and aroma pattern of Hanwoo (Korean cattle) beef for 8 d at $15^{\circ}C/RH$ 100% under 0% $O_2$/20% $CO_2/80%\;N_2$, 25% $O_2$/20% $CO_2/55%\;N_2$, 50% $O_2$/20% $CO_2/30%\;N_2$, and 75% $O_2$/20% $CO_2/5%\;N_2$-conditions. The reduction of $O_2$ and the induction of $CO_2$ were shown in the 25-75% $O_2$-groups during storage and total change rates of $O_2$ and $CO_2$ were followed in order: 25%>50%>75%. Catalase activity was not significantly different among all groups. During storage, glutathione peroxidase activity decreased by increasing the $O_2$ concentration and was followed at 8 d in order: 0%>25%>50%>75% (p<0.05). From 2 d of storage, TBARS content had significant (p<0.05) differences in order: 0%>25%>50%>75%. The CIE $L^*$ value was higher (p<0.05) in the 25-75% $O_2$-groups, compared with the 0% $O_2$-group. During the first time, the CIE $a^*$ value was higher (p<0.05) in order: 0%<25%<50%<75% but was lower (p<0.05) in the 25-75% $O_2$-groups from 2 d of storage than in the 0% $O_2$-group. The CIE $b^*$ value was higher (p<0.05) in the 25-75% $O_2$-groups than in the 0% $O_2$-group and had significant (p<0.05) differences at 0 and 8 d in order: 0%<25%<50%<75%. Aroma patterns with the electronic nose were clearly discriminated between the 0% $O_2$-groups and the 25-75% $O_2$-groups at 8 d of storage. Therefore, high oxygen reduced stabilities of antioxidant enzymes, lipid oxidation, and color in Hanwoo beef. Furthermore, antioxidant enzyme activities and lipid oxidation could affect aroma patterns.

• Food Science and Preservation
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• v.17 no.5
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• pp.733-740
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• 2010

Brown rice vinegars were prepared by agitated or static acetic acid fermentation using different yeast strains (Saccharomyces kluyveri DJ97, Saccharomyces cerevisiae JK99, Saccharomyces cerevisiae GRJ, or Saccharomyces cerevisiae H9). Organic acid contents and levels of volatile compounds were compared in vinegars prepared by different methods. The chosen yeast strain did not significantly affect the organic acid content of vinegar. In vinegars prepared by agitated acetic acid fermentation, organic acid contents were, in the order of descending abundance, acetic acid, citric acid, lactic acid, oxalic acid, and tartaric acid. In vinegars prepared by static acetic acid fermentation, no citric acid was detected, and lactic acid content was higher than that in agitated acetic acid fermented vinegar. The volatile compounds of both vinegars, analyzed by GC-MS, did not significantly differ when various yeast strains were used. Eighteen volatile compounds were detected in vinegar prepared by agitated acetic acid fermentation and 11 in vinegar prepared by static fermentation. Volatile compounds that can affect vinegar quality, including ethyl acetate and phenethyl acetate, were present at high concentrations in static acetic acid fermented vinegar. Electronic nose analysis showed that volatile chemical patterns differed between the two types of vinegar, but there were no significant differences in sensory scores between vinegars prepared using various yeast strains or by either of the two methods of fermentation.