• The Korean Journal of Food And Nutrition
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• v.35 no.5
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• pp.302-312
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• 2022

The purpose of this study was to investigate the Maillard reaction-related physicochemical properties of three maize varieties (Kwangpyeongok, Sinhwangok2ho and Gangdaok) after roasting them for different times (0, 15, 25, 40, and 55 minutes). The Maillard reaction is a non-enzymatic browning reaction involving reducing sugars and amino compounds. The content of reducing sugar, the causative agent of the Maillard reaction, decreased as roasting time increased. Gangdaok showed the lowest reducing sugar content of 1.04 mg/g after 55 minutes of roasting. In the elapsed roasting time, chromaticity 'L' and 'b' values decreased. At 55 minutes of roasting, wherein the Maillard reaction occurred most actively, Gangdaok showed the lowest 'L' value of 56.37 and the highest 'a' value of 7.60. Gangdaok had superior conditions for inducing the Maillard reaction compared to other varieties, and it is consider that 'flint-type', an endosperm characteristic, may have been the influencing agent. This study detected a total of 52 types of volatile aroma compounds (VACs), of which 28 were produced after roasting. Of the total VACs detected, 2-Formyl-5-methylfuran and 2-Furancarboxaldehyde accounted for 43.8~45.5% and have been confirmed to be the major VACs present in roasted maize. Most of the correlations between the Maillard reaction-related characteristics showed high correlation coefficients.

• 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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.10
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• pp.1555-1564
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• 2014

This study investigated the effects of combined treatment of immersion liquids (adjusted pH 4.5 with Citrus junos concentrate (CL), pH 5.5 with Prunus mume concentrate (PL), or no pH adjustment, pH 6.5, control) and high hydrostatic pressure (HHP, 450 MPa) on shelf-life and quality of mackerel. In this study, we measured changes in viable cell counts, pH level, volatile basic nitrogen, thiobarbituric acid reactive substances, color analysis, volatile organic compounds, and sensory evaluation of mackerel at $4^{\circ}C$ for 20 days. CL/HHP and PL/HHP treatments reduced viable cell counts by 3 log cycles during storage compared to the control. Mackerel treated with CL/HHP and PL/HHP showed significantly lower TBARS and VBN levels as compared to the control. After combined treatment, lightness and whiteness increased but redness decreased. VOCs tests showed that contents of alcohol, acid, and ketones in mackerel fillet treated with CL/HHP and PL/HHP were relatively reduced. Especially, CL/HHP and PL/HHP suppressed production of sulfur. In the sensory evaluation, aroma, taste, salinity, hardness, and springiness of mackerel treated with combined HHP showed higher scores than the control. These results suggest that immersion liquids and HHP treatments may increase shelf-life of mackerel and maintain quality during storage at $4^{\circ}C$.

• Korean Journal of Poultry Science
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• v.46 no.3
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• pp.137-154
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• 2019

This study was conducted to develop and compare Samgyetang broth from extract of pre-treated chicken feet. Chicken feet were subjected to non-heating (control), heating at $70^{\circ}C$ for 12 h in a hot air dryer, and heating at $180^{\circ}C$ for 1 h in an oven. The heat-treated chicken feet were extracted at $121^{\circ}C$ for 1 h and 2 h, respectively. The extract was placed in a pouch with whole chicken carcass ($470{\pm}10g$). The sealed Samgyetang retort was made according to the industrial method. The pH of the extract from preheated chicken feet was lower than that extracted from fresh chicken feet. The Thiobarbituric Acid Reactive Substances (TBARS) value of the preheated chicken feet extract was significantly lower (P<0.05) than that of fresh chicken feet extract, but there were no significant differences among the broths. As the extraction time increased, the pH and TBARS value decreased in the extract (P<0.05) but increased in the broth (P<0.05). According to the sensory evaluation test, the extract from 1 h hot air heating and drying was significantly better in appearance, aroma, and overall preference than the other treatments (P<0.05). The GC-MS results showed that benzaldehyde and benzothiazole, which are widely known to give meat and nuts flavor, were detected in those treatments (P<0.05). The Samgyetang broths prepared from 1 h hot air heating and drying extract were significantly higher in the overall acceptability according to the sensory test (P<0.05). In summary, the quality of retort Samgyetang broth can be improved by adding chicken feet extract which is subjected to heating and drying for 1 h.

• Korean Journal of Poultry Science
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• v.45 no.1
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• pp.53-62
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• 2018

This study was performed to evaluate the effect of lemon and cranberry juice on meat quality of chicken thighs during cold storage. Experimental groups were chicken thigh meat dipped into distilled water (CON), 1% lemon juice (LJ), 1% cranberry juice (CJ), and a mixture of 0.5% lemon juice and 0.5% cranberry juice (LCJ). The meat quality traits were determined at day 0, 3, 6, and 9 during cold storage at $4^{\circ}C$. The pH value of all treatments was lower than that of the control (P<0.05). Total microorganisms of CJ and LCJ at day 9 was 6.94 and 6.76 log CFU/g, respectively, whereas that of the control was 7.51 log CFU/g. The $a^*$ value of CJ and LCJ was higher than that of CON and LJ during storage (P<0.05), whereas the $b^*$ value of LJ, CL, and LCJ was lower than that of CON at day 6 and 9 (P<0.05). Overall acceptability of all treatments was significantly higher than that of CON after day 3. Thiobarbituric acid reactive substances and volatile basic nitrogen values were lower than those of the CON after day 3 (P<0.05). Principle component analysis (PCA) of the aroma pattern of all treatments was closer together, whereas PCA of the CON was scattered with the increase in storage days. This result suggests that dipping the chicken thigh meat into the lemon and cranberry juice could be beneficial to enhance chicken thigh meat quality by retardation of total microbes, lipid oxidation, and protein decomposition.

• Journal of Animal Science and Technology
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• v.49 no.6
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• pp.847-856
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• 2007

This study was conducted to determine the effect of cryoprotectants(sugar, sorbitol, polyphosphate) on quality properties of chicken breast surimi manufactured by pH adjustment(pH 11.0) during frozen storage. Final surimi was divided into experimental units to which the following treatments were randomly assigned: C(Alaska pollack surimi, two times washing, 4% sugar＋5% sorbitol＋0.3% polyphosphate additive); T1(chicken breast surimi, 0.3% polyphosphate additive); T2(chicken breast surimi, 5% sorbitol ＋0.3% polyphosphate additive); T3(chicken breast surimi, 4% sugar＋5% sorbitol＋0.3% polyphosphate additive). All amino acid contents of control were higher than those of all treatments, while T2 was higher in amino acid contents among the treatments. Shear force of all treatments were higher than that of control, but the breaking force, deformation and gel strength were lower. The TBARS(thiobarbituric acid reactive substances) and VBN(volatile basic nitrogen) values of all treatments were lower than those of control, The TBARS values of all treatments were increased with increased storage period. In sensory evaluation, the score of appearance, meat color and overall acceptability of control were higher than those of all treatments, but aroma, juiciness and tenderness were lower than those for all treatments.

• Journal of Animal Science and Technology
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• v.47 no.5
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• pp.837-850
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• 2005

This study was conducted to investigate the changes of quality characteristics on seasoned pork with Korean traditional 4 types seasoning such as soybean sauce(T1); Kimchi sauce(T2); pickled shrimps sauce(T3); onion sauce(T4). The seasoned samples were aged at 10±1℃ for 13 days. The results obtained were as follows; Except for T2, pH of treatments were significantly decreased(P<0.05) as aging period increased. Salinity(%) and saccharinity(%) of seasoned meat were tended to increased during aging period. Thiobarbituric acid reactive substances(TBARS) were increased significantly during storage in all treatment(P<0.05). T4 showed the highest TBARS among the all treatment groups. Volatile basic nitrogen(VBN) values of all treatments were significantly increased(P<0.05) as storage period increased. There were no significant differences in water holding capacity(WHC) among the all treatments, and those values were not changed by the passage of storage days. Shear force values of all treatments were tended to decreased by the passage of storage days. In surface color, the values of L*, a* and b* showed a tendency of increasing value along the storage days. The values of a* and b* of T2 were significantly higher than other treatments during aging period(P<0.05). In inner color, a* and b* values of T2 were significantly higher than those of other treatments during aging period(P<0.05). In the sensory evaluation of cooked meat, T3 treatment resulted in lower score in aroma, flavor, tenderness, juiciness and overall acceptability. The number of total plate counts and Lactobacilli spp. tended to increase with storage in all treatments group. The numbers of Escherichia coli were not changed by the passage of storage time.

• Journal of Life Science
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• v.20 no.1
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• pp.55-59
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• 2010

In this study, the physicochemical and sensory characteristics of chicken press ham not fed with citrus byproduct (T0) and fed with citrus byproduct (T1) were compared. There was not a significant difference in moisture, crude protein, crude fat, crude ash, crude fiber, Hunter's $L^*$ (lightness), $a^*$ (redness), $b^*$ (yellowness), hardness, springiness, cohesiveness, gumminess, chewiness, shear force, water holding capacity and pH between T0 and T1. There was not a significant difference between T0 and T1 in terms of the chicken ham's VBN (volatile basic nitrogen) content for the first three weeks of storage, but after the fourth week of storage, the VBN content was 15.1 and 13.7 mg% for T0 and T1, respectively, which implies that feeding citrus byproduct significantly reduced the VBN content. There was not a significant difference between T0 and T1 in terms of the chicken press ham's TBARS (2-thiobarbituric acid reactive substances) value for the first two weeks of storage. However, the TBARS value was 0.31 and 0.22 mg malonaldehyde/kg for T0 and T1 during the third week of storage, and 0.49 and 0.32 mg malonaldehyde/kg for T0 and T1 during the fourth week of storage. There was not a significant difference between T0 and T1 in terms of the chicken press ham's TPC (total plate counts) for the first three weeks of storage, but after the fourth week of storage, the TPC was 4.96 and 4.72 log CFU/g for T0 and T1, respectively, which implies that T1 showed a significantly lower TPC than T0. T1 showed significantly higher aroma, taste, and palatability of the chicken press ham than T0, but there was a not significant difference in texture and juiciness between T0 and T1.

• Korean Journal of Food Science and Technology
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• v.26 no.5
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• pp.500-506
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• 1994

For comparison of beef quality, four kinds of beef (Korean native cattle beef, dairy cattle beef, imported beef, cross-bred beef) were investigated through tenderness, juiciness and flavor related components measurement and organoleptic tests. Flavor related chemical components such as NPN, IMP, free fatty acid and free amino acids were analyzed, water holding capacity, contents of hydroxyproline and intramuscular fat were measured for evaluation of beef tenderness. Instron was also used for measuring beef tenderness as an objective method. Triangle test and descriptive analysis test were conducted for comparison and evaluation of preference of various beef samples. In hardness analysis using Instron, imported and cross-bred beefs had higher value than that of Korean native cattle or dairy cattle beef. Water holding capacity and pH of Korean cattle beef was higher than that of others. The intramuscular fat content of Korean cattle beef was highest, so it was expected juicier than other beef. In flavor related compound analysis, NPN content of Korean native cattle beef was the lowest, which shows it spent the least time among sample meats after slaughter. IMP, hypoxantine and inosine were most abundant in Korean native cattle beef. In free amino acids analysis showed that the proportion of basic acid and aromatic acid content of Korean native cattle beef was highest, whereas that of sulfur containing amino acid of imported beef was highest. TBA value of Korean native cattle beef was the lowest, and analysis of fatty acid composition revealed that the proportion of unsaturated fatty acid of Korean native cattle beef was higher than imported and dairy cattle beef, but similar to cross-bred beef. Organoleptic test was performed by triangle test and descriptive analysis. In triangle test, most panelist could distinguish Korea native cattle beef from imported beef and cross-bred beef, imported beef from cross-bred beef. In descriptive analysis which relys on subjective standards of panelists, there was no difference among beef in aroma, flavor and tenderness except juiciness. Even though contents of non volatile flavor compounds in Korean native cattle beef were higher than those of other beef samples, there were no significant differences in subjective panel test. The results showed that Korean consumers do not have common standards for beef quality evaluation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.3
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• pp.285-290
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• 2001

To utilize canned oyster processing waste water effectively, this study was carried out to prepare instant powdered soup using the waste water (IPSW), Instant powdered souu from oyster hot-water extracts (IPSE) was prepared by mixing hot-water extracts powder (15 g) with table salt (5 g), cream powder (19 g), milk replacer (12 g), wheat flour (20 g), corn flour (15 g), starch (5 g), glucose (7.5 g) and onion powder (1.5 g). In preparing IPSW, mixed powder from wash water and boiling liquid waste, instead of powder from hot-water extracts and table salt, was added (powder from boiling liquid waste: powder from wash water= 12: 8) and other additives were added in proportion to those in the IPSE, The IPSW consists mainly of carbohydrates (about $72\%$). It was not different from the IPSE. The volatile basic nitrogen, viable cell counts, coliform group of the IPSW contains 33.4 mg/100g, $2.2\times10^4CFU/g$, <180 MPN/100g, respectively, and its water activity has 0.257. So it was a hygienically safe and conservable instant food. The main fatty acids of IPSW were 16: 0 and 18: 1n-9. Its chemical score of protein was $61.4\%$ and its main inorganic matter was iron. According to a sensual evaluation, in contrast to the IPSE, the IPSW had a bit lower aroma but better taste, It was concluded from the above chemical and sensory evaluation that even the boiling liquid waste which had been mostly abandoned because of its high table salt content can be used as a good material for instant powdered soup if it's powdered and mixed adequately with powder from wash water, and its table salt content is properly adjusted.