• Korean Journal of Food Science and Technology
• /
• v.31 no.6
• /
• pp.1477-1483
• /
• 1999

In order to retain or remove the flavor components of onions, this study was performed to investigate the effect of seaweeds and adsorbents on volatile flavor components of onion juice by testing a sensory evaluation, measuring the amount of pyruvate and thiosulfinate, and investigating the changes of volatile components by SPME/GC. The main flavor compounds in raw onion juice were dipropyl tetrasulfide, 1-propenyl propyl trisulfide, methyl propyl trisulfide, dipropyl trisulfide. Volatile flavor compounds in onion juice treated with tangleweed, brown-seaweed, laver and celite showed a relatively decreasing tendency compared to untreated onion juice, but most of volatile flavor compounds in onion juice treated with activated charcoal and ${\beta}-cyclodextrin$ were removed. The result of the sensory evaluation with various materials for masking onion flavor showed a significant difference at the p<0.05 level. The amount of pyruvate and thiosulfinate treated with tangleweed, brown-seaweed, laver and celite showed little difference compared to untreated onion juice, but the amount of pyruvate and thiosulfinate treated with activated charcoal and ${\beta}-cyclodextrin$ decreased largely compared to untreated onion juice. As a result of the study, onion juice treated with tangleweed, brown-seaweed, laver and celite showed the effect of preserving the pungent taste and masking the onion flavor. Activated charcoal and ${\beta}-cyclodextrin$added to onion juice might have a role in removing the onion flavor by adsorbing volatile flavor compounds in onion.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.14 no.4
• /
• pp.370-374
• /
• 1985

To investigate the flavor components of sun-dried ray, Raja porasc, the contents of such as free amino acids, nucleotides and their related compounds, total creatinine, betaine, TMAO, fatty adds, and volatile compounds were analysed. The content of total free amino acids was 1773.3mg% on dry basis and the abundant amino acids were taurine, lysine, leucine, alanine, glycine, glutamic acid, proline, and valine in order and these amino acids accounted for 80% of total free amino acids in sun-dried ray. In the nucleotides and their related compounds, hypoxanthine was the most abundant. Ammonia-N was the most abundant, resulting 26.4% of extractive nitrogen which was 1965.6mg% and next free amino acid-N, total creatinine-N, and nucleotide-N in order. In the fatty acid composition of total lipid and neutral lipid, polyenoic acid was abundant holding 42.0%, 45.3% respectively. In phospholipid, the ratio of polyenoic acid and saturated fatty acid were similar to 39% respectively. The predominant fatty acids in total lipid, neutral lipid, and phospholipid were $C_{16:0},\;C_{22:6},\;C_{18:1},\;C_{18:0},\;and\;C_{20:4}$. In the volatile compounds, isocaproic acid, caproic acid, isobutyric acid, and butyric acid were the major portion of the 8 kinds of volatile fatty acids detected and 2-butanone, pentanal, and 2-methylpropanal were the major portion of the 8 kinds of volatile carbonyl compounds detected and also trimethylamine was the major portion of 2 kinds of volatile amines detected. It was presumed from the results that the reciprocal action of taste compounds such as free amino acids, nucleotides and their related compounds total creatinine, betaine, and TMAO and volatile compounds such as volatile carbonyl compounds, volatile fatty acids, volatile amines, and ammonia played an important role for the characteristics of flavor of sun-dried ray.

• The Korean Journal of Food And Nutrition
• /
• v.24 no.4
• /
• pp.567-576
• /
• 2011

A study was undertaken to examine the antioxidative activity and the quality attributes of broccoli stem powder pound cakes. Broccoli stem powder was added to the batter at a ratio of 5, 10 and 15% respectively. The antioxidant activity was estimated by DPPH free radical scavenging activity, the total phenolic compounds content and flavonoid content in Broccoli stem powder and pounds cakes. Antioxidative activity was highly correlated with the total phenolic and total flavonoids contents of broccoli stem pound cakes respectively($r$=0.937, $r$=0.981). The effect of cake improver on quality characteristics of cake broccoli stem powder and pound cakes were estimated in terms of the specific load volume, hardness, hunter value of crumb and crust and sensory quality of cakes. The specific volume were increased significantly with increasing substitution level of cake improver and broccoli stem powder($p$ <0.01). The lightness were significantly decreased with increases in broccoli stem powder of pound cake crust and crumb($p$ <0.01, $p$ <0.01). The hardness, chewiness and gumminess and cohesiveness were tended to reduce in both of powder. The consumer acceptability score for 5~10% broccoli stem pound cakes ranked significantly($p$ <0.01) higher than those of the other groups in taste, flavor and overall preference. This results showed that cake improver & broccoli stem powder are a good ingredient to increase consumer acceptability and the healthy.

• Korean Journal of Food Science and Technology
• /
• v.36 no.4
• /
• pp.542-546
• /
• 2004

Changes in contents of catechins, caffeine, free amino acids, and minerals in green tea loaves according to harvest periods were compared. Total catechin content increased from 40.61 to 52.04 mg/g, while that of caffeine decreased from 17.56 to 14.61 mg/g according to harvest periods. Regardless of harvest periods, composition of catechins was epigallocatechin (EGC)>epigallocatechin gallate (EGCg)>epicatechin (EC)>gallocatechin (GC)>epicatechin gallate (ECg)>catechin (C)>gallocatechin gallate (GCg)>catechin gallate (Cg). Free amino acid content in green tea leaves was highest in young loaves, and gradually decreased according to harvest periods. Theanine content was markedly decreased with leaf aging, suggesting taste of green tea may be changed from mild to bitter with increasing harvest period. Analyses of mineral elements in green tea leaves showed that Fe, Mn, and Mg increased with leaf aging, while Cu showed opposite trend. Results reveal that content of some chemical compounds in Korean (Posong) green tea was highly dependent on harvest period.

• Journal of Biosystems Engineering
• /
• v.41 no.2
• /
• pp.85-92
• /
• 2016

Background: The same plant, Camellia sinensis, is used to produce all types of tea, and the differences among the various types arise from the different processing steps that are used. Based on the degree of fermentation, tea can be classified as black, green, white, or oolong tea. Of these, black tea is the most or fully fermented tea. The oxidized polyphenolic compounds such as theaflavins (TF) and thearubigins (TR) formed during fermentation are responsible for the color, taste, flavor, and aroma of black tea. Results: Research indicates that an optimum ratio of TF and TR (1:10) is required to ensure a quality cup of tea. The concentrations of TF and TR as well as desirable quality characteristics increase as fermentation time increases, reaching optimum levels and then degrading if the fermentation time is prolonged. It is also necessary to control the environment for oxidation. There are no established environment conditions that must be maintained during the fermentation of the ruptured tea leaves. However, in most cases, the process is performed at a temperature of $24-29^{\circ}C$ for 2-4 h or 55-110 min for orthodox tea or crush, tear, and curl (CTC) black tea, respectively, under a high relative humidity of 95-98% with an adequate amount of oxygen. Conclusion: The polyphenolic compounds in black tea such as TF and TR as well as un-oxidized catechins are responsible for the health benefits of tea consumption. Tea is rich in natural antioxidant activities and is reported to have great potential for the management of various types of cancers, oral health problems, heart disease and stroke, and diabetes and to have other health benefits such as the ability to detoxify, improve urine and blood flow, stimulate, and improve the immune system.

• Korean Journal of Food Science and Technology
• /
• v.27 no.2
• /
• pp.257-263
• /
• 1995

As a primary step to develop natural preservative for extending the shelf-life of kimchi, the effect of 102 edible plants, 21 antimicrobial agents and related compounds on kimchi fermentation was studied. Among 42 oriental medicinal plants tested, Baical skullcap and Assam indigo were found to be highly effective for maintaining the fresh state of kimchi. Although Bugbane, Red mangolia, Bushy sophora, Szechuan pepper, Chinese quince and Scisandre significantly inhibit the growth of Lactobacilli, their effect was not high enough to be used as raw materials for kimchi preservative. When the effect of 32 herbs and spices was tested, peppermint, cinnamon, lemon balm, clove, hop, rosemary, sage, horseradish and thyme showed high antimicrobial activity against kimchi microorganisms. Among them, the effect of clove ranked top. When it was added to fresh kimchi, initial cfu value ($2.4{\times}10^{6}cfu/g$) changed little even after 2 day's fermentation ($2.6{\times}10^{6}cfu/g$). Sensory test was not a good criteria to evaluate the effect of herbs and spices, since their highly specific flavors affected the taste of kimchies. Twenty eight fruits, vegetables and related plants were tested, but only leaves of pine tree, persimmon and oak leaves showed a significant bactericidal effect, finally contributing to the storage of kimchi. In addition, when 21 natural preservatives and other compounds were added individually to fresh kimchi, nisin and caffeic acid could inhibit fermentation.

• Applied Biological Chemistry
• /
• v.35 no.4
• /
• pp.260-264
• /
• 1992

In present paper, we investigated the quality stability of sardine burgers during storage at $-20{\pm}2^{\circ}C$. During frozen storage of sardine burger, the PH were decreased, while volatile basic nitrogen contents were increased. The results of changes in peroxide values, thiobarbituric acid values, fatty acid compositions and color values during frozen storage showed that lipid oxidation and discolorization of antioxidant treated sardine burger and vacuum packed sardine burger could be effectively retarded. The changes in the taste compounds such as free amino acid, nucleotide and their related compounds, total creatinine, betaine and trimethylamine oxide, total amino acids and texture profile analysis of vacuum packed sardine burger were negligible during frozen storage. From the results of sensory evaluation and chemical experiments, the vacuum packed sardine burger could be preserved in good quality during frozen storage of 90 days.

• Food Science of Animal Resources
• /
• v.40 no.6
• /
• pp.908-923
• /
• 2020

The objective of this study was to compare tastes-related components and eating quality properties between Hanwoo steer and cow meats. Longissimus thoracis (LT) muscles with same quality grade (1⁺ grade) collected from left sides of the steer and cow carcasses were used for analyses of technological quality traits, free amino acids (FAAs), metabolites, nucleotides, fatty acids and sensory attributes. there were no differences occurring in the chemical composition (fat, protein, moisture and collagen) and technological quality traits (cooking loss, water holding capacity, shear force and color) between the two beef types (p>0.05). The cow meat exhibited significantly higher amounts of some FAAs associated with umami (e.g., glutamic acid and lysine), sweetness (e.g., proline and glutamic acid) and saltiness (e.g., histidine and glutamic acid) compared to the steer meat (p<0.05). Regarding the nucleotides, no differences occurred in all the identified nucleotides between the two beef types (p>0.05). A total of 27 metabolites were identified, however, only some compounds (e.g., acetate, creatine, creatinine, glucose and inosine, etc.) showed their significantly higher amounts in the cow meat compared with those in the steer meat (p<0.05). In terms of sensory aspects, the panelists found no differences in scores of all the eating quality traits between the two sex types of beef (p>0.05). Overall, excepts some variations in tastes-active compounds, there were no differences in the quality characteristics in general and eating quality in particular between the cow and steer meats when they were in the same quality grade.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.24 no.6
• /
• pp.925-931
• /
• 1995

Volatile compounds in Cheddar, Emmentaler, Parmesan and Roquefort cheese and cheese aroma were concentrated using a microsteam distillation-extraction apparatus and those compounds were analyzed with GC. The lipase-treated cheese aroma concentrates showed significantly higher level of short-chain free fatty acids than natural ripened cheese. The sensory properties of rancidity was high in Emmemtaler and Parmesan. Acidity and fruitness were shown high score in Roquefort. Correlation of free fatty acids and cheese flavor 'sharpness, rancidity and soapy' appear to be related(r=0.8239, 0.8918 and 0.7503), respectively. Methyl ketones, the most striking flavor components of Roquefort cheese showed high amounts in the series 2-heptanone > 2-nonanone > 2-pentanone > 2-undecanone. And the intensity of the Roquefort taste sensation 'acidity and fruitness' is linearly correlated with the methyl ketone concentrations(r=0.9284, r=0.9659).

• Animal Bioscience
• /
• v.37 no.7
• /
• pp.1277-1288
• /
• 2024

Objective: This study was aimed to investigate the effect of fresh and dried hydrolyzed Cordyceps militaris (CM) mushroom with proteolytic enzymes; bromelain (CMB), flavorzyme (CMF), and mixture of bromelain: flavorzyme (CMBF) on quality properties of spent hen chicken. Methods: Mushroom extract (CME) were combined with three proteolytic enzyme mixtures that had different peptidase activities; stem bromelain (CMB), flavorzyme (CMF), and mixture of stem bromelain:flavorzyme (CMBF) at (1:1). The effect of these hydrolysates was investigated on spent hen breast meat via dipping marination. Results: Hydrolyzation positively alters functional properties of CM protease. in which bromelain hydrolyzed group (CMB) displayed the highest proteolytic activity at 4.57 unit/mL. The antioxidant activity had a significant increment from 5.32% in CME to 61.79% in CMB. A significantly higher emulsion stability index and emulsification activity index compared to CME were another result from hydrolyzation (p<0.05). Texture properties along with the shear force value and myofibrillar fragmentation index were notably improved under CMB and CMBF in fresh condition. Marination with CM mushroom protease that was previously hydrolyzed with enzymes was proven to also increase the nucleotide compounds, indicated by higher adenosine 5'-monophosphate (AMP) and inosine 5'-monophosphate (IMP) in hydrolysate groups (p<0.05). The concentration of both total and insoluble collagen remained unchanged, meaning less effect from CM protease. Conclusion: This study suggested the hydrolyzation of CM protease with bromelain or a mixture of bromelain:flavourzyme to significantly improve functional properties of protease and escalate the taste-related nucleotide compounds and texture profiles from spent hen breast meat.