• Korean Journal of Food Science and Technology
• /
• v.48 no.1
• /
• pp.86-91
• /
• 2016

Oxidative stress caused by reactive oxygen species is ascribed to many neurodegenerative diseases like Alzheimer's disease. Phenolic antioxidants can reduce the oxidative stress. In this study, ripe fruits of Opuntia ficus-indica var. saboten (OFS) were extracted using 80% (v/v) aqueous ethanol. Total phenolic and flavonoid contents of the OFS fruits (100 g) were 409.9 mg gallic acid equivalents and 72.2 mg catechin equivalents, respectively. The OFS fruits had antioxidant capacity at 381.2, 298.2, and 3,219.9 mg vitamin C equivalents/100 g in ABTS, DPPH, and ORAC assays, respectively. The OFS fruits showed protective effects on PC-12 cells against oxidative stress in a dose-dependent manner, partly due to decrease of intracellular oxidative stress. Furthermore, the OFS fruits inhibited both acetylcholinesterase and butyrylcholinesterase. Consequently, these results suggest that the OFS fruits might be served as a source of functional materials to reduce oxidative stress in neuronal cells and to inhibit cholinesterases.

• Korean Journal of Food Science and Technology
• /
• v.40 no.2
• /
• pp.160-165
• /
• 2008

This study was conducted to analyze sensory profiles of commercial sojues using a standardized sensory evaluation procedure, and to investigate the effects of sensory characteristics and brands on consumer liking for soju. Descriptive analysis and consumer taste testing were conducted for seven commercial sojues. For the descriptive analysis, eight panelists generated and evaluated 12 flavor and one pain-sensation attributes for the soju, and there were significant differences among the soju samples for all the 13 sensory attributes. For the descriptive data, principal component analysis was performed to summarize the sensory characteristics of the sojues. For the consumer testing, 224 soju drinkers (20-29 year-olds) were recruited and randomly divided into two groups; a blind group and a group with the knowledge of brand. While the hedonic ratings obtained from the blind group didn't indicate significant differences among the sojues, the ratings obtained from the brand-informed group showed significant differences. Finally, the individual preferences of the 112 consumers in each group were investigated by preference mapping techniques.

• Korean Journal of Food Science and Technology
• /
• v.52 no.2
• /
• pp.177-182
• /
• 2020

This study evaluated the effect of steam heating, gamma irradiation, and ultraviolet (UV) irradiation on microorganism reduction in order to determine an effective sterilization method for red pepper powder. The effect of each treatment on the reduction of thermoduric bacteria and total aerobic bacteria in red pepper powder were as follows: 10 kGy gamma irradiation, reduction of 4 log and 6 log CFU/g, respectively; 12 mW/㎠ UV irradiation (264 nm UV-C), reduction of less than 1 log CFU/g; steam heating at 120℃ for 40 s, reduction of approximately 2 log CFU/g. High-temperature short-time processing at 110℃ for 30 s reduced the total bacterial count in Gochujang solution from 5.70 log CFU/g to 2.26 log CFU/g; at 121℃, the solution was commercially sterile. Steam heating resulted in 1, 2, and 4 log microbial inactivation in garlic, onion, and pepper powder, respectively. Steam sterilization, which consumers prefer over other methods, may be an effective method for reducing microorganisms in spice powders, including those in red pepper powder.

• Korean Journal of Food Science and Technology
• /
• v.52 no.2
• /
• pp.113-118
• /
• 2020

We investigated the quality characteristics and antioxidant capacities of Korean commercial yogurt. Twenty commercial yogurt samples exhibited a pH of 4.05-4.51, titratable acidity of 0.80-1.45%, viable counts of 6.65-9.39 log CFU/g, and total phenolic content of 0.71-2.92 mg gallic acid equivalent/g dry weight (dw). Lactic acid was the major organic acid detected by HPLC with UV detection, and its content was 5.4 times and 46.5 times higher than that of malic acid and citric acid, respectively. The tested commercial yogurt samples exhibited antioxidant potential (1.62-8.95 mM trolox equivalent/g, dw) measured based on scavenging activities of DPPH and ABTS radicals. The average antioxidant potentials of commercial set yogurt containing fruit syrup were significantly (p<0.05) higher than that of cream and plain yogurt. A positive linear correlation was observed between the total phenolic content and the antioxidant capacities, suggesting that phenolic components are likely to contribute significantly to the antioxidant potential of commercial yogurt.

• Journal of Food Hygiene and Safety
• /
• v.29 no.4
• /
• pp.253-259
• /
• 2014

This study was conducted to investigate survival of Bacillus cereus (B. cereus) on stainless steel and polyvinyl chloride (PVC) and its transfer from two material to lettuce. The stainless steel and PVC were innoculated with B. cereus and stored at 6 combination conditions (temperature : $20^{\circ}C$ and $30^{\circ}C$, relative humidity (RH) : 43%, 69%, and 100%). Although the total numbers of B. cereus at RH 43% and RH 69% were reduced by 3.53-4.00 log CFU/coupon within 24 h regardless of material type, the spore numbers of B. cereus was lasted at 3.0 log CFU/coupon. When two materials were stored at $30^{\circ}C$, RH 100%, the spore numbers of B. cereus was rapidly increased by 3.0 log CFU/coupon. In addition, the reduction rate of B. cereus was decreased in the presence of organic matter. Transfer rate of B. cereus from surface of stainless steel and PVC to lettuce was increased by 10 times in the presence of water on the lettuce surface. As a result of this study, the presence of B. cereus on produce contact surfaces can increase the risk of cross-contamination. Thus, it is important that the packing table and conveyer belt in post harvest facility should be properly washed and sanitized after working to prevent cross-contamination.

• Korean journal of food and cookery science
• /
• v.25 no.4
• /
• pp.445-451
• /
• 2009

In this study, the effects of Corchorus olitorius powder on the quality characteristics of emulsion type sausages during storage at $4^{\circ}C$ for 28 days was evaluated. Sausages were produced containing 0.5%, 1.0% and 1.5% C. olitorius powder. The pH values of sausage containing C. olitorius powder were higher than the control during 28 days of storage. The L and a values of sausage containing C. olitorius powder significantly decreased with increasing C. olitorius powder content; however, the b values significantly increased. The volatile basic nitrogen (VBN) and nitrite content of sausage containing C. olitorius powder were lower than that of the control. Especially, the VBN and nitrite content of sausages containing 1.5% C. olitorius powder were significantly lower compared to the control. In addition, sausages with $0.5{\sim}1.0%$ C. olitorius powder had higher hardness, cohesiveness, gumminess and brittleness than the control. In regards to the sensory evaluation, sausages containing 0.5% C. olitorius powder had the highest overall acceptability. Therefore, these results suggest that it may be possible to manufacture sausages containing 0.5% C. olitorius powder to help improve the overall quality of sausage.

• Food Science of Animal Resources
• /
• v.29 no.3
• /
• pp.356-363
• /
• 2009

This study was carried out to investigate the effect of hot boning and curing condition on the quality characteristics of ground chicken breast. Treatments were cured by four conditions follows; control (general curing method), T1 (after hot-boning and then immediately cured), T2 (after hot-boning and immediately cured, then frozen), and T3 (after hot-boning, immediately frozen, refrigerated and then cured). The pH of chicken breast in the state of pre-rigor was 6.22. The pH of cold storage or freezing chicken breast meat respectively were 5.70 or 5.61. The pH of T1 and T2 treatments were significantly higher than those of control and T3 treatment (p<0.05). After stored for 1 wk, the pH value of T1 treatment had a higher value than those of other treatments. T1 treatment had the highest water holding capacity and the lowest cooking loss among all treatments, regardless of the cooking methods. The reduction in diameter for T1 and T2 treatments was lower than those of control and T3 treatment (p<0.05). T1 treatment had the lowest fat loss and moisture loss among all treatments, and the emulsifying capacity of T1 treatment was the highest. The protein solubility of T1 treatment was significantly lower than that of T3 treatment.

• Korean Journal of Food Science and Technology
• /
• v.34 no.4
• /
• pp.631-636
• /
• 2002

Lethality of high intensity light pulse on the pre-determined microbial populations has been investigated. Prior to the treatment, Lactobacillus plantarum, Lactobacillus brevis, Leuconostoc mesenteroides and Pediococcus pentosaceus were cultivated separately onto the surface of Lactobacilli MRS agar. Pre-determined microbial populations were applied to the test media and these sample were exposed to high intense light source with an exposure time ranging from 1 to $2500\;{\mu}s$. Results showed that at least 200 light pulses of $1\;{\mu}s$ duration were required to reduce L. Plantarum cells by 90% at 25 kV, the greater the number of light pulses, the larger the reduction in viable cell numbers. Viable cells of L. plantarum and the others were reduced by more than 5 and 6 log cycles at the upper exposure level of $750\;{\mu}s$, respectively. These study shows that pulsed light emissions can significantly reduce populations of lactic acid bacteria on exposed surface with exposure times. Killing efficiency for L. plantarum significantly increased with decreasing the distance between the lamp and the surface of samples.

• Korean Journal of Food Science and Technology
• /
• v.34 no.3
• /
• pp.480-486
• /
• 2002

Six strains of intestinal pathogenic bacteria were inoculated into kimchi at the preparation time, and the influence of kimchi fermentation on the growth of these pathogenic bacteria was investigated. The population of coliform bacteria in the kimchi raw materials, and its changes in the kimchi sample during fermentation were also determined. Among the raw materials, highest populations of coliform bacteria were detected in ginger and green onion, followed by Chinese cabbage, red pepper, and garlic. Populations of pathogenic bacteria (inoculated strains) and coliform bacteria in kimchi decreased as pH decreased with fermentation. Coliform bacteria disappeared at pH 3.9 in Chinese cabbage kimchi samples. Clostridium perfringens ATCC 13124, Listeria monocytogenes ATCC 19111, Salmonella typhimurium KCTC 1625, Staphylococcus aureus KCTC 1621, Vibrio parahamolyticus ATCC 27519, and Escherichia coli O157 H:7 ATCC 43894 were not detected at pH values less than 4.1, 3.7, 3.8, 3.8, 3.7, and 3.7 in Chinese cabbage kimchi, and at pH values less than 4.5, 4.0, 4.2, 4.2, 4.2 and 4.1 in mustard leaf kimchi, respectively. The juice of mustard leaf and allyl isothiocyanate exhibited high antimicrobial activities on the pathogenic bacteria, whereas the lowest on lactic acid bacteria. These results indicated that fermentation is useful to improve the safety of kimchi, and the antimicrobial effect of mustard leaf kimchi is mainly due to the major pungent compound of mustard leaf, allyl isothiocyanate.

• The Korean Journal of Food And Nutrition
• /
• v.30 no.4
• /
• pp.703-709
• /
• 2017

This study analyzed the effect on weight and average daily gain, carcass grade, and blood characteristics and immunity in case of dietary addition of pegmatite to Hanwoo steers. Relative to Hanwoo steers, initial body weight was $257.3{\pm}11.74kg$ (8-months old after birth). Forty-eight Hanwoo steers were fed for 24 months using random arrangement (4 treatment plots${\times}$4 heads${\times}$3 repeat). The treatment plot (498.75~500.82 kg) had higher weight during the early fattening stage compared with that of the control plot (474.37 kg) (p<0.05). Regarding total cholesterol of the blood, the value was similar to one during initiation of testing, but the value increased gradually based on the progress of fattening. In addition, the triglyceride was considerably low in T2~T3 plots with high addition of pegmatite during the late fattening stage compared with other treatment plots (p<0.05). This study revealed a tendency in the IgG content that represented immunity as the addition of pegmatite became higher (p>0.05). This study found that the treatment plot (441.55~452.10 kg) had higher carcass weight compared with the control plot (436.30 kg). However, this study revealed that the treatment plot (2.30~2.55 points) had higher carcass quantity grade compared with the control plot (2.11 points). This study found that the control plot (3.55 points) had higher carcass quality grade compared with the treatment plot (2.67~3.09 points) (p>0.05). With studies combined, it was determined that dietary addition of pegmatite to the feed as clay minerals in fattening Hanwoo steers would improve feed intake, body weight gain and carcass quantity grade.