• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.26 no.3
• /
• pp.221-229
• /
• 1993

In this study fermentation of fresh ascidian was attempted to widen the utility of ascidian. Fresh deshelled and sliced ascidians were fermented for 90days at $25^{\circ}C$ with different salt contents of 5, 10, 15 and $20\%$ (w/w) and at $5^{\circ}C$ with 5 and $10\%$ salt. Changes of such components during fermentation as free amino acids, nucleotides and the related compounds, volatile basic nitrogen(VBN), trimethyl amine(TMA), amino nitrogen and total creatinine were determined. VBN increased rapidly after 30days of fermentation at $25^{\circ}C$ while slowly in cases of fermentation at $5^{\circ}C$ and with high salt concentration. Amino nitrogen and the total creatinine also increased gradually until 45 days and 30days of fermentation, respectively, hereafter tended to decrease. ATP and ADP seemed to degrade rapidly in fresh ascidian post harvest and AMP, IMP and inosine also degraded down to hypoxanthine during fermentation. After 45days of fermentation, in the free amino acid composition of fermented ascidian were taurine, proline, glutamic acid, histidine, lysine, alanine and valine in order. The amino acids known as sweetner like prolline, lysine, alanine and glycine were in increased in fermented ascidian. The result of sensory evaluation of fermented ascidian pretreated with acid or sulfite solution showed that the peculiar taste and flavor of ascidian remained without browning for 45days fermentation at $5^{\circ}C$.

• Journal of Animal Science and Technology
• /
• v.51 no.1
• /
• pp.61-68
• /
• 2009

The effects of hot-air dried tomato powder (HADTP) with 0% (C), 0.25 (T1), 0.50 (T2), 0.75 (T3) and 1.00% (T4) addition to the pork patties on the physicochemical and sensory properties during storage at $-20^{\circ}C$ for 20 days were studied. Cooking loss, thiobarbituric acid reactive substances (TBARS), volatile basic nitrogen (VBN) and CIE $L^*$ values of all products were increased (p<0.05) significantly as the storage period increased, while the pH values were decreased (p<0.05). The CIE $a^*$ and $b^*$value of all samples showed a tendency of decreasing value through the storage days. The pH and cooking loss of T4 were significantly lower (p<0.05) than those of other treatments. The TBARS values of treatments were significantly lower (p<0.05) compared to those of control, but CIE $a^*$ and $b^*$ values of treatments were higher (p<0.05) than those of control at day 20 of storage. VBN values of treatments were significantly lower (p<0.05) than those of control at day 20 of storage. In the sensory evaluation, color and overall acceptability in T3 and T4 were higher (p<0.05) than the others until 15 days of storage. In conclusion, pork patties with 0.75~1.00% HADTP had a higher acceptability, redness and lipid oxidative stability during freeze storage than products without HADTP.

• Food Science of Animal Resources
• /
• v.29 no.5
• /
• pp.573-578
• /
• 2009

This study examined the effect of gamma irradiation on shelf-life extension and sensory characteristics of dak-galbi. Commercial dak-galbi sauce was gamma-irradiated at 0, 5, 10, 15, 20, 25, and 30 kGy. The dak-galbi sauce (200 g) was then added to diced chicken (800 g) for cooking, and the cooked dak-galbi samples in vacuum bags were stored at $35^{\circ}C$ for 5 d. Dak-galbi samples were analyzed on d 0, 1, 2, 3, 4, and 5 for microbial analysis (plate count agar), thiobarbituric acid (TBARS) and volatile basic nitrogen (VBN) measurements, and on d 0 for sensory evaluation. On d 0, total bacterial populations were below detection limit after dak-galbi marinated with the gamma-irradiated (${\geq}15\;kGy$) sauces were cooked, and the samples marinated with higher dose irradiated dak-galbi sauce had lower (p<0.05) bacterial populations during storage. TBARS values of the dak-galbi samples marinated with non-irradiated sauce were not different ($p{\geq}0.05$) with those marinated with irradiated sauces on d 0, and the TBARS values increased (p<0.05) during storage at $35^{\circ}C$, regardless of irradiation dose. In the VBN analysis, there was no difference ($p{\geq}0.05$) in VBN values among irradiation doses on d 0, but VBN values decreased (p<0.05) as irradiation dose increased during storage. Moreover, there were no significant differences ($p{\geq}0.05$) in sensory characteristics among irradiation doses. These results indicate that use of gamma irradiation on dak-galbi sauce may be useful in shelf-life extension without compromising the sensory characteristics of dak-galbi.

• Korean Journal of Poultry Science
• /
• v.37 no.3
• /
• pp.265-273
• /
• 2010

The objective of this study was to investigate the effects of addition of green tea extracts on physicochemical properties and shelf-life of seasoned chicken with soy sauce during cold storage. Treatments (C, T1 and T2) containing various levels (0, 1 and 2%, respectively) of green tea extracts were manufactured, and we investigated pH, meat color ($L^*,a^*,b^*$), volatile basic nitrogen (VBN), thiobarbituric acid reactive substances (TBARS), total plate counts, fatty acid composition and sensory scores during cold storage for 16 days. T1 and T2 have more dark color than control during storage time. VBN, TBARS and total plate count of control were significantly higher than those of T1 and T2 at the latter storage time (p<0.05). Also, VBN, TBARS and total plate count of all treatments was increased with storage time. Linoleic acid was the highest value in control which had the highest value of TBARS in day 16 (p<0.05). Aroma value of control was significantly higher in storage time except day 16 than those of T1 and T2 (p<0.05). Acceptability value of control was significantly higher than those of T1 and T2 in day 4, 8 and 12 (p<0.05).

• Journal of Food Hygiene and Safety
• /
• v.23 no.3
• /
• pp.233-238
• /
• 2008

To evaluate biochemical safety of gejang distributed in Korea, 33 samples were collected and analyzed for indicator microorganisms, pathogen, parasite, pH, volatile basic nitrogen(VBN), salinity, 3-MCPD, histamine, and synthetic food colors. Total plate counts of gejang were the range of 3 to 7 log cfu/g and coliform were the range of ND to 4 log cfu/g. Vibrio parahaemolyticus was detected from 4 samples, and Escherichia coli(1 log cfu/g) and copepoda were detected from 1 sample among those. pH and VBN value of samples were the range of 6.69 to 8.10 and 21.99 to 94.55 mg%, respectively. The ranges of salinity concentration for ganjang chamgejang, ganjang ggokgejang, and ganjang dolgejang were $11.6{\sim}32.6%,\;2.8{\sim}20.5%$, and $11.6{\sim}13.3%$, respectively. But, the range of salinity concentration of yangnum gejang was $2.6{\sim}9.4%$, which was lower than ganjang gejang. Besides, 3-MCPD, histamine and synthetic food colors were not detected. From the results, most of gejang was appropriate for Korea national standard for food regulation, but still biological hygiene control for raw materials, processing, and distribution should be improved.

• Korean Journal of Food Science and Technology
• /
• v.48 no.4
• /
• pp.301-305
• /
• 2016

This study was conducted to investigate changes in pH, volatile basic nitrogen (VBN), thiobarbituric acid (TBA), $a^*$ (redness), shearing force, and microbial content (total plate count; TPC) in beef during freezing storage at -1, -5, and $-20^{\circ}C$ for 21 days. TPC as an effective quality indicator was used to identify the decay point by regression analysis. The pH, TBA values, and TPC significantly increased with storage at all tested temperatures (p<0.05). VBN significantly increased and shearing force significantly decreased with storage at -1 and $-5^{\circ}C$ (p<0.05). TPC showed significant correlation with temperature at $-1^{\circ}C\;(R^2=0.891)$, $-5^{\circ}C\;(R^2=0.856)$, and $-20^{\circ}C\;(R^2=0.444)$. The decay points at -1, -5, and $-20^{\circ}C$, were 27, 52, and 84 days, respectively. The results suggest that a freezing temperature of $-5^{\circ}C$ is effective for short-term storage of beef.

• Korean Journal of Food Science and Technology
• /
• v.41 no.5
• /
• pp.515-521
• /
• 2009

The DEFT (direct epifluorescent filter technique)/APC (aerobic plate count) test was utilized to screen powdered Ramen soup samples (RS-1, RS-2) whether or not they have been microbial-decontaminated. The initial microbial loads of commercially-packaged samples were log DEFT 6.46 (RS-1) and 7.05 (RS-2), but the viable bacterial counts were log APC 2.74 (RS-1) and 1.95 (RS-2), respectively; this finding showed that they have been already decontaminated by methods other than irradiation. The same samples were then subjected to gamma irradiation at 0, 5 and 10 kGy in order to evaluate the microbial and physicochemical changes during post-irradiation storage for 6 months under room conditions ($10{\pm}3^{\circ}C$). The DEFT count was constant in irradiated samples even at different doses, but APC decreased with dose increases; this implies that the log DEFT/APC increased in a linear fashion with dose. No coliforms, yeasts and molds were detected in any of the samples, whereas the initially detected aerobic bacteria ($5.49{\times}10^2CFU/g$) were inactivated by 5 kGy or more and no growth was observed during the subsequent storage period. The pH of RS-1 was reduced by irradiation (p<0.01), but increased (p<0.01) with increasing storage time. Irradiation induced a reduction in volatile basic nitrogen (VBN), whereas an increase in thiobarbituric acid (TBA) values was observed. The storage time proved more influential than irradiation up to 10 kGy in terms of changes in the VBN and Hunter’s color values of powdered Ramen soups.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.35 no.1
• /
• pp.15-20
• /
• 2002

Quality variation of plastic pouch packing of Changran-Jeotgal produced by improved process and conventional process were investigated during storage at 10, 20 and $30^{\circ}C$, respectively. The kind of plastic pouch used in this study were polyethylene/nylon/linear low density polyethylene (PE/Ny), polyethylene terephthalatefpolyethyleneflinear low density polyethylene (PET) and low density polyethylene (PE). In the higher storage temperature, the faster increase of$ CO_2$, concentration and volume of pouch packing in all kinds of pouch. However, the highest value of pH, L-value, volatile basic nitrogen (VBN) and viable cell counts were shown in PE, the next was PET and PE/Ny, Overall, Changran-Jeotgal produced by improved process showed a little change of physical and chemical characteristics than conventional process. From above results, relationship between quality parameters were predicted pH, L-value, VBN and sensory score were highly correlated, therefore, these parameters is expected to uses as shelf-life indicated elements in cease of plastic pouch packaging.

• Korean Journal of Food Science and Technology
• /
• v.38 no.3
• /
• pp.325-330
• /
• 2006

To determine freshness and detect changes in quality of beef and pork during storage, we manufactured a freshness indicator and monitored the surface pH, volatile basic nitrogen (VBN), thiobarbituric acid reacted substance (TBARS), total bacterial counts, electronic nose analysis, and sensory evaluation. Both beef loin and pork belly had a change in the color of the freshness indicator after storage of 6 days at $2^{\circ}C$. VBN and TBARS levels and total bacterial counts reached the decay point at the time of the color change of the freshness indicator attached to the surface of the beef and pork samples. Sensory evaluation also indicated that the samples were unacceptable by an 'off' odor on day 6 of storage. There were significant differences in electronic nose analysis for samples from day 0, day 6, and day 10 of storage. These results suggest that this freshness indicator should be useful in determining the expiration date of beef and pork products during marketing by indicating the microbial safety as well as the physicochemical and sensory changes.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.35 no.6
• /
• pp.761-767
• /
• 2006

To determine freshness and quality change of chicken products during storage, we manufactured freshness indicator and monitored the surface pH, volatile basic nitrogen (VBN), thiobarbituric acid reacted substance (TBARS), total bacterial counts, electronic nose analysis, and sensory evaluation. All chicken products (drum, wing, thigh) had a change in color of freshness indicator after storage of 3 days at $4^{\circ}C$, indicating poor quality at the time. VBN, TBARS values, and total bacterial counts reached the decay point at the time of color change of freshness indicator attached to the surface of chicken samples. The sensory evaluation also indicated sample was not acceptable by off-odor at day 4 of storage. According to electronic nose analysis to examine off-odor, there were significant differences in terms of principal component analysis values among chicken samples of day 0, day 3, and day 5 of storage. These results suggest that freshness indicator should be useful in determining expiration date of chicken products during marketing by indicating the microbial safety as well as physicochemical and sensory change.