• Korean Journal of Food Science and Technology
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• v.30 no.6
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• pp.1267-1272
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• 1998

The changes in physicochemical properties of gamma irradiated porks were investigated during storage at different temperature and periods. TBA values increased according to the increment of irradiation dose levels. TBA values of nonirradiated and irradiated samples drastically increased with storage period and temperatures at both $5^{\circ}C\;and\;-20^{\circ}C$. The acid value of porks stored at $5^{\circ}C$ was increased rapidly with the elapse of storage period in both nonirradiated and irradiated samples. However, the value decreased with increasing irradiation dose levels. VBN values increased more rapidly in nonirradiated samples than in irradiated samples with the storage period. Especially, VBN value of nonirradiated pork was four times higher than that of 3 kGy-irradiated one. No significant differences in the composition of fatty acids were observed in gamma irradiated samples. Free amino acids were changed with storage periods, but were not significantly affected by gamma irradiation.

• Food Science of Animal Resources
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• v.42 no.6
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• pp.953-967
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• 2022

The objective of this study was to determine effects of aging methods (wet-aged, dry-aged, and packaged dry-aged) during 60 d on quality traits and microbial characteristics of beef. Wet-aged beef was packed by vacuum packaging and stored in a 4℃ refrigerator. Dry-aged beef was used without packaging. Packaged dry-aged beef was packaged in commercial bags. Dry-aged and packaged dry-aged samples were stored in a meat ager at 2℃-4℃ with 85%-90% relative humidity. Meat color, crust thickness, aging loss, cooking loss, Warner-Bratzler shear force (WBSF), texture profile analysis, Torrymeter, meat pH, water activity, volatile basic nitrogen (VBN), thiobarbituric acid reactant substances (TBARS), and microbial analysis were measured or performed every 15 d until 60 d of aging time. Meat color changed significantly with increasing aging time. Differences in meat color among aging methods were observed. Aging losses of dry-aged and packaged dry-aged samples were higher than those of wet-aged samples. Wet-aged beef showed higher cooking loss, but lower WBSF than dry-aged and packaged dry-aged beef. VBN and TBARS showed an increasing tendency with increasing aging time. Differences of VBN and TBARS among aging methods were found. Regarding microbial analysis, counts of yeasts and molds were different among aging methods at the initial aging time. Packaged dry-aged and dry-aged beef showed similar values or tendency. Significant changes occurred during aging in all aging methods. Packaged dry aging and dry aging could result in similar quality traits and microbial characteristics of beef.

• Food Science of Animal Resources
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• v.43 no.3
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• pp.454-470
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• 2023

This study analyzed the microbiological (Lactobacillus spp., Staphylococcus spp., mold, yeast, aerobic bacteria) and physicochemical properties [pH, salinity, water activity, volatile basic nitrogen (VBN), and thiobarbituric acid reactive substances]. The starters were used by mixing Debaryomyces hansenii separated from Korean Doenjang (D) and fermented sausage (S). The starter was inoculated with dry-cured ham and aged for 6 weeks at 20℃ and 25℃, respectively. The aerobic bacteria, Lactobacillus spp., and Staphylococcus spp. of D, S, and DS treatment showed significantly higher values at 25℃ than at 20℃. Among them, S25 treatment showed a high tendency. At week 6, the mold of the S25 treatment was significantly higher than the S20 treatment, and the yeast was higher in 25℃ than 20℃ (p<0.05). The pH of all treatment groups increased with the aging period. Compared with that at 25℃, the pH was significantly higher at 20℃ (p<0.05). The water activity showed a significant decrease as the aging period increased, and the treatment of D25, S20, and DS20 showed a significantly higher value at week 6 (p<0.05). Compared with that at 20℃, the VBN content was higher at 25℃. At week 6, the VBN contents of the C20, S25, and DS25 groups were higher than those of the other treatment groups. Therefore, inoculation of D. hansenii separated from fermented sausage produced in Korean starter at 25℃ is expected to improve the safety of harmful microorganisms and physiochemical properties in dry-cured ham.

• Journal of the Korean Society of Food Culture
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• v.39 no.2
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• pp.119-126
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• 2024

This study was conducted to examine the microbiological quality indicators (total bacterial count and coliform count) and physicochemical quality indicators (pH, redness, volatile basic nitrogen [VBN] content) of meat according to various storage temperatures (-20~15℃) and packaging methods (wrap, vacuum). Based on these results, we proposed a safe consumption period. Redness, pH, and VBN content were not considered appropriate for setting the expiration date, as the redness and pH of the meat after spoilage were better than the standard values for both vacuum and wrap packaging (p<0.05). Additionally, the VBN content at 2 and 4℃ increased slightly (fresh level) until the initial time of spoilage (1.0×10⁶ colony-forming unit [CFU]/cm²) and then increased rapidly thereafter. Therefore, the results were not consistent with microbial spoilage. When the decay point was evaluated based on the presence of microorganisms, vacuum packaging extended the storage period approximately 2.5-fold when compared with wrap packaging, and the meat could be stored at 2 or 4℃ for 40 or 23 days, respectively. Therefore, to evaluate meat quality, microbial indicators should be considered first. The microbiological standards proposed in this study can be used for safety management during the distribution of meat. However, to ensure meat safety, additional investigations of appropriate indicators of freshness must be conducted.

• Journal of Animal Science and Technology
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• v.50 no.1
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• pp.99-110
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• 2008

This study was conducted to determine the effect of pH adjustment and the addition of cryoprotectants on the storage properties of chicken breast surimi. Surimi as a control was prepared with Alaska pollack by two times of washing treatment and addition of cryoprotectants(4% sugar, 5% sorbitol and 0.3% polyphosphate). Three types of surimi were manufactured by different cryoprotectant conditions(T1: 5% sorbitol+0.3% polyphosphate, T2: 4% sugar+5% sorbitol+0.3% polyphosphate, T3: 2% salt+4% sugar+5% sorbitol+0.3% polyphosphate) and frozen after adjusting the surimi to pH 11.0. The amino acid and saturated fatty acid composition were significantly higher in the control. EAA(essential amino acid), FAA(amino acid in relation to flavor), SAAA(amino acid in relation to saccarinity) and FRAA (fragrant amino acid) were significantly higher in the control. The TBARS(thiobarbituric acid reactive substances) and VBN(volatile basic nitrogen) were increased with storage times. TBARS and VBN values were significantly higher in the control and T3 than the other treatments. The VBN was significantly higher in control and T3 than other surimi samples. Chicken breast surimi adjusted to pH 11.0 had higher in microorganisms than the control, and T1 sample had the highest total plate count. Sensory evaluations were significantly higher in the control and T3 than the other samples. Especially, the overall acceptability of T3 was similar to the control.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.3
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• pp.221-229
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• 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 $5^{\circ}C$.

• Food Science of Animal Resources
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• v.33 no.6
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• pp.796-805
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• 2013

This study was conducted to investigate the relationship between quality factors and freshness or palatability of Hanwoo beef according to storage condition. The drip loss, cooking loss, volatile basic nitrogen (VBN), thiobarbituric acid reactive substance (TBARS), total viable counts (TVC) and sensorial characteristics of Hanwoo beef (raw and cooked) were investigated during storage for 36 d at 0 and $10^{\circ}C$. The drip loss, cooking loss, VBN, and TBARS were increased during storage period. The correlation between these factors and freshness was shown to be highly significant at both $10^{\circ}C$ than $0^{\circ}C$. Especially, correlation of between the cooking loss and freshness of Hanwoo beef showed high significance (p<0.01) at higher storage temperature. The correlation coefficient between factors such as VBN, cooking loss, and TVC and palatability were decreased with increased storage temperature. As a statistical analysis result, a multiple regression equation of $Y_1=10.768-0.706X_1$ (Drip loss) with $R^2=0.87$ was obtained for freshness evaluation of Hanwoo beef. Also, multiple regression with drip loss ($X_1$) and TVC ($X_5$) increased the coefficient of determination for sensorial palatability ($Y_2$) to $R^2=0.95$ with a regression equation of $Y_2=9.702-0.438X_1(Drip\;loss)-0.232X_5(TVC)$.

• Korean Journal of Agricultural Science
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• v.25 no.2
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• pp.168-175
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• 1998

To evaluate the storage characteristics of pheasant meat products, contents of aerobic, anaerobic and food poisoning bacteria as well as VBN were measured during storage at various temperatures. 1. During the storage Escherichia coli and food poisoning bacteria including Salmonella, Shigella and Staphylococcus were not detected from any of the pheasant meat products. 2. Total plate counts of aerobic and anaerobic bacteria increased with storage temperature, showing more than $10^6CFU/g$ of most pheasant meat products within 5~10 days of storage at $20^{\circ}C$ and $30^{\circ}C$. However, frank sausage, loin ham, pressed ham and salad showed less than $10^5CFU/g$ in 20~30 days of storage at $20^{\circ}C$. 3. When stored at $10^{\circ}C$, smoked product, electric roasted product and pressed ham showed the bacterial counts of more than $10^4CFU/g$ within 10 days of storage. Frank sausage, loin ham and salad, however, showed less than $10^3CFU/g$ in 10 days of storage at $10^{\circ}C$. 4. VBN contents of smoked product, electric roasted product and frank sausage exceeded edible limit of 20 mg%, showing more than 40 mg% and 80 mg% within 5 days and 10 days, respectively, of storage at $10^{\circ}C$. In contrast, loin ham, pressed ham and salad had the VBN of less than 20 mg% in 10 days of storage at $10^{\circ}C$. In summary, while pheasant meat products in general appear to be prone to microbial growth, loin ham and salad are thought to have a longer storage period than others, showing about 10 days of preservation at $10^{\circ}C$. Products other than loin ham and salad are suggested to be stored frozen or refrigerated at below $10^{\circ}C$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.9
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• pp.1317-1324
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• 2015

The objective of this study was to examine both antioxidant activities and quality characteristics of sausages made from a mixture of purple sweet potato powder and pigment. Five sausages were manufactured: F0 (control), F1 (0.15%-sodium nitrite), F2 (0.2%-purple sweet potato pigment), F3 (0.2%-purple sweet potato pigment and 5%-purple sweet potato powder), and F4 (0.2%-purple sweet potato pigment and 10%-purple sweet potato powder). Sausages were stored at $4{\pm}1^{\circ}C$ for 30 days. Total polyphenol, 2,2-diphenyl-l-picrylhydrazyl (DPPH) radical scavenging activity, acid value, peroxide value, volatile basic nitrogen (VBN), and total bacterial cell contents were analyzed. Total polyphenol content and DPPH radical scavenging activity increased according to the amount of purple sweet potato, whereas acid value, peroxide value, and VBN decreased. Addition of 0.2% purple sweet potato pigment increased lipid oxidative stability and protein deterioration inhibitory effect compared to F0, but not to the levels of 0.15% sodium nitrite. However, F2 showed the lowest pH during storage due to the pH (2.52) of the pigment. Microorganism analysis revealed that total bacterial counts of sausage added with 0.2% purple sweet potato pigment were significantly lower (P<0.05) than that of sodium nitrite-supplemented sausage. As a result, purple sweet potato powder and pigment demonstrate antioxidative activity and lipid oxidative stability in sausages, making them suitable ingredients for manufacturing sausages.

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