• Korean Journal of Food Science and Technology
• /
• v.38 no.1
• /
• pp.42-46
• /
• 2006

Rheological properties of the dough added with milk proteins and gums was studied to investigate the possibilities as anti-staling agents. Also, physical properties of the resultant bread baked from the frozen dough after 8 weeks of storage at $-20^{\circ}C$ were examined. The 4 sets of their combinations of milk proteins and gums, $casein-{\kappa}-carrageenan$ (CK), casein-sodium alginate (CA), $whey-{\kappa}-carrageenan$ (WK), and whey-sodium alginate (WA), were added to dough to examine their possible anti-staling effects. Rheological properties of dough were evaluated, and physical properties of resultant bread baked from frozen dough after 8 weeks storage at $-20^{\circ}C$ were examined. Addition of all treatments increased gelatinization temperature and water absorption, and lowered miximum viscosities and extension of doughs, compared to the control. Doughs added with CA and WA showed longer development times than that of the control. Addition of WK and WA resulted in lowest dough extensions. Treated bread showed lower moisture content decrease during storage at $5^{\circ}C$ for 4 days. Breads baked with frozen doughs after 6 weeks storage at $-20^{\circ}C$ showed similar results. Although textural hardness of breads increased with storage at $5^{\circ}C$, CA- and WA-added breads were less affected, showing they effectively retarded staling of breads.

• Korean Journal of Food Science and Technology
• /
• v.23 no.5
• /
• pp.532-537
• /
• 1991

Effect of storage temperature fluctuation on quality of frozen breaded raw shrimp was studied. Storage experiments were undertaken as follows; First, after storage at $-20^{\circ}C$ for 20 days or 40 days, storage temperature of materials were raised to $-15^{\circ}C\;or\;15^{\circ}C$, and then stored at these temperatures, And second, by repeating for 5, 10 and 15 times by 3 conditions ($-20{\rightarrow}-15^{\circ}C{\rightarrow}-20^{\circ}C,\;-20{\rightarrow}-10^{\circ}C{\rightarrow}-20^{\circ}C\;-20{\rightarrow}-5^{\circ}C{\rightarrow}-20^{\circ}C$) with temperature fluctuation during storage. Quality changes were measured by determining extractability of salt-soluble protein, volatile basic nitrogen, thiobar-bituric acid, pH and microbiological changes at regular intervals. Rise in storage temperature from $-20^{\circ}C\;to\;-15^{\circ}C$ had not caused significant change on it's quality, but rise up to $-5^{\circ}C$ caused some change in quality without relationship with storage period before temperature rise. Fluctuation of storage temperature from $-20^{\circ}C\;to\;-15^{\circ}C$ of frozen breaded raw shrimp did not cause noticeable changes on it's quality. But temperature fluctuation from $-20^{\circ}C\;to\;-10^{\circ}C\;or\;-5^{\circ}C$ caused remarkable changes of it's quality, according to the increase of fluctuation times and temperatures.

• Journal of the Korean Applied Science and Technology
• /
• v.8 no.1
• /
• pp.69-78
• /
• 1991

Frog legs were stored before and after 30, 60, 90, 120 days at $-30^{\circ}C$ and $-70^{\circ}C$. The amounts of triglycerides, glycolipide and phospholipids by TLC and composition of fatty acids by GC were shown in this experiment, there fore, I have got these following results. 1. The amount of PL in frog legs consisted of 80% of the total lipids before storage. As the days of storage was longer, the amount of TG was increased, while PL and GL were decreased. 2. TG and ES & HC were composed of 66% to 77% of the neutral lipids composition before storage. As the days of storage was longer, the amount of MG, DG. FFA and ES & HC were increased, while FS and TG were decreased. 3. PE and PC were composed of 78% to 81% of the phospholipids composition before storage. As the days of storage was longer, the amount of FA and PS were increased, while PC and PE were decreased. 4. The composition of fatty acids in neutral lipids of frozen frog legs at $-30^{\circ}C$, 120 days was studied, Capric acid. Stearic acid, Behnic acid. Oleic acid and Linoleic acid were increased as compared with initial neutral lipids.

• Food Science of Animal Resources
• /
• v.18 no.1
• /
• pp.1-8
• /
• 1998

This study was conducted to investigate the effects of $\alpha$-, ${\gamma}$-, $\delta$-Tocopherols on oxidative stability of lipid in hamburger patties during frozen storage. Hamburger patty samples were prepared with the addition of tocopherol by fat basis: control, treat 1 (control+0.02% $\alpha$-tocopherol), treat 2 (control+ 0.02% ${\gamma}$-tocopherol were cooked at 85$^{\circ}C$ for 3 minutes and the stored at -1$0^{\circ}C$ or 3$0^{\circ}C$). The fatty acids composition of the hamburger samples were analyzed during the storage periods (1, 20, 40, 60 and 80 days). there was no difference in the fatty acids composition among control and treatment groups in early storage time; however, content of unsaturated fatty acid was decreased in control group and slightly decreased or almost not changed in treatment groups as the storage period passed. No difference in the ratio of saturated fatty acid : unsaturated fatty acid (SFA : USFA) and saturated fatty acid : monounsaturated fatty acid : unsaturated fatty acid (SFA : MUFA : PUFA) between control and treatment groups at early storage time. However, SFA : USFA and SFA : MUFA : PUFA was decreased in control and slightly decreased or not changed in all treatment groups as the storage period passed.

• Microbiology and Biotechnology Letters
• /
• v.10 no.1
• /
• pp.9-14
• /
• 1982

Three common species of lactic acid bacteria, Lactobacillus casei, Lactobacillus bulgaricus, and Streptococus lartis were tried to store in frozen state for various periods up to four months and their stabilities during the storage were evaluated. A needle of culture suspension was transferred to 10 $m\ell$ of 10% reconstituted skim milk and frozen immediately. After storage under said conditions the storage tubes were thawed and incubated under optimum growth temperatures for 48 hours after which plate counts and acidity determinations were made. The same incubation and analyses were repeated with organisms transferred from the previous culture tubes. No significant deterioration in both survival and acid producing activity were observed during the four month storage except that some decrease in acid forming by L. bulgaricus appeared after 60 days of storage. Among the three species tested L. casei was found to be most stable and the fast was reconfirmed with scale-upped fermentation experiments using the same organism.

• Food Science and Preservation
• /
• v.5 no.1
• /
• pp.89-96
• /
• 1998

The antibacterial activity of clove (Eugenia caryophyllata Thumb) in culture troth against S. aureus was tested at 35, 5, -20, 50, 55 and 60$^{\circ}C$. Tryptic soy broth(TSB) containing 0∼0.5%(w/v) of clove was inoculated with 105∼107 CFU/ml of S. aureus and incubated at each temperature. The growth of S. aureus occured at 0.1% clove after a prolonged lag period while viable cells of S. aureus decreased more than 2 log cycles at 0.3 and 0.4% clove during 12 hours storage at 35$^{\circ}C$. During 32 days of refrigerated storage at 5$^{\circ}C$, survivors of S. aureus were decreased with the progress of time and increasing clove concentration. At the presence of 0.2, 0.3 and 0.4% clove, bacterial cells were dead after 32, 20 and 16 days of refrigerated storage, respectively. During 32 days of frozen storage at -20$^{\circ}C$, survivors of S. aureus were decreased less than 0.5 log cycle at 0% clove. At the presence of 0.1∼0.4% clove, survivors were decreased 2.5∼3.0 log cycles after 1 day and then decreased 0.4∼0.8 log cycles through the frozen storage. There were small changes in populations of S. aureus in TSB between different concentrations of clove during frozen storage. The D-values of S. aureus at clove 0, 0,2, 0.4% were 28.53, 15.14, 8.9 min at 50$^{\circ}C$, 18.43, 10.32, 6.74 min at 55$^{\circ}C$ and 12.78, 9.88, 5.72 min at 60$^{\circ}C$, respectively. The D-values for S. aureus were decreased with the increasing temperature and clove concentration.

• Tunnel and Underground Space
• /
• v.2 no.1
• /
• pp.123-151
• /
• 1992

“Norwegian Tunnelling in General" will cover the following subjects : - Short introduction to the geology of Norway - Major considerations in rock installations - Hydropower plants, roads, tunnels, oil and gas storage in rock, drinking water storage, sewage plants, frozen food storage, defence and civil defence projects, including sports arenas and swimming pools, etc.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.54 no.6
• /
• pp.861-868
• /
• 2021

To confirm the influence of modified starch on frozen storage stability, the microstructure and sensory characteristics of fish cakes, called Eomuk in Korea, by using seven varieties of starch, including native starch (NS), physically treated corn starch (MS) and modified starch [treatment with acetate (SA-1, SA-2 and SA-3), hydroxypropyl (HS), and acetylated distarch adipate (ADA)] were evaluated. Scanning electron microscopy (SEM) photographs showed fish cakes with NS had a finer and denser network structure than those made with modified starches. During frozen storage, fish cakes with HS and ADA exhibited a stable structure, as evaluated by porosity and rough surface. The results of the sensory evaluation showed that modified starch, including HS, SA-2 and ADA, increased the taste and firmness of the fish cakes, while NS, MS and the modified starch SA-3 resulted a decrease in the sensory properties during storage. Therefore, HS, SA-2 and ADA are suitable additives to improve the sensory quality of frozen fish cakes.

• Journal of Life Science
• /
• v.25 no.7
• /
• pp.740-747
• /
• 2015

This study was carried out to evaluate changes in the meat quality and antioxidation activity in the loin and ham of Korean Native Black Pigs (KNBP) during frozen storage at −18℃ for 150 days. The pH value of the loin was decreased as storage days progressed, while the pH value of the ham showed no consistent changes with storage days. The lightness (L*) of the loin did not show any significant reduction until day 120, whereas L* of the ham was significantly declined throughout the storage period (p<0.05). The redness (a*) values of the loin and ham were significantly decreased as storage progressed. The water holding capacity of the loin was decreased by day 30 and that value was maintained until the end of storage. The initial total numbers of microorganisms in the loin and ham were 4.88 and 5.16 Log CFU/g, respectively and these numbers were significantly decreased by day 30 (p<0.05). The levels of 2-thiobarbituric acid reactive substances (a measurement of lipid oxidation) in the loin and ham ranged from 0.057-0.069 and 0.052-0.087 mg MDA/kg meat, respectively, until storage day 150. Volatile basic nitrogen values of the loin and ham ranged from 15.13-16.55 and 16.05-16.23 mg%. Oxygen radical absorbance capacities and carnosine contents of the loin and ham were significantly decreased during frozen storage for 3 months (p<0.05). In summary, the meat quality of the loin and ham from KNBP was somewhat decreased during frozen storage. However, the levels of antioxidants and dipeptides with antioxidant activity were significantly decreased in pork loin and ham during frozen storage.

• Korean Journal of Food Science and Technology
• /
• v.38 no.1
• /
• pp.59-67
• /
• 2006

Effects of ${\alpha}-amylases$ and emulsifiers on characteristics of frozen bread dough were examined during 12 weeks of storage. Fungal or bacterial ${\alpha}-amylase$ and various emulsifiers, including monoglyceride (MG), sodium stearoyl-2-lactylate (SSL), and diacetyltartaric acid ester of mono- and diglycerides (DATEM), were added to frozen dough individually and as mixtures Height of frozen dough at maximum development time, total volume of $CO_2$ gas, and retention volume increased with increasing content of emulsifiers. indicating addition of enzymes and emulsifiers had significant effect on flexibility of starch-gluten complex in dough. Frozen dough made with bacterial ${\alpha}-amylase$ showed slightly higher pH during storage than that of frozen dough with fungal ${\alpha}-amylase$. Bread made from frozen dough prepared with both enzymes and emulsifiers showed lower specific loaf volume than that of control during storage, whereas highest specific loaf volume was obtained with addition of fungal ${\alpha}-amylase$ with SSL+MG and bacterial ${\alpha}-amylase$ with MG.