Biofilms are complexly structured communities of microorganisms composed of surface-attached microorganisms, where their effects on the host have been controversial. In this study, we investigated the potential biofilm-forming capacity of Lacticaseibacillus rhamnosus LRH020 (DSM25568) by detecting genes known to promote biofilm formation. It was shown that the aggregation substance gene (asa 1) was presented in the LRH020 strain. Therefore, we investigated the phenotypic activities of the gene asa1 via two methods: biofilm formation and autoaggregation activity. It was shown that the strain LRH020 had significantly less ability to form biofilm compared to the positive control strain Enterococcus faecalis ATCC 19433. Furthermore, LRH020 exhibited biofilm-forming activity comparable to Lacticaseibacillus rhamnosus GG (LGG), widely used probiotics. The auto-aggregation activity of LRH020 was also within the safe range similar to that of LGG. In conclusion, this study shows that both biofilmforming and auto-aggregation activities of the LRH020 are comparable to one of the most studied probiotics strains, LGG.

Probiotics are live microorganisms that confer health benefits onto the host when administered at adequate doses. Most widely used probiotics, such as lactobacilli and bifidobacteria, are known to be elements of healthy gut microflora and hence are not considered a threat to the host. However, probiotics may pose a risk in certain populations with compromised immune systems or defects in gut barrier functions. Herein, we evaluated the safety of Bifidobacterium breve BB077, according to the safety evaluation guidelines for probiotics produced by the National Institute of Food and Drug Safety Evaluation (NIFDS). The results show that B. breve BB077 is both non-hemolytic and non-cytolytic. In contrast, B. breve BB077 exhibited higher streptomycin and tetracycline resistance than the suggested NIFDS standard cut-off values. Hence, a genetic analysis of the streptomycin and tetracycline resistance genes was performed to determine the origin of antimicrobial resistance. Streptomycin and tetracycline resistance was shown have arisen from chromosomal mutations and considered intrinsic to the taxonomic group. In conclusion, the B. breve BB077 strain might be safe for human consumption.

Effects of pH and salt concentration on rheological and thermal properties of Pacific whiting surimi were investigated. As pH increased from 6 to 7.5, failure shear stress and strain values increased from 15.4 to 31.32 kPa, whereas lightness values (L * ) decreased from 86.22 to 78.86. Storage modulus (G') followed a trend similar to failure shear stress. A linear relationship (r 2 =0.89) was found between G' and failure stress values as a function of pH. Increasing salt concentration up to 1% increased failure shear stress to 27.14 kPa without salt to 34.30 kPa, and strain values from 1.73 to 1.91, whereas further increase had a negative effect. The relationship between dynamic rheological data and failure shear stress was not linear, indicating that salt concentration cannot be used as an index for estimating final gel quality. The transition temperatures obtained from temperature sweep measurements of Pacific whiting surimi at different salt concentrations showed similar peak temperatures as DSC thermograms, indicating lower stability due to increased salt concentration.

The purpose of this study was to investigate the extraction yield and physicochemical characteristics of mucin from the epidermal mucus of Misgurnus mizolepis. Ninety percent ethanol produced the highest yield of mucin. At higher concentrations, mucin had more elastic properties, as revealed by dynamic viscoelasticity measurements. Differential scanning calorimetry (DSC) demonstrated that mucin is a thermostable glycoprotein. Denaturation enthalpy increased as mucin concentration increased. Mucin inhibited the growth of both Escherichia coli and Bacillus cereus, but had better antimicrobial activity in the former. Mucin also exhibited antioxidant activity, equivalent to 66.64% of that of L-cysteine. Mucin inhibited elastase activity and MMP-1 & MMP-2 expression activity, and induced hyaluronic acid expression. It is indicating that mucin is effective in moisturizing and anti-aging the skin. Thus, mucin from the epidermal mucus of Misgurnus mizolepis could have great potential as a non-food material in various industries.

The purpose of this study is to optimize the extraction conditions (time, pH, and temperature) for water-soluble dietary fiber (SDF) and solids from Opuntia ficus-indica (OFI) stems and to evaluate the functionality of the optimized extract. The maximum extraction yield was obtained when 100% distilled water was used, indicating that ethanol hampered the extraction. The extraction yields were lower at higher temperatures and lower pHs. The maximum extraction of SDF (27.92%) and solids (5.6 g) was achieved with a 7-h extraction at 50oC and pH 7.0, with desirability being 0.958. The stem extract obtained under the optimum extraction conditions had an antioxidant capacity of 118.10 mg vitamin C equivalents (VCE) using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. In a medium containing 30% extract, the growth of E. coli was reduced by 34%, while that of B. cereus was reduced by 23%. These results suggest that OFI stems can be used as a functional resource.

The rate of salt and sugar into pickled cabbages was determined, and physicochemical characteristics, such as sensory, texture, and pH, of vinegar pickled cabbages during storage were examined at different storage temperatures and vinegar concentrations. The rate of salt and sugar penetration was faster in smaller size and on leaves rather than the stem of cabbage. Also, higher salt and sugar concentration and higher storage temperatures led to increase in salt and sugar permeation rate. As a result of sensory test, lower storage temperature is the most suitable, and 6% vinegar concentration was the mostly appropriate. Hardness and cohesiveness were decreased significantly at the initial 1st week storage time, but storage temperature did not show any significant effect. Addition of vinegar contents enhanced the hardness, but decreased cohesiveness. The pH was lowered with increasing vinegar content, indicated most significant factor on pickled cabbage. In general, salt and sugar contents rather than storage temperature have greater influence on permeation rate, and especially, addition of vinegar affects the texture of pickled cabbage.

The purpose of this study was to utilize the stem of Opuntia ficus-indica and to optimize the extraction conditions and standardize extract process for water soluble dietary fiber and solid. Extraction process was optimized by applying various conditions such as pH, ethanol concentration, extracting temperature and time. Maximum extraction yield for water soluble dietary fiber and solid were obtained using 100% water, indicating that ethanol hampered extraction. Also, extraction was unstable with higher heat, longer extraction time, and low acidic conditions. Maximum extraction of water soluble dietary fiber (27.92%) and solid (5.6 g) were obtained at 50°C, pH7, and 7 hr extraction time. Extract had antioxidant capacity at 1105.98 mg vitamin C equivalents (VCE) on ABTS assay and 118.10 mg VCE on DPPH assay.

Physicochemical characteristics of vinegar pickled cabbages during storage were examined. 3x3 cm cube-shaped stems and leaves of cabbages examined in different pickling condition (salt 2, 4, 6, 8% and sugar 5, 10, 15, 20% brix) for 12 hours, and salt and sugar penetration rate were measured at every 2 hours. The vinegar pickled cabbages were stored for 4 weeks at 3 different temperature conditions (5, 15, and 25℃), and sensory test and TPA test were performed at intervals of every week. The rates of salt and sugar penetration were faster on the leaves than on the stem of cabbage. Also, increase in salt and sugar concentration of solutions led to increase in salt and sugar permeation rate. As a result of sensory test, both leaves and stems of cabbages stored at 5℃ did not show any significant difference with storage time. However, preference degree of cabbages stored at 15 and 25℃ decreased significantly as increasing the storage time. Hardness and cohesiveness of pickled cabbage were increased significantly as the storage time increased, but storage temperature did not give any effect on them.

Differences in sugar and salt penetrarion rates of radish depending on size and concentration of solution were examined. 2x2x2 and 4x4x4 cm cube-shaped radish examined in different pickling condition (salt 2, 4, 6, 8% and sugar 5, 10, 15, 20% brix). After 12hr storage, Salt penetration rate of radish cut into 2x2x2 cm was faster than that of 4x4x4 cm in all salt solution. Size dependent sugar penetration showed same tendency with size dependent salt penetration. Also, increase in salt and sugar concentration led to increase in salt and sugar permeation rate.

Although rice production gradually increased in Korea, rice consumption has been significantly reduced during the last decade. To increase rice consumption, it is necessary to develop a wide range of rice-processed foods and functional rice materials. In association with digestion in rice-functional materials, people are interested in resistant starch (RS). The purpose of this study was to develop the citrated organic rice flour by dry process with different treatments and to investigate its physicochemical properties. Citric acid (0, 20, 30, 40% dry basis) was mixed with organic rice flour and reacted at 105oC and 150oC for 5 h. The degree of substitution increased with increasing citric acid concentration and reaction temperature. In DSC, when reacted at 105oC, onset temperature gradually decreased with increasing citric acid concentration but no DSC thermal characteristics were observed when reacted at 150oC. Relative crystallinity determined by XRD did not greatly change at 105oC but dramatically decreased at 150oC. As citric acid concentration and reaction temperature increased, rapidly digestible starch, slowly digestible starch, and total starch decreased but RS significantly increased. Therefore, RS content in organic rice flour increased with dryprocessed citric acid treatment and this could be applicable to produce functional foods for diabetes.

Differences in sugar and salt diffusion rates of cabbage depending on size and part were examined. Whole, 3x3 and 5×5 cube sliced cabbage examined indifferent pickling condition (salt 2, 4, 6, 8% and sugar 5, 10, 15, 20% brix). After 12hr storage, salt absorption depending on part was determined to be higher in leaf, followed by stem in all salt solution. Sugar distribution was also determined to be higher in leaf, followed by stem, showing same trend with salt diffusion. Salt diffusion was found to be highest in 3×3 sliced cabbage. Where as 5×5 sliced cabbage and then whole cabbage showed lower diffusion rate in all brix sugar solution. Size dependent sugar diffusion showed same tendency with size dependent salt diffusion. Also, increase in salt and sugar concentration led to increase in salt and sugar permeation rate.

Opuntia is a cactus with fruits and is also called prickly pear. Extraction process of water soluble fiber from opuntia stem powder was optimized by applying various conditions such as ethanol concentration, temperature and pH. Fiber extraction was highest in 0% ethanol and lowest in 100% ethanol, indicated that hot distilled water extraction produced maximum water soluble fiber. Among temperature range from 50 to 90°C, water soluble fiber was extracted mostly at 50°C and leastly at 90°C, showing decrease in fiber with increase in temperature. On the other hand, pH higher than 7 did not show any significant difference in fiber extraction, while fiber extraction decreased in lower pH 7. Conclusively ethanol hampered extraction of water soluble fiber from opuntia stem powder and extraction was not stable with higher heat and low acidic condition.

Quality characteristics such as texture and sensory properties of garaetteok(Korean rice cake)made with organic rice flour treated withcitric acid were investigated. Compared to rice flour without addition of citric acid,rice flour treated with citric acid showed a significantly lower viscosity and viscoelasticity level as the concentration of citric acid increased. Hardness of garaetteokmade with citric acid showed a similar trend in viscoelasticity changes, whereas cohesiveness was not significantly affected by the pretreatment of citric acid.Garaetteok of 0.5% citric acid pretreatment showed the highest scores in hardness, springiness, chewiness and overall acceptability.However,flavor and taste of garaetteokof citric acid pretreatment were lower than those of the control.

The objective of this study was to determine rheological properties of cold water-soluble potato starch. Scanning Electron Microscopy (SEM) study showed that granule size of cold water-soluble potato starch was 10-60 μm, and shape was dimple in the middle, likely due to starch shrinkage after swelling during treatment. Cold water-soluble starch was prepared by ethanol (60%) and 3 M NaOH. The cold water solubility of native potato starch was low at 4.43±2.9%, whereas the solubility of cold water-soluble starch was high at 81.01±0.9%. The DSC diagram showed a gelatinization peak temperature of native starch but no such peak for treated starch. In dynamic tests, cold water-soluble starch showed decreased storage modulus (G') and loss modulus (G'') with increasing temperature, while native starch showed a continuous increase in G' and G''. This results indicated that cold water-soluble starch showed different granule structure and rheological properties.

Recently, amorphous granular starch (AGS) or non-crystalline granular starch (NGS) is of great interest because it has specific physicochemical properties compared to native starches. Various approaches have been taken to prepare gelatinized starch while still maintaining its granular shape. The granular cold-water soluble starch (GCWS) can be prepared by alcoholic-alkaline treatment or by using liquid ammonia and ethanol. However, these starches exhibit significant deformation and shrinking, and chemical treatments may raise safety issues for their potential food applications. Therefore, in this study, the optimization of preparation method for amorphous granular potato starch (AGPS) was investigated using ethanol and heat treatments. Response surface methodology (RSM) and central composite design (CCD) were used to find the optimum conditions for AGPS preparation based on granule integrity and birefringence. Optimum conditions were 53.3% ethanol and 93.87oC heat treatment for 15 min. Prepared AGPS maintained its granular structure and lost birefringence, crystallinity, and DSC amylopectin melting peak, suggesting that proper AGPS could be made using optimized conditions.

The purpose of this study was to formulate the optimal ratio of tofu ice cream made with crushed tofu and soybean milk. Also, to compare characteristics of tofu ice cream and soybean ice cream. Mix viscosity, overrun and melting down are measured as characteristics of ice cream. The optimal mixing ratio of tofu ice cream was determined by response surface methodology based on overall quality. As a result of optimization, tofu ice cream was made with 65.90% tofu cream (9% solid contents), 4.35% whipping cream, 14.35% canola oil, 15.00% sugar, 0.2% emulsifier and 0.2% guar gum. Soybean ice cream made with three different treated (blanched, steamed, roasted) soybean and each preprocess are treated for 0-20 min. Mix viscosity was enhanced preprocessing time increasing. Also, overrun and melting down was decline preprocessing time increased. As a result of comparison of ice cream overall quality, 15 min roasted soybean ice cream was shown the best quality.

The purpose of this study was to formulate the optimal mixing ratio for Korean vinegared cabbages harvested in fall from Haenam, Hongseong and Gyeongsan regions. The general compositions such as moisture and ash, and hardness were not significant different among 3 cabbages. The vinegared cabbage was made with vinegar, salt and sugar, and stored at 5oC for 5 d. The diffusion of salt, sugar and vinegar to the cabbage was completed within 3 h. The optimal mixing ratio of those components was determined by response surface methodology (RSM) based on overall preference. As a result of analysis, optimal mixing ratio of Haenam vinegared cabbage was 8.94% vinegar, 1.88% salt, and 18.18% sugar, whereas 8.91% vinegar, 2.12% salt, and 17.97% sugar in Hongseong vinegared cabbage, lastly 8.24% vinegar, 2.50% salt, and 18.26% sugar in Gyeongsan vinegared cabbage. Storage characteristics were investigated at different storage times and temperatures using overall preference, texture, and pH. Overall preference and texture were enhanced after 1 wk storage, but vinegared cabbage was spoiled after 3 wk at 20oC. Change in pH was the fastest during 1 wk at all temperatures, and then reached equilibrium.

주스의 품질악화를 초래하는 효소를 불활성화시키기 위해서 감귤 주스와 사과 주스 추출물에 초고압 처리와 열처리를 하여 각 시료의 PPO와 POD의 불활성화 정도를 확인하고 동역학 모델에 적용하여 이들의 불활성화 특성을 연구하였다. 감귤 주스와 사과 주스에서 모두 PPO가 POD보다 열과 압력에 대해서 상대적으로 내성을 갖는 것을 알 수 있었으며, 초고압 처리 과정을 거쳤을 때 보다는 열처리 과정을 거쳤을 때 PPO와 POD가 효과적으로 불활성화되는 것을 확인할 수 있었다. 초고압 기술은 처리 후에도 제품의 영양분과 색의 변화에 영향을 미치지 않기에, 최상의 상태와 품질로 제품을 제공 할 수 있는 장점을 가지고 있지만, 효소를 불활성시키기에는 부족하다는 단점을 가지고 있다. 이를 보완하여 산업적으로 이용되어지기 위해서는 영양분이 파괴되지 않는 열 처리 조건을 잡고, 효소를 효과적으로 불활성시킬 수 있는 초고압 처리 조건과 결합하여 최상의 결과를 얻을 수 있는 조건을 찾는 연구가 필요하다고 판단된다.