• Korean journal of food and cookery science
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• v.24 no.6
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• pp.912-918
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• 2008

This study was conducted to evaluate the quality characteristics of Backsulgies prepared using different ratios (0, 10, 20, 30, 40%) of trehalose after 4 days of storage. As the concentration of trehalose increased, the moisture content of the Backsulgies decreased. Furthermore, increased levels of trehalose, resulted in significantly lower L and b values. However, the a values did not differ significantly in response to the addition of trehalose. The total cell counts of Backsulgies also decreased as the level of trehalose increased, which indicates that microorganisms were inhibited by its addition. Furthermore, the hardness of the Backsulgies decreased as the level of trehalose increased, whereas the hardness of the Backsulgies increased as the storage time was extended. Finally, the sensory evaluations revealed that the chewiness and hardness of Backsulgies decreased as the level of trehalose increased.

• Culinary science and hospitality research
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• v.16 no.1
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• pp.13-23
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• 2010

The principal objective of this study was to develop the optimal recipe for muffins prepared with replacement of sucrose with trehalose. The effects of trehalose on properties and staling of muffins during storage days(0, 1, 3, 5 days) were evaluated in terms of height, volume, weight, specific volume, baking loss rate, crumbscan, colorimeter, texture analyzer and sensory evaluation. Crust thickness of muffins containing trehalose evaluated with crumbscan decreased as the content of trehalose increased. Lightness(L value) of muffins with trehalose increased for the storage days, but muffins without trehalose decreased. yellowness(b value) increased significantly as the trehalose content increased. Hardness value of muffins was reduced by adding trehalose; however, the resilience value of muffins with trehalose increased significantly. Finally, the sensory evaluation revealed that muffins with 25% of trehalose showed the best result in texture, taste and overall preference.

• Journal of the Korean Applied Science and Technology
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• v.35 no.2
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• pp.568-577
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• 2018

This study was conducted to evaluate the quality characteristics. Trehalose was used to manufacture rice bread in two ways: one was to substitute trehalose for sugar by (0, 25, 50, and 75%) trehalose in each sample and the other was to analyze the temporal changes in rice bread on Day 0, on Day 2, and on Day 4. The results concerning the characteristics of specific volumes, water content, water activity, variation in weight and height, physical property test, and sensory test and measurements of the temporal changes are as follows: First, as for variation in specific volumes, rice bread containing trehalose had the content and temporal changes decrease significantly (p<0.001). Second, as for texture, a higher trehalose content led to a slightly lower level of hardness. As for the temporal changes, addition of trehalose is generally effective in decreasing hardness of rice bread. the sample containing trehalose showed an almost similar value. The control group not containing trehalose showed the significantly lowest level of cohesiveness, springiness, Chewiness. Finally, the sensory evaluations revealed that the taste, Flavor, and Sweetness was at a significantly higher level in the group with trehalose substituted for sugar than in the control group. An increase in the trehalose content led to an increase in overall eating quality.

• KSBB Journal
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• v.18 no.1
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• pp.8-13
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• 2003

Recombinant trehalose synthase from Thermus caldophilus GK24 showed an ability to produce trehalose from maltose. The activity of the partially purified enzyme was not influenced by most metal ions at 1 mM but was inhibited by 10 mM $Co^{2+}$, $Mn^{2+}$, and $Fe^{2+}$. Enzyme activity varied during prolonged reaction due to changes in the environmental conditions. Thus, the reaction was carried out for an extended time with optimized conditions of $45^{\circ}C$ and pH 7.0. An yield of 32.9% was reached at $60^{\circ}C$ after reaction for 22 h, and, maximum trehalose conversion (69.2%) was attained at $25^{\circ}C$. The yields obtained using enzyme dosages of 10, 25, and 50 U/g were 62.3, 62.3 and 59.0 %, respectively, though the initial conversion rate was higher when the higher dose was used. Similar profiles of trehalose production yields were observed with reaction working volumes of 10 ml to 2,000 ml.

• KSBB Journal
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• v.22 no.2
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• pp.84-90
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• 2007

Trehalose is non-reducing disaccharide which is found in bacteria, fungi, plants and insects. Trehalose has been determined by several analysis methods. To monitor the concentrations of trehalose in a process, enzymatic methods have more advantage over others, e.g. more specific. In this work, trehalase was immobilized on VA-epoxy polymer and applied to FIA systems. The behaviours of these FIA systems were characterized and used to monitor the trehalose concentrations. Use of optical detection technique was chosen for trehalose-FIA system. On-line monitoring data and off-line data were measured by HPLC.

• Korean Journal of Food Science and Technology
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• v.42 no.3
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• pp.304-309
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• 2010

Instant Baekseolgi containing 0, 1, 2, and 3% trehalose prepared using a microwave oven, after which quality characteristics were investigated over 24 hr. The sample was prepared to internal and external parts. The moisture content of Baekseolgi without trehalose (control) was not reduced. However, the presence of trehalose reduced moisture content of two different groups (p<0.05). Weight reduction of Baekseolgi was decreased with increased threhalose content (p<0.05). The hardness, and chewiness of Baekseolgi with trehalose was decreased with increased trehalose (p<0.05). However adhesiveness, springiness, and cohesiveness were not significantly changed. The results of sensory evaluation showed that moisture and hardness were reduced between the internal and external parts of the Baekseolgi with increased trehalose (p<0.05). This study shows that the addition of trehalose to Baekseolgi had a positive impact on quality characteristics, including moisture content, weight reduction, texture, and sensory properites.

• Culinary science and hospitality research
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• v.20 no.3
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• pp.113-124
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• 2014

This study investigated the quality characteristics of Yanggeng sweetened with various amounts of trehalose (0, 40, 60, 80, 100 % of trehalose) and their changes during storage times. The moisture content, color value, $^{\circ}Brix$, pH, texture profile, QDA and acceptance for samples were tested. As a result of the mechanical tests, moisture content and pH were increased while hardness were decreased with increased trehalose content. Also, moistness, gloss and after taste were increased with increased trehalose in the sensory attribute difference test. Acceptance test showed Yanggeng with 60% trehalose and 40% sucrose obtained the highest scores on flavor, taste and overall acceptability. During storage in refrigerator, Yanggeng sweetened with higher % of trehalose showed significantly higher moisture content, and lower syneresis and hardness than the control sweetened with only sucrose. The results of the sensory test showed that 60% trehalose Yanggeng was the highest in flavor, after taste, and overall acceptability.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.7
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• pp.992-998
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• 2010

This study investigated changes of quality during storage period with 6 types of Backsulgie manufactured by adding enzyme (BS-300 0.3%) and trehalose (3%, 6%) to minimize the changes of quality and tried to determine their optimal combination ratio. When Rapid Visco Analyzer (RVA) gelatinization properties of rice powder were examined, adding both of enzyme and trehalose to the powder increased stability of process and reduced retrogradation. In comparison of the degree of retrogradation of Backsulgie by using Differential Scanning Calorimetry (DSC), the sample with enzymes and trehalose suppressed retrogradation. Moreover, the retrogradation effect became larger by using both of enzyme and trehalose and it was the largest in the sample with 0.3% enzyme and 6% trehalose. Enzyme and trehalose added to Backsulgie were found to improve water retention, to minimize changes of texture and color during storage of Backsulgie. Therefore, optimal combination ratio of Backsulgie is 0.3% enzyme with 6% trehalose added Backsulgie.

• Microbiology and Biotechnology Letters
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• v.44 no.4
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• pp.497-503
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• 2016

This study aimed to optimize the culture conditions of recombinant Escherichia coli expressing otsBA using crude glycerol for the enhanced production of trehalose. The effects of culture temperature and isopropyl ${\beta}$-D-1-thiogalactopyranoside (IPTG)-induction were investigated. Trehalose production and cell growth were highest when cells were cultured at $37^{\circ}C$ and induced with IPTG. The concentrations of IPTG, validamycin A, and NaCl were optimized using Box-Behnken design. Statistical analyses of the experimental data revealed that the concentrations of IPTG and NaCl had significant effects on trehalose production, but that of validamycin A did not. Contour plot analysis and model calculation showed that the highest amount of trehalose could be produced at 298 mM NaCl and 0.1 mM IPTG. Under these optimal conditions, the optical density at 600 nm and trehalose production were $5.4{\pm}0.2$ and $304{\pm}15mg/l$, respectively.

• Food Engineering Progress
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• v.14 no.3
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• pp.235-242
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• 2010

This study was to investigate the combined effect of enzyme and trehalose addition on the retrogradation rate and quality changes in a Korean traditional rice cake, Backsulgi. As for the enzyme, a commercial maltogenic amylase, Novamyl, was used. From texture profile analysis and sensory tests, the optimum enzyme content for the preparation of Backsulgi was determined to be 0.1%. Backsulgi was prepared with the fixed content of Novamyl (0.1%) and different ratios (5, 10, 15%) of trehalose, and physicochemical and sensory properties were examined for 3 days of storage at ${25^{\circ}C}$. As trehalose content increased, the water activity of Backsulgi decreased. In Hunter's color value, L- and a-values of trehalose-added samples were significantly lower than those of control. In texture profile analysis, hardness of Backsulgi decreased with trehalose content. During storage, a increase in hardness and a decrease in cohesiveness were typically observed for all samples. However, those changes were significantly reduced with trehalose content. The retardation of retrogradation with the enzyme and trehalose addition was confirmed using calculated Avrami rate and time constants. These results revealed that combined treatments of 0.1% Novamyl and 10% trehalose could produce Backsulgi of better sensory quality with retarded retrogradation compared to separated treatment.