• Journal of Applied Biological Chemistry
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• v.59 no.1
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• pp.69-74
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• 2016

The objective of this study was to examine the combined effect of fumaric acid with mild heat on the inactivation of microorganisms on spinach. Spinach leaves were inoculated with Escherichia coli O157:H7 and Listeria monocytogenes. Based on the results of single treatment of fumaric acid (0.1, 0.3, and 0.5%) or mild heat (40, 50, and $60^{\circ}C$) regarding the inactivation of the inoculated bacteria, the optimal condition for the combined treatment was suggested to be 0.5% fumaric acid and mild heat treatment at $50^{\circ}C$ for 5 min. The combined treatment of fumaric acid with mild heat caused 2.53 and 2.62 log reductions of the populations of L. monocytogenes and E. coli O157:H7, respectively. In addition, during storage of fresh spinach at $4^{\circ}C$ for 12 d, the combined treatment reduced initially the populations of total aerobic bacteria by 2.77 log CFU/g compared with the control. In particular, after 12 d of storage, the population of total aerobic bacteria for the combined treatment sample was 4.84 log CFU/g, whereas the control sample had 6.66 log CFU/g. Color and vitamin C content of spinach samples were not altered significantly by the combined treatment during storage. These results indicate that the combined treatment of fumaric acid with mild heat is an effective method to control microorganisms on spinach during storage.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.4 s.152
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• pp.607-614
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• 2006

This study was carried out to suggest the optimal spinning process condition which provides a proper range of tenacity and biodegradability as textile fibers. The effects of the melt spinning speed and heat treatment on the mechanical property and biodegradability of polylactic acid fiber were investigated. Polylactic acid(PLA) was spun in a high spinning speed of $2000{\sim}4000m/min$. Each specimen was heat-treated at $100^{\circ}C$ during 30min. Mechanical properties such as breaking stress and the degree of crystallinity were evaluated using WAXS. Biodegradability was estimated from the decrease of breaking stress, weight loss, and the degree of crystallinity after soil burial. Experimental results revealed that heat treated specimens showed higher breaking stress than untreated specimens, but the increase was not so high as was expected from the remarkable change of crystallinity by heat treatment. It was concluded that breaking stress was more influenced by spinning speed than heat treatment. In the soil burial test, however biodegradability calculated from weight loss was more influenced by heat treatment than spinning speed.

• Korean Journal of Food Science and Technology
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• v.20 no.3
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• pp.317-325
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• 1988

The effects of various heat treatments of soy milk prepared from soy protein concentrate on growth and acid production by five species of lactic acid bacteria were investigated. Sensory property and sedimentation characteristics of soy yogurt prepared from heat-treated soy milk were also evaluated. Heat treatment of soy milk stimulated acid production by all cultures. Acid production was generally proportional to degree of heat treatment and acid production by all cultures except Streptococcus lactis was maximum in soy milk heated at $121^{\circ}C-1min$. However, viable cell count was not changed markedly by heat treatment of soy milk. Sensory property of soy yogurt beverage (SYB) prepared from soy milk heated at $95^{\circ}C-30min$ was better than that of unheated sample while sensory property of SYB prepared from soy milk heated at $121^{\circ}C-15min$ was inferior to that of unheated sample. Heat treatment of soy milk generally retarded sedimentation of curd in SYB.

• Current Research on Agriculture and Life Sciences
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• v.31 no.1
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• pp.25-29
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• 2013

As a specialty oil, furan fatty acids have gained special attentions since they are known to play important roles in biological systems including human. Although several studies reported chemical synthesis of furan fatty acids, their synthesis consisted of complicated chemical multistep with chemical catalysts. Recently, a simple one-step heat treatment method was developed to produce a novel furan fatty acid, 7,10-epoxy-octadeca-7,9-dienoic acid (7,10-EODA) from a dihydroxyl fatty acid 7,10-dihydroxy-8(E)-octadecenoic acid (DOD). In this report we studied about optimization of environmental conditions for the maximum production of 7,10-EODA from DOD by heat treatment. Production of 7,10-EODA was maximized at over $85^{\circ}C$ for at least over 48 hour in hexane. Solvent volume for maximum production should be over 300 mL per 10 mg DOD.

• Food Science and Preservation
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• v.20 no.1
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• pp.23-29
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• 2013

To extend the shelf-life of freshly cut lotus roots, the effect of their heat treatment in water at $50^{\circ}C$ was investigated and compared with that of their treatment using 1 percent ascorbic acid and citric acid during their storage. In addition, consecutive heat and acid treatment was applied to freshly cut lotus roots to determine its synergy effect. The level of molds in the sample that was treated with $50^{\circ}C$ water for 60 minutes was the lowest among the treatments and 3.89 log CFU/g after 12-day storage, whereas the population of the control was 6.81 log CFU/g for the same number of days. During the storage, the surface color of the samples showed higher ${\Delta}E$ values and lower L values than that of the initial sample. The color with the heat treatment hardly changed, unlike in the control. The consecutive treatments with hot water and acid showed less quality loss than the simple heat treatment. The marketable quality was maintained for three days without any treatment, for nine days with the heat treatment, and for 12 days with the consecutive treatments of hot water and acid. The consecutive treatments with hot water and acid, especially with 1 percent citric acid, extended the shelf-life of the freshly cut lotus roots by inhibiting the growth of microorganisms and the browning.

• Korean journal of food and cookery science
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• v.18 no.5
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• pp.487-494
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• 2002

This study was conducted to investigate the thermal stability of water-soluble and fat-soluble vitamins dissolved in water and milk by various heat treatments. Vitamin samples were prepared by dissolving them in water and milk at various concentrations, and were heat treated for 30 min at 65$\^{C}$, 15 sec at 85$\^{C}$, 5 sec at 100$\^{C}$, 121$\^{C}$ at 15 min, the levels of residual vitamin were measured by using HPLC. Milk samples were fortified with vitamins before and after UHT treatment. As heating over 100$\^{C}$, riboflavin in water were destructed more than 92% but fortified in milk showed less than 20% destruction, suggesting that riboflavin was protected by milk components. Also retinol heated ever 100$\^{C}$ was more stable in milk than in water. L-Ascorbic acid and cholecalciferol(D$_3$) showed a similar destruction rate in water and in fortified milk. L-ascorbic acid was easily destructed by UHT treatment. Destruction of thiamin and tocopherol was increased in fortified milk. Among tour capsulated water-soluble vitamins, L-ascorbic acid was much more stable compared with powder form. Nicotinic acid and folic acid either in capsule or powder form showed a slight destruction by heat treatment. The results suggested that the fortification of unstable vitamins such as L-ascorbic acid, thiamin, tocopherol and cholecalciferol(D$_3$) should be made in milk after heat treatment.

• Journal of the Korean Wood Science and Technology
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• v.51 no.1
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• pp.49-57
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• 2023

This research aimed to evaluate the durability of Samama (Anthocephalus macrophyllus) wood treated with boron preservatives, citric acid (CA), and heating against termites. Wood samples were impregnated firstly with 5% boron solutions, such as boric acid, borax and boric acid + borax combination at 1:1 (w/w). The second impregnation used 5% CA. The impregnations were conducted in a pressure tank at 7 kg/cm² for 4 hours. After impregnation, the samples were heat treated at 80℃ or 160℃. All the treated and control samples were exposed to decay fungi, drywood termites and subterranean termites based on SNI 7207:2014 standard. The results showed that boron preservatives reduced fungal attacks on Samama wood. The combination treatment of boric acid, CA and heat treatment at 160℃ was also effective to increase the resistance of Samama wood against white- and brown rot fungi, and drywood termites. Heat treatment consistently improved the resistance of Samama wood from decay fungi.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.1
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• pp.65-69
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• 2010

In this study, we compared two methods(an acid treatment in strong acid reflux and a heat treatment in air atmosphere) for hydrophilic surface treatment of multi-walled carbon nanotubes(MWNT) to enhance the capcity of $RuO_2$/MWNT composite electrode materials for ultracapacitor. Both treatments generated a number of defects on the surface of MWNT by the breakage of $\pi$ bond in graphene layer at which carboxyl groups were introduced. However, the degree of hydrophilicity generated by strong acid treatment was higher than that by heat treatment in air, which was revealed by the quantitative measurement of surface carboxyl groups by using Boehm titration. The increased hydrophilicity save rise to an improved dispersity of $RuO_2$ nanoparticles on MWNT. Finally, the improved dispersity resulted in the capacity enhancement of composite electrode materials for ultracapacitor.

• Carbon letters
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• v.9 no.2
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• pp.137-144
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• 2008

The commercial activated carbons are typically prepared by activation from coconut shell char or coal char containing lots of inorganic impurities. They also have pore structure and pore size distribution depending on nanostructure of precursor materials. In this study, two types of commercial activated carbons were applied for EDLC electrode by removing impurities with acid treatments, and controlling pore size distribution and contents of functional group with heat treatment. The effect of the surface functional groups on electrochemical performance of the activated carbon electrodes was investigated. The initial gravimetric and volumetric capacitance of coconut based activated carbon electrode which was acid treated by $HNO_3$ and then heat treated at $800^{\circ}C$ were 90 F/g and 42 F/cc respectively showing 94% of charge-discharge efficiency. Such a good electrochemical performance can be possibly applied to the medium capacitance of EDLC.

• Journal of the Mineralogical Society of Korea
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• v.20 no.4
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• pp.247-253
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• 2007

The effect of heat treatment and acid leaching of siliceous mudstone on the purity of silica precursors, such as sodium silicate and silicic acid, was studied. As well as the temperatures for the heat treatment of siliceous mudstone, the concentrations of hydrochloric acid and sulfuric acid were varied to achieve the highest content of silicon in the precursors while minimizing energy and chemical consumption. It was found that the optimum conditions were achieved at the heat treatment temperature of $600^{\circ}C$ and hydrochloric acid of 1.56 M. The relative concentrations of silicon in the synthesized sodium silicate and silicic acid were as high as 99.2 and 99.5%, respectively.