• Korean Journal of Food Science and Technology
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• v.36 no.2
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• pp.239-245
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• 2004

Storage quality of minimally processed onion as influenced by hot-water dipping was investigated to examine feasibility of mild heat treatment as efficient post-processing method. fresh onions were peeled, trimmed, and dipped in hot water at various temperatures ($50-80^{\circ}C$) for 1 min. Heat-treated onions were cooled, de-watered, packaged in low density polyethylene (LDPE) film pouches ($63\;{\mu}m\;thickness$), and stored at $10^{\circ}C$. Samples treated at higher temperatures ($70-80^{\circ}C$) showed significant increases in flesh weight loss and discoloration during storage as compared to others. Hot-water dipping remarkably reduced initial microbial load of prepeeled onions, with over 1 log cycle decrease in aerobic bacterial count. After 7 days storage, no significant differences in viable aerobe count were observed among treated and untreated samples, with both showing $10^{6}-10^{7}\;CFU/g$. For sensory attributes including discoloration, wilting, decay, and visual quality, onions treated with hot-water dipping at $60^{\circ}C$ scored highest. Results suggested hot-water dipping at specific condition as practical post-processing treatment could effectively prolong shelf life of minimally processed onion.

• Food Science and Preservation
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• v.17 no.4
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• pp.541-546
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• 2010

Wild-garlic (Allium victorialis L.) is a perennial plant found in worldwide and has been considered as a favorite vegetable due to its particular smell and taste. However, the study of biological activity of wild-garlic and the development of processed food are in rudimentary. In this study, we evaluated several biological activities, including antioxidant, antimicrobial, and inhibitory activities against human thrombin, $\alpha$-amylase and $\alpha$-glucosidase, of Ulrung wild-garlic. Analysis of the composition showed that Ulrung wild-garlic is nutritive although it is perishable. The color of fresh juice was stably maintained during 10 days-storage at $4^{\circ}C$, but rapidly discolored by heat treatment at $70^{\circ}C$ for 1 h. During heat treatment, the contents of total sugar and total polyphenol were decreased to 75% and 50%, respectively, and acidity was increased from 0.069% to 0.111%. In a while, the brix, reducing sugar, and total flavonoids showed minor changes. The fresh juice showed strong DPPH scavenging activity, reducing power and antibacterial and antifungal activity, but the heat-treated juice lost the antioxidant and antimicrobial activities. The inhibitory activities against human thrombin and $\alpha$-amylase and $\alpha$-glucosidase was negligible in both fresh juice and heat-treated juice. These results suggested that the antioxidant and antimicrobial components in wild-garlic are heat-liable and volatile. Based on our results, we propose non-heat treatment products for processed wild-garlic, for example, fresh juice-added beverage or fermented liquors using wild-garlic.

• Food Science and Preservation
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• v.25 no.1
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• pp.52-61
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• 2018

In this study, vineger was produced after heat treatment of Elaeagnus multiflora juice and its fermentative characteristics were investigated. The heat-treated juice and vinegar of E. multiflora were similar in fruit color, with b values (redness) of 39.48 (juice) and 37.56 (vinegar). After 10 days of fermentation of E. multiflora fruit, the acetic acid bacteria viable cell number, pH, acidity, reducing sugar content, and alcohol content were 4.59-4.62 log CFU/mL, 3.14-3.45, 0.2-2.12%, 0.69-35.24 mg/mL, and 0.2%, respectively. The heat-treated juice and vinegar showed significantly higher radical scavenging and digestive enzyme inhibitory activities than untreated samples, and the levels of soluble phenolics, soluble flavonoids, flavan-3-ol derivatives, and phenolic and derivatives were increased. Additioinally, the heat-treated vinegar contained major organic acids, such as acetic acid (21.82 mg/mL), and major flavan-3-ols and phenolic acids, such as catechin ($72.24{\mu}g/mL$), catechin gallate ($273.36{\mu}g/mL$), epigallocatechin gallate ($68.35{\mu}g/mL$), protocatechuic acid ($12.84{\mu}g/mL$), and salicylic acid ($42.29{\mu}g/mL$). At $25{\mu}L/mL$ treatment, DPPH and ABTS radical scavenging activities and ${\alpha}$-glucosidase and pancreatic lipase inhibitory activities were 79.66%, 93.99%, 90.12%, and 64.85%, respectively. This result suggested that it is possible to produce new types of vinegar and beverages, using heat-treated E. multiflora juice.

• Food Science and Preservation
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• v.6 no.4
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• pp.456-462
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• 1999

The radish juice inoculated with mixed culture of Leuconostoc mesenteroides and Lactobacillus brevis was fermented and stored. Radish juice was heat-treated for 30 min at 65$^{\circ}C$ and 15 min at 80$^{\circ}C$, and stored for 8 weeks at 25$^{\circ}C$, 15$^{\circ}C$, and 5$^{\circ}C$, respectively. When the radish juice was heat-treated, any bacteria were not detected and any quality changes were not occured. On the other hand non-heated radish Juice, pH was decreased and acidity was increased during storage. The turbidity of the heat-treated radish juice was higher than that of the non-heated juice when it stored at 5'E. From the sensory evaluation, the pasteurization condition of 15 min at 80$^{\circ}C$ was not appropriate because the fresh smell of Dongchimi was decreased and the cooked smell was increased. The radish juice stored at 5$^{\circ}C$ without heat-treatment was evaluated to have the best quality. The storage period of the non-heated radish juice was shown to be extended over 8 weeks at 5$^{\circ}C$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.3
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• pp.576-581
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• 2004

Foxtail Millet Yakju were treated with heat ($65^{\circ}C$/15 min) or high hydrostatic pressure ($25^{\circ}C$ (RT) and $65^{\circ}C$ (HT)/400 MPa/10 min), and stored for 64 days at l$0^{\circ}C$, $25^{\circ}C$ and 37$^{\circ}C$. Changes in microbial counts, enzyme activity and quality of Yakju during storage were measured. Total viable cells were about 10$^2$ CFU/mL, and remained almost constant during storage at l$0^{\circ}C$ and $25^{\circ}C$, while decreased significantly at 37$^{\circ}C$, and undetected after 55 days of storage in heat- and pressure(RT)-treated, but after 25 days in pressure(HT)-treated Yakju. Lactic acid bacteria and yeast in heat- and pressure-treated Yakju were not detected during storage. The relative activities of a -amylase in heat- and pressure(RT)-treated were more than 100%, while those in pressure(HT)-treated were less than 40% during storage of 64 days at l$0^{\circ}C$. However, at $25^{\circ}C$ and 37$^{\circ}C$ the relative activities in untreated and pressure(RT)-treated were decreased greatly and then reached at the point of the activities of heat- and pressure(HT)-treated. The relative activities of glucoamylase in untreated and pressure(RT)-treated were decreased as the increase of the storage temperature during storage, while those in heat- and pressure(HT)-treated increased slightly as the increase of storage period at 1$0^{\circ}C$ and $25^{\circ}C$, and had no change at 37$^{\circ}C$. pH in heat- and pressure-treated had almost no change. Turbidity and reducing sugar in heat- and pressure-treated increased as the increase of storage temperature during storage.

• Toxicological Research
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• v.29 no.2
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• pp.129-135
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• 2013

Salmonella is one of the major pathogenic bacteria that cause food poisoning. This study investigated whether heat-killed as well as live Lactobacillus protects host animal against Salmonella infection. Live and heat-killed Lactobacillusacidophilus was administered orally to Sprague-Dawley rats for 2 weeks before the rats were inoculated with Salmonella. Rise in body temperature was moderate in the group that was treated with heat-killed bacteria as compared to the Salmonella control group. The mean amount of feed intake and water consumption of each rat in the heat-killed bacteria group were nearly normal. The number of fecal Salmonellae was comparable between the live and the heat-killed L. acidophilus groups. This finding shows that L. acidophilus facilitates the excretion of Salmonella. Moreover, the levels of pro inflammatory cytokines, including tumor necrosis factor (TNF)-alpha and interleukin (IL)-1 beta, in the heat-killed L. acidophilus group were significantly lower when compared to the levels in the Salmonella control group. These results indicate that nonviable lactic acid bacteria also could play an important role in preventing infections by enteric pathogens such as Salmonella.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.8
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• pp.990-996
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• 2006

This research was conducted to evaluate the changes in allergenicity of shrimp by physical treatments using competitive indirect enzyme-linked immunosorbent assay (Ci-ELISA). Shrimp was subjected to physical treatments such as high hydrostatic pressure (HHP), sonication, autoclave and microwave. Heat-stable protein (HSP) purified from raw shrimp was used as a major allergen. The binding ability of monoclonal IgG and shrimp-allergic patients' IgE to HSP treated with HHP decreased, increasing the pressure up to 400 MPa. Especially, it became less than 50% at 400 MPa. The binding ability of mAb to HSP treated with sonication (10, 20, 30 and 60 min) decreased with the treated time. Especially, it became less than 60% with the treatment for 60 min. The allergenicity change of HSP treated with autoclave and microwave little decreased. The binding ability of mAb to HSP during the treatment for 20 min became more than 70%. The results suggest that allergenicity of HSP in raw shrimp be more easily lost by HHP or sonication treatment than by autoclave or microwave treatment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.10
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• pp.1265-1269
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• 2017

This study was performed to evaluate the effects of combined treatment of clove bud essential oil (CBEO) and mild heat (MH) on inactivation of Escherichia coli O157:H7 inoculated onto red oak leaves. Combined treatment of 0.2% CBEO with MH at $50^{\circ}C$ exhibited the highest inhibitory effect against E. coli O157:H7 among treatments, resulting in 1.45 log reduction compared with water washing treatment. In addition, inhibitory effect of the combined treatment was maintained during storage of red oak leaves at $4^{\circ}C$ for 9 days, showing 1.67~2.25 log reductions compared with non-treated samples. Thus, these results indicate that combined treatment with CBEO/MH can be used to ensure the microbiological safety of fresh leaf vegetables such as red oak leaves during storage.

• Food Science and Preservation
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• v.20 no.3
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• pp.386-393
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• 2013

This study was conducted to investigate the change in quality attributes of fresh-cut potatoes with heat and browning inhibitor treatment (CW: dip in the cold water for 30 sec at $4^{\circ}C$, HW: dip in the water for 60 sec at $55^{\circ}C$, AA: dip in the 0.1% solution of ascorbic acid for 60 sec at $4^{\circ}C$, HA: dip in the 0.1% solution of ascorbic acid for 60 sec at $55^{\circ}C$) during storage at $5^{\circ}C$. During storage, fresh-cut potatoes treated with HA showed the lowest value in surface color. PPO and PAL activities of fresh-cut potatoes treated with HA were gradually increased during storage. Hardness, weight loss, soluble solids content and moisture content had no significant difference between the treatments. In sensory acceptance, fresh-cut potatoes treated for HA marked the best quality. Conclusively, heat and browning inhibitor treatment showed the positive effect on browning inhibition while maintaining the quality of fresh-cut potatoes.

• Food Science and Preservation
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• v.3 no.1
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• pp.55-60
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• 1996

To obtain the basic data on precooling effects for establishment the suitable postharvest handling technique or method of keeping high quality of vegetalble corn, the sweet, supersweet and waxy corn, (Danok #2, Cocktail #86 and Chalok #1), being mainly consumed as vegetables in Korea, were precooled with ice or vacuum cooling method immediately after harvest. The vacuum cooling was the most effective for the field heat removal of vegetable corn. It took only 30 min. at 4 to 5 torr of cold chamber pressure of vacuum precooler to lower the corn temperature from 30 to 2$^{\circ}C$. The ice cooling was also thought to be a useful precooling method with relatively short cooling time of 6 hrs. The vegetable corn treated with vacuum or ice cooling showed low and stable respiration rates of 25.5 to 43.5 CO2 mg/kg/hr. when stored at 0∼2$^{\circ}C$ while the samples stored at room temperature (20∼25$^{\circ}C$) without precooling were as high as 64.1 to 245 CO, mg/kg/hr.