• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.12
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• pp.1784-1791
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• 2016

Garlic was subjected to eight different cooking methods (raw, boiling, steaming, microwave cooking, deep-frying, oven-roasting, pan-frying, and pan-roasting) utilized for typical Korean cuisine. Garlic was analyzed for antioxidant activities and physicochemical properties to elucidate effects of cooking. Garlic cooked at higher temperatures showed significantly lower lightness and higher yellowness (P<0.001). In particular, deep-frying and pan-frying resulted in lowest lightness and soluble solid content, indicating that non-enzymatic browning reactions were more facilitated. Compared with raw garlic, all cooked garlic tended to have lower thiosulfinates, presumably due to decomposition into polysulfides and/or leaching into cooking water and oil. Microwave cooking retained organic acids, total reducing capacity, and flavonoids, which can be attributed to low microwave intensity and shorter cooking time under which heat-labile bioactive components might have undergone less decomposition. Cooking significantly increased metal-chelating activity (P<0.001). In addition, oven-roasting and pan-roasting enhanced total reducing capacity and flavonoid content, indicating that thermal treatments increased the extractability of bioactive components from garlic. However, boiling, deep-frying, and pan-frying, in which garlic is in contact directly with a hot cooking medium, reduced antioxidant activities. Deep-frying resulted in largest reduction in DPPH radical scavenging activity of garlic, which correlated well with reduction of total reducing capacity and flavonoid content. The results show that the antioxidant activity of garlic could be affected by cooking method, particularly heat intensity and/or direct contact of the cooking medium.

• Food Science of Animal Resources
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• v.42 no.5
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• pp.849-860
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• 2022

The myofibril protein (MP) isolate-saccharide graft reactions was prepared using the Maillard reaction with saccharides. The effects of various saccharides on protein functionality and quality of the Maillard reaction were investigated and compared with those of MP. The grafting degree of the MP isolate-saccharide graft reaction was significantly higher in the reducing sugar-treated groups (lactose, glucose, fructose, and palatinose). The browning intensity of the MP isolate-saccharide graft reaction with fructose, sucrose, and erythitol was higher than that observed in the control reaction (p<0.05). MP that reacted with reducing sugars (glucose, fructose, palatinose, and lactose) had fainter bands than MP that reacted with non-reducing sugars (sucrose, erythitol, trehalose, sorbitol, and xylitol). MPs conjugated with glucose exhibited higher protein solubility. The palatinose and lactose treatments were maximum in water binding capacity, though no significant difference in oil binding capacity among the saccharide treatments was observed. The emulsion stability of the MP isolate-saccharide graft reaction with palatinose and erythitol was higher than that of the control reaction. Therefore, reducing sugars have good protein functionality in the MP isolate-saccharides graft reaction.

• Korean Journal of Food Science and Technology
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• v.20 no.5
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• pp.704-710
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• 1988

This study was, firstly, to investigate water holding capacity in terms of variation of moisture sorption isotherms of seasoned squid treated with sodium lactate, glycerol, propylene glycol, sorbitol, mannitol, sodium benzoate, potassium sorbate and calcium propionate, and secondly, the effect of humectant treatments on storage stability was studied. The criteria for storage stability was based on three quality factors, namely, lipid oxiations, color development by non-enzymatic browning reactions and lipid oxidation, and mold growth. The effect of humectants on equilibrium moisture content was in the following increasing order; mannitol < sorbitol < sodium lactate < propylene glycol < glycerol. The experimental data indicated that sodium lactate has, in practice, potentially positive effect on processing of seasoned squid. During the storage period of 60 days, TBA values increased in all samples tested as humectants concentrations increased up to 10%. However, in the range of 1-7% sodium lactate treatment, the degree of lipid oxidation, browning reactions and mild growth were not high enough to affect the quality of seasoned squid, when compared with conventionally manufactured ones.

• Food Science and Preservation
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• v.31 no.1
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• pp.15-23
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• 2024

Storage temperature profoundly influences the storability of paprika (Capsicum annuum L.). However, the impact of storage temperature on storability and its association with the antioxidant activity of paprika are poorly understood. In this study, we evaluated the storage attributes, activity, and gene expression levels of antioxidant enzymes in paprika stored at 4, 10, and 20℃ for 14 d and then at 20℃ for an additional 5 d (14+5 d; retail conditions). Storage at 10℃ effectively mitigated pitting, stalk browning, shriveling, and decay while significantly enhancing the marketability of paprika. The fruits stored at 4℃ were prone to pitting, whereas those stored at 20℃ were sensitive to stalk browning and decay. Moreover, paprika stored at 10℃ exhibited higher 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) activity and total phenolic content than those stored at 4 and 20℃, indicating improved antioxidant activity. Additionally, storage at 10℃ upregulated the expression levels of the antioxidant genes, catalase and peroxidase, suggesting the mechanism underlying the quality enhancement of paprika. Our findings suggest that paprika storage at 10℃ alleviates chilling injuries, preserves the quality and marketability, and enhances the antioxidant potential of paprika. These findings provide insights into how temperature influences the quality and minimizes post-harvest losses during the storage and distribution of paprika.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.5
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• pp.607-611
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• 1999

Carrageenan are sulfated polymers containing galactose and anhydrogalctose units, and is used for its gelling, thickening, stabilizing, emulsifying, and suspending properties. However, carrageenan is limited to use beyond $0.03\%$ as food additives because of its high degree of gelling and viscosity with low solubility. The use of ultrasound significantly reduced the viscosity of $\lambda$-carrageenan solutions. The optimal parameters of ultrasound for reduction of carrageenan molecular weight were temperature, $10^{\circ}C$ ultrasound intensity, 114.7 $W/cm^2$ ; carrageenan concentration, $2\%$; treatment time, 10 min. The molecular weights of control, ultrasound peak 1, and peak 2 were approximately 250,000, 184,000, and 67,000 daltons, respectively. The lower molecular weight of $\lambda$-carrageenan showed the higher solubility, the lower alcohol precipitation ratio and the lower emulsifying capacity. Browning degree of both control and lower molecular $\lambda$-carrageenans was not significantly different.

• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.128-137
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• 1999

In this study, shiitake mushrooms were dried by hot air, vacuum and freeze drying methods and theire physical properties were compared. Since the pore size affects the amount of absorption, the characteristics of water sorption were investigated at various humidities and temperatures. Results showed that the freeze dried product had the greatest pore area and the highest absorption capacity. However, all the dried samples showed similar quality. The browning degrees were severely changed with increased relative humidities and temperatures. Among these drying methods, the freeze drying gave the greatest change in browning degree. The GAB monolayer moisture contents of the dried shiitake mushroom were $5.3{\sim}7.7%$. The prediction model was also provided using parameters such as relative humidity, temperature and pore area.

• Food Science and Preservation
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• v.30 no.6
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• pp.983-990
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• 2023

This study was conducted to develop a preservation technology that can induce changes in physicochemical properties to effectively utilize of persimmon leaves. The application effects of steaming or freezing technique were investigated. Astringent persimmon leaves were steam-blanched (100℃, 30 sec) or frozen (-20℃, 15 d), followed by hot-air drying (50℃). The physicochemical properties of the extract obtained by hot-water leaching from the dried leaves were compared. The extract of leaves dried without pretreatment was used as a control. L* value was higher in steamed than in control and frozen. a* value was highest in the control. The browning index was higher in the frozen and lower in the steamed than in the control. Soluble solids were the highest in the steamed and the lowest in the frozen. Sucrose content was relatively high in the steamed, and the glucose and fructose contents were relatively high in the frozen. Total polyphenol content and DPPH radical scavenging activity were higher in steamed and lower in frozen than in control. Thus, it was confirmed that steam or freeze pretreatment after harvesting persimmon leaves affects the extraction yield, color, antioxidant capacity and component changes of dried persimmon leaves. Unlike steaming, freezing pretreatment showed the effect of promoting decomposition and browning reactions, and it is considered useful when such an effect is needed.

• Korean Journal of Agricultural Science
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• v.24 no.2
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• pp.290-297
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• 1997

Danored is considered as the most favorable grape variety for national wine manufacturing in terms of sugar, organic acid contents, annual production amount, as well as quality control convenience after harvest. This study was canied out to know the influence of suspended solid(SS) and skin contact time(SCT) with Danored variety on the white wine quality. The results are summarized as follows; 1. Suspended solid and skin contact time did not greatly influence on the chemical composition of Danored juice. But skin contact time provided slightly increaseness to the content of phenol compounds 2. Suspended solid accelerated fermentation rate of white wine manufacturing. Although the content of suspended solid are less amount than 0.3% in must, wine fermentation was completed to dryness in concentration of sugar. 3. When the content of suspended solid was around 3%, higher alcohol in white wine was increased by the 20%. This result is relatively small increasement compared to the other reported results. 4. Because Danored contained less amount of phenol compounds comparison with other grape varieties, browning capacity in white wine was much favorable to quite low concentration. Especially, phenolic compounds was decreased remarkably as one of fermentation characteristics of Danored variety. 5. As a result of sensory evaluation, wine quality was A-1> B-1> A-2> B-2 in its favorable ranking orders. It was so concluded that A-1 might be the most acceptable one from this study.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.12
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• pp.1813-1818
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• 2015

Grape seed extract (GSE) was added to grape seed oil to improve the oxidative stability of the grape seed oil during storage. To measure the oxidative stability of grape seed oil, peroxide value, acid value, and conjugated diene value were measured, and changes in browning, vitamin E, fatty acid composition, and polyphenol content of oil were examined. In the case of grape seed oil with GSE, peroxide value, acid value, and conjugated diene value were lower than those of grape seed oil. The magnitude of increase in absorbance of grape seed oil with GSE was less than that of additive-free grape seed oil, whereas the magnitude of decrease in vitamin E isomers in grape seed oil with GSE was less than that of grape seed oil with no additive. Changes in fatty acid composition were also similar. However, polyphenol contents showed the greatest reduction in grape seed oil containing GSE. GSE contributes to the oxidation stability of grape seed oil, but the antioxidant capacity of GSE was lower than that of butylated hydroxytoluene.

• Korean Journal of Food Science and Technology
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• v.36 no.3
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• pp.490-500
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• 2004

Brown rice grains were coated by spraying aqueous protein solution extracted from rice bran using 10% ethanol, and dried at room temperature. Coating procedure was repeated 1-5 times to determine effect of repeated coating, Quality changes in coated brown rice grains were observed during 8 weeks storage. Most coated rice grains gave lower peroxide and acid values, which indicate antioxidative effects of coating. Lipase and lipoxygenase activities generally decreased in grains coated more than three times. Microscopic images of whole kernel and longitudinal section revealed cracking on all brown rice grains including control, and hydration rate constants were not significantly different among treated grains. Compared to non-coated brown rice grains, those coated more than three times, after 8 week storage, showed better quality retention observed in (meaning not clear) higher water-binding capacity, lower gel consistency decrease, less browning, and better textural properties in cooked rice, resulting in better sensory quality.