• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.2
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• pp.286-290
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• 1998

The effects of cooking methods and storage time on folate content in spinach were determined by boiling for 1, 2, 3, 4, 5, 10 and 20min in distilled water or by microwave blanching for 20, 40, 60, 80, 100 sec. The folate content of cooked spinach was decreased to 80.7% after 1min boiling, and to 5.5% after 20min boiling. The folate recovered from the cooked spinach and cooking water was 101.1% after 1min, 68.0% after 2min and 51.3% after 3min. The relative folate content leached out of the cooked spinach into the cooking water varied from 20.2% after 1min boiling to 88.8% after 20min boiling. Total folate content of spinach was decreased to 45% by microwave heating for 40sec. However, the spinach cooked by microwave heating retained more folate due to the minimal loss of folate into cooking water. More than 90% of folate content of spinach was retained during 1 to 2 weeks of storage at 4$^{\circ}C$.

• Korean journal of food and cookery science
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• v.19 no.1
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• pp.83-95
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• 2003

Investigations were conducted on the changes in carotenoids content, and quantification of cis-trans-${\beta}$-carotene Isomers in pureed and cooked carrot and spinach during storage. The isomerization and degradation of carotenoids were monitored by high-performance liquid chromatography on a C$\_$30/ reversed-phase column with diode-array detection. The results showed that lutein, ail-trans-${\beta}$-carotene, ${\alpha}$-carotene, 9-cis-${\beta}$-carotene and 13-cis-${\beta}$-carotene were present in carrot and spinach. Zeaxanthin and cryptoxanthin were present in raw spinach. The contents of lutein, zeaxanthin, cryptoxanthin, ${\alpha}$-carotene and all-trans-${\beta}$-carotene in pureed and cooked carrot and spinach decreased with increasing storage period. The 9-cis and 13-cis carotenoid isomers were the major types formed in cooked carrot during storage. Cooking was not found to alter the carotenoid profile of the sample, but increased the total amount of carotenoids compared with pured ones. This increase could be explained that cooking itself increased the extraction efficiency and inactivated the enzymes degradating carotenoids.

• Food Science of Animal Resources
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• v.37 no.1
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• pp.105-113
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• 2017

The effect of fermented spinach extracts on color development in cured meats was investigated in this study. The pH values of raw cured meats without addition of fermented spinach extract or nitrite (negative control) were higher (p<0.05) than those added with fermented spinach extract. The pH values of raw and cooked cured meats in treatment groups were decreased with increasing addition levels of fermented spinach extract. The lightness and yellowness values of raw cured meats formulated with fermented spinach extract were higher (p<0.05) than those of the control groups (both positive and negative controls). The redness values of cooked cured meats were increased with increasing fermented spinach extract levels, whereas the yellowness values of cooked cured meats were decreased with increasing levels of fermented spinach extract. The lowest volatile basic nitrogen (VBN) and thiobarbituric acid reactive substances (TBARS) values were observed in the positive control group with addition of nitrite. TBARS values of cured meats added with fermented spinach extract were decreased with increasing levels of fermented spinach extract and VBN values of curing meat with 30% fermented spinach extract was lower than the other treatments. Total viable bacterial counts in cured meats added with fermented spinach extract ranged from 0.34-1.01 Log CFU/g. E. coli and coliform bacteria were not observed in any of the cured meats treated with fermented spinach extracts or nitrite. Residual nitrite contents in treatment groups were increased with increasing levels of fermented spinach extract added. These results demonstrated that fermented spinach could be added to meat products to improve own curing characteristics.

• Journal of the East Asian Society of Dietary Life
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• v.22 no.2
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• pp.278-289
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• 2012

This study investigated the quality characteristics of $Jajang$ noodles with added spinach (20%, 30% and 50% based on water). Significant increases ($p$<0.05) were found in cooked weight, water absorption of cooked noodles, turbidity of soup, while soup volume did not changed in proportion to the addition of spinach. Decrease of L and a values and an increase of b values were shown with the increase of spinach concentration. For textural properties, hardness was the lowest in 50% spinach noodles and the highest in 20% spinach noodles. The cohesiveness and springiness values of 20% and 30% spinach noodles were superior to those of the control, but a rise in spinach concentration (50%) lead to a reduction these values. In a sensory evaluation, the most acceptable sample was the 30% spinach noodle sample. These results suggest an addition of 30% spinach is suitable for spinach $Jajang$ noodle processing.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.8
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• pp.1358-1365
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• 2018

Objective: The effect of pre-converted nitrites from natural sources (spinach, lettuce, celery, and red beet) on color development in raw and cooked pork sausage was investigated in this study. Methods: The pork sausage was manufactured with six treatments: NC (negative control, nitrite free), PC (positive control, 150 ppm sodium nitrite), FS (3.0% fermented spinach extracts), FL (3.0% fermented lettuce extracts), FC (3.0% fermented celery extracts), and FR (3.0% fermented red beet extracts). Results: The pH value of the pre-converted nitrites groups was lower than those treated with 150 ppm sodium nitrite (p<0.05). The color values of raw and cooked pork sausage added with pre-converted nitrite showed slightly lower and/or similar lightness, lower redness, and higher yellowness values than PC. Color development (redness values) of cooked samples added with FS was higher than those of the NC and other treatments (FL, FC, and FR). Additionally, treatments with FS and FL were most effective for reducing thiobarbituric acid reactive substances and volatile basic nitrogen than the NC. Conclusion: Effects of natural nitrites from fermented vegetables on shelf stability of raw and cooked pork sausages were investigated. Fermented spinach extract was much more useful for maintaining the color development, but also inhibiting lipid and protein oxidation of cooked pork sausage. Therefore, pre-converted nitrite from spinach as a natural nitrite could be used as another natural nitrite source for making processed meat products.

• Journal of the East Asian Society of Dietary Life
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• v.22 no.2
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• pp.190-198
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• 2012

This research evaluated and analyzed the level of acceptability of spinach according to blanching time by testing consumer taste of corresponding countries for the purpose of globalizing Korean food. General taste, appearance, flavor, and texture of spinach blanched for 20 seconds were highly evaluated by Koreans and Japanese ($p$<0.05), who are used to the method of slightly blanching, mixing, and eating spinach. On the other hand, general taste, appearance, flavor, and texture of spinach blanched for 5 minutes was highly evaluated by the French ($p$<0.05), who are used to eating boiled spinach. Concerning the result of JAR, there were clear differences in hardness and boiling level according to country among spinach samples, even though they were blanched for the same time and mixed with the same spices. Koreans and Japanese evaluated that hardness and boiling level of spinach blanched for 20 seconds were proper, whereas the French evaluated that spinach scalded for 20 seconds was too raw and crispy. Under the same context, French consumers evaluated that hardness and boiling level of spinach blanched for 5 minutes was proper, whereas Koreans and Japanese evaluated that spinach blanched for 5 minutes was boiled too much. These results show that familiarity level is an important driver of affecting the preference levels for three kinds of spinach according to country.

• Korean journal of food and cookery science
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• v.24 no.1
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• pp.106-113
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• 2008

This study investigated the effects of gamma irradiation on microbial, physical, and sensory qualities as well as the antioxidant activity of cooked spinach. At 3 kGy of gamma irradiation, microbial growth was inhibited until 4 weeks and 5 days at storage temperatures of 4 and $25^{\circ}C$, respectively. The dose of 2 kGy did not significantly affect hardness; however, Hunter color system values for lightness, redness, and yellowness were changed. Low dose gamma-irradiation (up to 2 kGy) did not significantly affect the antioxidant activity of the cooked spinach. Also, based on a triangle sensory test, the gamma-irradiated cooked spinach was not significantly different from the control. These results, suggest that applying gamma irradiation to cooked vegetables at doses lower than 2 kGy can be recommended to extend shelf-life and maintain quality.

• Korean journal of food and cookery science
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• v.20 no.1
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• pp.34-41
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• 2004

The retention rate of riboflavin in two cooked vegetable salads (spinach salad and sesame leaf salad) were examined at every cooking stage, holding temperature and holding time, with various cooking methods, and a better food preparation method developed. The riboflavin contents of the samples were analyzed by HPLC, with fluoresence detection. The changes in the pH and water contents of the samples were measured during the holding stage at various temperatures and times. There were significant differences in the riboflavin contents during the various preparation and cooking processes, such as trimming, washing, boiling and parching etc. The retention rates of the riboflavin with the various holding methods and cooking temperature were also significantly different. The boiling process caused large losses of riboflavin: in the cases of spinach salad and sesame leaf salad these were 78％ and 52％ respectively. The pH and water contents showed faster change during 0-6 hours than during 6-12 hours.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.2
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• pp.281-285
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• 1998

For the purpose of improving the qualities of carrot, spinach and cooked rice, the effects of food height(0mm: H0, 5mm: H5, 10mm: H10, 15mm: H15) for microware blanching and reheating on physicochemical properties were investigated. In carrot blanching, color values of each treatment were not different, and cutting forces of microware blanching carrots were decreased as carrot height increased. In spinach blanching, the shape of orignal form was changed as height increased. In cooked rice reheating, H10 had the highest overall acceptance score. Physicochemical properties were changed by food hight of microwave blanching and reheating on food.

• Culinary science and hospitality research
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• v.16 no.3
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• pp.298-306
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• 2010

This study was conducted to develop soybean paste sauce with walnuts and sesame seeds and apply it to cooked spinach to examine the applicability of the sauce. Two factors of soybean paste sauce, soybean paste and glutinous rice paste, were need to decide the quantity of the ingredients. Nine soybean paste sauces were produced with various compounding ratio of soybean paste and glutinous rice paste, and color, viscosity and sensory evaluations were performed. Sensory evaluations were measured by 7-point Likert scale. Color($4.08{\pm}1.22$), taste($4.72{\pm}1.24$), viscosity($4.96{\pm}1.39$) and overall quality($4.24{\pm}1.51$) of the sample(soybean paste 400 g, glutinous rice paste 400 g) got the highest scores. Therefore, the sample(soybean paste 400 g, glutinous rice paste 400 g) was applied to cooked spinach. Cooked spinach using developed sauce and cooked spinach using general soybean paste were prepared and performed sensory evaluation. As a result, all sensory items score of cooked spinach using developed sauce were higher than that using general soybean paste. Especially, taste($4.96{\pm}1.15$) and overall quality($0{\pm}1.16$) of cooked spinach using developed sauce were significantly higher than taste($4.38{\pm}1.53$) and overall quality($3.56{\pm}1.53$) of cooked spinach using commercial soybean paste(p<0.05). Consequently, the applicability of soybean paste sauce using natural seeds was confirmed.