For the investigation of the quality loss of mulberry during distribution, the deterioration rate, microorganism growth, and sensory quality of mulberry kept at 20, 10 and 0℃, respectively, were investigated. Based on the results, the optimum temperature for extending the freshness of mulberry was examined in the temperature range of -1.5 to 1.5℃. The level of mold in the mulberry kept at 20 and 10℃, respectively, was much higher than that kept at 0℃. The quality of the mulberry deteriorated seriously after two days at 20℃, after six days at 10℃, and after 12 days at 0℃. The marketability of mulberry as determined via sensory evaluation was much more prolonged by decreasing the keeping temperature from 20 to 0℃. To extend the freshness of mulberry using these results, the optimum temperature was evaluated at the range of -1.5 to 1.5℃ for 25 days. During storage, the changes in the color and pH of the berry were not significantly different by storage temperature, but the microbial levels and deterioration rate increased in the order of 1.5, 0, and -1.5℃. In particular, the firmness of the mulberry decreased rapidly at 1.5℃, showing a significant difference from the others. The titratable acidity and sugar contents decreased gradually at all the applied temperatures. The anthocyanin content decreased sharply at 1.5℃ but gently changed at -1.5℃. Through the sensory results of this study, it was adjudged that the marketability of mulberry could be maintained about 0.7 times at 1.5℃ and 1.3 times at -1.5℃ compared with the marketability at 0℃, respectively.
This study was conducted to investigate the effect of mature stages on quality of Rafito tomatoes (Lycopersicon esculentum Mill.) during storage at low temperature. Tomatoes grown in greenhouse were harvested at three different mature stages (turning, pink, and red), packaged with a 30-μm-thick polyethylene film, and then stored at 5 and 10℃, respectively. The changes in firmness, soluble solids content (SSC), titratable acidity (TA), colour, lycopene content, decay, and chilling injury were measured on a weekly basis. After three weeks of storage, chilling injury and decay were found to have individually occurred at 5 and 10℃, respectively. As there was little change in quality at 5℃, it was concluded that red tomatoes could maintain their good quality for two weeks. The normal postharvest ripening was inhibited in the turning and pink tomatoes during storage at 5℃. The turning and pink tomatoes showed improved quality after two-week storage at 10℃. In particular, the turning fruits showed the highest firmness throughout the storage period. Furthermore, the red colour, SSC/TA, and lycopene content of the turning fruits reached the same levels as with the red fruits after two-week storage at 10℃. These results suggest that red tomatoes should be stored at 5℃ to inhibit decay, and that the optimum temperature for early-harvested tomato (turning and pink) is 10℃ for the ripening process after harvest.
This study aimed at investigating the quality changes of Yukwa during storage using the various item packaging methods present in the domestic market. The samples consisted of a self-adhesive-oriented polypropylene (OPP)film pouch (P1), a heat-sealed OPP film pouch (P2), and a polystyrene (PS) tray with a polyethylene terephthalate (PET) lid (P3). These were stored at 25℃ up to eight weeks. Throughout the storage period, the acid values of all the study samples remained under the Korean hygiene regulation limit of 2.0 mg KOH/g. The P2 samples showed both the slowest decrease in water content and the slowest increase in hardness value during storage. Sensory evaluation also showed that the P2 samples were the only ones that maintained their market value of 5.0 throughout the eight-week assessment period.
The effect of phytoncide solution treatment on the browning and quality of fresh-cut iceberg lettuce during storage was studied. The treatments were applied as four solutions adjusted at 10℃: distilled water (DW) as the control; edible ethanol (EE); 1% (v/v) phytoncide essential oil from pine needle diluted with distilled water (DP); and 1% (v/v) phytoncide essential oil diluted with edible ethanol (EP). Fresh-cut lettuce was dipped in each solution for 60 sec, was rinsed with distilled water, was packaged with an OPP film bag, and was then stored at 4℃ for 12 days. The EP group had a significantly high level of total soluble solids, titratable acidity, and carbon dioxide, and low total bacteria counts, pH, and oxygen. The sensory score of color in the EP group recorded a high value, but the EE and EP groups recorded low scores in aroma and taste during the storage period. Alcohol and phytoncide were vaporized by opening the package for two hours, and the score of the aroma and taste of EP showed no differences from those of the other groups. Based on the above results, it was determined that the phytoncide essential oil diluted in edible alcohol with 1% solution inhibited the browning of and microbial growth in fresh-cut lettuce, and will be a useful natural compound in maintaining the quality of fresh-cut produce.
This study investigated that anti-browning effects of Atractylodis Rhizoma Alba extract and L-cysteine combination. Mushrooms were dipped in solutions (0.1% Atractylodis Rhizoma Alba extract containing 0.05% L-cysteine) for 3 min. The dipped mushrooms were packaged in a polystyrene (PS) tray and wrapped with a polyvinyl chloride (PVC) film, and stored for 14 days at 10℃. The browning inhibition activity (Hunter L, a, b color scale and tyrosinase inhibition activity) and quality changes (weight loss rate, gas composition, firmness and sensory evaluation) were analyzed during storage period. After 14 days, the Hunter L and ΔE value of mushrooms treated in 0.1% Atractylodis Rhizoma Alba extract containing 0.05% L-cysteine were 87.24 and 5.56, respectively. The mushrooms treated with 0.1% Atractylodis Rhizoma Alba extract containing 0.05% L-cysteine also showed higher firmness (13.31 N) and smaller weight loss rate (2.87%) than the untreated mushroom (11.42 N, 3.04%) on storage day 14. During storage period, the sensory evaluation showed that overall acceptability of mushrooms treated with 0.1% Atractylodis Rhizoma Alba extract containing 0.05% L-cysteine were higher than those of the untreated mushrooms, except those that were stored for five days. Overall, the mushrooms treated with 0.1% Atractylodis Rhizoma Alba extract containing 0.05% L-cysteine had a higher tyrosinase inhibition activity than the untreated mushrooms during storage period. This study suggests that the browning of the mushrooms treated with 0.1% Atractylodis Rhizoma Alba extract containing 0.05% L-cysteine solution were inhibited, and the that their shelf life was extended.
This study investigated the quality characteristics between spring cultivars of Kimchi cabbage(Brassica rapa L. ssp. pekinesis). We measured the weight, length, width, formation index, midrib thickness and moisture contents of fresh Kimchi cabbage for characteristics of growth. And we analyzed the free sugar, amino acid, organic acid, mineral, pectin and cellulose contents of fresh Kimchi cabbage. The hardness and firmness were measured for texture of fresh Kimchi cabbage. The weight of 'K-power' cultivar was the highest than other cultivars. The ‘Jeongsang’ cultivars was the thinnest midrib thickness in cultivars, but it was not significantly different. The free sugar levels of spring cultivars was the highest in ‘Chunkwang’. Malic acid content of ‘Jeongsang’ was significantly different among spring cultivars. Also amino acid content of ‘K-power’ and ‘Chunkwang’ were significantly different among spring cultivars Mineral content in ‘K-power’ and ‘Bomaknorang’ were greater than that of other cultivars. Especially Na, Ca and Mg contents of ‘K-power’ and ‘Bomaknorang’ were higher four times than that of other cultivars. Pectin content of ‘Jeongsang’ was higher than that of other cultivars, but it was not significantly different. Hardness and Firmness were not significantly different among spring cultivars.
In this study, wheat doenjang was manufactured using Korean wheat meju and soybean meju, and its quality were investigated according to mixing ratio of meju. The general characteristics such as moisture contents, pH and salinity of wheat doenjang, which is fermented and aged at 25℃ for 70 days, were slightly decreased time dependently as similar pattern. The pH of wheat doenjang ranged from 4.95 to 5.11% and generally ecreased with aging. The moisture contents was 54.5~57.5%, and there was no significant differences in the aging period. Also, there was no significant changes in the salt contents. The amino-type nitrogen contents were 376.27~600.91 mg% at day 70 of the aging period, and showed 3 fold change compared to the initial contents. The reducing sugar contents showed significant difference between the samples, and repeated fluctuation in the aging period. Wheat meju sample A, which contains 50% of soybean meju, showed the highest antioxidation ability. In addition, wheat meju sample A showed the highest score in the sensory evaluation of the colour, taste, flavor, and overall acceptability. Therefore, wheat doenjang manufacturing at a 1:1 of mixing ratio will lead to desirable quality of wheat doenjang.
To evaluate peanut sprouts as a functional food material, the quality characteristics and antioxidant activities of soybean yoghurt with different percentages (0.5, 1.0, 2.0, and 3.0%) of peanut sprout powder (PSP) contents were investigated. The pH of soybean yogurt with PSP decreased in a time- and dose-dependent manner during fermentation, whereas the titratable acidity increased under the same conditions. The Hunter L value (lightness) decreased while the b value (yellowness) and a value (redness) increased as the PSP concentration in soybean yogurt increased. Prior to fermentation, the sugar content of the soybean yogurt increased as the PSP level increased, but the contents decreased as fermentation progressed. Meanwhile, the viscosity of the soybean yogurt increased during fermentation, and the lactic acid bacteria population was higher than that of the control. The sensory properties, including the flavor, color, taste, and overall acceptability, of the soybean yogurt containing 0.5 and 1% PSP, respectively, were higher than those of other tested yoghurts (with 0, 2.0, and 3.0% PSP contents). The antioxidant activity of the soybean yogurt significantly increased at the PSP concentrations of over 1.0%. These results suggest that the addition of PSP has beneficial effects on the quality and functionality of soybean yogurt, and that the addition of 1.0% PSP is the most suitable for manufacturing soybean yogurt.
This study was conducted to investigate changes in the main volatile flavor components of oriental melon during the process of alcohol fermentation via SPME (solid phase micro extraction). The flavor components of oriental melon were shown to have mainly included melon and green flavors. The green flavor was identified to be nonanal, 1-butanol, 1-octen-2-ol and benzene, and its relative concentration was shown to be 16.66%. The nonanal concentration was shown to have been reduced among the green-flavor components, but no significant change in remaining components was observed. Mainly, sweet flavor tended to increase, and the relative concentration of benzene was particularly shown to have increase by 25.58%, accounting for the highest relative concentration. The amount of green-flavor components, except for 1-butanol, was shown to have significantly decrease after alcohol fermentation. Then, no component of green-flavor, which causes an offensive smell, was found during fermentation and aging. Meanwhile, the volatile flavor components, which are consist of acids, were shown to have been produced during alcohol fermentation. In particular, octanoic acid, which causes off-flavor, was shown to be 60.99%, a very high relative concentration during the aging stage. In addition, acetic acid with a pungent sour flavor tended to be produced. A further study on the improvement of flavor in the production of oriental melon wine is required.
The objective of this study was to evaluate the changes in the physicochemical and microbiological characteristics of pork loin meat through microwave treatment. The microwave treatment was divided into two groups: continuing microwave treatment (CW) and holding microwave treatment (HW). The microwave treatment resulted in a whiter color (L value) and affected the a, b value. The initial pH was 5.51~5.74, but it increased to 6.32~6.51 when the pork loin samples were stored for three days. During storage for 14 days, the pH changes were not significantly different (p>0.05). The thiobarbituric-acid values of all the pork loin samples increased along with the storage period, and decreased with increasing microwave dose. The volatile basic nitrogen (VBN) content of the control was higher than those of the other samples, and the VBN content decreased along with the microwave dose. The total plate counts of the pork loin samples decreased with increasing microwave dose. The study results indicated that T2 (100 W, HW) is most effective for the safety of pork loin meat without decreasing the meat’s physicochemical and microbiological characteristics.
This study was performed to confirm physiological activities according to parts of new pear cultivars (Gamcheonbae, Manpungbae, Chuwhangbae, Hanareum) and Niitaka pear. The total polyphenol compound contents of pear peel, flesh and core were 178~235, 95~113, 177~229 mg/100 g as tannic acid equivalent, respectively. There were differences in the contents by cultivars, Chuwhangbae and Hanareum cultivars showed high contents. The total flavonoid contents of the pear peel, flesh and core were 29.2~40.2, 24.3~34.3, 26.9~38.8 mg/100 g, respectively and those of Chuwhangbae and Gamcheonbae cultivars showed comparatively high values. The electron-donating ability was high in Chuwhangbae, Gamcheonbae and in the pear peel (29.7~57.7%), core (29.1~38.2%), flesh (7.6~17.7%), in that order. The nitrate scavenging activity was highest in that pear peel (21.0~49.8%), followed by the core (11.8~16.2%) and flesh (7.8~9.7%), but there was little difference by cultivar.
This study was conducted to investigate the physicochemical characteristic of Carthamus tinctorius L. seed and to assess its total phenol content, total flavonoids content and antimicrobial activity. The moisture, crude protein, crude fat, crude ash and carbohydrates of the Carthamus tinctorius L. seed were 5.58, 37.16, 13.69, 3.52, and 40.05%, respectively. Total amino acid in Carthamus tinctorius L. seed was 391.99 mg%. The major free sugar of Carthamus tinctorius L. seed were fructose(3.29%) and sucrose(1.74%). Linoleic acid(79.46%) was a major fatty acids in the crude fat of Carthamus tinctorius L. seed. The K and Ca contents were the highest in Carthamus tinctorius L. seed. Total phenol and total flavonoids contents of the ethanolic extract were 55.52 ± 0.99 mg GAE/g and 78.69 ± 0.91 mg QE/g, respectively. The extract from Carthamus tinctorius L. seed showed growth inhibitory effect on Staphylococcus aureus, Salmonella typhimurium, Escheria coli, Candida albicans, Bacillus cereus, Listeria monocytogenes, Vibrio parahaemolyticus, and Clustridium perfringens. These results indicate that the Carthamus tinctorius L. seed extract can inhibit food pathogen associated with total phenol and total flavonoids contents.
The phenolic compounds of water extracts from Prunella vulgaris were highest at 9.25 mg/g, respectively, when various extraction solvents were used. The optimum condition for extracting phenolic compounds from Prunella vulgaris was extraction in water for 18hr. The DPPH-scavenging activities of Prunella vulgaris were highest at the water extracts. The ABTS radical cation decolorization was higher than 40% in the range of 0~100% ethanol extract section. The antioxidant protection factor on the lipophilic phenolic metabolites was shown to be 1.1 PF in the water extracts from Prunella vulgaris. The TBARS was lower than the control (0.53 μM) in all the sections. The tyrosinase inhibitory effect, which is related to skin whitening, was above 40%, and for the anti-wrinkle effect, the elastase inhibition activity was above 40% at 0.2 mg/mL. The astringent effect of the Prunella vulgaris 40%ethanol extracts was 98.1% at 1 mg/mL. As a result, it can be concluded that Prunella vulgaris has the potential to be used as a cosmetic material.
Thermal processing of (+)-catechin was carried out at 121℃ for different reaction times (1, 2, 3, 6, and 12 h). The reacted products, compounds (1) and (2), were isolated and quantified via HPLC analysis. The antioxidant properties of processed (+)-catechin and its isolated compounds for different reaction time was measured via radical scavenging assays using DPPH and ABTS+ radicals. Additionally, the anti-obesity efficacy of the thermal treated (+)-catechin was evaluated via porcine pancreatic lipase assay. The reacted (+)-catechin for 3 h had a slightly higher antioxidant capacity than that the parent (+)-catechin. Products 1 and 2, which were isolated from the reacted mixture during 3 h, showed an antioxidant capacity, and these two compounds may be responsible for the antioxidant capacity of processed (+)-catechin. Simple thermal treatment of (+)-catechin can be used to produce (+)-epicatechin (1) and protocatechuic acid (2) with enhanced antioxidant and anti-adipogenic effects.
To verify the multiplication of microorganisms on the surface of strawberries, the fate of E. coli DH5α::gfp at different temperatures, times and strawberry extract concentrations were measured. The population of E. coli DH5 α::gfp rapidly increased by 7.36~7.78 log CFU/g at 25~30℃ for 24 hr and slowly increased by 6.49~8.49 log CFU/g at 10~20℃ for 48 hr. However, E. coli DH5α::gfp did not grow at 10~15℃ on the surface of the strawberries, regardless of the contact times with the bacterial suspension. E. coli DH5α::gfp reached 1.52~3.26 log CFU/g at 20℃ as the contact frequency increased from two to six times. The contact frequencies did not significantly differ. In the case of the six-time contact on the surface of the strawberry at 25 and 30℃, the E. coli DH5α::gfp increased by 5.17 and 5.01 log CFU/g. The effects of the strawberry extracts on the growth of E. coli DH5α::gfp showed that sterilization and non-sterilization do not affect the growth of microorganisms for 96 hr. In the minimal broth, the growth of E. coli DH5α::gfp increased by 1 log CFU/g for 96 hr. In less than 50 percent of the strawberry extracts, the growth rate of E. coli DH5α::gfp was higher than in the control and increased by 4 and 5 log CFU/g at 50 and 25 percent of strawberry extracts, respectively. Therefore, E. coli DH5α::gfp can multiply and survive on the surface of strawberries when it comes into contact with the fruit extract.
Central composite design along with response surface methodology (RSM) was applied to improve the fermentation process in onion (Allium cepa) wine production. The effects of different fermentation parameters (time, temperature, and initial sugar content) were found to be significant with respect to the physicochemical and sensory properties of wine. The maximum score for the alcoholic content was obtained at 29.27℃ fermentation temperature, 103.43 h fermentation time, and 27.52 °Brix initial sugar content. The maximum score for overall palatability was obtained at 39.27℃ fermentation temperature, 57.28 h fermentation time, and 22.14 °Brix initial sugar content. The coefficients of determination (R2) were 0.9620 and 0.9060 for alcoholic content and overall palatability, respectively. The ranges of the optimum fermentation conditions (28~32℃, 80~90 hr, and 20~25 °Brix) were obtained by superimposing the response surfaces with regard to the alcoholic content and overall palatability of onion wine.
The objective of this study was to assess the quality characteristics of yanggaeng prepared with different ratios of blueberry powder: 0%, 3%, 6%, and 9%. The moisture content of the control yanggaeng was lower than that of any other blueberry added groups. The pH decreased while the titratable acidity and the Brix increased as the amount of blueberry powder increased. The lightness (L) and yellowness (b) were the highest while the redness (a) was the lowest in the controls. Texture profile analysis showed that the hardness of the added groups were higher than that of the control which were the lowest. The total polyphenol content and DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity increased as the amount of blueberry powder increased. The results of consumer acceptance test revealed that the color preference was the highest in the 9% added group while the smell, taste, texture and the overall acceptability showed no significant differences groups. Based on these results, it is suggested that yanggaeng with up to 9% added blueberry powder can be developed as products without adverse effects on sensory characteristics.
The physicochemical and sensory properties of herb samgyetang, ginseng chicken soup added with medicinal herbs were investigated to determine the optimum addition level of medicinal herbs. The pH of herb samgyetang decreased with increasing addition level of the Acorus gramineus addition level, and the soluble solid content increased as the Codonopsis lanceolata addition level increased. The herb samgyetang with the highest Codonopsis lanceolata addition level had the lowest L* and b* value. In contrast, the a* value increased with increasing Codonopsis lanceolata addition level. In sensory evaluation, the highest color, taste, and overall acceptability scores were obtained by the herb samgyetang with the highest Codonopsis lanceolata addition level. In conclusion, the optimum addition levels of medicinal herbs for herb Samgyetang are as follows: Platycodon grandiflorum 4 g, Acorus gramineus 4 g, Codonopsis lanceolata 12 g, Schizandra chinensis 6 g, Atractylodeslancea 4 g, Glycyrrhiza uralensis 4 g, and Zizyphus jujube 4 g.
The purpose of this study was to evaluate the mortality rate, weight gain, and protein, lipid cholesterol, and total amino acid contents in processed-sulfur-diet chicken meat. Also investigated were the antioxidant activity and glutathione content of blood plasma. The mortality of the processed-sulfur-diet chickens was relatively reduced, and their weight increased compared to the normal-diet chickens. Although the glutathione content decreased in the processed-sulfur-diet chicken blood plasma, the antioxidant activity increased compared with the normal-diet chickens. Also, there was no difference in the total cholesterol contents of the blood, but the level of HDL cholesterol increased while that of LDL cholesterol decreased. Furthermore, there were no changes in the total amino acid and protein contents, but the fat content was significantly reduced. As no toxicity was found in the DT 40 cells in the MTT assay, it can be concluded that dietary sulfur in chicken feed can improve the quality of poultry products.
Omija (Schizandra chinensis B.) slices were dehydrated with 20, 40, and 60% (w/w) red algae extract (RAE), and 40% of RAE was selected as the proper processing concentration considering the dehydration efficiency and cost of the dehydrating agent. The RAE-treated omija samples were compared with the hot-air dried samples in terms of the qualities such as the rehydration capacity and total phenolic contents. The rehydration ratios of the RAE-treated samples were greater than those of the hot-air dried samples by 31%. The total phenolic contents of the RAE-treated samples (1304.8 mg GAE/100 g) were higher than those of the hot-air dried samples (999.5 mg GAE/100 g). Therefore, omija slices can be dehydrated with RAE without quality loss.