The capacity of a pressure fan can be designed based on the air flow resistance of containers packed with fruits and vegetables in a pressure cooling system. This study was conducted to develop an air flow resistance model that was dependent on changes in the air flow rate and the method of stacking containers. The air flow resistance of a container packed with uniformly shaped balls was 1.5 times greater than the sum of the air flow resistance of a vacant container and that of a wire net container packed with only balls. In addition, the air flow resistance increased exponentially as the width of the stacks increased; however, the air flow resistance did not increase greatly as the length and height of the stacks increased, which indicates that the air flow resistance is primarily influenced by the width of the stack in the air flow direction. The air flow resistance in two lines of stacking was up to 17% less than that of the width of the stack. It was also possible to determine the air flow resistance using a function of the air flow resistance through a single container and develop a prediction model. A prediction model of air flow resistance that is dependent on the stacking method and the air flow resistance of a single container was developed.
This study was conducted to assess the possibility of preserving frozen vegetables (Aster scaber, soybean sprouts, Chinese cabbage, green pumpkin, and Welsh onion) for a long period and of using them after such storage by measuring changes in quality due to their preservation. Various freshly harvested vegetables were blanched under optimal conditions (that were determined in a preliminary experiment), quick-frozen at –40℃ for 24 h, and stored at –20℃. The change in the chromaticity of the frozen A. scaber, soybean sprouts, Chinese cabbage, green pumpkin, and Welsh onion did not vary. The hardness of the frozen A. scaber, green pumpkin, Chinese cabbage and Welsh onion did not change during the preservation period, whereas the hardness of the cotyledon and hypocotyl of the soybean sprouts significantly increased on the sixth month of their storage. The total bacterial counts of the A. scaber during the preservation period remained constant at 103 CFU/g, whereas those of soybean sprouts, Chinese cabbage, green pumpkin, and Welsh onion decreased slightly to 102 CFU/g. Coliform was not detected in any of the samples. The sensory evaluation showed that the preservation period that was used in this study did not significantly affect the marketability of the frozen vegetables. Therefore, it was considered that A. scaber, soybean sprouts, Chinese cabbage, green pumpkin, and Welsh onion can be safely preserved by freeze-storing them for up to 12 months.
To determine the appropriate harvest maturity of mulberry to prolong the freshness during distribution, mulberries were classified into three groups (80%, 90%, and 100%) based on their degree of maturity and then compared for their firmness, color, anthocyanin, soluble solids content, pH, titratable acidity, viable cell, mold and sensory quality. They were then investigated for quality changes by maturity under different distribution temperature at 20℃, 10℃ and 0℃. Immediately after harvest, the 80% matured mulberries were shown to be the firmest and 1.74 and 2.64 times firmer than 90% and 100% matured mulberries respectively. The more mature the mulberries were the lower the “a” value was while anthocyanin content was higher. The soluble solids content and pH of mulberries increased as they matured. Less mature the mulberries were the higher titratable acidity was and lower microbial levels in mulberries were. In terms of sensory quality, color of the 100% matured mulberries was the highest but the 90% matured mulberries were most preferred based on other sensory indexes. In comparison to storability of mulberries by maturity, although the firmness of the 80% matured mulberry decreased rapidly, they were the firmest during distribution periods. The level of mold of the 100% matured mulberries was higher than others. Moreover, the more mature mulberries were the quicker they deteriorated. According to quality indexes, depending on maturity and sensory evaluation of mulberry distributed at different temperatures, the storability of the 80 and 90% matured mulberries were higher than that of the 100% matured mulberries. In conclusion, judging by their sensory quality, the 90% matured mulberries were more appropriate for harvesting than the 80% matured mulberries.
This study was conducted to investigate the effects of pretreatment and different packaging methods on the physicochemical properties of cold vacuum-dried peaches. All the dried peach samples were stored such as N2 gas substitution, vacuum and passive packaged with polyethylene (PE) film and oriented polypropylene (OPP)/aluminum (Al)/PE film at 40℃ for 50 days. The weight change, pH, soluble solids content, titratable acidity, soluble solid-acid ratio (SS/TA), delta E, browning degree and phenolic compounds were analyzed. The weight change and pH were lower in the 0.1% vitamin C-treated group and were significantly lowest in the vacuum-treated OPP/AL/PE. The soluble solids content and the SS/TA were higher in the non-treated groups than in the vitamin C-treated groups. According to the packaging methods, the L* values were higher in the vacuum, N2 gas and passive package, in that order. In addition, the browning degree and the delta E value were lower in the pretreated groups and significantly lowest in the vacuum-treated OPP/AL/PE with 0.1% vitamin C group. The phenolic compounds were high for the pretreated groups, according to the packaging methods (vacuum > N2 gas> passive), and the OPP/AL/PE was significantly higher than the PE. These results suggest that different packaging materials and pretreatment methods affected the quality of the dried peaches, and the vacuum- OPP/AL/PE film packaging group showed a high quality.
Strawberries are among the leading ready-to-eat agricultural products that have superior taste and nutrition. Thus, consumer concerns about the safety of eating strawberries are growing. To evaluate the contamination levels of strawberries according to their cultivation methods (nutriculture, pesticide-free culture and organic farming) and parts [fruit (flesh), stalk (pedunle) and leaf (calyx)], 1,020 parts of strawberry samples were collected at 12 farms in Nonsan-si and quantitatively or qualitatively examined for the indicators of food safety and food poisoning bacteria. The total aerobic bacteria count in the whole samples was 2.3~6.8 log10 CFU/g, and coliform bacteria were detected in 14.2% of the whole samples with a contamination level range of 2.1~4.5 log CFU/g. E. coli were detected in 0.9% of the whole samples with a contamination level range of 2.1~2.8 log CFU/g. The analysis of the bacterial levels according to the cultivation methods showed that the total aerobic bacteria and coliform counts were higher in the strawberries that were grown via organic farming than in those that were grown via nutriculture and pesticide-free culture. However, the E. coli counts of the strawberries that were grown via organic farming and via pesticide-free culture were similar and differed from that of the strawberries that were grown via nutriculture. The analysis of the contamination levels according to the parts of the strawberries showed that the total aerobic bacteria, coliform and E. coli counts of the fruits, stalks and leaves of the strawberries did not significantly differ. Staphylococcus aureus was detected in two organically grown strawberries, but Salmonella spp., Listeria monocytogenes and E. coli O157:H7 were not detected in the whole samples. These results show that the bacterial contamination levels of the strawberries differed based on their cultivation methods. Thus, a suitable method of reducing the bacterial contamination levels of strawberries according to their farming methods is needed
This study was conducted to investigate the food value of Cudrania tricuspidata at its various maturation stages. The pH, total acid and reducing sugar contents of its fruit juice were determined to have been 4.2~5.1, 1.4~2.0% and 5.4~8.6%, respectively. The general chemical components of its fruit were observed as 76~80% moisture, 2.2~3.5% crude protein, 1.7~2.9% crude fat, 0.8~1.2% ash and 14.5~16.4% carbohydrate. Its free sugar, glucose and fructose contents were determined. The fructose contents of both its ripened and over-ripened fruits were higher than their glucose contents. Organic acids such as oxalic acid, citric acid, tartaric acid, malic acid and succinic acid were detected, and the concentration of the malic acid and the succinic acid were found to have been most abundant. The K content was higher than the amounts of other minerals, such as Ca, Fe, K, Mg, Na and P. Its vitamin C and the total amount of its dietary fiber were 127.5~149.2 mg% and 22.7~38.7%, respectively. Its insoluble dietary fiber content was higher than its soluble dietary fiber content. Its total polyphenol and flavonoid content were 18.9~19.6 mg% and 40.9~48.2 mg%, respectively.
In this study, the proximate compositions, minerals, free amino acids, total polyphenol and flavonoids of figs were analyzed according to their cultivars. The proximate compositions showed moisture at 85.37∼87.28%, crude ash at 0.38∼0.43%, crude lipid at 0.20∼0.26%, crude protein at 0.39∼0.81%, carbohydrate at 11.23∼13.66% and crude fiber at 5.12∼7.55% (dry base). The amount of the following minerals in the figs were highest, in this order: K 〉Ca 〉Mg 〉Na. The total polyphenol contents were highest in this order: Dauphine (198.91∼261.64 mg/kg), Banane (211.07 mg/kg) and Horaish (169.90∼174.33 mg/kg). The total flavonoid contents were highest in this order: Banane (84.52 mg/kg) 〉Dauphine (60.47∼68.71 mg/kg) 〉Horaish (44.12∼44.60 mg/kg). The quercetin contents were highest in this order: Dauphine, 2.40∼3.54 mg/kg; Banane, 3.54 mg/kg; and Horaish, 2.40∼2.75 mg/kg; but the flavonoid contents were lowest in this order: Dauphine, 1.11∼1.16 mg/kg; Banane, 1.14 mg/kg; and Horaish, 1.09∼1.11 mg/kg. The free amino acid content of the figs was 199.70∼328.77 mg/100 g; their essential free amino acid contents, 46.45∼67.46 mg/100 g; and their GABA (γ-aminobutyric acid) contents, 13.57∼26.69 mg/100 g.
In recent years, polyphenol-rich herbs, fruits and processed foods, which are made of plant origin, have attracted much attention due to their potential health benefits. Pomegranate (Punica granatum L.) is an important source of bioactive compounds and has been used to treat diseases because of its medicinal properties. This research was focused on characterizing Korea’s national cultivar and a similar product from California, USA. To evaluate their bioactive compounds and pharmacological activities, their anti-oxidation and cancer inhibition properties, as well as their organic acid and free sugar contents, were investigated. The national cultivar had low total sugar and high organic acid contents, contrary to the imported product. The results showed that the peel of national cultivar had high polyphenol and ellagic acid contents compared to imported product. The free radical scavenging capacity was evaluated via 2,2-diphenyl-1-picrylhydrazyl (DPPH) and its positive correlation with the total polyphenol contents was found. The anti-cancer activity of methanol extracts revealed growth inhibition against the prostate cancer cell. These results signify that while pomegranate, national cultivar, is more sour than the imported product, its health benefits could be excellent. Also, the polyphenol compound content of the non-edible part (such as the peel and the seed) was higher than that of the juice. Thus, it is suggested that the byproduct of the juice extraction could be potentially used in other fields such as medicine or dietary agents.
This study was conducted to analyze the sensory profiles of commercial rice cookies and snacks in the market and to provide fundamental data on the development of rice cookies and snacks. The sensory characteristics of 10 kinds of Korean commercial rice cookies and snacks were evaluated using a sensory test and were analyzed via quantitative description analysis (QDA) and principal component analysis (PCA), depending on their rice contents and processing methods. The rice cookies and snacks with less than 30% rice contents and that were fried were preferred, and their grainy attribute was related to the preference for them. Then 27 kinds of commercial rice cookies and snacks from three countries, Japan, the U.S.A. and China, were also evaluated and compared with those from Korea. While the Korean commercial rice cookies and snacks were sweet, grainy and crispy, those of Japan were not sweet and instead, were salty and crispy.
The nutritional composition, bioactive components and antioxidant activities of the first and second sprouts of Kalopanax pictus, Cedrela sinensis and Acanthopanax cortex were investigated to increase the utilization of these sprouts. The moisture and crude lipid contents of the first sprout were higher than those of the second sprout, and the crude fiber and carbohydrate contents were higher in the second sprout. The organic acid content of the first sprout was higher than that of the second sprout. The second sprout had higher free amino acid contents in K. pictus and C. sinensis, and the first sprout had a higher content in A. cortex. Especially, the second sprout of K. pictus and C. sinensis had a higher level of glutamic acid, which is a major taste component of foods, than the first sprout. The second sprouts of all the samples had higher mineral levels than the first sprouts. In contrast, the first sprouts had higher total polyphenol and flavonoid contents and showed a higher antioxidant activity level, except for the DPPH radical scavenging activity of the A. cortex. The results of this study show that the nutritive value of the second sprout was higher than that of the first sprout, but the bioactive components value of the second sprout was lower than that of the first sprout. Therefore, additional research is needed on the cultivation condition required to maintain the nutritive values and the antioxidant activities of these sprouts.
The organic acids, fuel oil contents and antioxidant activities of Yakju with the addition of rice varieties were investigated. The rice cultivars that were used in this study were Ilmi rice, Hopyung rice, Hopum rice, Hanarum rice, Anda rice and Indica rice. The study results are as follows: the pH values of Ilmi Yakju and Hanarum Yakju were 4.14 and 4.07, respectively, and those of the other Yakjus, 3.92~3.98. The total titratable acid content of the Yakju for which Indica rice was imported from Thailand was highest among the samples. The reducing sugars content of the Yakju for which Indica rice was used was higher than that of the other samples. The ethanol content of the Hanarum Yakju was higher than that of the other Yakjus, and the lowest ethanol content was found for the Indica Yakju. The major organic acid component of the Yakju was lactic acid. The total organic acid content was highest in the Indica rice Yakju. The amounts of the following main fusel oils were highest, in the following order: 2-butyl alcohol, 2-pentanol, N-propyl alcohol, acetaldehyde, ethyl acetate, methyl alcohol and 2-methyl-1-propyl alcohol. The DPPH free radical scavenging activity of the Indica rice Yakju was much higher than that of the Ilmi rice Yakju and the Hanarum rice Yakju. Also, the SOD activity of the Indica rice Yakju was strongest among all the samples. The total polyphenol content of the Indica rice Yakju was the highest among all the samples.
The objective of this study was to evaluate the quality characteristics of mungbean starch gels that were prepared with different concentrations (0, 0.5, 1.0 and 1.5%) of peach seed powders (PSP), which exhibit antioxidant characteristics. Mungbean starch gel samples were prepared and subjected to quality characteristics such as moisture content, general components, color, texture profile analysis, total polyphenol contents, DPPH radical scavenging activity, and sensory qualities. The L-value and the a-value for color decreased significantly, whereas the b-value increased significantly as the PSP concentration increased (p<0.05). In the texture profile analysis, the mungbean starch gel with 1.5% PSP showed significantly lower degrees of hardness, cohesiveness, springiness, gumminess and brittleness (p<0.05). The total polyphenol content was highest in the 1.5% PSP to which mungbean starch gel was added, which also showed a higher than 70% DPPH radical scavenging activity level in a dose-dependent manner (p<0.05). In the sensory test of the mungbean starch gel, its sensory scores for flavor and taste were highest in the 0.5% PSP to which mungbean starch gel was added.
To establish the optimal manufacturing conditions of soybean koji, soybean Koji prepared with Aspergillus oryzae 6-M-1 and Bacillus subtilis 3-B-1 isolated from traditional Korean meju. During 7 days of making Koji, the amount of amino-type nitrogen was getting more increase. The amount of amino-type nitrogen of Koji prepared with A. oryzae 6-M-1 was 686.16 mg% (w/w), that of Koji with B. subtilis 3-B-1 was 643.46 mg% (w/w) at seventh day of making Koji. The α-amylase activity of Koji prepared with A. oryzae 6-M-1 was 1472.54 unit/g, that of Koji with B. subtilis 3-B-1 was 791.00 units/g on the seventh day of the making. The acidic protease activity of Koji prepared with A. oryzae 6-M-1 was 309.00 unit/g, that of Koji with B. subtilis 3-B-1 was 135.88 unit/g at 7th day of making. The amount of amino-type nitrogen and enzyme activities of soybean Koji prepared with A. oryzae 6-M-1 and B. subtilis 3-B-1 were produced more than those of wheat flour Koji made in factory. Sensory evaluation on a commercial doenjang and doenjangs prepared with A. oryzae 6-M-1 and B. subtilis 3-B-1 was not significantly different at p<0.05.
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℃, HW: dip in the water for 60 sec at 55℃, AA: dip in the 0.1% solution of ascorbic acid for 60 sec at 4℃, HA: dip in the 0.1% solution of ascorbic acid for 60 sec at 55℃) during storage at 5℃. 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.
This study was performed to investigate the four-week repeated-dose toxicity of the crude antifungal compounds produced by Lactobacillus plantarum AF1 (Lb. plantarum AF1), a lactic acid bacterium isolated from kimchi, in male and female rats. Sprague-Dawley male and female rats were divided into four groups, with 10 animals in each group. The test article was administered once daily by gavage to rats at dosage levels of 0, 500, 1,000, and 2,000 mg/kg/day for four weeks. There were no test-article-related deaths or abnormal clinical signs in both the male and female rats during the observation period. Furthermore, no differences in the body weight changes, food intake and water consumption levels of the control and treatment groups were found. The hematological parameters, serum biochemical analysis results, histopathological examination results and all other findings also showed no significant or dose-dependent changes. There were also no changes in the organ weights upon the administration of the crude antifungal compounds produced by Lb. plantarum AF1. These results suggest that the oral administration of the crude antifungal compounds produced by Lb. plantarum AF1 had no adverse effects up to a dosage level of 2,000 mg/kg in both male and female rats.
This study was conducted to investigate changes in the physicochemical properties (proximate compounds, reducing sugar, organic acid, ATP and related compounds, and free amino acid) of beachu kimchi (BK) with octopus, abalone, squid and webfoot octopus added during its storage at 4℃ for 35 days. The crude protein content of the seafood Kimchi, 1.98∼3.41%, was higher than that of the BK. The organic acid level did not significantly differ in the four kinds of seafood during their fermentation, and their malate and succinate contents decreased while their lactate content increased. The levels of the ATP and related compound substances of the hypoxanthine contents were high but decreased during their fermentation. However, 3.40 μmol/g of IMP was detected in the Kimchi with octopus added; 0.67 μmol/g in the Kimchi with abalone added; and 1.80 μmol/g in the Kimchi with squid added after they were fermented for 21 days, but the same were not detected in the BK. The taurine and γ-amino-n-butyric acid contents of the free amino acids in the seafood Kimchi were approximately two to 10 times and 1.5 to three times higher than in the BK, respectively.
The objective of this study was to characterize the bactericidal effect of 461nm visible-light LED on three common foodborne bacteria: Escherichia coli O157:H7, Staphylococcus aureus and Vibrio parahaemolyticus. Tests were conducted against pathogen strains that were treated with 461nm LED for 10 h at 15°C. The E. coli (ATCC 43894, ATCC 8739 and ATCC 35150) and the S. aureus (ATCC 27664, ATCC 19095 and ATCC 43300) had average reductions of 2.5, 6.6, 1.5, 2.5 and 2.0 log CFU/mL, respectively, after they were exposed for 10 h to 461nm LED light (p<0.05). In contrast, V. parahaemolyticus (ATCC 43969) had 6 log CFU/mL reductions after it was exposed for 4 h to 461nm LED light. The results showed that both the Gram-positive and Gram-negative bacteria were inactivated with 461nm LED light exposure. Also, the Gram-negative bacteria were more sensitive to the LED treatment than the Gram-positive bacteria. These results show the potential use of 461nm LED as a food preservation and application technology.
Microbiological contamination of 4 vegetables (garlic, red pepper, perilla leaf and lettuce) collected from 10 restaurants around university was examined. The vegetables were evaluated for total plate count, coliforms, psychrophiles, yeast, and Staphylococcus aureus. The results of total plate count showed the highest value as 5.4±0.69 log CFU/g in lettuce, following by 4.8±1.53 log CFU/g in red pepper, 4.5±1.65 log CFU/g in perilla leaf and 3.4±1.27 log CFU/g in garlic. The contamination level of coliforms and psychrophiles were highest in red pepper with maximum as 4.7 log CFU/g and 8.2 log CFU/g, respectively. Red pepper of psychrophiles showed the highest average value as 5.0±1.82 log CFU/g followed by 4.2±1.91 log CFU/g in lettuce, 4.7±1.55 log CFU/g in perilla leaf and 2.4±2.10 log CFU/g in garlic. The average number of yeasts were highest in perilla leaf with 4.4±1.41 log CFU/g and were lowest in garlic with 0.9±1.41 log CFU/g. The contamination level of S. aureus was detected in 27 samples among the total 40 samples with the range of 0.5-5.2 log CFU/g. In conclusion, the microbial quality of the fresh vegetables evaluated in this study was not very good. Therefore, it needs to be enhanced through the good sanitation management and production and distribution methods to improve the safety of fresh vegetables.
This study was designed to investigate the formation of ethyl carbamate (EC) during the ripening of Maesil with sugar and Soju (19.5~35% alcohol contents) using a homemade method. Maesil, sugar and Soju were purchased at ordinary market in June of 2012. The preparation of sample for analysis was conducted by method of Henry et al. The analysis of GC/MS was used SIM mode (m/z 89, 74, 62). Quantification was performed in terms of the 62 ion and was based on an internal standard procedure. Good linearity was obtained with a regression coefficient (r2 = 0.993). Low detection limits (LOD) was achieved 4.31 ug/kg and recovery for alcohol was 74.8%. During 90 days, fermentation with sugar was not detected EC (under LOQ). 15 days ripened Maesil wine contained EC between non detected~32.7 ug/kg and 90 days ripened Maesil wine was 19.7~87.4 ug/kg. Higher proportion of Maesil and Soju increased EC contents. EC levels were increased 32.7 ug/kg to 87.4 ug/kg in the ratio of Maesil to 35% alcohol-Soju (1:1). In the ratio of Maesil to 35% alcohol-Soju (1:3) was increased non detected to 69.7 ug/kg. After 90 days, Maesil wine was filtered Maesil through a seive and ripened by 180 days to investigate the formation of EC compared with non filtered. Treatment of filtered, EC contents was much higher level compared with non filtered. Therefore, this result showed that alcohol contents contribute to increase EC formation more than Maesil.
As byproducts of chicken slaughtering, chicken feathers are produced and mostly discarded without proper treatment, which results in serious environment pollution. Therefore, the appropriate treatment and utilization of chicken feathers are needed. In particular, chicken feathers can be used as protein sources for the preparation of protein hydrolysates, considering that chicken feathers have a large amount of proteins. In this study, chicken feather protein hydrolysates were prepared and their iron-binding peptides were isolated. Chicken feather protein was extracted from feathers of slaughtered chicken, and its hydrolysates were prepared via hydrolysis with Flavourzyme for 8 h. Then the chicken feather protein hydrolysates were ultra-filtered to obtain small peptide fractions and fractionated using Q-Sepharose and Sephadex G-15 columns to isolate their iron-binding peptides. Two major fractions were produced from each of the Q-Sepharose ion exchange chromatography and the Sephadex G-15 gel filtration hromatography. Among the fractions, the peptide fraction with a high iron-binding activity level, F12, was isolated. These results suggest that chicken feather protein hydrolysates can be used as iron supplements.