'Fuyu' (Diospyros kaki L.) is an important sweet persimmon cultivar, and the fruits are often stored in a modified atmosphere after harvesting in South Korea. However, blossom-end browning and darkening of fruit often occur after harvest or during storage, which decreases fruit quality in the fresh fruit market. High fruit calcium concentration would reduce oxidation of phenolic compounds in the cytoplasm such oxidation is responsible for fruit browning. This study investigated the effects of soluble calcium fertilization and foliar application, and indole-3-butyric acid (IBA) fertilization on fruit quality and browning. Trees received one of the following five treatments: 1) control (no calcium or IBA); 2) calcium fertilization (Ca FG, 2 mL per tree); 3) calcium foliar application (Ca FA, 2 mL); 4) calcium and IBA fertilization (Ca+IBA) 5) IBA fertilization (IBA, 2 mL. Fruit calcium concentration was highest in trees treated by Ca FA, and lowest in control trees. Generally, fruit calcium concentration was high in the stem end but low in the blossom end, which usually first develops fruit-browning symptoms. There were no apparent differences in fruit qualities such as firmness, soluble solid content, and weight among treatments. Fruit browning occurred at frequencies of about 14%, 20%, and 50% on Ca FA, Ca FG, and control trees, respectively. Therefore, the improved fruit calcium level seen when trees received Ca or IBA application tended to prevent fruit browning, which increased fruit quality and storage properties.
We evaluated the physicochemical properties and sensory characteristics of, bioactive compounds in grape juice prepared from different grape varieties grown in Korea, such as Campbell Early, Steuben, and Muscat Bailey A (MBA), with respect to heating time (30, 45, or 60 min) and temperature (60 ℃, 70 ℃, 80 ℃, or 90 ℃). We found that long heating time and high temperature, especially treatment at for 60 min, significantly affected the physicochemical properties and bioactive compound levels of grape juice. Among the grape juice varieties, Campbell Early juice had the highest level of bioactive compounds. Sensory evaluation scores showed that heating of musts at 80 ℃ for 30 min was associated with the most preferred sensory attributes for Campbell Early grape juice, whereas the most preferred juices from Steuben and MBA grapes were from musts heated at 70 ℃ for 60 min and at 70 ℃ for 30 min, respectively. The bioactive compounds of juice from the three grape varieties were optimal using the above-mentioned processing times and temperatures.
Response surface methodology (RSM) is frequently used for optimization studies. In the present work, RSM was used to determine the antimicrobial activitiesof grapefruit seed extract (GFSE) and a lactic acid mixture (LA) against Staphylococcus aureus, Bacillus cereus, Escherichia coli, Salmonella typhimurium, Pseudomonas fluorescens, and Vibrio parahaemolyticus. A central composite design was used to investigate the effects of independent variables on dependent parameters. One set of antimicrobial preparations included mixtures of 1% (w/w) GFSE and 10% (w/w) LA, in which the relative proportions of component antimicrobials varied between 0 and 100%. In further experiments, the relative proportions were between 20% and 100%. Antimicrobial effects against various microorganisms were mathematically encoded for analysis. The codes are given in parentheses after the bacterial names, and were S. aureus (), B. cereus (), E. coli (), S. typhimurium (), P. fluorescens (), and V. parahaemolyticus (). The optimum antimicrobial activity of the 1% (w/w) GFSE:10% (w/w) LA mixture against each microorganism was obtained by superimposing contour plots ofantimicrobial activities on measures of response obtained under various conditions. The optimum rangesfor maximum antimicrobial activity of a mixture with a ratio of 1:10 (by weight) GFSE and LA were 35.73:64.27 and 56.58:43.42 (v/v), and the optimum mixture ratio was 51.70-100%. Under the tested conditions (a ratio of 1% [w/w] GFSE to 10% [w/w] LA of 40:60, and a concentration of 1% [w/w] GFSE and 10% [w/w] LA, 70% of the highest value tested), and within optimum antimicrobial activity ranges, the antimicrobial activities of the 1% (w/w) GFSE:10% (w/w) LA mixture against S. aureus (), B. cereus (), E. coli (), S. typhimurium (), P. fluorescens (), and V. parahaemolyticus () were 24.55, 25.22, 20.20, 22.49, 23.89, and 28.04 mm, respectively. The predicted values at optimum conditions were similar to experimental values.
We investigated how supercritical affected sterilization and enzyme inactivation in dongchimi, a conventional Korean fermented food. The growth of bacteria, including lactic acid bacteria, in dongchimi juice tended to decrease with increased pressure and temperature during treatment with supercritical . D values were affected by pressure more than by temperature. The lowest total number of cells and D values of lactic acid bacteria were observed after treatment with supercritical at 25 MPa and ; these conditions also reduced polygalacturonase activity in radishes by approximately 40.3%. Supercritical can be used as an alternative method of sterilization and enzyme inactivation, minimizing sensory loss and textural changes in vegetable materials.
This study attempted to examine the profitability and marketing costs of seed potato under contract farming system of BADC (Bangladesh Agricultural Development Corporation) with the help of primary and secondary data. Total 45 contract farmers were randomly selected. Attempts were made to calculate costs, returns and profitability of seed potato production under contract farming system, and to identify marketing channels of seed potato. The field level data were collected by a farm survey during the months of April 2005 through direct interviews with contract farmers and registered dealers using a structure survey questionnaire. The results showed that the gross return per hectare was Tk. 252,464 for all categories of farms. Cost of seeds, fertilizers, pesticides, irrigation and human labor were critical inputs for profitability of seed potato. Cobb-Douglas production function analysis was used to determine the effects of the key variables to seed potato production under contract farming system. The elasticity of seed potato production was at 0.727 for all categories of farms. The findings exhibited that the summation of elasticity of different inputs for seed potato production was less than one, implying that the production function exhibited decreasing returns to scale. Registered dealers and Upazila Sales Centers were involved in seed potato marketing formed a straightforward marketing channel. The total marketing costs of registered dealers were Tk. 759.49 per ton of seed potato. The net marketing margin of registered dealers was estimated at Tk. 465.51 per ton of seed potato. The selected contract farmers and registered dealers faced a number of problems and some of recommendations were suggested.
Quality changes in fresh-cut potatoes during storage at after treatment with low-temperature blanching and antibrowning agents were studied. Fresh-cut potatoes were treated by dipping for 1.5 min in a browning inhibitor solution containing 0.5% (w/v) ascorbic acid, 0.5% (w/v) citric acid, 0.5% (w/v) sodium chloride, 0.1% (w/v) trehalose, and 0.005% (w/v) biotin, at , with subsequent cooling for 1.5 min and storage at . The browning properties of fresh-cut potatoes were examined by measurement of polyphenol oxidase (PPO) activity and total phenolic content. Changes in quality attributes over a 14-day period were assessed in terms of titratable acidity, pH, water-soluble solid level, and gas analysis at . During storage, PPO activity increased, with the lowest activity seen after about 7 days of storage. Treatment with antibrowning solution at increased visual sensory attributes during storage. Low-temperature blanching in distilled water more effectively inhibited browning compared with exposure to browning inhibitor solution, as assessed after 7 days of storage. Fresh-cut potatoes respired aerobically after different treatments during storage at .
We investigated changes in quality during storage of cookies prepared with pine needle powder these are functional foods. We chose the quantity of pine needle powder (0%, 3%, 6%, or 9%, by weight) and storage time (1 day, 3 days, or 5 days) as independent variables and conducted sensory tests, measured chromaticity, and investigated physical properties. Differences in sweetness (p
Total phenolic content and the antioxidative activity (DPPH radical-scavenging capacity) of 29 fruits and vegetables were determined. The total phenolic contents of plum (1.06 mg GAE/g fresh weight) and cherry (0.95 mg GAE/g fresh weight) were high, whereas those of banana, carrot, and cucumber (each at 0.07 mg GAE/g fresh weight) were low. In the DPPH radical-scavenging assay, apple mango extract showed the highest value(92.8%) among the 29 ethanol extracts tested, followed by paprika (75.4%), beet (75.3%), and cherry (75.1%). In the inhibition assay, cherry (34.95% inhibition) and grape (31.03%) showed the highest activities among the 29 fruits and vegetables examined.
The quality attributes of frozen dough mixed with milk proteins (casein: C and whey protein: W) and polysaccharides (sodium alginate: A and K), and with 1.6% (w/w) wheat flour, were investigated to improve the quality of dough. Addition of milk protein-polysaccharide mixtures increased water absorption, as assessed by farinography, compared with control material. Dough prepared with CA and WA mixtures showed longer development times and increased valorimeter values compared with control samples. However, addition of milk protein-polysaccharide mixtures decreased dough stability, elasticity, and strength. Gelatinization temperature and the temperature at maximum viscosity, as measured by amylography, increased on addition of milk protein-polysaccharide mixtures, but the maximum viscosity decreased compared with control samples. The control showed a lower dough volume than did dough prepared with CA and WA mixtures. These results indicate that addition of milk protein-polysaccharide mixtures, especially CA and WA, improved the quality of frozen dough,and could be useful to prevent bread becoming stale.
To explore cattail pollen powder as a functional food ingredient, we analyzed the general components of pollen powder, tested changes in the physical properties of dough containing the powder, and investigated the process ability of powder-containing dough in bread making by adding 3%, 6%, or 9% by weight of pollen powder to wheat flour. Cattail pollen powder consisted of (all w/w) 12.7-13.2% water, 15.7-17.8% crude protein, 1.3% crude fat, 7.5-7.7% free sugar, 14.7-18.6% crude fiber, 3.4-4.9% pollen, and 49.7-55.9% soluble nitrogen-free extract (NFE). Analysis of the physical properties of dough mixed with pollen powder showed that as more pollen powder was added, the absorption rate increased, but dough stability decreased. With increasing levels of cattail pollen powder, the falling number decreased, and amylase activity increased. Fermentability was highest in dough made with 3% by weight of pollen powder, and the bread product made from such dough had the greatest volume. As more cattail pollen powder was added, the moisture activity in dough tended to decrease to a greater extent than seen in control dough, and this tendency increased with time. We found that longer storage periods were associated with greater hardness and springiness, which indicated degradation in product quality. Therefore, it is suggested that bread products containing cattail pollen powder should be consumed within 3 days of preparation. In a taste survey, bread baked with 3% (w/w) cattail pollen powder scored highest in all questionnaire items.
To decrease human intake of animal fats, changes in the physicochemical characteristics of pork loins prepared by different cooking methods (boiling, steaming, baking, and frying) were investigated. The moisture content of the cooked meat decreased with all methods, and the crude lipid content decreased with all methods except frying. The cooking loss and the moisture drain rate of the cooked meats were greatest during frying, whereas the lipid drain rate was greatest with steaming. The pH value increased during all cooking processes tested. The acid value and refraction index of meat fat markedly increased by steaming and frying, respectively. The hardness, gumminess, chewiness, and cohesiveness of the meat increased notably during frying. The springiness decreased by both boiling and steaming, but rarely by baking or frying. The CIE (lightness) value markedly increased by both boiling and steaming, and the CIE (redness) value decreased notably during both boiling and steaming. The CIE (yellowness) value increased by both baking and frying, but usually did not increase with either boiling or steaming. The composition of fatty acids was not significantly affected by any cooking methods except frying.
We developed a surface washing system for ginseng. The washing system was developed using different treatments and conditions and characterized in terms of product hardness, weight loss, and change in temperature and color. Optimal results were obtained using a surface washing system involving a washing conveyor speed of 1.0 L/min, a water pressure of , a washing nozzle angle of , a washing height of 5 cm, a 1-sec reciprocating washing nozzle cycle, a dehydration wind velocity of 30 m/sec, and an internal drying temperature of . A surface washing system using a washing conveyor speed of0.8 L/min, a water pressure of , a washing nozzle angle of , a washing height of 3 cm, a 1-sec reciprocating washing nozzle cycle, a dehydration wind velocity of 30 m/sec, and an internal drying temperature of resulted in ginseng that was stained yellow.
The mushroom Agrocybe chaxingu was analyzed to evaluate the nutritional value of this potential food. The moisture content was 88.9% in the fruiting body of A. chaxingu, and the proportions of ash, crude fiber, carbohydrate, crude protein, and crude fat were 0.9%, 1.4%, 7.2%, 2.5% and 0.4% by weight, respectively. A. chaxingu contained 1.29 mg/100 g edible weight of vitamin , and the contents of vitamin , vitamin , and vitamin C were 0.15 mg, 0.32 mg, and 18.4 mg per 100 g of wet mushroom. Potassium (3,318 mg/100 g, dry basis) was found at the highest concentration in A. chaxingu. In addition, the mushroom contained many other minerals (all figures are mg per 100 g of dried mushroom) such as phosphorus (909.7), magnesium (141.3), sodium (12.7), zinc (7.4), iron (6.5), copper (2.8), manganese (0.8), and nickel (0.1). The results indicate that A. chaxingu is a valuable nutrient source.
We investigated the antioxidative effects of solvent extracts of doenjang fermented using Bacillus subtilis DJI (DJI doenjang) in vitro. The solvents used for extraction were ethanol, n-hexane, and water. The antioxidative activities of DJI doenjang solvent extracts were measured by estimation of peroxide value, the presence of linoleic acid level, and nitrite scavenging activity, the Rancimat test, and 1,1-diphenyl-2-picryl hydrazyl (DPPH) free-radical generation, in comparison with the commercial antioxidant butylated hydroxytoluene (BHT). The peroxide value of an ethanol extract was lower than those obtained using n-hexane and water extracts. Furthermore, the peroxide value of the ethanol extract was similar to that obtained after BHT treatment. The nitrite scavenging activity was 23.36% after addition of 600 ppm DJI doenjang ethanol extract, and the DPPH free-radical scavenging activity was 19.06% under same condition, which shows that DJI doenjang ethanol extract exhibited lower antioxidative capacities than did BHT. In the Rancimat test, the ethanol extract (11.20 min induction time), n-hexane extract (7.58 min induction time), and water extract (8.26 min induction time) after treatment with 600 ppm DJI doenjang extracts demonstrated longer induction periods than did BHT (6.94 min). These results indicate that DJI doenjang has potential anti-oxidative activity.
We investigated the natural antimicrobial activities of Capsella bursa-pastoris water, methanol, and ethanol extracts. Antimicrobial activities of these extracts and sodium benzoate on Bacillus cereus, Staphylococcus aureus, and Escherichia coli were compared. The inhibition zone diameters of the methanol and ethanol extracts of Capsella bursa-pastoris were 13-20 mm and 12-20 mm, respectively, which were larger than those of sodium benzoate (11-15 mm). The minimum inhibitory concentrations of Capsella bursa-pastoris methanol and ethanol extracts were 12.5-20 mg/mL. These results indicate that Capsella bursa-pastoris methanol and ethanol extracts can be used as natural antimicrobial agents.
We evaluated the microbiological quality of a facility in which freshly cut onions were prepared. The total plate counts on walls, equipment, and raw materials were ND (not detected) to CFU/100 , CFU/100 , and CFU/g, respectively. No coliforms were detected on walls however, coliforms were detected at concentrations of ND to CFU/100 and CFU/g on equipment and raw materials, respectively. The total plate counts for falling and floating bacteria in the processing plant were ND to CFU/plate and , respectively. Pathogenic microorganisms such as Escherichia coli, Salmonella spp, Staphylococcus aureus, and Listeria monocytogenes were not detected on walls, equipment, or raw materials. Overall, the results of the study indicate that hygiene control at the fresh-cut processing plant should be improved.
Microbial contamination levels in a fresh-cut leafy vegetable processing plant were evaluated. Total plate counts of samples collected from the walls, equipment, and raw materials ranged from CFU/100 , CFU/100 , and CFU/g, respectively. No coliforms were detected on walls; however, equipment and raw materials contained coliforms in concentrations ranging from ND (not detected)to CFU/100 and CFU/g, respectively. Additionally, total plate counts for falling and floating bacteria in the processing plant were CFU/plate and , respectively. Pathogenic microorganisms such as Escherichia coli, Salmonella spp, Staphylococcus aureus, or Listeria monocytogenes were not detected on walls, equipment, or raw materials. Overall, the results of this study indicate that hygiene control in the fresh-cut processing plant should be improved.
We focused on the condition of washed, fresh ginseng in the market and analyzed consumer attitudes to the product to improve the consumption of fresh ginseng. A preference for fresh ginseng was high among every age class, and was particularly notable in older individuals. Fresh ginseng was usually eaten as ginseng chicken soup, mostly in summer and winter, and as a valuable health food, rather than because of desirable qualities of taste or smell. A total of 66.5% of those surveyed reported that they had purchased fresh ginseng, mostly from big discount stores. Such stores were preferred as outlets owing to a reputation for quality and shopper convenience (the stores were located near interviewees' homes). More than 70% of purchasers emphasized that they chose to purchase in department stores and traditional markets owing to the reputation for quality of such sources. Most consumers considered quality to be a prime element in purchase decisions. A total of 32.9% of those surveyed had bought washed fresh ginseng to give as a gift to a friend. Of those surveyed, 67.1% had never bought washed fresh ginseng. The following reasons were proposed to explain the preference for purchase of ginseng with attached soil. Most consumers (40.2%) thought the soil was a reflection of quality. Those who preferred washed fresh ginseng considered that the material was hygienic and convenient to store. When questioned about their intention to buy washed fresh ginseng, 55.0% of consumers replied in the affirmative and 17.1% in the negative. When consumers were asked whether they would be willing to pay an additional charge for the washing and packing of fresh ginseng, 58.8% answered in the affirmative.
The effect of gamma irradiation on the storage stability of Undaria pinnatifida was investigated. A three-log reduction in total aerobic bacteria in U. pinnatifida samples was obtained by irradiation with 3 kGy. During storage for 2 weeks, the viable counts of microorganisms in non-irradiated U. pinnatifida increased to 6 log CFU/g. However, irradiation of U. pinnatifida by 5 kGy eliminated microorganisms. The Hunter of U. pinnatifida was slightly increased after 5 kGy of irradiation. The hardness properties of U. pinnatifida decreased during storage, but were not changed by irradiation with up to 3 kGy. These results indicate that low-dose irradiation (3 kGy) could be effective for improvement of the storage stability of U. pinnatifida.
Fifty-four sesame oils were assayed for authenticity by measurement of linolenic acid content (which is less than 0.5% by weight in genuine oil). Sesame oils (A-F) from major companies and oils (G-J) extracted from sesame seeds in our laboratory were used as standards for comparison. By fatty acid composition analysis, 33 of 54 samples showed levels of linolenic acid more than 0.5% by weight. In addition, the ratio of linoleic acid to oleic acid (C18:2/C18:1) in samples A-F ranged from 1.05 to 1.12, whereas the 54 collected samples showed a wide range of ratios, from 0.92 to 2.21.