• Food Science and Preservation
• /
• v.16 no.2
• /
• pp.166-171
• /
• 2009

The effects of vacuum precooling(VP) on the shelf-life of polyethylene film(PE) packaged King oyster mushrooms(Pleurotus eryngii) during storage at $-1^{\circ}C$ were investigated. VP was conducted below $0^{\circ}C$ in a $-1^{\circ}C$ cold chamber of 40 minutes, and mushrooms were stored for 30 days in batches of 1kg. The weight loss of the VP-treated mushroom was slightly lower than that of control. The $O_2$ concentrations of VP-treated mushroos, within 4 days of storage, were 2.44-14.50 %/kg-package/hr, thus higher than control values(2.01-8.19%/kg-package/hr). $CO_2$ generation of VP-treated mushrooms, again within 4 days of storage, was 0.47%/kg-package/hr, thus lower than that of controls(0.58%/kg-package/hr). The $CO_2/O_2$ ratio peaked on day 4 of storage in the control group, tbut no such peak was observed in VP-treated mushrooms. In the VP-treated fungi, lightness was higher, and redness and yellowness lower, than in controls, at all storage times.. In VP-treated mushrooms, strength, hardness and chewiness were significantly higher than in controls, but there were no significant differemces in springiness or cohesiveness. Softening and breakdown of under-cap wrinkles were observed in control mushrooms stored for 30 days, but occurred to a lesser extent in VP-treated fungi. Stipe reticulum tissue vessels in the 30 day-stored VP-treated mushrooms were relatively well-defined and clear, but were softer and diffuse in the control fungi. The results thus confirmed that VP after harvest enhanced mushroom shelf-life and PE packaging prolonged storage time. The data will have industrial applications.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.56 no.3
• /
• pp.212-218
• /
• 2011

This study was performed to determine the relative quality of mungbeans harvested in bulk after applying a labor-saving cultivation (LSC) method, compared to mungbeans harvested three different times under the conventional cultivation condition. There was no significant difference in starch, crude protein, and vitexin or isovitexin content of seed according to the cropping system or harvest time. The mungbeans grown under the LSC method had the highest crude fat content, followed by mungbeans from the third-, the second- and the first-harvest mungbeans under the conventional cultivation. No significant difference was found in the composite ratio of saturated fatty acids to unsaturated fatty acids according to cropping system or harvest time. The second-harvest mungbeans grown under the conventional cultivation condition had 17 different types of fatty acids, while the third-harvest mungbeans grown under the conventional cultivation and those grown under the LSC condition had the fewest types of fatty acids with 12. Of the major saturated fatty acids, palmitic acid and arachidonic acid had the highest composite ratio in the first conventional cultivation followed by the second, the third and the LSC. However, stearic acid showed the opposite tendency. Of the major unsaturated fatty acids, linoleic acid had the highest composite ratio in the first conventional cultivation, followed by the second and third conventional cultivation and the LSC. Amylogram characteristics of the mungbeans were significantly different according to cropping system and harvest times. The mungbeans harvested after the first conventional cultivation had significantly higher pasting temperature, peak viscosity, holding strength viscosity, final viscosity and breakdown, while mungbeans harvested after the third conventional cultivation had significantly higher setback viscosity. In contrast, the mungbeans harvested under the LSC methods had a significantly lower amylogram value. When harvest rate, color values and amino acid content of sprout were measured, mungbeans grown under the LSC conditions had a low harvest rate of sprout, but had Hunter's color values and amino acid content of sprout similar to those of mungbeans grown under the conventional cultivation condition.