• Food Science and Preservation
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• v.11 no.3
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• pp.313-318
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• 2004

This study was conducted to compare development of browning in minimally processed mushrooms (Agaricus bisporus Sing.) by picking season and postharvest holding time of the raw material. 'White' type of the mushrooms were harvested and minimally processed immediately after harvest or holding at 2$^{\circ}C$ for 7 days after picking in 4 seasons. The processed mushrooms were kept at 5$^{\circ}C$, and changes in surface color and content of total phenolic compounds of the mushrooms were measured. Respiration rate of the whole mushrooms was ranged from 9.55 to 17.93 mL C0$_{2}$/kg$\cdot$ hr, and the rate was low in mushrooms harvested in summer and autumn compared with those picked in spring and winter. Hunter L value of the mushrooms decreased rapidly just after slicing, especially in summer-harvest mushrooms. The mushrooms processed with the raw materials stored at 2$^{\circ}C$ for 7 days after harvest showed the lowest 'L' value among the sliced mushrooms prepared at different holding time. Consequently, summer-harvest mushrooms and the mushrooms kept at 2$^{\circ}C$ for more than 7 days after harvest would be unsuitable for minimally processing due to rapid browning.

• Food Science of Animal Resources
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• v.37 no.4
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• pp.518-528
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• 2017

Quality characteristics of frozen cylindrical pork loin were evaluated following different tempering methods: 27.12 MHz curved-electrode radio frequency (RF) at 1000 and 1500 W, and forced-air convection (FC) or water immersion (WI) at $4^{\circ}C$ and $20^{\circ}C$. The developed RF tempering system with the newly designed curved-electrode achieved relatively uniform tempering compared to a parallel-plate RF system. FC tempering at $4^{\circ}C$ was the most time-consuming process, whereas 1500 W RF was the shortest. Pork sample drip loss, water holding capacity, color, and microbiological quality declined after WI tempering at $20^{\circ}C$. Conversely, RF tempering yielded minimal sample changes in drip loss, microstructure, color, and total aerobic bacteria counts, along with relatively uniform internal sample temperature distributions compared to those of the other tempering treatments. These results indicate that curved-electrode RF tempering could be used to provide rapid defrosting with minimal quality deterioration of cylindrical frozen meat block products.