Steam blanching

Materials. About 100 lbs of fresh broccoli (Brassica oleracea var. pompejana, cultivar Valiant 501) from Patterson Frozen Foods was picked early in the morning, placed on dry ice and transported to Davis within two hours. A portion of the sample was frozen in a blast freezer immediately while the other portion was steamed-blanched at 99°C (210°F) for 3.5 min, cooled at room temperature, bagged and frozen. Both samples were stored in lock-top plastic bags at -20°C. All of the chemicals used were of reagent grade and deionized water was used. 

Table 8.5 The effect of steam blanching and drying temperature on chlorophyll retention in basil leaves...

DRAKE s R and CARMICHAEL D M (1986), Frozen vegetable qnality as influenced by high temperature short time (HTST) steam blanching , J Food Sci, 51, 1378-1379. 

In addition to water and steam blanching, use of micro-wave energy was demonstrated to be a convenient and effective method of blanching [7] and superior in retention of ascorbic acid. The texture of rehydrated, microwave-blanched freeze-dried spinach was firm, chewy, and highly acceptable. 

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