Physical, chemical and sensory quality of microwave-blanched snow peas

Snow peas were blanched using four methods [conventional boiling water (BW); steam (ST); microwave (MW); and microwave blanched in heat sealable bags (MWB)], then held frozen at (similar to18C) for four weeks. Immediately after blanching, MWB-blanched snow peas retained more reduced ascorbic acid (RAA; 72%), than other treatments. Blanching treatment had no effect on lightness (L* value). With the exception of BW-blanched peas, blanching significantly altered color. After frozen storage, MWB- and MW-blanched samples both contained about 26 mg/100 g RAA, significantly more RAA than other treatments. MWB-blanched peas generally had as high or higher sensory appearance, aroma, flavor, texture and general acceptability scores than other treatments. These results imply that blanching snow peas in a heat-sealable microwave bag, prior to frozen storage, produces a product of equivalent sensory quality and superior nutritional quality compared with more conventional blanching methods.