Broccoli (cv. Empress) obtained from a local supplier was blanched within 15 h of harvest. It was blanched by four methods in covered containers: conventional boiling water (1900 mL., 4 min) (BW), steam (300 mL. water, 4 min) (ST), microwave heated in 1 L glass containers (60 ml water, 4 min, 700 W) (MW), and microwave heated in 1 L Seal-a-MealTM bags (45 ml water, 4 min) (MWB). Aliquots were frozen at -18C for 4 weeks. Fresh unblanched broccoli peroxidase activity ranged from 389 to 829 unitdmin; activity was essentially zero immediately afrer all blanching treatments. The highest reduced ascorbic acid (RAA) content occurred in fresh unblanched broccoli. Some peroxidase regeneration occurred during frozen storage. Immediately after blanching, all blanched broccoli had lower RAA content than control broccoli. MW-blanched broccoli retained the greatest amount of RAA and had appearance, visual color, texture scores, and chroma of florets and stems equivalent to ST-blanched broccoli. MW-blanched broccoli had flavor and general acceptability scores similar to BW-blanched broccoli. Afer 4 weeks in frozen storage, MW-blanched broccoli had the highest RAA content. Consumer purchases are based primarily on external characteristics such as visual appearance and texture. An important component of visual appearance is color (Gnanasekharan et al. 1992). Loss of green color is a major limiting factor in shelf-life of broccoli (Shewfelt et al. 1984). Color can be stabilized 'Please send correspondence to M. Susan Brewer.

7ke objective of these studies was to evaluate the effects of blanching at various microwave power levels (30%. 55%, 70%, 100%) for various times (0, 1, 2, 3, 4 min) on peroxidase inactivation, and ascorbic acid and color preservation in broccoli, green beans and asparagus. As power level and time increased, moisture losses increased. Actual ascorbic acid concentration (mg/lOO g) increased, but when adjusted for moisture loss, it decreased.Microwave treatment at any power level for as little as 1 min reduced peroxidase activity. However, at higher powers (70% and 100%), less time was required to achieve the maximum reduction. Microwave heating at 70% or 100% caused some darkening (decreased L* value). Hue angle decreased (less green) at 55 %, 70% and 100% power afier 1 min of treatment. Overall, microwave power level and time had greater effects on moisture, RAA content and onperoxidase activity than on color.

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 (-18C) for four weeks. Immediately afer 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. Afer frozen storage, MWB-and MW-blanched samples both contained about 26 mg/lOO g RAA, significantly more RAA than other treatments. MWB-blanched peas generally had as high or higher sensory appearance, aroma, jlavor, 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.