Effects of Blanching Method on the Quality Characteristics of Frozen Peas

Abstract

This study evaluated the effects of microwave blanching prior to freezing as an alternative pretreatment for frozen peas. Peas were blanched (steam‐, boiling water immersion‐, microwave‐ or microwave‐blanched in a bag), frozen and evaluated after 0, 6 and 12 weeks for moisture and ascorbic acid content, peroxidase activity, visual appearance and instrumental color, and after 6 and 12 weeks for aroma, flavor and texture. All blanch treatments reduced peroxidase activity by 97% compared with controls (unblanched); blanching methods did not differ. Steam blanching resulted in significantly better ascorbic acid retention than all other treatments; microwave blanch treatments were either equivalent to or better than boiling water immersion. Both microwave treatments darkened (L* value) peas. Microwave‐blanched peas were visually greener than other treatments, but their appearance was less intact. Aroma and flavor were similar among blanch treatments. Texture of boiling water immersed peas was similar to the two microwave treatments.

Modelling kinetics of watercress (Nasturtium officinale) colour changes due to heat and thermosonication treatments

“…Lin and Brewer (2005) showed, in a study with frozen peas that after microwave and water blanching the peas were also greener. Brewer, Begum, and Bozeman (1995) reported significant darkening of stems and florets of broccoli after microwave blanching.…”

Effect of blanching on the dielectric properties and microwave vacuum drying behavior of Agaricus bisporus slices

“…However, no such phenomenon occurs during MWB because vegetable tissues can be easily penetrated by internal heat (Lin & Brewer, 2005;Ramesh et al, 2002). Moreover, little water is applied during MWB; therefore, soluble molecules and ions are retained in the tissues of A. bisporus.…”

“…Hot water blanching (HWB) is mainly used to inactivate enzymes, but it is also used to remove air from the intercellular spaces in fruits and vegetables (Krokida, Kiranoudis, Maroulis, & Marinos-Kouris, 2000;Lin & Brewer, 2005;Ramesh, Wolf, Tevini, & Bognar, 2002). Microwave blanching (MWB) is considered to be superior than conventional blanching because it reduces nutrient loss, shortens drying time, and maintains porosity of dried materials (Kowalska, Lenart, & Leszczyk, 2008;Vadivambal & Jayas, 2007;Walde et al, 2006).…”

Effect of microwave assisted blanching on the ascorbic acid oxidase inactivation and vitamin C degradation in frozen mangoes

“…Comparative studies reported in literature have not provided enough understanding about the underlying differences between the water and microwave blanching in terms of nutritional value of the frozen products (Bernas & Jaworska, 2003;Lin & Brewer, 2005;Tosun & Yucecan, 2008). Although there are available data in the literature regarding thermal inactivation kinetics of AAO, the residual activity of this enzyme after thermal treatment of broccoli, pumpkin (Cucurbita maxima), carrots (Daucus carota subsp.…”