The traditional gravimetric and volumetric methods of measuring water imbibition were compared to a new method, water-holding capacity, to study water uptake in black bean cotyledons with and without the hard-to-cook defect. Water-holding capacity was found to be more reliable in measuring water taken up by the cotyledon since the former methods measure gross water uptake, including a layer of bulk water existing between the seedcoat and cotyledons of hard-to-cook beans. Total water uptake, as measured by the water absorption method, was greatest for hard-to-cook beans. Using the water-holding capacity method, however, hard-to-cook beans were found to bind approximately 25% less water during soaking than control beans.

Free-radical scavenging, reducing, and phase II enzyme-inducing activities of aqueous and 5% aqueous ethanol extracts of freeze-dried root tissue of four beet (Beta vulgaris L.) strains (red, white, orange, and high-pigment (red) phenotypes) were determined. Aqueous and ethanolic tissue extracts of the regular and high-pigment red phenotypes were most capable of inhibiting metmyoglobin/H(2)O(2)-mediated oxidation of 2-2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and 2,2'-azobis-(2-amidinopropane) dihydrochloride (AAPH)-mediated bleaching of beta-carotene. These same extracts were also most efficient at reducing ABTS radical cation and inducing quinone reductase in murine hepatoma (Hepa 1c1c7) cells in vitro.

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Quinone reductase (QR)-inducing activity of aqueous and ethanolic extracts of common vegetables was determined using a murine hepatoma (Hepa 1c1c7) cell bioassay. QR induction observed for aqueous extracts reached 13-fold for corn, 8-fold for kale, and 5-fold for snap beans. QR induction of ethanol extracts reached about 3-fold for both garlic and snap beans, and about 2-fold for both red beetroots and kale. These aqueous extracts were effective inhibitors (kale ~ red beetroots > corn ~ green beans > garlic) of the generation of 2-2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) radical cation (ABTS l+ ) by metmyoglobin and H 2 O 2 , whereas the ethanolic extracts were not inhibitory. Aqueous extracts reduced pre-formed ABTS l+ more effectively ( > 95% inhibition) than did ethanolic extracts (~50 to 90% inhibition). All vegetable extracts inhibited oxyradical-mediated b-carotene bleaching, where kale and red beetroot extracts exhibited the strongest protective effect.

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