Red onion

Anthocyamdins Cyanidin, delphinidin, malvidin, pelargonidin, peonidin, petunidin, Blueberries, blackberries, cranberries, egg plants, pomegranates, plums, raspberries, red onions, red potatoes, red grapes, red radishes, strawberries, other red-purple fruits and vegetables... 

In the center of each tortilla, spoon a line of brown rice, then add tofu, onion, red pepper, tomato, and avocado. Fold in sides of tortilla to hold ingredients together. 

Medium anthocyanin content products (>10 mg < 100 mg) Apple (red varieties), black bean, cranberry, eggplant, gooseberry, plum, red currant, red onion, red radish, rhubarb, strawberry... 

Grapefruit Sugar Peanut flour H/bture onions Red beelSL boiled... 

Four cyanidins with 4 -glucosidation were recently isolated in minor amounts from pigmented scales of red onion. Two were the only anthocyanins with B ring sugar substitutions and no glycosyl moieties in anthocyanidin position 3, whereas the other two were also glycosilated at the usual position 3. ... 

Among the disaccharides with more limited occurrence in anthocyanins, lathy-rose was found in dark red berries of Fatsia japonica and linked to one of the major anthocyanins in black carrots. " Until now, laminariobiose was only detected in red onions. A very rare disaccharide 2"- 3-glucopyranosyl-P-galactopyranose was found in anthocyanins from dwarf dogwood. ... 

Terahara, N., Yamagnchi, M.-A., and Honda, T., Malonylated anthocyanins from bulbs of red onion. Allium cepa L., Biosci. Biotechnol. Biochem., 58, 1324, 1994. 

Fossen, T. and Andersen, 0.M., Anthocyanins from red onion. Allium cepa, with novel aglycone. Phytochemistry, 62, 1217, 2003. 

Dilution to 1 20 eliminated inhibition in onion, oat, ryegrass, red clover, and cheatgrass. Further dilution to 1 40 limited inhibition to lettuce, carrot, and Palmer amaranth. At this concentration lovegrass germination was promoted. The addition of 0.1%... 

Lenthionine has the characteristic shiitake flavor. It is formed from the precursor, lentinic acid 14 by complex reactions involving a C-S lyase enzyme.30 Cyclic polysulfides occur in other Basidiomycete mushrooms (Genus Micromp-hale and Colly bid), in some red alga, and in seeds of Parkia speciosa. The latter contain lenthionine and 1,2,4-trithiolane (1,2,4-trithiacyclopentane) 17 as well as compounds with 4, 5, or 6 sulfur atoms.31 These seeds are valued in Indonesia for a unique, onion-like odor. Djenkolic acid and dichrostachinic acid S -[(2-carboxy-2-hydroxyethylsulfonyl)-methyl]cysteine are converted by a C-S lyase enzyme to cyclic polysulfides djenkolic acid yields 1,2,4-trithiolane and 1,2,4,6-tetrathiepane the latter is also formed from dichrostachinic acid.32... 

Yellow and red onions (Allium cepa) were reported to be poor antioxidants toward oxidation of methyl linoleate (Kahkonen and others 1999) in contrast to their high antioxidant activity toward oxidation of LDL (Vinson and others 1998). Garlic (Allium sativum L) was reported to have four times more antioxidant activity than onions when using the ORAC assay (Cao and others 1996). 

Marlett JA. 2000. Changes in content and composition of dietary fiber in yellow onions and Red Delicious apples during commercial storage. J AOAC Int 83 992-996. 

A new poly(7-oxobomene-5,6-dicarboxylic acid-Wod -norbomene)-coa(cd silica has been synthesized and applied for the separation of flavonoids in model systems and in the extracts of onion, elder flower blossom, lime blossom, St. John s Wort and red wine. Separation was performed in a (150 X 4 mm i.d. particle size 7 /rm) column at room temperature. Flavonoids (quercitrin, myricetin, quercetin, kaempferol and acacetin) were separated with gradient elution water-ACN (20 mmol TFA) from 78 22 to 70 30 v/v in 3min. The flow rate was 2 ml/min. The separation of the standard mixture is shown in Fig. 2.51. It has been stated that the method is rapid, accurate and the MS detection makes possible the reliable identification of flavonoids [153],... 

The separation and identification of two novel anthocyanins from red onion, Allium cepa, have also been reported. Scales of 2.37 kg red onion were cut and extracted twice with methanol containing 0.5 per cent TFA. The extract was filtered, extracted with ethyl acetate and the aqueous phase was further purified in an ion-exchange and an SEC column. SEC separation was performed in a Sephadex LH-20 column (100 X 5 cm i.d.) applying methanol-water-TFA (39.6 60 0.4, v/v) as the mobile phase at a flow rate of 2.5 ml/min. 

Fig. 2.117. The structures of 5-carboxypyranocyanidin 3-0-/Fglucopyranoside (1) and 5-car-boxypyranocyanidin 3-0-(6"-0-malonyl-/Tglucopyranoside (2) isolated from red onions. Reprinted with permission from T. Fossen et al. [257].

The experiment with 0.5 g/mL of erode extracts of different parts of Allium plants (bulb, green leaf, white stalk) showed the inhibition of acrosin and trypsin activities, mostiy the red onion and garlic extracts. These results demonstrated that spermicidal effect of Allium extracts is determined also by their capacity of protease inhibition. The red onion extract shows the higher antioxidant capacity and a very low cytotoxicity. 

The values of acrosin activity obtained by the method based on the Kennedy et al. assay are summarized in Table 41.1. The boar semen ( 6.5 x 10 spermatozoa/mL) was treated, or not, with plant extract (0.5 g/mL) and the inhibition of acrosin activity indicates the spermicidal effect of plant extracts, about 50% for red onion extract and 25% for garlic extract, for instance. 

The micrographs obtained yiitkAPA assay show that treated spermatozoa with Allium extracts had low acrosin activity, especially the slides treated with garhc (Fig. 41.1a) and red onion extracts (data not shown). The untreated spermatozoa had protein-digested halos generated by acrosin activity on the gelatin substrate films (Fig. 41.1b). 

Acrosin Sperm/PBS (1 0.1) Sperm/red onion Sperm/onion Sperm/garlic... 

Red Green onion onion onion stalk bulb leaf... 

Trypsin inhibition activity was determined by measuring the decrease of trypsin activity in the presence of Allium extracts. The results obtained with different types of extracts (bulb, stalk, green leaf-0.5 g/iuL) are presented in Fig. 41.2. All determinations were carried out in triplicate. The higher inhibition activity was obtained with red onion bulb extract (18.55 0.14 Ul/min or 27.94 0.21 U/g fresh plants). Onion bulb extract shows also a high trypsin inhibition (18.48 0.035 UFmin, 27.83 0.053U/g), and all extracts of garlic (bulb, leaf and stalk) show activities between 11.05 1.615 - 13.185 0.205 Ul/min (16.64 2.42 - 19.86 0.31 U/g). 

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