Green vegetables extraction

Khachik, R, Beecher, G.R., and Whittaker, N.R, Separation, identification and quantification of the major carotenoid and chlorophyll constituents in extracts of several green vegetables by liquid chromatography, J. Agric. Food Chem., 34, 603, 1986. 

The isomerization of all-trans-[3-carotene under N2 atmosphere by photosensitization action of eight chlorophyll compounds naturally present in the extracts of green vegetables was investigated by illumination with fluorescent white light (3000 lux) at 12°C to minimize the thermal degradation (O Neil and Schwartz 1995). All chlorophylls showed similar isomeric distribution and efficiency, 9-d.s- 3-carotene is the main isomer formed. On the other hand, the illumination of all-fran.s-(3-car-otene without chlorophylls indicated that the main isomer formed was 13-d.s- 3-carotcnc, probably due to the population of a different triplet state manifold by direct photolysis. 

The major sources of folate are green vegetables, citrus fruits, legumes, egg yolk, wheat germ, and yeast [417]. This vitamin can be added only in the form of pteroylmonoglutamic acid [402]. The multiplicity of forms, low stability, low concentration, and the complex extraction and detection techniques make the analysis of folate in food a difficult task. 

Vegetables, fruits Extract sample with THF/MeOH (1 1) + MgC03 + internal standard (J3-apo-8 -carotenal or, for green vegetables, echinenone). Filter. Partition into petroleum ether containing 0.1 % BHT. Saponify (ambient), extract unsaponifiables with petroleum ether (saponification applied to fruit samples and peppers only). Vydac 201 TP54 Cl8 5 /zm (metal frits replaced with Teflon frits) 250 X 4.6 mm... 

Dark green vegetables Blanch leaves in boiling water. Homogenize with water containing 0.5% ascorbic acid. Extract an aliquot of the resultant mixture with acetone/ petroleum ether (3 2) containing 0.5% BHT by shaking for 10 min. Reextract until colorless (3 extractions). Saponify (ambient) the combined solvent extracts. Vydac 201 TP Clg 5 /zm 250 X 4.6 mm MeOH/CH,C1,/ H,0, 80 15.2 4.8 A ]-trans-, 9-cis-, 13-cis-/3-carotene, all-trans-a-carotene Vis 450 mn 177... 

In general, microwave cake appeared to lack many of the nutty, brown, and caramel-type aromas observed in the conventional cake and was in fact more similar to the batter. Table 2 summarizes the predominant aranas noted from each extract in decreasing order. The predominant aromas in both batter and microwave cake were green vegetable notes. Brown, caramel, and potato notes were observed less frequently. The conventional cake profile contained more brown, caramel notes followed by butter, cucumber, potato, and finally, green vegetable aromas. 

Carotenoids are 40-carbon compounds made up of eight isoprene units. Carotenoids serve as light absorbing molecules in photosynthesis and also protect certain tissues from the deleterious effects of light. Beta-carotene is the precursor of vitamin A (which does not occur in plants). Beta-carotene occurs abundantly in the liver oils of fish and is extracted from that matrix commercially. Nutritionists recommend tomatoes, carrots, and green vegetables in daily quantities in order that carotenoids can be converted into vitamin A, a compound necessary for vision and other vital functions. 

In order to protect the aging population from stroke, it is crucial to explore methods that may retard or slow the molecular cascade associated with oxidative stress, excitotoxicity, and neuroinflammation. Diet enriched in antioxidant and antiinflammatory agents (curcumin, green tea, and ferulic acid) (Fig. 3.11) may lower the risk of stroke. Many studies indicate that dietary supplementation with fruit or colored vegetable extracts can decrease the age-enhanced vulnerability to oxidative... 

Fresh green vegetables should first be homogenized in 2-propanol to deactivate lipases, which otherwise might be activated by some organic solvents. The solids are further extracted with chloroform/2-prop-anol. The lipids in both extracts are combined. 

Sensory evaluations were carried out in the University of Wisconsin Sensory Analysis Laboratory under conditions prescribed for sensory analysis (32). Panelists were instructed to cut-open sealed pouches, smell samples, and then record observations on ballots which contained horizontal line scales (l=weak, 7=strong) for each attribute (33). Data in Table IV shows that both TBHQ- and crude caraway seed extracts-treated broccoli florets received significantly lower sensory scores for the unpleasant sulfurous aroma. However, there was no significant difference in the sulfurous aroma between TBHQ- and caraway-treated samples. Additionally, both caraway seed and TBHQ treatments resulted in higher scores for green vegetable aromas and overall pleasantness. 

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