Vegetables digestion

Protein is an important component of most foods. Nearly everything we eat contains at least a small amount of protein. Lean meats and vegetables such as peas and beans are particularly rich in protein. In our digestive system, proteins are broken down into small molecules called a-amino acids. These molecules can then be reassembled in cells to form other proteins required by the body. 

Nitric Acid and Organic Substances. Mixts of perchloric and nitric ac are frequently used to digest (render w sol) organic materials such as animal and vegetable oils, milk, homogenized animal tissues, etc. If the mixts are heated too... 

With few exceptions, small particles of vegetable foods are generally stripped of their more accessible nutrients during digestion in the GI tract. In this way starch, protein, fat and water-soluble small components (sugars, minerals) are usually well absorbed. This is not always the case, however, for larger food particles or for molecules that cannot diffuse out of the celF tissue. Neither is it the case for the lipid-soluble components. These need to be dissolved in lipid before they can be physically removed from the cell to the absorptive surface, since the cell wall is unlikely to be permeable to lipid emulsions or micelles, and the presence of lipases will strip away the solvating lipid. 

Garrett, D.A., Failla, M.L., and Sarama, R.J., Estimation of carotenoid bioavailability from fresh stir-fried vegetables using an in vitro digestion/Caco-2 cell culture model, J. Nutr. Biochem., 11, 574, 2000. 

A novel TLC spectrofluorometric method for identification and determination of selenium in different food samples of animal and vegetable origin has been proposed [30]. The procedure involves the digestion of food sample (1 to 5 g) in the presence of cone. HNO3 (5 ml), 70% HCIO4 (10 ml), and FIjO (10 ml) in a 250-ml Kjeldahl flask reduction of Se(VI) into Se(IV) complexation of the isolated selenium with 23-diaminonaphthene (DAN) extraction of the resultant Se—DAN complex with cyclohexane and spectrofluorometric determination followed by confirmation of the presence of Se in the sample by TLC using thin layers of MN-300 cellulose powder. 

Vegetation Ashed, digested with HN03-H202, oxalate and Fe precipitations, anion exchange, solvent extraction, electrodeposition a -Spectroscopy 0.3 fCi/g 73-109% Cooper et al. 1993... 

Sediment, fish, vegetation (total lead) Digestion of sample with acid and heat dilution with water AAS 50 ng/g (sediment) 10 ng/g (fish and vege-tation) No data No data Chau et al. 1980... 

As a safer alternative to digestion of vegetable matter with perchloric acid, alkaline oxidation of sulfur compounds to sulfate by sodium hypobromite, and reduction of sulfate to hydrogen sulfide by hydriodic acid/formaldehyde/phosphinic acid is recommended. 

It has recently been reported that a fraction of food starch, named resistant starch (Asp and others 1996), is not digestible by humans. Nowadays resistant starch is considered a DF constituent and is a major constituent of IDF in starchy foods. However, resistant starch is absent in most fruits and vegetables, with the exception of bananas, which contain more than 15% dry weight when the fruit is unripe (Gofii and others 1996). 

Appreciable amounts of polyphenols (PPs) associated with both IDF and SDF have been reported in fruit, vegetables, and beverages (Tables 8.3 and 8.4). These compounds may be considered DF constituents in view of the similarity of their properties in terms of resistance to digestive enzymes and colonic fermentability. 

Serrano J, Goni I and Saura-Calixto F. 2005. Determination of 3-carotene and lutein available from green leafy vegetables by an in vitro digestion and colonic fermentation method. J Agric Food Chem 53 2936-2940. 

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