Procyanidin beans

Thousands of polyphenols from fruits (grapes, apples, etc.), vegetables (horse beans), and teas have been identified, many having good coloring properties, especially anthocyanins and some flavonoids. Well-documented reviews discuss the coloring capacities of some polyphenols including procyanidins. - Detailed presentations of anthocyanin and flavonoid properties and analysis are included in Sections 2.3, 4.3, and 6.3. The soluble proanthocyanidins of the colored horse bean Viciafaba L. seed coats were isolated and separated by solvent partition. 

Proanthocyanidins (PAs), also known as condensed tannins, are oligomeric and polymeric flavan-3-ols. Procyanidins are the main PAs in foods however, prodelphinidins and propelargonidins have also been identified (Gu and others 2004). The main food sources of total PAs are cinnamon, 8084 mg/100 g FW, and sorghum, 3937 mg/100 g FW. Other important sources of PAs are beans, red wine, nuts, and chocolate, their content ranging between 180 and 300 mg/100 g FW. In fruits, berries and plums are the major sources, with 213.6 and 199.9 mg/100 g FW, respectively. Apples and grapes are intermediate sources of PAs (60 to 90 mg/100 g FW), and the content of PAs in other fruits is less than 40 mg/100 g FW. In the majority of vegetables PAs are not detected, but they can be found in small concentrations in Indian squash (14.8 mg/ 100 g FW) (Gu and others, 2004 US Department of Agriculture, 2004). 

Protein-Procyanidin Interaction and Nutritional Quality of Dry Beans... 

This paper presents research data that delineate the relationship of dry bean proteins to dry bean procyanidins, and discusses the constraints protein-procyanidin interaction places on nutritional quality of dry beans. 

Polymeric procyanidin extraction from black beans (Phaseolus vulgaris L. cv. Black Turtle Soup) and purification was a... 

The method of Kato and Nakai (27) for determining protein surface hydrophobicity was adapted for evaluating procyanidin binding to BSA and Gl. The procedure is based on the fact that the fluorescence quantum yield of cis-parinaric acid increases 40-fold when cis-parinaric acid enters a hydrophobic environment from a hydrophilic environment. The digestion of BSA by trypsin in the presence of procyanidin dimer, procyanidin trimer and black bean procyanidin polymer was evaluated by discontinuous sodium dodecyl sulfate (SDS) slab gel electrophoresis and a picryl sulfonic acid (TNBS) assay (28). 

Heat-denatured Gl exhibited a surface hydrophobicity greater than that of native Gl. The increase was not unexpected since hydrophobic groups are commonly oriented towards the center of proteins in aqueous solvents. Heat denaturation of protein exposes hydrophobic groups to the solvent. Binding of denatured Gl to bean procyanidin oligomer was predominantly hydrophobic. 

Common bean procyanidins are capable of both hydrophilic and hydrophobic interaction with protein. Hydrophilic interactions are favored with a hydrophilic glycoprotein like common bean globulin Gl, while hydrophobic interactions are favored after protein denaturation, when protein hydrophobic groups are exposed to the solvent. 

Figure 5. Scatchard plot of procyanidin trimer and bean globulin G1 at 19C.

Common bean protein and procyanidin interactions can be hydrophilic or hydrophobic, depending on the sites on the protein available for interaction. Thermal processing can denature the protein and change the type of interaction possible. Once bean protein is denatured, hydrophobic interactions between the protein and procyanidin are likely. Since the strength of hydrophobic interactions increases with increased in temperature, the interaction between protein and procyanidin will be enhanced during thermal processing. Removal of procyanidin will be easiest prior to thermal processing. 

Acute long term doses of procyanidins and food have a reduced toxicity compared to procyanidin intubated alone. Dietary long term doses of procyanidins are normally encountered in human dietary patterns in various areas of the world. Recommendations to increase common bean consumption will not result in any adverse effects to populations consuming large quantities of beans. 

Rigaud 1, Escribano-Bailon MT, Prieur C et al (1993) Normal phase high performance liquid chromatographic separation of procyanidins from cacao beans and grape seeds. 1 Chromatogr 654 255-260... 

Catechin and the proanthocyanidin prodelphinidin B3 are, respectively, the major monomeric and dimeric flavan-3-ols found in barley and malt where prodelphinidin B3 is the main contributor for the radical scavenging activity [Dvorakova et al., 2007], Proanthocyanidins have also been detected in nuts. Hazelnuts (Corylus avellana) and pecans (Carya illinoensis) are particularly rich in proanthocyanidins containing ca. 5 g kg, whereas almonds (Prunus dulcis) and pistachios (Pistachio vera) contain 1.8-2.4 mg kg 1, walnuts (Juglans spp.) ca. 0.67 g kg, roasted peanuts (Arachis hypgaea) 0.16 g kg, and cashews (Anarcardium occidentale) 0.09 g kg 1 [Crozier et al., 2006c]. Dark chocolate derived from the roasted seeds of cocoa (Theobroma cacao) is also a rich source of procyanidins [Gu et al., 2004], Monomeric flavan-3-ols and the proanthocyanidin B2, B5 dimers, and Q trimer are found in fresh cocoa beans (Fig. 1.13). Flavan-3-ols have also been detected in mint... 

Procyanidins. Catechin (Fluka) and epicatechin (ex. cacao beans) were recrystallized and dried before use. The oligomers epicatechin-(4/ — 8)-epicatechin and [epicatechin-(4/ — 8)]3-epicatechin were obtained from the ethyl acetate sol-... 

For the analysis of cocoa samples, the beans were ground using a mortar and pestle [27] or a laboratory mill [28,29] to obtain a homogeneous material. Then, to analyze procyanidins and alkaloids, these were first defatted between three and four times with n-hexane to remove the fat from the cocoa matrix. Second, an off-line liquid-liquid extraction (LLE) was performed to extract the procyanidins and alkaloids from this matrix. Various solutions formed by acetone were used as the extraction solutions. These were acetone/water (70/30, v/v) [27], acetone/water/acetic acid (70/28/2, v/v/v) [18], and acetone/water/acetic acid (70/29.5/0.5, v/v/v) [28,29] (see Table 14.1). Afterwards, the extracts were sonicated [18] or vortexed [28,29] and centrifuged. The supernatants were combined from the centrifuged tubes and filtered with glass wool [28,27]. Finally, the organic solvent of these extracts was removed by rotary evaporation at a temperature between 30°C and 40°C. 

Different cocoa procyanidin extracts obtained from cocoa beans, cocoa nibs, cocoa liqnor, and cocoa powder were analyzed, and their concentrations of procyanidins ranged from 6 to 30 mg/g of lyophilized extract [28,29]. These cocoa sources corresponded to the Forastero variety from Ghana (West Africa). The cocoa extract from the nibs was the most abundant in procyanidins, followed by the extracts from bean and cocoa liquor, and the lower procyanidin concentration was observed in the extract from cocoa power [28]. 

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