| Journal of Agricltural and Food Chemistry - American Chemical Society |
| DOI: dx.doi.org/10.1021/jf3015975 |
| Available online |
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| Impact of Processing on the Noncovalent Interactions between Procyanidin and Apple Cell Wall |
| Le Bourvellec C..a, b, Watrelot A. A.a,b , Ginies C.a, b, Imberty A.c, Renard M. G. C. C.a, b |
| a UMR408 Sécurité et Qualité des Produits d’Origine Végétale, INRA, F-84000 Avignon, France |
| b UMR408 Sécurité et Qualité des Produits d’Origine Végétale, Université d’Avignon et des Pays de Vaucluse, F-84000 Avignon,
France |
| c Centre de Recherches sur les Macromolécules Végétales, CERMAV-CNRS (associated with Université de Grenoble and ICMG),
F-38041 Grenoble Cedex 9, France |
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| Abstract |
| Procyanidins can bind cell wall material in raw product, and it could be supposed that the same mechanism of
retention of procyanidins by apple cell walls takes place in cooked products. To evaluate the influence of cell wall composition
and disassembly during cooking on the cell walls' capacity to interact with procyanidins, four cell wall materials differing in their
protein contents and physical characteristics were prepared: cell wall with proteins, cell wall devoid of protein, and two processed
cell walls differing by their drying method. Protein contents varied from 23 to 99 mg/g and surface areas from 1.26 to 3.16 m2/g.
Apple procyanidins with an average polymerization degree of 8.7 were used. The adsorption of apple procyanidins on solid cell
wall material was quantified using the Langmuir isotherm formulation. The protein contents in cell wall material had no effect on
procyanidin/cell wall interactions, whereas modification of the cell wall material by boiling, which reduces pectin content, and
drying decreased the apparent affinity and increased the apparent saturation levels when constants were expressed relative to cell
wall weight. However, boiling and drying increased apparent saturation levels and had no effect on apparent affinity when the
same data were expressed per surface units. Isothermal titration calorimetry indicated strong affinity (Ka = 1.4 × 104 M−1)
between pectins solubilized by boiling and procyanidins. This study higllights the impact of highly methylated pectins and drying,
that is, composition and structure of cell wall in the cell wall/procyanidin interactions. |
Keywords: boiling, tannins, porosity, pectins, calorimetry |
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