INFLUENCE OF CELL WALL CALCIUM CONTENT IN FRUIT FIRMNESS DURING THE RIPENING OF PLUMS (PRUNUS DOMESTICA L.).

‘Rainha Claudia Verde’ is a regional cultivar of Prunus domestica L. well adapted to a specific region in the south of Portugal. In order to understand the postharvest behavior of this cultivar produced in different orchards, cell wall poly-saccharides and cell wall calcium fruit content were studied during ripening in two consecutive years. During harvest period pectic fractions soluble in water, carbonate and KOH were prepared from alcohol-insoluble residue (AIR) of plums. Galacturonic and neutral sugars contents were measured during fruit ripening and fruit firmness was also evaluated. The calcium fruit level was determined in the AIR during harvest season as well as in dry matter. Fruit firmness was significantly higher in the second year and was probably related with calcium fruit content and pectic polysaccharides. There was a significant difference in calcium fruit content between orchards, and this might influence the overall fruit texture during the postharvest period. During fruit ripening water soluble pectic polysaccharides did not change significantly, which corresponded with the small decrease in tissue firmness. The occurrence in the supernatant of the cellulosic residue of highly branched polysaccharides might be the consequence of matrix material associated with microfibrilar phase. Depolymerization of the hemicellulosic fraction was not evident during plum ripening. The loss of fruit firmness is a consequence of many cellular events which are influenced by external factors. The knowledge of calcium content in the cell wall and the pectic poly¬saccharides could be of great importance to local farmers to predict fruit texture

Impact of food eviction on the nutritional status and adequacy of nutritional intake on children with food allergy

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The origin of pinking phenomena in white wines: An update

Pinking is the term used to describe the appearance of a salmon-red blush color that may appear in bottled white wines, produced solely from white grape varieties. It is perceived as an undesirable phenomenon for both, wine consumers and winemakers. Although with seasonal and regional variations, the pinking has been observed worldwide, with predominance in white wines produced from Vitis vinifera L. grape varieties. The pinking origin of Síria white grapes has been studied in detail and it has been shown that the origin of the pinking phenomenon in white wines from Vitis vinifera L. Síria grape variety are anthocyanins, mainly malvidin-3-O-glucoside. The minimum amount of anthocyanins needed for the visualization of the wine pink color was 0.3 mg/L. Further studies in other white monovarietal wines that occasionally suffer from this defect, like white wine from Malvasia Fina grape variety, Loureiro grape variety, Sauvignon Blanc grape variety and Albariño grape variety, have shown that this wines produced from this grape varieties also show low amounts of anthocyanins, mainly malvidin-3-O-glucoside. These results show that the presence of low but visible detectable anthocyanins as the origin of the pinking phenomena is also observed in other white grape varieties besides that of Síria