Organic acid metabolism changes during postharvest dehydration process in grape (Vitis vinifera L.) berries

Abstract

[Excerpt] After detachment from the plant and until cell death, fruits remain metabolically active, resulting in compositional modifications. For certain food products, postharvest controlled stresses are applied to induce desired physical or chemical changes. In the case of grapes, a gradual dehydration process is normally utilized for raisin production and also for the production of special wines [1]. Postharvest dehydration, in general, causes changes in texture, color, taste and nutritional value of food due to the high temperatures and long drying times required in the process [2]. Present in all plants, organic acids support various and different aspects of cellular metabolism and have great influence in the organoleptic properties of wines and grape juices [3,4]. Little is known, however, regarding how the organic acid metabolism is affected by such industrially applied dehydration processes. Thus, to better understand the metabolism of the organic acids during postharvest dehydration, we applied an industry-mimicking slow dehydration process for eleven days at 50ºC to intact berry clusters and employed several molecular and biochemical techniques.[...]