Influenţa condiţiilor de păstrare asupra unor compuşi bioactivi din fructele de pădure şi contribuţia acestora asupra sănătăţii umane

Abstract

The main criteria underlying this research consist in assessing the influence of the principal storage technologies on the content of some bioactive compounds contained by berry fruits. To balance fluctuations in product supply and market demand, fresh berry fruits often require short-or long-term storage in order to extend the supply of the berry fruits beyond the end ofthe harvest season. Understanding the interaction between the fruits and the environment is crucial for obtaining the most suitable conditions for extending shelf life. Portions of 250 g of strawberries, cranberries, gooseberries, blackberries or raspberries contain considerably more than the minimum daily requirement of vitamin C, while most of the other fruit can provide more than half the daily requirement. In order to freeze the berries fruits, generally no pretreatments are applied and therefore no changes in nutritive values occur during storage if proper packaging is used. During thawing, however, losses may occur. The fruits were monitorized in three fixed time points of refrigerated storage conditions at 20C, and also after different freezing condition (-180C in laboratory freezing condition and from supermarket freezing condition). The biological material studied was represented by 4 types of berries, as follows: Vaccinum myrtillius, Ribes rubrum, Rubus fructicocus and Rubus idaeus which were asseassed in terms of quality in fresh condition (T0 –moment), and after 3, respectively 7 days of refrigerate storage condition as well as after 6 month of freezing (in bulk and packaged in polyethylene bags). The soluble dry matter substances content was noticed to decrease in refrigerated storage condition between T1 and T2 time points (p<0.001). As concerning the differences in vitamin C content between fruits storage in bulk and packaged with polyethylene film were highlight significantly higher values (p<0.001) for all analyzed species that were packaged also in freezing storage conditions. When compared to the other fruits tested, the red gooseberries (43.5 mg/ 100 g), followed by raspberries (35.6 mg/ 100 g) were evidenced by their high vitamin C content. By keeping the fruits refrigerated for 7 days, although the sensory characteristics have undergone major changes, a significant decrease in vitamin C content is noted, however its final values at Tf moment are still remarkable: 27.8 mg/ 100 g for currants and 24.3 mg/ 100 g for raspberries