المساهمة في دراسة التغييرات الكيميائية لمحتوى ثمار نخيل التمر دقلة نور و دقلة بيضاء خلال مراحل تشكله .

Abstract

This study investigates the fruits of date palm, Phenicus dactylifera L, for the two species of Deglet Nour and Degla Beida. It Determines the identification and estimation of the quantitative chemical content and studies the antioxidant activity of date palm fruits (Deglet Nour and Degla Beida) during its formation during the different stages of maturity (Al-Hababouk, Al-Jamri, Kalaal El-Mouloin, Wet, Dates). The results showed that there was no difference in the pH between all stages of fruits of the two cultivars, and it was estimated at 6.76 and 6.2 in each of the Deglet Nour and Degla Beida. The electrical conductivity was a constant value in all stages of maturity for each of the two classes. As for the electrical conductivity, it was a constant value in all stages of ripening for each of the two cultivars. (12.85µs/cm) All studied fruits have an inverse relationship between the ratio of the water content and the sequence of ripening stages, and a direct relationship with the ratio of the dry matter estimated by the ripening date at 60.13% for Deglet Nour, 65.24%. for Degla Beida.The results also showed the richness of the fleshy portion of the fruit Deglet Nour carbohydrates with the superiority of the class Deglet Nour(77.4%) over the class of Degla Beida(75.5%), low protein content (0.22-1.6%) and fats (0.35-0.86%). Whereas, methanolic extracts of fruit samples belonging to the same variety showed similar yield ratios, but among the varieties it was for Degla Beida(22%) and for Deglet Nour(20.66%). The results also showed a high phenolic content in the first stages of fruit development and the superiority of the white dillelas cultivar (29.96 - 354.49) mg/100g over the Deglet Nourvariety (25.17 - 285.09) mg/100g. As for the content of flavonoids, it exceeded the class of Degla Beida(0.36 - 4.84) mg / 100g over the class of Deglet Nour(2.7-10.9) mg / 100g. Antioxidant activity using the DPPH test showed that the antioxidant activity decreased gradually during the stages of fruit development. The IC50 values of the Al-Habbabuk phase for Degla Beida13.98µg / ml, for Deglet Nour27 µg / ml, and in the al-Jamri phase it was between (32.39 µg / ml 89.5- ). There was no activity in the other stages (Deglet Nour; Degla Beida) at the range of concentrations specified in the study (200-1.56) g /ml.