Biochemical Changes in Fruit of an Early and a Late Date Palm Cultivar During Development and Ripening (original) (raw)
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'Lonet-Mesaed' is one of early season date palm cultivars consumed at both the Bisir and the Rutab stages as a result of low soluble tannins level. Growth and compositional changes during development and ripening of 'Lonet-Mesaed' date palm fruit were studied in two successive seasons. The results showed that fruit and flesh weight, diameter and length gradually increased during development until week 14 from pollination (maturity or Bisir stage) but slightly decreased thereafter during ripening at week 16 from pollination (ripening or Rutab stage). The changes in these parameters showed a clear sigmoidal pattern for fruit growth. Seed weight rapidly increased especially from week 6 to 10 (cell elongation or Kimri stage), slightly increased from week 10 to 12 and then decreased at week 16 from pollination. Flesh/seed ratio was sharply decreased from week 6 to 10 from pollination but then gradually increased until ripening. TSS and flesh dry weight percentage slightly increased from week 6 to 10 from pollination and then rapidly increased during maturation and ripening. Acidity percentage sharply decreased from week 6 to 8, remained relatively constant until week 12 from pollination and then slightly increased during maturation and ripening. The concentration of vitamin C increased from week 6 to 8 from pollination but sharply decreased thereafter during maturation and ripening. On a fruit basis, the amount of vitamin C (mg/fruit) increased from week 6 to 8 and decreased at week 10 from pollination with slight changes during maturation and ripening. Total phenol concentration gradually increased during development, slightly decreased during maturation and then sharply decreased during ripening. As amount per fruit total phenols followed a similar pattern as for the concentration. The concentration of soluble tannins increased from week 6 to 8, decreased with fluctuation from week 8 to 14 and then sharply decreased during ripening. However, as amount per fruit, the soluble tannin content gradually increased during development, slightly decreased during maturity and then sharply decreased during ripening. On a dry weight basis, the concentration of all nutrient elements (nitrogen, potassium, phosphorus, magnesium, calcium, sodium, zinc, iron, copper and manganese) gradually decreased during development and more progressively during ripening.
Date palm (Phoenix dactylifera L.) is an important part of human diet due to the impressive panel of sugars, polyphenols, antioxidants and essential elements. In this study, ten elite indigenous Pakistani date palm cultivars were characterized for their fruit morphological and biochemical traits at three fruit ripening stages. Results depicted significant distinction in size, shape and fruit dimensions during their different softening patterns. Moreover, the moisture contents, soluble protein contents, total phenolic contents (TPC), antioxidant activity (AA), specific activity of catalase (CAT) and peroxidase (POD) were high at khalal stage, followed by rutab stage, and lowest at tamar stage. On the converse, pH and reducing sugars (glucose and fructose) increased up to the full-ripe stage in all the investigated cultivars. Pearson's test was also established in fruit morphological parameters and sugar components. The disparity in nutritional composition mainly depended on the type of cultivar and fruit maturation stages. Our findings revealed that the indigenous date palm germplasm was the potential source of sugar contents and variety of antioxidants and could possibly be used as functional food components.
Food Chemistry, 2012
The physicochemical composition changes during palm ripening were studied. The activities of invertase and cell wall-modifying enzymes, namely pectin methylesterase (PME), β-galactosidase (β-Gal), endo-1,4-β-D-glucanase (EGase), and cellulase were monitored during growth and ripening of Shahani, Piarom and Deiry cultivars with different textures. Also, we estimated the concentrations of six organic acids by HPLC. Reducing sugars, most of organic acid, pH and TSS increased up to the full-ripe stage of all date types. On the contrary, moisture, macro and microelements and proteins decreased during the same period. Despite a considerable rise in invertase activity (200 units) during ripening of Shahani, no significant trend could be discerned in Deiry cultivar (8 units) at different stages. Our results also showed that cell wall enzymes were increased in activity during ripening and these increases were coincident with fruit softening. Furthermore, our results showed that the composition and the variation of the chemical compositions mainly depended on the cultivar and maturity stage.
Changes in Endogenous Hormones in Fruit during Growth and Development of Date Palm Fruits
2011
The length and diameter of pollinated and un-pollinated fruits of two date cultivars, piarom and shahani, were measured. Concentration of endogenous hormones in pulp during different stages of fruit growth and development were also determined by spectrophotometric techniques. The results indicated that a relatively rapid increase of fruits length occurred until 15 weeks after pollination thereafter, growth rate was moderate. In two cultivars, auxin and zeatin content, similar to gibberellins (GA) were increased gradually during the early fruit growth stage and the highest value was detected at 12 and 16 weeks after pollination, respectively. Changes in ABA levels were closely associated with ripening. In conclusion, data on un-pollinated fruits show the same pattern of growth, though at a different rate un-pollinated fruits contained lower hormones levels than pollinated fruits in both cultivars. Comparing hormonal changes pattern curve in the fruits of this cultivars, it is seen th...