RETRACTED: Impact of drying methods on composition and functional properties of date powder procured from different cultivars

Abstract

The present study was designed to evaluate the effect of two different drying methods, that is, spray drying and oven drying on physicochemical and nutritional attributes of date flesh powder of dhakki, aseel, and rabi varieties. Date powders were prepared using mixture of maltodextrin and acacia gum (50:50) as drying aid at the rate of 0.4 kg per 1.0 kg of date fruits (dry weight basis). The oven‐drying conditions were 60°C for 48 hr, whereas in spray drying, flow rate of 30 ml/min at 150°C was maintained. Date powder was obtained in both treatments from three varieties. Nutritional profile in all six powders was explored specifically with quantification of sugars using HPLC‐RI, followed by physicochemical characterization. The total phenolic compounds, color ( L * a * b * values), hygroscopicity, bulk density, wettability, solubility index, and glass transition temperatures (using differential scanning calorimetry, DSC), were determined for the date powders. The nutritional profile and total phenolic contents and sugars (sucrose, fructose, and glucose) were significantly different for the varieties, while treatments showed insignificant effect. The physicochemical characteristics of date powder varied significantly with respect to the date varieties. The colored values were affected due to treatments also, and the spray‐dried powders showed better color values. The drying methods also showed effects in some parameters such as wettability time. Similarly, bulk density was different in both treatments for rabi and aseel. The glass transition temperatures were significantly varied in varieties due to difference in sugar contents, but within the treatments, they remain unaffected. The highest glass transition temperature of spray‐dried rabi was 53.2 ± 1.31°C.

Effect of inulin concentration on physicochemical properties and antioxidant activity of date powders obtained by hot-air tray dryer

“…Our results are comparable with the findings of Moghbeli et al (2019) who reported moisture contents ranging from 1.48% to 3.45% for spray-dried date powders including pectinwhey protein complexes. Similar moisture contents were also reported by Raza et al (2019) for maltodextrin/gum arabic mixture-containing date powders obtained through ovendrying at 60°C (1.55-2.59%) and spray-drying (1.47-2.55%). On the other side, our findings are lower than those of Botrel et al (2016) (5.06-6.78%) who investigated the utilization of different ratios of inulin (20% or 30%) to produce araticum (Annona crassiflora) pulp powder using cabinet convective air dryer at 70, 80 or 90°C.…”

“…Inulin-containing date powders had ash contents of between 8.09% and 13.09% (Table 1). Comparatively low ash contents in date powders (4.73-5.76%) with maltodextrin/ gum arabic mixture were declared by Raza et al (2019). This remarkable difference may be the result of various drying-aid agent concentrations used in these studies and different accumulation of minerals in fruits due to cultivars, climate, growing location, and cultivation practices (organic/ conventional) (Boussaa et al, 2020;Kapoulas, Milenković and Mirecki, 2013;Marzouk and Kassem 2011).…”

“…However, it should be kept in mind that different drying techniques cause changes in TPC of fruit powders in different ways. For instance, Raza et al (2019) stated that oven-drying at 60°C for 48h yielded maltodextrin/ gum arabic mixture-containing date powder with higher TPC (77.24-438.94 mg GAE/100g) than spray-drying technique (76.92-411.77 mg GAE/100g). The sensitivity of date palm fruit phenolics to high drying temperatures was also proved by Shahdadi, Mirzaei, Daraei Garmakhany, Mirzaei and Ghafori Khosroshahi (2013), Manickavasagan et al (2015), Shahdadi, Mirzaei and Daraei Garmakhany (2015), İzli (2016) and Moghbeli et al (2020).…”

“…Solubility values of date powders ranged from 11.29% to 12.62% (Table 1) and inulin ratio did not significantly affected this characteristic. In other studies, highly soluble (66-88.60%) date powders including maltodextrin or gum arabic and maltodextrin/gum arabic mixture were produced through spray-drying or oven-drying techniques (Manickavasagan et al, 2015;Raza et al, 2019). Date powders obtained in the current study had considerably lower water solubility than spraydried guava (85.87-95.43%), cast-tape-or spray-dried mango powders (77.22-79.17%) including maltodextrin as drying-aid agent (Patil, Chauhan and Singh, 2014;Zotarelli, Durigon, da Silva, Hubinger and Laurindo, 2020).…”

Studies on Effect of Addition of Date Pit Powder and Soy Protein Isolate on Physicochemical Properties of Date Bars

“…Ash content remained unchanged during 90 days of storage time. Raza et al (2019) concluded that ash content of dried date powder procured from different cultivars remained unchanged after 2 months of storage period.…”