Effects of Extraction and Evaporation Methods on Physico-Chemical, Functional, and Nutritional Properties of Syrups from Barhi Dates (Phoenix dactylifera L.)

Abstract

Date fruits (Phoenix dactylifera L.) are rich in sugar and also contain a substantial amount of phenolic compounds. Therefore, date fruits can be used to produce an alternative sweetener, having lower glycemic index than sucrose. This study investigated the effects of extraction and evaporation methods on various properties of the syrups prepared from Barhi dates. Extraction of date juice with the aid of pectinase or cellulase significantly enhanced the production yield, total phenolic content, and antioxidant activities determined by Ferric Reducing Antioxidant Power and Oxygen Radical Absorbance Capacity assays. Syrups prepared without enzyme application had about 6–7 times higher apparent viscosity than those prepared from the enzyme-assisted extracted juices. Vacuum evaporation produced syrups with significantly lighter color and inferior antioxidant properties than open heating. Properties of date syrups prepared with or without enzyme-assisted extraction followed by open heat evaporation were not different. They had a glucose-to-fructose ratio close to 1:1, received good sensory acceptability scores of above 6 on a 9-point hedonic scale, contained a safe level (<40 mg/kg) of 5-hydroxymethyl-2-furfuraldehyde, and exhibited similar glass transition and melting temperatures; while a greater inhibition on α-amylase activity was observed in syrups obtained from enzyme-assisted extraction. The in vivo glycemic measurement revealed that the syrup prepared with the aid of Pectinex and open heating was classified as low glycemic index (GI = 55) and medium glycemic load (GL = 11). Thus, enzyme-assisted extraction of date juice using Pectinex could be used to produce a healthy natural sweetener from low quality date fruits.

The Effect of Sugar Replacement with Different Proportions of Khalas Date Powder and Molasses on the Nutritional and Sensory Properties of Kleicha

“…Foods are classified based on their GL as low (GL ≤ 10), medium , and high (GL ≥ 20). Date molasses is classified as having a low glycemic load with a value of 11.29 [46], and dates, in general, are considered to have a medium glycemic load of 13.58 [47]. A high glycemic load is associated with the rapid release of triglycerides into the bloodstream [48].…”

Approaches to Enhance Sugar Content in Foods: Is the Date Palm Fruit a Natural Alternative to Sweeteners?

“…Date fruits also show beneficial properties, such as antitumor, anticancer, antioxidant, anti-mutagenic, anti-inflammatory, gastroprotective, hepatoprotective and nephroprotective effects [ 75 , 76 , 77 ]. Moreover, date fruits have demonstrated antibacterial activity attributed to bioactive compounds like phenolic molecules [ 78 ].…”