The date of date palm, (Phoenix dactylifera) Mazafati cultivar, was selected from the Bam region in Iran. All samples obtained were in tamr stage. The aim of this study was to investigate the best extraction method to achieve the highest amount of sugar from dates flesh. In this research, water extraction was assessed by ultrasonic water-bath, stirring condition and also alcohol extraction with Ethanol and Methanol as the four different treatments. Sugar compounds e. g glucose, fructose and sucrose were determined using High Performance Liquid Chromatography (HPLC). The results show that the ultrasonic extraction method produce the highest yield of the sugar compounds compare with the other extractions methods (p<0.05).
Keywords: date fruit, sugar analysis, water extraction, alcohol extraction, ultrasonic
Date fruit is a product of date palm (Phoenix dactylifera) which is native in Northern Africa and Middle East, especially in Iran. This is also cultivated in other parts of the world. The five largest producers are Egypt, Iran, Saudi Arabia, United Arab Emirates, and Algeria which account for about 65% of the total world production. Iran contributes to approximately 15% of the world `s production and is the second major producer after Egypt (~17% of world production). During 2000 to 2007 the production of dates increases by 2.1%, i.e. 6626329 tones to 6768774 tones, respectively. However, only 37.14% of this fruit that was harvested in 2007 was consumed fresh. This was mainly due to the fast degradation of the fruit upon storage consumption (FAO, 2007). Additionally, lack of suitable technology to store the fresh fruit at the temperature climate also posed this problem.
For sugary food there are many physico-chemical characteristics like sugar composition, water activity, Color, rheology/texture, melting point and etc that can evaluate the quality of these foods.
Dates have high total sugar contents, e.g. between 65%- 88 %( Al-hooti, Jiuan, & Quabazard, 1995; Al-Farsi, Alasalvar, Morris, Baron, & Shahidi, 2005a; Myhara, Karkalas, & Taylor, 1999). Varied amount of sugar extracted from dates are associated to the variety of the fruit and also the method of extraction (Elleuch et al., 2008; Ismail, Haffar, Baalbaki, Mechref, & Henry, 2006).
Many researches were evaluated on dates range from the investigation on the antioxidant activity (Biglari, AlKarkhi, & Easa, 2008; Mansouri, Embarek, Kokkalou, & Kefalas, 2005), the chemical composition and characteristic (Elleuch et al., 2008), Compositional and functional characteristics of date syrups (Al-Farsi et al. 2007), to the effect of ultrasound on the extraction process (Entezari, Nazary, & Khodaparast, 2004).
In date’s syrup industry, the fruits are mixed with water and heated for around one hour at temperature more than 50 °C so that sugar, can be extracted. Some investigation showed that this method damages some nutritive components and darkens of the extracted...