Scientific Study

Abstract: This work is a contribution to give value addition to second grade dates (with hard texture) by the production of enzymatically treated syrup with high commercial value. It was observed that the pulp: water at ratio 1:3 treated with 50 U of pectinase and 5 U of cellulase during 120 min at 50°C gave the highest recovery of total soluble solids (72.37 g of total soluble solids /100g fresh basis) and the lower turbidity (186.45 NTU) compared with control without enzyme addition (Total soluble solids yields: 66.34 g of total soluble solids /100g fresh basis and turbidity: 1513 NTU). Physicochemical measurements indicated that carbohydrates were predominant in all date varieties as well as their syrups (˜ 69.59-83.76 g/100g dry matter in dates and ˜ 62.14-74.68 g/100 g fresh weight in syrup). Allig variety was characterised by a high content of reducing sugars content (˜ 77.91 g/100g dry matter); contrary to deglet Nour (˜ 23.17 g/100g dry matter) and Kentichi (˜ 21.3 g/100g dry matter). The CIE L* a* b* colour values of the enzyme-treated date syrup of Deglet Nour; Allig and Kentichi variety showed lighter colours (L* values ranging from 24.16 to 44) than the control without enzyme (L* values ranging from 0.545 to 17.2). Hedonic evaluation showed that enzyme-treated date syrup was more appreciated by consumers. Microbiological study showed that date syrups were free from aerobes; molds; coliforms and enterobacteriaceae and were microbiologically stable during five months storage. Results suggested that enzymatic treatment could be used for production of date syrup with high commercial value.