Valorisation agroalimentaire des dattes par la production de confiture : analyse technico-économique et optimisation du procédé de transformation

Abstract

This research aims to evaluate three varieties of dates (Ghars, Azerza, Timdjouhart) to select the most suitable for producing a healthy, high-quality date jam, by leveraging abundant raw material supply, developing new industrial production methods, and supporting the economy. A series of chemical and physical analyses were carried out, examining pH, electrical conductivity, water content, dry matter, ash content, sugar content (Brix), titratable acidity, along with microbiological analyses, to determine the variety best suited nutritionally and technologically. Results showed the pH ranged from 5.83 for Ghars, 6.18 for Azerza, and 5.97 for Timdjouhart, values close to neutrality, which are good for food preservation. Electrical conductivity was highest in Ghars (1208 µS/cm), followed by Timdjouhart (1177), and lowest in Azerza (1072), reflecting differences in mineral salt concentration. Regarding moisture, Timdjouhart had the lowest water content (35%) compared to Ghars (39%) and Azerza (38%), favoring higher sugar concentration and a firmer texture for the jam. Dry matter was highest in Timdjouhart (65%), then Azerza (62%), and Ghars (61%), an important advantage that reduces cooking time and preserves nutrients. Ash content was 4.5% in Ghars, versus only 3% in Azerza and Timdjouhart. Brix measurements, indicating soluble sugar concentration, showed Ghars and Timdjouhart reaching a high, identical rate (53.5%), significantly higher than Azerza (46%), offering natural sweetness and better preservation. Titratable acidity was highest in Timdjouhart (0.203), followed by Azerza (0.159), then Ghars (0.121), ensuring a good balance between sweetness and acidity and limiting microbial growth. In light of these results, Timdjouhart appears the most suitable variety for producing a healthy, high-quality date jam. It combines high dry matter content, which reduces cooking time, rich sugar content for natural sweetness and good preservation, and balanced acidity providing pleasant flavor and microbiological safety. These features make Timdjouhart the ideal choice for a nutritious jam with firm texture and harmonious taste.