In Turkey, most of the apricots are sun-dried: it is a simple low-cost system that doesn't need much energy. The fruit is placed on canopies or stones and left there until the water percentage drops to 20% without washing or pre-treatments.
To diminish deterioration and browning, facilitate drying, guarantee colour stability and improve the overall quality of the products, some pre-treatment such as sulphuring is advisable.
Researchers from the University of Catania, in cooperation with the Turkish Universities of Çukurova e Nevşehir, studied the effect of sulphuring on the chemical and physical characteristics and aromatic compounds of Alkaya apricots, a new variety grown in Malatya. The region cultivates over 50% of the domestic production destined to the fresh produce market and 90-95% of the domestic production destined to the dried apricot market.
Colour, texture, moisture, pH, total soluble solids, sugars, organic acids and 5-hydroxymethyl furfural content were determined and aroma compounds were quantified and identified by GC-MS-FID. Sulphuring treatment before sun-drying had significant effects on some physical and chemical properties (pH, titratable acidity, total acids and colour parameters) as well as on aroma compounds.
As regards colour stability, browning was significantly higher in unsulphured fruit. A total of 45 aroma compounds were identified in both sulphured and unsulphured dried apricots.
Aroma compound levels in sulphured apricots were much lower than in unsulphured apricots: pyrazines were detected only in unsulphured apricots and the significantly higher level of norisoprenoids, lactones, esters, pyrazines and furfural in unsulphured dried apricots was attributed to carotenoid degradation, long-chain fatty acid oxidation, thermal degradation and Maillard reaction. Sulphuring in fact slowed down all these processes and reduced ester formation thanks to its antioxidant action.
Source: Letizia Inserra, Turgut Cabaroğlu, Kemal Şen, Elena Arena, Gabriele Ballistreri, Biagio Fallico, 'Effect of sulphuring on physicochemical characteristics and aroma of dried Alkaya apricot: a new Turkish variety', 2017, Turkish Journal of Agriculture and Forestry, Vol. 41, pag. 59-68. doi:10.3906/tar-1607-60
Colour, texture, moisture, pH, total soluble solids, sugars, organic acids and 5-hydroxymethyl furfural content were determined and aroma compounds were quantified and identified by GC-MS-FID. Sulphuring treatment before sun-drying had significant effects on some physical and chemical properties (pH, titratable acidity, total acids and colour parameters) as well as on aroma compounds.
As regards colour stability, browning was significantly higher in unsulphured fruit. A total of 45 aroma compounds were identified in both sulphured and unsulphured dried apricots.
Aroma compound levels in sulphured apricots were much lower than in unsulphured apricots: pyrazines were detected only in unsulphured apricots and the significantly higher level of norisoprenoids, lactones, esters, pyrazines and furfural in unsulphured dried apricots was attributed to carotenoid degradation, long-chain fatty acid oxidation, thermal degradation and Maillard reaction. Sulphuring in fact slowed down all these processes and reduced ester formation thanks to its antioxidant action.
Source: Letizia Inserra, Turgut Cabaroğlu, Kemal Şen, Elena Arena, Gabriele Ballistreri, Biagio Fallico, 'Effect of sulphuring on physicochemical characteristics and aroma of dried Alkaya apricot: a new Turkish variety', 2017, Turkish Journal of Agriculture and Forestry, Vol. 41, pag. 59-68. doi:10.3906/tar-1607-60