Malatya apricot gum: A source of natural gum and its physicochemical, functional and antioxidant properties

Gums are commonly used in the food industry for their functional properties. However, the growing demand for sustainable and alternative sources has drawn attention to the need for identifying and characterizing non-conventional gum sources with comparable or enhanced features. This study aimed to investigate the exudate gum from apricot trees (Prunus armeniaca) in Malatya as a potential alternative. Since the composition and physicochemical properties of plant exudates can be affected by climate and growing region, our aim was to investigate the differences in the properties of the gum collected from Malatya apricot trees. The crude gum (CG) was purified (PG) and analyzed for its composition and properties. Approximate compositional analysis showed that CG consisted of 68.20 % carbohydrates, 2.23 % protein, 12.37 % moisture, and 4.37 % ash. These values, except for moisture content and fat, increased upon purification. The gum had a molecular weight of 5.55 × 10⁵ Da, which remained unchanged upon purification. Galactose and arabinose were the main components of the sugar composition of the gum, with minor contributions from xylose and rhamnose, which showed variations in ratio after purification. Color metrics also indicated an increase in lightness (L*) and yellowness (b*) and a decrease in greenness (a*) after purification. The native pH of PG solution was found to be similar to that of CG and below 7 due to the presence of uronic acid residues in the gum structure, as confirmed by FTIR analysis. The total phenolic content was determined to be 1.14 mg GAE/g in CG and 1.17 mg GAE/g in PG, resulting in a higher antioxidant capacity for the latter. Purification also increased the content of dietary fibers from 1.61 % to 2.85 %. DSC analysis revealed that PG had higher thermal stability compared to CG. SEM images demonstrated that the gum particles were irregularly shaped, non-uniformly sized, and had rough and indented surfaces. Based on their Carr's index and Hausner ratio, both forms of apricot gum were classified as good flowable powders. These findings demonstrate the similarity of apricot gum to other tree exudates and highlight its potential as a new gum source. However, further studies are needed to determine its potential for industrial applications.