عنوان مقاله [English]
Background and objectives: Dairy Spreads are solid and spreadable food products that merely made from milk or milk products that contain 10 to 80% milk fat. samanou is a traditional Iranian dessert that is prepared by cooking a mixture of wheat flour and green malt extract. The aim of this study was to assessment the effect of adding xanthan gum (0, 0.5 and 1%) and chia seed (0, 0.5 and 1%) on physical stability and textural and rheological properties dairy spread containing samanou powder.
Material and methods: In the present study, the frequency sweep rheological test was performed by a rheometer. During this test, first the linear viscoelastic range is determined and then in the frequency range of 0.1 to 100 Hz, temperature of 10 ° C and constant strain of 1%, the rheological properties of the spread including storage modulus (G′), loss modulus (G′′) and loss tangent (G′′ /G′) were measured. Emulsion stability was measured using a centrifuge based on oil separation (g). texture evaluation was performed by backward extrusion and spreadability tests with a texture analyzer to determine of firmness (N), cohesievness (N), consistency (Ns) and spreadability (N) parameters.
Results: The results showed that the effect of adding xanthan gum and chia seed flour on increasing the cohesievness, consistency, firmness and reducing the spreadability of the produced spread was significant (p<0.05). Increasing the concentration of xanthan and chia seed flour from zero to 1% increased the cohesiveness and firmness and also redused the spreadability of the produced spread compared to the control sample. The treatment containing 1% xanthan and 1% chia seed flour had the highest firmness and the least spreadability, respectively. spreads containing xanthan were more consistency than spreads containing chia seed flour, so the highest and lowest consistency were in the treatment containing 1% xanthan and without chia seed flour (67.53±12.66 N.s) and the treatment prepared from 1% Chia seeds flour without xanthan of (37.36±17.5 Ns), respectively. The lowest and highest cohesievness were in the treatment containing 0.5% xanthan (-0.05±0.22 N) and the treatment containing 1% xanthan and 0.5% chia seed flour with a score of -0.31±0.39 N respectively. Spreads containing xanthan gum and chia seed flour were more stable than the control sample, so that the control sample had the highest oil separation and the lowest physical stability (0.476±0.13 gr). In frequency sweep test, 1% strain was determined as the best strain corresponding to the linear viscoelastic range. by simultaneous increasing the concentration of xanthan and chia seed flour, the amount G′, G′′ and G′′ /G′ decreased. The presence of chia seed flour in the spread formulation, unlike xanthan gum, increased the amount of G′ and G′′. The maximum amount of G′ and G′′, as a result of the highest elasticity, , consistency and , firmness belonged to the treatment containing 0.5% xanthan and the treatment containing 1% xanthan and 0.5% chia had the lowest amount of G′ and G′′ Dedicated to himself.
Conclusion: application minimum concentrations of xanthan (0.5%) and chia seed flour (0.5%)
improved the textural properties of dairy spreads containing samanou powder. Increasing the concentration of chia seed flour, unlike xanthan, weakened the internal bonds and reduced the consistency of the product. The presence of xanthan compared to chia seed flour had a greater effect on preventing phase separation and increasing the stability of dairy spread containing of samanou powder. In all frequency ranges, the amount of storage modulus was greater than the drop modulus, and the spreads produced behaved like a gel viscoelastic solid.
Keywords: Dairy spread, Samanou powder, Xanthan, chia seed flour, textural and rheological properties.