Characterization of Hydrocolloids Extracted from Fenugreek and Sweet Basil Seeds and Their Effect on Rheological Properties of Wheat Starch Paste

Abstract

Starch-hydrocolloid systems are crucial texturizing agents, ingredients and additives in many food products. The aim of this work was to investigate the effect of extraction temperature on the composition and properties of hydrocolloids extracted from milled fenugreek and sweet basil seeds, as well as the effect of the obtained non-starch polysaccharide preparations on the rheological properties of wheat starch paste. Hydrocolloids were extracted from milled seeds of fenugreek and sweet basil at room temperature (PFRT and PSBRT, respectively) and at 70 °C (PF70 and PSB70, respectively), with the extraction yields ranging from 32 to 47%. Extracted hydrocolloids contained polysaccharides (mainly high molar mass galactomannan) and protein. Preparations extracted at 70 °C from fenugreek (PF70) and sweet basil (PSB70) seeds were characterized by a higher content of polyphenols (16.2% and 50.9%, respectively), as well as higher antioxidant properties compared to preparations extracted at room temperature (PFRT and PSBRT). The 6% share of the fenugreek and sweet basil seed preparations obtained by extraction at room temperature increased the consistency index and reduced the flow behavior index compared to the starch paste without the preparations. The share of fenugreek seed and sweet basil preparations increased (p < 0.05) the tan δ parameter of the starch paste compared to the starch paste without the preparations.