Dados do Trabalho

Título

EFFECT OF BALL MILL TREATMENT ON THE PHYSICOCHEMICAL PROPERTIES, ELECTROPHORETIC PROFILE AND DAMAGED STARCH OF CHICKPEA FLOUR

Introdução

Chickpea is a pulse that has stood out due to its technological properties and nutritional qualities, mainly containing starch (33-47%) and proteins (18-25%) in its composition. Ball milling has been used to promote changes in the techno-functional properties of proteins and starch from various food matrices. This study aimed to evaluate the effects of ball milling using different rotation speeds on protein physicochemical properties (solubility and zeta potential), electrophoretic profile and damaged starch of commercial chickpea flour.

Material e Métodos

Chickpea flour – CF (8.3% moisture, 3.3% ash, 19.3% proteins, 4.0% lipids and 65.1% carbohydrates) was treated in a planetary ball mill with zirconium oxide jar (250 ml) and balls (diameter: 3 mm) in a ratio of 1:10 w/w (flour: balls) and rotation speeds of 250 and 340 rpm for 60 min (BM250 and BM340). Solubility was evaluated at pH 7. To measure zeta potential, aqueous dispersions (1 mg/g of protein) were prepared, adjusting the pH to 7 with subsequent centrifugation (20,000 x g for 30 min at 25°C) and filtration through qualitative filter paper. The electrophoretic profile of the flours was evaluated using non-reducing and reducing SDS-PAGE. Damaged starch was evaluated by Chopin SDmatic equipment (AACC 76-33.01 method).

Resultados e Discussão

Solubility varied from 70.97 (CF) to 68.44% (BM340), and there was no significant difference (p>0.05) among treatments. The zeta potential values were -35.2 mV (CF and BM250) and -36.2 mV (BM340); only the BM340 sample was statistically different (p<0.05). The electrophoretic profiles obtained under non-reducing and reducing conditions showed no alteration as a function of treatment conditions, suggesting protein oxidation (disulfide bond formation) did not occur. Concerning damaged starch, there was an increase in the content from 6.39 (CF) to up to 14.58% (BM340), indicating a change in the starch structure.

Conclusão

These results indicated that the treatment conditions were insufficient to promote modifications in the proteins physicochemical properties and electrophoretic profile. However, increased damaged starch content can impact the techno-functional properties of the flour and promote new characteristics in its application as an ingredient.