Peptídeos bioativos da microalga Spirulina e sua aplicação em um alimento extrusado tipo snack

Abstract

The search for ingredients that bring health benefits is reinforced by the consumer who is signaling a demand for healthier foods. In this perspective, there is an interest in the application of antioxidants from natural sources due to the damages caused by the excessiveconsumption of the synthetics used by the food industry. The bioactive peptides of Spirulina microalgae represent an alternative of ingredients to be incorporated, making possible the consumption of processed foods with greater nutritive value, besides the functionality. In this work the objective was to use bioactive peptides of Spirulina sp. in food development. For this, an enzymatic hydrolysis process was carried out with subsequent separation in a 4 kDa membrane ultrafiltration system. The raw material Spirulina sp., Protein hydrolyzate and isolated peptides were evaluated for thermal stability by Differential Scanning Calorimetry and Thermogavimetry analyzes and antioxidant capacity by ABTS, reducing power and chelating activity. These same products were added in a corn snack type food, in which characteristics such as texture, color and antioxidant capacity were evaluated, comparing with the control (without addition). The enzymatic hydrolysis process generated peptides with antioxidant activity, being this activity greater in relation to the raw material, presenting different profiles of antioxidant capacity for the fractions obtained. Moreover, the thermal stability results showed that the hydrolysis process increased the stability of Spirulina, showing in the fraction <4 kDa the temperature up to 141 ° C. This same fraction showed lower mass loss during the thermal process (38%). The snacks produced presented high fracturability and hardness when added with the fraction smaller than 4 kDa. The addition of the hydrolyzate and the peptide fractions were close to the yellow coloration of the contr ol. Finally, the added snacks with fraction < 4 kDa presented greater free radical inhibition using ethanol as extraction solvent and the snacks added with fraction > 4 kDa had greater capacity to donate electrons and reduce oxidative species for the same solvent. The results of this study demonstrate that peptides with antioxidant activity were produced during the hydrolysis of Spirulina sp. and their bioactivity is best achieved when in the form of isolated peptides, which can be used as natural antioxidants in the food industry.