The influence of different pressure magnitudes and solvents on the functional properties and color stabi-lity of blackberry (Rubus plicatus L.) extracts

Abstract

Phenolics have a protective effect against many diseases, such as cancer, cardiovascular diseases, hypertension and diabetes, owing to the antioxidant capacity they form. Blackberries are known as a functional food due to their high phenolic content. In this study, the extracts were obtained from untreated and hydrostatic pressure (300 MPa or 600 MPa) treated blackberry puree using water, ethanol, methanol and acetic acid (1%) or hydrochloric acid (1%) added forms of these solvents. Then the phenolic content, antioxidant capacity and color values were determined on the 0th and 7th days. The highest phenolic content and antioxidant capacity were obtained with alcohol extraction with added hydrochloric acid, and the lowest values were obtained with water extraction. It was determined that hydrochloric acid extracted more phenolic substances than acetic acid and increased the antioxidant capacity. It was found that L* values were lower, a* and b* values were higher in samples with high phenolic content. Compared with the untreated samples, it was determined that the pressure increased the phenolic content and antioxidant capacity (p<0.05). The effect of 600 MPa was found to be more pronounced in the presence of acid-added solvents. A correlation was detected between the phenolic contents, antioxidant capacities, and color values. As a result, extraction in hydrochloric acid-added ethanol medium is recommended to increase the functional properties of blackberry fruit.