Dados do Trabalho

Título

IMPACT OF HIGH-INTENSITY ULTRASOUND-TREATED BLUEBERRY PULP ON THE QUALITY OF SKYR YOGURT: ANALYSIS OF PH, ACIDITY, MOISTURE, SYNERESIS, PROTEIN, AND ASH

Introdução

Yogurt is a widely appreciated fermented dairy product known for its nutritional and sensory properties. The incorporation of fruit pulps, such as blueberry, further enriches it. However, its quality can be affected by pulp processing and storage. This study evaluated the impact of high-intensity ultrasound (HIU) applied to blueberry pulp, focusing on the quality of yogurt enriched with this pulp in terms of pH, acidity, moisture, syneresis, protein, and ash content.

Material e Métodos

The blueberries were crushed and pasteurized at 85°C, with HIU applied at powers of 160W, 320W, 480W, and 640W for 3 minutes, while a control sample remained untreated. The product was stored at 4°C and analyzed on days 1, 7, 14, and 21.

Resultados e Discussão

On day 1, the pH of the 160W, 320W, and 480W samples averaged 4.400, differing from the pasteurized, control, and 640W samples. On days 7 and 14, the processed samples had an average pH of 4.149, differing only from the control sample, while on day 21, no significant differences were observed among the samples. The acidity of the samples remained constant on days 1, 7, and 14, with an average of 1.14g of lactic acid/100g. The moisture content of the 160W (0.847), 320W (0.854), 480W (0.853), and 640W (0.852) samples showed no significant differences. However, the 640W and 160W samples did not differ significantly from the pasteurized sample (0.841), which did not differ from the control sample (0.833). Syneresis was lower in the 640W sample (0.331) and did not differ significantly from the 480W (0.338) and 160W (0.342) samples. These, in turn, did not differ from the 320W sample (0.347), which showed no difference compared to the pasteurized sample (0.353) and the control (0.365). The samples showed no significant differences in protein and ash content.

Conclusão

Ultrasonic treatment of blueberry pulp had a positive impact on yogurt quality, mainly in terms of water retention and reduced syneresis. pH and acidity did not show significant changes due to ultrasonic treatment but stabilized over time, suggesting an important role of bacterial fermentation. The values of protein and ash also did not vary with the type of treatment used.