Dados do Trabalho

Título

ULTRASOUND-ASSISTED INTERMITTENT HYDRATION OF PUMPKIN SEEDS: IMPROVING THE WATER UPTAKE, GERMINATION AND QUALITY OF A CLEAN LABEL INGREDIENT

Introdução

The inclusion of pumpkin seeds in human diet is an excellent strategy to combat malnutrition, as this agro-industrial byproducts has high nutritional and biological value and can be widely explored in the food industry. Germination can be an alternative to enhance the nutritional and biological quality of this residue. However, this process is slow and costly. Thus, the development of new strategies, such as the use of ultrasound, is interesting to optimize the hydration and germination time aiming to overcome these challenges.

Material e Métodos

Therefore, this work investigated the ultrasound (US)-assisted hydration kinetics (1-4 cycles of 10 min, intermittent ultrasound application - 38 W.L-1/ 25 kHz/ 25 or 45 °C) of pumpkin seed and its impact on the germination kinetics, as well as on the nutritional and biological quality of germinated flours. The Peleg and Weibull models were used to model the hydration kinetics, while the Gompertz model was employed to model the germination kinetics that occurred during 72 hours at 25 °C with moisture control (80-85%).

Resultados e Discussão

After germination, the flours underwent analyzes for proximate composition, reducing sugars, soluble proteins, and phenolic compounds. Sonication reduced hydration time by up to 54.3%, decreased the germination lag phase by 19.3%, and increased maximum germination capacity by up to 5% (p<0.05). Furthermore, ultrasonic treatment led to greater rootlet length (≤19.4% at 25 °C and ≤15.7 % at 45 °C) after 72h of germination (p<0.05). Regarding the flour quality, ultrasound increased the protein and lipid content by up to 23% and 8.4%, respectively, compared to non-ultrasound-treated germinated flour (p<0.05) (with the best result observed for the sample sonicated for 4 cycles of 10 min at 45 °C). In addition, samples sonicated for 2 cycles of 10 min showed an increase in the concentration of reducing sugars (up to 79%), total phenolic compounds (up to 85%), and soluble protein (up to 51%).

Conclusão

These findings proved that ultrasound-assisted hydration, especially above two intermittent sonication cycles, has great potential to optimize pumpkin seed germination and provide flour with improved nutritional and biological quality.