Extraction and modification of Achachairu's seed (Garcinia humilis) starch using high-intensity low-frequency ultrasound

This study aimed to evaluate the effect of ultrasound high-intensity low-frequency on the extraction and modification of the characteristics of the starch from achachairu seeds. The ultrasonic treatment was applied to the seeds and starch at the power of 300 W at 25.48 kW/m(2) and 25 kHz, with different exposure times (T1-10, T2-30, and T3-60 min). The modified starches (T1, T2, and T3) were characterized considering physical-chemical, physical, morphological, thermal, structural, and viscoamylographic properties. The starch shelf life was evaluated for absorption the water and oil and syneresis index over 35 days. The results revealed that ultrasound-assisted extraction achieved higher yield (42.05%) and higher starch content (74.94 g/100 g) creating pores on the surface of the granules which reduced crystallinity by 16.92%. However, the crystal structure for sample A + V, after 60 min of exposure, was maintained. The clarity parameter of the starch paste decreased from 32.63% to 27.01% due to the exposure time. Starch (T3) presents greater stability in water absorption, oil and syneresis index (during storage) and is considered a thickening and emulsifying agent. Ultrasonic treatment can optimistically modify achachairu seed starch properties, making it a promising technology, both for starch extraction and modification. Practical applications Ultrasound-assisted starch processing can significantly alter the starch properties of achachairu seeds. In this work, new information about the extraction and modification of starch using ultrasound as pretreatment are obtained. Furthermore, the results indicate possibilities of increasing the commercial value of the starch from the seeds of achachairu, considering the range of uses of starches for food and nonfood purposes.