Ultrasound‐Assisted Detoxification of Free Gossypol from Cottonseed Meal

Abstract To decrease NaOH consumption in the process of removal of free gossypol ( FG ) in cottonseed meal ( CSM ), ultrasound was applied in the detoxification experiments. The effects of various factors on the removal efficiency were studied by single‐factor experiments, and detoxification conditions were optimized by response surface methodology. The result indicated that removal ratio of FG increased with increasing NaOH concentration (0.5–1.5 g/L), ultrasonic power (0–1,000 W), treatment time (0–20 min) and pulse duration (1–5 s); however, further increase of pulse duration (6–7 s) resulted in a decrease. The removal ratio even reached 95.82 ± 2.75% ( n = 3) under optimal conditions of NaOH concentration (1.5 g/L), sonication time (16 min) and pulse duration (5 s). The Box–Behnken design generated satisfactory mathematical models that accurately explained the behavior of the system, allowing one to predict the removal efficiency of FG in CSM . Practical Applications Cottonseed meal ( CSM ) has long been considered as a good source of protein for animals. However, a polyphenolic compound, particularly free gossypol ( FG ), that existed in CSM limits its application as feeding stuffs. The findings in the present study demonstrated the beneficial effects of ultrasound on the removal efficiency of FG in the detoxification experiments. The application of ultrasound can not only significantly decrease the NaOH consumption but also improve the detoxification effect compared with conventional detoxification method using only NaOH solution. Therefore, this study exhibits a new detoxification technique and is of practical significance.