Deodorization of Oviductus ranae: Establishment of ultrasound-composite natural products method

Oviductus ranae (OR) is often used in health food and preparation of delicious dishes, but its fishy odor seriously affects its quality. In this study, we aimed to develop an efficient deodorization method for OR, and systematically evaluated the effects of ultrasound treatment (UA), rosemary/asparagus extract treatment (AR) and its combined ultrasound-plant extract treatment (UAR) on the deodorization of fishy substances and the oxidative stability of fats/proteins in the OR. The results of GC-MS showed that the three treatments, namely, UA, AR and UAR, could significantly (p ​< ​0.05) reduce the content of the main fishy substances (aldehydes, ketones and alcohols) in the OR). content of the main fishy substances (aldehydes, ketones and alcohols) in the OR, with the UAR treatment having the best deodorizing effect. Compared with the control group, UAR treatment significantly reduced the contents of nonanal, octanal, hexanal and hexanol, the main fishy substances, by 71.3 ​%, 86.0 ​%, 25.2 ​% and 50.0 ​%, respectively. Meanwhile, UAR treatment significantly improved the oxidative stability of the product: the thiobarbituric acid reactive substances (TBARS, secondary products of lipid oxidation) value was reduced by 60.0 ​% compared with that of the control group, indicating that the lipid oxidation was effectively inhibited; the total sulfhydryl content was significantly increased by 26.5 ​%, suggesting that the oxidative damage of proteins was significantly reduced. The intelligent sensory analysis of the electronic nose and electronic tongue further confirmed the superiority of UAR treatment, and its deodorization effect was significantly better than that of single UA or AR (p ​< ​0.05). In conclusion, UAR not only significantly reduced the main fishy substances of OR, but also effectively inhibited lipid and protein oxidation during processing, which laid a solid foundation for the improvement of the quality of OR and the development of high-value products.