Development and optimization of novel processing methods of fruit extracts of medicinal crop Cornus officinalis

Developing novel processing approaches is an effective way to improve the industrial utilization and production of crops. Dogwood (Cornus officinalis Sizb. et Zucc.) is an industrial crop in the Cornaceae family, which has been used as a traditional Chinese medicine with good medicinal values. Nevertheless, little is reported on the processing technology of C. officinalis products. In this study, we conducted a comprehensive study on the development and optimization of novel processing methods of C. officinalis fruits. The processing approach of fermentation was first used to obtain fruit extracts of C. officinalis. The fresh fruits and dried fruits were used as raw materials of fermentation. Three different parameters including sugar content, SO2 addition and yeast inoculation were chosen as variables to determine the best fermentation condition using response surface methodology (RSM). The contents of total organic acids, total iridoid glycosides, and seven medicinal active ingredients were estimated to reveal the accumulation change of bioactive products during processing. The results showed that the main-fermentation time of fresh fruits is 12–16 days, and the after-fermentation time is 30–35 days, while the main-fermentation time of dried fruits is 16–20 days, and the after-fermentation time is 30–35 days. Compared with dry-fruit extracts, fresh-fruit extracts have better quality with higher contents of medicinal active ingredients. Collectively, these results provide valuable references for the processing of C. officinalis products. Moreover, the novel processing approaches of fermentation proposed in this study will shed light on further development of other medicinal crops.