The combination of microwave irradiation, ultrasonication treatment, and enzyme-assisted extraction approach was applied to study the extraction efficiency and antioxidative activity of curcumin from turmeric (Curcuma longa L.) using Response Surface Optimization (RSM). The effects of the power and treatment time of microwave irradiation and ultrasonication treatment, the types of enzymes, the amounts, and interaction time of pectinase on the extraction efficiency were studied. RSM was used to select the optimum extraction conditions by implementing Box-Behnken design. The extraction ratio and antioxidant activity of extracted species are 2.89% and 83.95% under the optimal conditions, respectively, which are close to the predicted values, and are much higher than the single extraction approach. Our results show that a versatile approach for biological compounds extraction from agricultural and natural products was successfully developed, and the bioactivity of extracted species could be kept well by using our proposed combination extraction methods.

The suitability of five apple varieties (Ralls, Qinguan, Fuji, Delicious, and Cattle) for fresh-cut processing was compared based on the evaluation of weight loss, firmness, color, titratable acid (TA), polyphenoloxidase (PPO) activity and peroxidase (POD) activity, and the impact of pulsed electronic field (PEF) on fresh-cut apples’ quality was explored. The results showed that the changes to Delicious apples in terms of the color parameter, firmness, and weight loss were comparable to or lower than the other samples, while the TA content was higher than the other samples during storage. Therefore, Delicious was selected for the study of the effects of PEF on fresh-cut apples. By measuring the physicochemical properties and microbiological characteristics within 10 days of storage, it was found that the PPO and POD activity of apples treated with PEF at 3 kV/cm on the 10th day decreased the most, with 44.61% and 36.48% decreases, respectively. In addition, apples treated with 5 kV/cm showed the greatest decrease in malondialdehyde (MDA) content and the number of microorganisms, 63.98%, and 9.17%, respectively. In general, the PEF-treated apples retained a high level of quality. These results suggested that PEF treatment is a promising technology for extending the storage period of fresh-cut apples.