## 3 Processing and Extraction
### Ultrasound Assisted Extraction
#### 3.2.1 Polyphenolic Compounds
The impact of ultrasound treatment on other unconventional methods of extraction was also investigated. [PERSON] et al. (2010) combined UAE with enzymatic treatment of pectinase. The mechanism of enzyme impact on the extraction process was provided in the following text. Raspberry pomace obtained from the wine industry was freeze-dried until the moisture content was \(<\)5%. After 12 h at \(-\)18 \({}^{\circ}\)C, it was milled to 0.45 mm as the maximum size of particles. Conditions of UAE were determined using RSM. The most efficient parameters of anthocyanin extraction were chosen as follows: temperature 43.94 \({}^{\circ}\)C, ultrasound power 290.9 W, time 30 min and pectinase dosage 0.16%. S-L ratio and type of solvent were constant and ranged from 1/30 and 60% (\(v/v\)) acidulated ethanol, respectively. To evaluate the mathematical method the following conditions were set: temperature 44 \({}^{\circ}\)C, power of ultrasound 290 W, time 30 min and pectinase dosage 0.16%. The obtained value of anthocyanin yield was 0.853 mg/g of pomace (dm) vs. the predicted 0.888 mg/100 g. Enzymatic extraction with US treatment was compared with conventional extraction methods: SLE with hot water, SLE with acidulated ethanol and EAE (without US). US resulted in the highest extraction efficiency and TAC values in obtained extracts. AA measured in DPPH and RP (reducing power) assays reached the highest values when US was used. The AA value of the product extracted using US, as determined in an ABTS assay, was not significantly different from conventional EAE but was significantly increased compared to the AA values of extracts obtained in both SLEs. [PERSON] et al. [111] used UAE to extract polyphenic compounds from chokeberry by-products from a filter-tea factory, produced from pomace remaining after juice pressing. The most efficient parameters were chosen using RSM for every quantitative factor individually (TPC, TFC, monomeric anthocyanin content and proanthocyanins content). The common optimal parameter for all the measured properties of extracts was the temperature set at 70 \({}^{\circ}\)C. Other values of conditions predicted as the most efficient were as follows: for TPC--206.64 W and 80.1 min; for TFC--210.24 W and 75 min; for monomeric anthocyanins content--216 W and 70 min; and for proanthocyanins content--199.44 W and 70 min for power and time, respectively. The observed values of yields for individual compounds were 15.058 mg GAE/mL extract (vs. predicted 15.41 mg GAE/mL), 10.436 mg CE/mL (vs. predicted 9.86 mg CE/mL), 2.09 mg C3 GE/mL (vs. predicted 2.26 mg C3 GE/mL) and 19.82 mg CE/mL (vs. predicted 20.67 mg CE/mL) for TPC, TFC, monomeric anthocyanins content and proanthocyanins content, respectively. [PERSON] et al. [112] used UAE to extract polyphenic compounds from blueberry wine pomace. The experiment was designed using RSM and optimal parameters were predicted as follows: temperature 61 \({}^{\circ}\)C, S-L 1:22, time 24 min. It resulted in extraction yields of 16.03 mg GAE/g pomace and 4.19 mg C3 GE/g pomace for TPC and TAC, respectively. (Predicted values were 15.81 mg GAE/g pomace for TPC and 4.12 mg C3 GE/g pomace for TAC.) Compared to the conventional method, the SLE method with acidulated ethanol (70%) used as a solvent running for 35 min and with applied optimal conditions for UAE (temperature--61 \({}^{\circ}\)C; S-L ratio--1/22), UAE appeared to be significantly more efficient, despite a shorter extraction time. There were seven anthocyanins also identified, which were present in both extracts: deplinidin-3-O-glucoside, deplinidin-3-O-arabinoside, petunidin-3-O-glucose, cyanidin-3-O-arabinoside, cyanidin-3-O-glucose, malvidin-3-O-glucose and malvidin-3-O-arabinoside. [PERSON] et al. [113] designed an experiment with different extraction methods (PEF-assisted--mentioned in the following text and high voltage electrical discharge-assisted). UAE with variable conditions of time, temperature and solvent type was conducted.