# Haskap Juicing Method Effects on Haskap Juice Quality
## 3 Results and Discussion
### Total Flavonoid Contents in Processed Haskap Juices  
Flavonoids, as a class of polyphenic secondary metabolites in plants, play very important roles in biological activities in plants [69]. Flavonoids are responsible for the color and aromas of flowers and fruits and abiotic and biotic stress resistance. For human and animal health, flavonoids are applied to neurosciences, diabetes and obesity treatment, cancer treatment, and cardiovascular disease treatment [70]. In our research, the centrifugal juicer has demonstrated advantages for the extraction of flavonoids (Figure 5), which were about 40 mg QE/100 g higher than the processed juices obtained from the steam juicer method, and more than 10 mg QE/100 g flavonoids compared to the press method. Corresponding to the total phenolic contents in each treatment (Figure 2), the total flavonoid contents in three treatments showed similarly ranking trends by method. Figure 4: Ascorbic acid content in steam juicer-, press- and centrifugal juicer-processed samples. Ascorbic acid concentration was evaluated as ng/\(\mu\)L in each sample. Each sample had three replicates in the assay. Different letters above each bar indicate statistically significant difference (\(p<0.05\)) separated via Tukey’s HSD. Based on our various test results, the steam juicer showed lower flavonoid contents compared with the other two methods, and the haskap products from the centrifugal juicer contained more components and nutritional compounds. The mechanisms of the juicing methods might explain some of our results. The centrifugal juicer uses spinning blades and a high-speed centrifuge to extract every nutrient from the fruits. Therefore, the juice usually contains lots of pulp. This might explain why the haskap juices obtained from the centrifugal juicer contained the most components. The steam juicer processes juice through the steaming process, which could reduce microorganisms and most of the enzymes in the fruits. Due to the high temperature, many of the health benefits associated with fruit juice can be destroyed [71]. With the bladder wine pressuremethod, water pressure is used to press the fruits, more gently than the centrifugal juicer, and accordingly it contained a moderate amount of haskap components compared with the other two methods in our research. Although it had been reported that haskap has a high juice yield, its nutrition was easily destroyed by thermal processing [72]. To improve its juice quality and customer consumption, haskap juicing methods need to be studied and developed further. Juicing processes from other fruits may be examined and applied to haskap research. For example, fully automatic fresh apple juicers have been developed to make the juicing process more convenient [73]. Likewise, banana juicing machines functions on several processes, such as kneading, compressing, and filtration [74]. Analytically, Fourier transform infrared (FT-IR) spectroscopy has been applied for the evaluation of juice qualities [75]. Ohmic heating methodology may also be applied to heat rapidly and uniformly, and its treatment could have a positive effect on juice qualities [76]. Cold plasma treatment is another technique that has been shown to effectively reduce mycotoxins and positively affect the physical stability and brightness of jujube juice [77]. The high-pressure carbon dioxide (HPCD) technique as a non-thermal technology could be applied to several inactive enzymes, ultimately elongating the juice's storage life [28]. Pasteurization systems, such as helical heat exchanger and ohmic heating, could not only deactivate bacteria and endogenous enzymes, but it also could influence favorable sensory and nutritional characteristics [78]. Advanced technologies may be helpful in future hashap juice research, such as ultra-high-performance liquid chromatography or ion-trap time-of-flight mass spectrometry [12]. Supercritical fluid extraction of iridoids and fatty acids have previously been applied for haskap [17].