# The Effect of Processing Methods on Phytochemical Composition in Bergamot Juice
## 4 Discussion
### Proximate and Phytochemical Content in Bergamot Juices Obtained with Different Extraction Systems  
As regarding the proximate constituents of Ep-1 BJ (hand squeezed bergamot juice), results were in accordance with the previous report ([PERSON], 2016). As showed in Table 1, juice extraction techniques used in this study did not significantly affect same proximate constituents related to juice quality parameters: soluble solids, acidity, L-ascorbic acid, and free sugars. The range of variability of total acidity of the samples analyzed, expressed as g/L of monohydrated citric acid, was 37-41 g/L. These values were in good agreement with those previously reported by  
Figure 4: Pearson test correlation coefficients (\(r\)) among the antioxidant activity index (AAI) and the content (mg/kg) of flavanone glycosides, ascorbic acid, quaternary ammonium compounds, and limonoid aglycones in the BJ (\(p<0.05\)). [PERSON] et al [21] and [PERSON] et al. [14]. As for total acidity content, in this study, significant differences were not observed due to different juice extraction techniques considering both soluble solid and free sugars content (Table 1). If compared to the other citrus juices, the amount of free sugars in bergamot was comparable with that of grapefruit and lemon [14; 22]. In citrus juices, pectin was one of the major components of the suspended cloud material that imparts desirable appearance, texture, and flavor [30]. Since the amount of pectins was higher in the albedo and in the membranes, the content of pectins present in the juice depended on the juice extraction system used. Highest values were found in BJ obtained by the \"hard extraction process\" (Ep-3) compared to the juices obtained by the \"soft extraction process\". Results from Table 1 also showed that juice extractor pressure affected the water-soluble and total pectins content that increased about 1.5-folds in Ep-3 BJ. Based on the contents of L-ascorbic acid found in all samples, BJ was a good source of vitamin C; in fact, a serving of BJ (240 mL) would cover the adult reference daily intake (RDI). A glass of BJ also provided approximately 100 mg of stachyrine (\(N\),\(N\)-dimethyl-\(L\)-proline) making this compound a valid biomarker of orange or other citrus juice consumption [31; 32]. Furthermore, \(N\),\(N\)-dimethyl-\(L\)-proline could contribute to the fine direct/indirect regulation, the endothelial function via the modulation of nitric oxide synthase and cellular senescence pathway [9; 10]. A randomized, crossover, double-blind, controlled study performed in overweight and obese subjects showed that stachyrine was a useful biomarker to differentiate the intake of orange juice containing different amount of flavanones [32]. Furthermore, the study reported a positive correlation between the consumption of orange juice with a high content of flavanones and the improved relation of oxidative stress and inflammatory biomarkers [32]. The content of flavanone glycosides in hand squeeze (Ep-1) BJ (Table 2) were in good agreement with the data of flavonoid content in bergamot juice reported in literature [14; 15; 16]. The most abundant flavanone glycosides in bergamot fruits were naringin, neohesperidin, and neoericotrin. Among these, naringin was found to lower total cholesterol and low-density lipoprotein cholesterol levels in plasma [33] and has been also evaluated for its probable protective actions on pre-neoplastic lesions [34]. A clear technological effect on the flavanone glycosides (Table 2, Figure 2) and limonoid aglycones (Table 2) could be suggested, depending on the juice extraction system used. Limonoid aglycones showed numerous pharmacological activities [7] and were the most abundant in seeds and peels [16; 25]. This could explain the significatively high level (\(p<0.05\)) of limonin and nomilin in EP-3 BJ compared to other juices. The increase of flavanone glycosides with increasing extraction pressure were in agreement with [PERSON] et al.