Identification and Characterization of Glucosyltransferase That Forms 1-Galloyl-β-d-Glucogallin in Canarium album L., a Functional Fruit Rich in Hydrolysable Tannins

Hydrolysable tannins (HTs) are useful secondary metabolites that are responsible for pharmacological activities and astringent taste, flavor, and quality in fruits. They are also the main polyphenols in Canarium album L. (Chinese olive) fruit, an interesting and functional fruit that has been cultivated for over 2000 years. The HT content of C. album fruit was 2.3–13 times higher than that of berries with a higher content of HT. 1-galloyl-β-d-glucose (βG) is the first intermediate and the key metabolite in the HT biosynthesis pathway. It is catalyzed by UDP-glucosyltransferases (UGTs), which are responsible for the glycosylation of gallic acid (GA) to form βG. Here, we first reported 140 UGTs in C. album. Phylogenetic analysis clustered them into 14 phylogenetic groups (A, B, D–M, P, and Q), which are different from the 14 typical major groups (A~N) of Arabidopsis thaliana. Expression pattern and correlation analysis showed that UGT84A77 (Isoform0117852) was highly expressed and had a positive correlation with GA and βG content. Prokaryotic expression showed that UGT84A77 could catalyze GA to form βG. These results provide a theoretical basis on UGTs in C. album, which will be helpful for further functional research and availability on HTs and polyphenols.

Optimizing Total Phenolic and Oleuropein of Chinese Olive (Olea europaea) Leaves for Enhancement of the Phenols Content and Antioxidant Activity

China, as a contrary climate to the Mediterranean-climate region, is massive in planting olive (Olea europaea) cultivation as an important oil crop. Nonetheless, Chinese olive leaves have received little attention and there is little information about the phenols content. Therefore, in this study, a multiple-response optimization was performed to maximize the total phenolic and oleuropein content (TPC and OEC) by ultrasound-assisted extraction, and the aged and young leaves prepared from six Chinese cultivars from January to December were investigated concerning seven main phenolic composition. Under optimal conditions (power 260 W, time 10 min, liquid-solid ratio 30 mL/g, and 50% ethanol), the highest TPC (197.32 mg/g DM) and OEC (74.68 mg/g DM) were obtained. Findings revealed that the optimal olive leaves for phenolic compounds were the young leaves in spring and winter, being oleuropein and luteolin-4′-O-glucoside present in higher level, and the “Koroneiki” and “Jiufeng” cultivars were relatively stable. Furthermore, antioxidant potential of the phenol extract and oleuropein was also evaluated based on the reducing power and scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH)and superoxide radical assays, and a higher antioxidant effect of oleuropein was observed compared to the phenol extract. In addition, oleuropein showed anticancer activity against HeLa cells, with a minimum inhibitory concentration (EC50) value of 0.19 mg/mL at 48 h. These findings revealed an attractive source of biological substances for further development and utilization of Chinese olive leaves.

Spain's reputation in China: analysing its effects on attitudes towards Spanish olive oil

PurposeThe objective of this paper is to analyse the elements that influence Spain's reputation among Chinese consumers, and to evaluate to what extent this country's reputation has an impact on their perceived quality of Spanish olive oil (SOO) and their intentions to purchase and recommend SOO.Design/methodology/approachThis study was carried out by surveying 399 potential olive oil consumers in China (256 of whom were familiar with olive oil and 143 of whom had no previous familiarity with the product, although they stated their intentions to consume it). The proposed hypotheses were tested using covariance-based structural equation modelling (CB-SEM).FindingsThe results show that: (1) Spain's reputation among Chinese consumers can be principally explained by its appealing environment and advanced economy; (2) reputation does not have a direct impact on intentions to purchase and recommend SOO (summary construct effect), but rather has an indirect impact thanks to the perceived quality of SOO (halo effect), and (3) familiarity with olive oil moderates these relationships.Originality/valueNo previous study has analysed this question for this food product category (olive oil), country of origin (Spain) and target market (China). This study, therefore, provides new empirical evidence regarding the formation process of Spain's reputation among Chinese olive oil consumers and the effect of the country of origin on the Chinese olive oil market. These results provide countries' policymakers with criteria for competitive country reputation management.

Identification and Structural Elucidation of Anti-Inflammatory Compounds from Chinese Olive (Canarium Album L.) Fruit Extracts

Chinese olive (Canarium album L.), a rich source of polyphenols, can be used as a functional food ingredient. We previously showed that the ethyl acetate fraction of this extract (CO-EtOAc) is an effective anti-inflammatory agent. Therefore, here, we aimed to screen the bioactive fractions extracted from CO-EtOAc using different isolation techniques, and purify the bioactive compounds based on their cytotoxic and anti-inflammatory abilities. CO-EtOAc was fractionated using silica gel and Sephadex column chromatography, and the active compounds were isolated and purified by high-performance liquid chromatography (HPLC). The structures of the resulting compounds were identified using proton nuclear magnetic resonance (NMR) spectra. Activity-directed fractionation and purification were used to identify the following active compounds with anti-inflammatory effects using lipopolysaccharide (LPS)-stimulated mouse macrophages: sitoindoside I, amentoflavone, tetrahydroamentoflavone and protocatechuic acid. For the first time, sitoindoside I and tetrahydroamentoflavone were isolated from Chinese olive, and the anti-inflammatory compounds of CO-EtOAc were identified, suggesting its potential for used as a health food ingredient.