| Blueberries(Semen Trigonellae) are the variety of berries, which play important roles in treating human diseases, including antioxidative, anti-inflammatory and pro-cardiovascular properties. Besides, blueberries are inexpensive plant sources for anthocyanins. Blueberries can be processed into various products, including fruit juice, jam and health foods. However, there are still some problems for the processing of blueberries, such as the varieties and selectivities. Based on the current problems about blueberries, the first part of the paper mainly studied the characteristics of 10 blueberry cultivars(Blomidon, Fundy, Cumberland, Northblue, Northland, Imer, Reka, Polaris, Patriot, and Chippewa). The basic physical and chemical indexes(p H, soluble solids, acidity, and the content of total sugar, spectral characteristics), the content of antioxidants(total phenol, total anthocyanins, flavonoids), and aroma components were detected and evaluated. The results were as follows:(1) There was a slight difference of buffer coefficient and content of soluble solids between blueberry cultivars. The content of total sugar of the ten blueberries was in the range of 60.00-140.40 mg/m L. ‘Fundy’, ‘Reka’ had higher ratio of sugar and acid compared with the other cultivars, while ‘Chippewa’,‘Northland’ ‘Imer’ and‘Imer’ had lower ratio of sugar-acid.(2) The content of anthocyanins in blueberries accounts for a large proportion of total phenol content, while the anthocyanins-phenol ratio was between 51.14% and 88.64%. ‘Cumberland’ showed the highest total anthocyanins content(0.829±0.011mg/m L).(3) Twenty-five kinds of aromatic compounds were identified in 10 blueberry cultivars, mainly including alcohols, esters, aldehydes, ketones and hydrocarbons. ‘Cumberland’ contained the most kinds of aroma components, which reached 18 kinds.Anthocyanins are one of polyphenols, which have a great theoretical research value and become one of the hotspots in the research field of health foods. The second part of this paper was to identify the main anthocyanins in the ten blueberry varieties by HPLC-MS and to estimate antioxidant activity of anthocyanins extracts by the DPPH, ABTS, FRAP and hydroxyl radical methods. The results were as follows:(1) The anthocyanins composition in blueberry cultivars was different. Seven anthocyanins were characterized in ‘Polaris’ ‘Northblue’ and ‘Imer’, while less anthocyanins were detected in ‘Reka’.(2) In the range of anthocyanins concentration, all of the anthocyanins extracts exhibted strong antioxidant activity. The antioxidant activity of anthocyanins increased with the increase of concentration in our measure range, and showed a dose-dependent.(3) The anthocyanins of ‘Polaris’ possess the strongest antioxidant activity, while the anthocyanins of ‘Blomidon’, ‘Chippewa’, ‘Patriot’ exhibited less antioxidant activity.Acrylamide(AA) is known to be a neurotoxic, genotoxic, and potential carcinogenic compound. The presence of AA in foods causes public health concerns. However, there has relatively less report on whether anthocyanins can reduce AA-induced oxidative damage in Hep G2 cells. In the third part of this paper, using AA as harmful substances, we determined the cell viability and enzyme activity combined with Hep G2 cells. The results were as follows:(1) When the concentration of anthocyanins were less than 20μg/m L, there was no significant damage effect to Hep G2 cells.(2) When Hep G2 cells treated with AA at a concentration of 10mmol/L, the cell viability severely decreased to 60.60%, demonstrated that AA can cause damge to Hep G2 cells. While anthocyanins(5, 10, 20μg/m L) can significantly increased cell viability, anthocyanins(5, 10, 20μg/m L) can inhibit the cytotoxicity induced by AA(p<0.01)(3) AA can markedly increased the levels of MDA and decreased the activity of SOD and CAT(p<0.01), while anthocyanins(5, 10, 20μg/m L) pretreatment could improve SOD, CAT activity and decrease MDA levels,demonstrated that anthocyanins could protect Hep G2 cells against AA-induced damage.Overall, different blueberry cultivars possess different characteristics. Besides, its anthocyanins exhibted strong antioxidant activity and could protect Hep G2 cells against AA-induced damage. The current findings may provide scientific basis for production of blueberry cultivars and development of anthocyanins, which is an important active ingredients extracted from natural plant sources. |
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