跳至主要内容

Processing Effects on Phytochemical Content and Antioxidative Potential of Ginger Zingiber officale

Ginger, Zingiber officinale Roscoe, is widely cultivated in tropical and subtropical countries where it is mainly used as food spice and for medicinal purposes. In the foods and beverages industry, ginger is used as an additive for its aroma and pungency. The chemical composition of fresh ginger varies with varieties or cultivar, the location for which the ginger is cultivated [3], extraction methods and the processing methods.

Ginger is rich in antioxidants and phytochemicals with anti-inflammatory, antimicrobial and anticancer properties. However, there are limited studies on the antioxidant and scavenging power of processed ginger. The objectives of this study were to determine the effects that processing has on the total phenolic and flavanoid content of ginger and its antioxidant potential using 1,1-Diphenyl-2-picrylhydrazyl (DPPH), Radical-Scavenging Activity and Ferric Reducing Antioxidant Power (FRAP). Fresh ginger (FG) was used as a control with oven drying (OD) sun drying (SD) and freeze drying (FD) as processing methods.

This study observed that selected processing methods resulted in significant (P < 0.05) differences in total phenol and flavonoid contents, as well as the free radical scavenging activity and ferric reducing antioxidant power. The highest total phenolic content was observed in freeze dried ginger (FD) (1021.15 mg GAE/100g) and the lowest was observed in fresh ginger (FG) extracts (514.02 mg GAE/100g). At the lowest concentration (12.5 mg/ml), inhibition of DPPH by FG was 9.25 which was the lowest of all ginger extracts. FD and SD ginger exhibited the greatest effect in DPPH inhibition at the lowest concentration (12.5 mg/ml). The highest FRAP was observed in SD (35.28 ± 0.69 mmol Fe [II]/mg) and the lowest observed in OD extracts (27.78 ± 0.63 mmol Fe [II]/mg).

According to the results in this experiment, total phenols in the processed ginger were higher compared to the unprocessed ginger. Freeze dried ginger had the highest phenolic and flavonoids compared to other processed ginger (OD and SD). Similar results was seen where FD had showed higher potency in ferric reducing antioxidant power and percentage DPPH inhibition. However, at concentration of 50 mg/ml processed and fresh ginger had the same DPPH inhibition percentage. At higher concentration (100 mg/ml), FG was a better free radical scavenger compared to the processed ginger.

Article by R. Offei-Oknye, et al, from USA.

Full access: http://t.cn/EtfeFv0
Image by Stephen Buchan, from Flickr-cc.

评论

发表评论

此博客中的热门博文

Does Immigration Promote the Investment of the Monopolistic Firm?

In the present paper, we examine the effect of increasing uncertainty of immigrants’ growth on the optimal timing of investment of a firm that has a monopolistic power over the labor market. It is revealed that when the uncertainty of immigrants’ growth is more than a threshold level, increasing uncertainty of immigrants’ growth accelerates the optimal timing of firms’ investment and enhances the economic growth, even if the uncertainty of immigrants’ growth is formulated by the geometric Brownian motion, which is in sharp contrast to the standard result that an increase in the uncertainty postpones the optimal timing. With an increase in the immigrants over the past ten years, workforces in the host countries have been growing significantly to the extent that the immigrants represent 70% of the increase in the workforce in Europe, and 47% in the United States as OECD indicates. In the present paper, we attempted to investigate the effect of increased uncertainty caused by the growi...
发表评论
阅读全文

Education Policy Implementation: A Mechanism for Enhancing Primary Education Development in Zanzibar

Education is one of the fundamental rights of individuals; therefore, the government of a country needs to develop and strengthen educational policy and quality as well as to ensure that everyone has equal access to basic education. The improvement of access and quality of education in the world is becoming as an essential factor in development, whereas the basic education (primary school), is acknowledged as a foundation of the higher educational development for every country. To fulfill this goal, governments introduce several policies and procedures; however, it requires some reforms and participation from the politician, policymakers, and other stakeholders to re-examine educational policy so that it can lead to multiplication and betterment of the reforms. Educational reforms actually focus on accountability. A positive educational development and reform is very challenging and needs more effort and strategy on how to use and utilize the resources effectively as such it can achie...
发表评论
阅读全文