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

Incorporation of High-Altitude Balloon Experiment in High School Science Classrooms

High-altitude balloon is a balloon, filled usually with helium or hydrogen that ascends into an area called “near space” or stratosphere. The most common type of high-altitude balloons are weather balloons. Other purposes include use as a platform for experiments in the upper atmosphere. Modern balloons generally contain electronic equipment such as radio transmitters, cameras, or satellite navigation systems, such as GPS receivers. The mission of the High-Altitude Balloon Experiment (HABE) is to acquire supporting data, validate enabling technologies, and resolve critical acquisition, tracking, and pointing (ATP) and fire control issues in support of future space-based precision pointing experiments. The use of high-altitude balloons offers a relatively low-cost, low-vibration test platform, a recoverable and reusable payload, worldwide launch capability, and a 'near- space' emulation of the future space systems operational scenarios. More recently, several university...
1 条评论
阅读全文

Electron Spin and Proton Spin in the Hydrogen and Hydrogen-Like Atomic Systems

Read full paper at: http://www.scirp.org/journal/PaperInformation.aspx?PaperID=52202#.VIj7tMnQrzE Author(s) Stanisław Olszewski * Affiliation(s) Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland . ABSTRACT The mechanical angular momentum and magnetic moment of the electron and proton spin have been calculated semiclassically with the aid of the uncertainty principle for energy and time. The spin effects of both kinds of the elementary particles can be expressed in terms of similar formulae. The quantization of the spin motion has been done on the basis of the old quantum theory. It gives a quantum number n = 1/2 as the index of the spin state acceptable for both the electron and proton ...
发表评论
阅读全文

Fermented Brown Sugar Residue Prolongs the Caenorhabditis elegans Lifespan via DAF-16

Fermented brown sugar residue (FBSR) is generated in the course of purifying biomass ethanol from the yeast fermentation products of brown sugar. It contains abundant nutrition and is used in various industrial applications including as fertilizer and feed. Meanwhile, brown sugar has attracted attention as a health food and is thought to prevent cardiovascular diseases, hypertension, and brain stem diseases. Furthermore, polyphenol, contained in brown sugar, reduces oxidative stress and inhibits glucose absorption. DAF-16 is a transcription factor regulated downstream of the insulin signaling pathway and is one of the main factors contributing to aging and lifespan in C. elegans . Therefore, to determine the precise roles of the DAF-16 transcription factor in stress tolerance and life span, it is necessary to elucidate the signaling pathways involved in DAF-16 activation. This study was designed to elucidate the molecular mechanisms controlling the physiological stress toleran...
发表评论
阅读全文