Evaluation of antioxidant activities and phenolic subtype contents of ethanolic bran extracts of Thai pigmented rice varieties through chemical and cellular assays

2014 ◽  
Vol 50 (4) ◽  
pp. 990-998 ◽  
Author(s):  
Worawat Surarit ◽  
Chalerm Jansom ◽  
Nusiri Lerdvuthisopon ◽  
Supranee Kongkham ◽  
Pintusorn Hansakul
Food Research ◽  
2019 ◽  
Vol 4 (2) ◽  
pp. 547-556
Author(s):  
U. Tobgay ◽  
P. Boonyanuphong ◽  
P. Meunprasertdee

Pigmented rice is considered as the good source of phytochemicals which contains more phenolic contents and higher antioxidant activities compared with non-pigmented rice. However, those phytochemicals are normally extracted using inorganic solvent, using water was rarely found. This study was aimed to compare extraction methods on antioxidant contents and activities of two types of Thai pigmented rice (black glutinous rice and red non-glutinous rice). Pigmented rice was extracted either conventional method alone or a combination of ultrasonic plus conventional method with different solvents (methanol and hot water). Phenolic contents were analyzed by spectrophotometric assay and high-performance liquid chromatography (HPLC). Antioxidant activities were investigated by radical scavenging capacity (ABTS and DPPH). The results showed that ultrasonic pretreatment significantly enhanced the total phenolic, flavonoid, anthocyanin contents and higher antioxidant activities compared with conventional extraction irrespective of solvents and rice varieties. Ultrasonic methanol (UM) extraction proved to extract significant higher content of all the compounds analyzed in both the rice varieties. In contrast, hot water (HW) extracts exhibited the lowest amount of bioactive compounds. However, there was no significant difference between methanol extraction alone and ultrasonic pretreatment with hot water extract on antioxidant contents for black glutinous rice. The contents of individual anthocyanins and flavonoids (cyanidin 3-O-glucoside, peonidin 3-O-glucoside, and quercetin) were significantly increased with ultrasonic pretreatment compare to the conventional method in black glutinous rice while failed to detect the red rice variety. The black glutinous rice contained significantly higher contents of all analyzed compounds and antioxidant activities than red rice. In conclusions, our results demonstrated that ultrasonic pretreatment significantly enhanced antioxidant extraction with higher activities compared with conventional extraction irrespective of solvents and rice varieties. Furthermore, the efficiency of ultrasonic together with hot water extraction was almost equal to methanol extraction which was the one effective solvent for extracting antioxidant.


2018 ◽  
Vol 8 (12) ◽  
pp. 561 ◽  
Author(s):  
Iyiola Oluwakemi Owolabi ◽  
Bandhita Saibandith ◽  
Santad Wichienchot ◽  
Chutha Takahashi Yupanqui

Background: Pigmented rice varieties are gaining interest due to their superior nutritional and phenolic properties compared to white rice varieties. With the rising risk of diabetes, cereals with higher protein contents should be consumed with rice. Adlay is one of the underutilized crops with higher protein contents and other functional properties. The germination process is one of the easy and innovative techniques for improving functional properties in seeds. In this study, two pigmented rice varieties and adlay seeds were soaked (24 h) and germinated for 12, 24, 36, and 48 h. The physicochemical properties, polyphenolic profiles, and the antioxidant activities of these samples were evaluated.Results: Purple rice (PR) demonstrated the highest values for polyphenolic contents, with 9 compounds detected for antioxidant activities. There were 6 compounds detected for red rice (RR). The adlay seeds had the least concentrations of phenolic compounds, with 6 compounds  and higher nutritional properties identified. New compounds were synthesized. Among the rice samples, 24 h soaking (S24) gave the best results for phenolic and antioxidant properties, with 24 h germination in adlay seeds. 48 h germination yielded better results for the nutritional values in all the samples.Conclusion: The present study demonstrates how the process of soaking is a cheap and less time-consuming process of improving bioactive compounds and antioxidant activities in pigmented rice varieties and adlay seeds. Keywords: polyphenols; antioxidant; pigmented rice; adlay; germination.


2010 ◽  
Vol 16 (4) ◽  
pp. 329-336 ◽  
Author(s):  
S. Butsat ◽  
S. Siriamornpun

This study was designed to investigate the free and bound phenolic acids as well as their antioxidant activities in husk of 12 Thai rice varieties consisting of pigmented rice and normal rice. The pigmented rice husk gave higher free total phenolic contents than normal rice husk. However, there was no significant difference in bound total phenolic contents between pigmented rice and normal rice husks. Ferulic and p-coumaric acids were the major phenolic acids in the free fraction of pigmented rice husks, whereas vanillic acid was the dominant phenolic acid in the free fraction of normal rice husks. On the other hand, p-coumaric acid was highly found in bound form of both pigmented and normal rice husks. The antioxidant activity of husk extracts was positively correlated with the total free phenolics content and individual of phenolic acids especially ferulic acid. On the basis of this study, it is suggested that the rice husk could be a potential phenolic acid source and may therefore offer an effective source of natural antioxidant. Our findings provide valuable information on phenolic acids composition and antioxidant activity of husk for further food application.


2007 ◽  
Vol 36 (5) ◽  
pp. 527-533
Author(s):  
Hye-Kyoung Han ◽  
Sung-Sook Choi ◽  
Jin-Chul Shin ◽  
Ha-Sook Chung

2015 ◽  
Vol 51 (1) ◽  
pp. 46-53 ◽  
Author(s):  
Ninnart Chinprahast ◽  
Teerapat Tungsomboon ◽  
Patlapa Nagao

2012 ◽  
Vol 77 (7) ◽  
pp. C759-C764 ◽  
Author(s):  
Hyun-Il Jun ◽  
Geun-Seoup Song ◽  
Eun-In Yang ◽  
Young Youn ◽  
Young-Soo Kim

Agriculture ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 167 ◽  
Author(s):  
Kifayatullah Kakar ◽  
Tran Dang Xuan ◽  
Saidajan Abdiani ◽  
Imran Khan Wafa ◽  
Zubair Noori ◽  
...  

Rice is an important staple food for Afghans. Its production has been increased, and attention is needed to improve grain quality. Experiments were conducted to evaluate the growth, yield, physicochemical properties, antioxidant activity, and morphological structures of four exotic rice varieties widely grown in Afghanistan (Attai-1, Jalalabad-14, Shishambagh-14, and Zodrass). Antioxidant activities, including 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), of rice grain were determined. A scanning electron microscopic observation was conducted on the cross-cut section of dehulled rice grains. The results showed a wide variation among four rice varieties for growth, grain yield, physicochemical properties, antioxidant activities, and morphology. Tiller and panicle number per hill, 1000-grain weight, grain yield, and antioxidant activities were found to be highest in Jalalabad-14. Attai-1 showed lower amylose, protein, and lipid contents with a high number of perfect grains, consequently enhanced taste point (score of quality). Grain yield, protein, and amylose contents showed a negative correlation with antioxidant activities. Accumulated structures in Attai-1, Shishambagh-14, and Zodrass were normal; however, Jalalabad-14 increased protein bodies and its traces in the amyloplasts. Information on yield potential, grain quality, and nutritional value of these exotic rice varieties may useful for sustainable food provision and nutritional improvement of rice in Afghanistan.


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