scholarly journals Improvement of Thanaka Powder by Gamma Radiation: Microbial and Chemical Properties

Author(s):  
Wachiraporn Pewlong ◽  
Surasak Sajjabut ◽  
Sirilak Chookaew ◽  
Jarurattana Eamsiri ◽  
Khemruji Khemthong ◽  
...  

Thanaka powder is made from the stem bark of the Hesperethusa crenulata plant. Most Burmese women use it on the skin of the face as sun protection, a moisturizing agent and acne treatment. For a hygiene purpose, gamma radiation is currently used to control microorganisms and insect contamination in many products. In this experiment, the the effects of gamma radiation on the microbial numeration, total phenolic content, antioxidant activity, and chemical constituent alterations in Thanaka powder were investigated. Gamma irradiation was applied to powder samples at 5, 10, 15 and 20 kGy. The total bacterial count and total yeast and mold count were decreased with increasing irradiation dose. Gamma irradiation at a dose of 5 kGy was sufficient to reduce the microbial load in the powder to meet the standards of microbial quality for cosmetic products in Thailand. No significant change in the DPPH activity of the Thanaka powder was observed after irradiation. Additionally, the radiation process caused significant increases in total phenolic content, FRAP value and arbutin content. At a dose of 20 kGy, the total phenolic content, FRAP value and arbutin content were significantly higher than the non-irradiated Thanaka powder at 7.45, 9.59 and 16.04%, respectively.

Food Research ◽  
2021 ◽  
Vol 5 (6) ◽  
pp. 172-177
Author(s):  
B. Yudhistira ◽  
N.A. Choiriyah

Roselle contains high phenolic compounds, mainly anthocyanins that are not stable with pH, metal ions, light exposure, temperature, oxygen, and enzymatic activity. The stability of phenolic compounds can be improved by nanoencapsulation. This research was aimed to evaluate the effect of inulin, inulin-chitosan and inulin-chitosan-maltodextrin with varying concentrations as encapsulants towards the physicochemical properties and encapsulation efficiency of nanocapsules product by spray drying. Roselle extract nanocapsules were prepared using various types and concentrations of encapsulants (inulin, inulin-chitosan and inulin-chitosan-maltodextrin). The solubility of nanocapsules ranged from 69.31 - 83.2%, while the hygroscopicity of nanocapsules was varied, approximately 17.89 - 23.79%. Nanocapsules moisture content was approximately 2.83 - 4.27%, while the total phenolic content of nanocapsules ranged from 6.74 - 13.41 mg GAE/g DW. The total anthocyanin of roselle extract nanocapsules was approximately 2.25 - 4.82 mg/g DW. The encapsulation efficiency of phenolic compounds in this study were approximately 60.31 - 77.13%. Nanocapsules with inulin-chitosan-maltodextrin (2.4%-2.4%-0.2%) had good properties of nanocapsules such as good solubility, high total phenolic content and total anthocyanin content. Nanocapsules with 5% inulin and inulinchitosan-maltodextrin (2.4%-2.4%-0.2%) had particle size of 641.4 and 411.1 nm respectively. The nanocapsules had a spherical shape, smooth surfaces but also a few had indentations.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Nii Korley Kortei ◽  
George Tawia Odamtten ◽  
Mary Obodai ◽  
Victoria Appiah ◽  
Felicia Akuamoa ◽  
...  

Dried Pleurotus ostreatus mushrooms stored in polythene and polypropylene packs were exposed to gamma radiation from a cobalt-60 source at doses of 0, 0.5, 1, 1.5, and 2 kGy at a dose rate of 1.7 kGy/hr and stored for a period of 1 month. Total phenolic contents, flavonoids, and free radical scavenging activity DPPH (2,2′-diphenyl-1-picrylhydrazyl) were determined using aqueous, ethanol, and methanol extracts by Folin-Ciocaultaeu method as a source of potential natural antioxidants. Total phenol content ranged 0.56 ± 0.01–10.96 ± 1.7 mg/GAE, flavonoids ranged 1.64 ± 0.05–8.92 ± 0.6 mg/QE, DPPH radical scavenging activity also ranged 7.02 ± 0.10–13.03 ± 0.04%, and IC50 values also ranged 0.08–0.16 mg/mL. Statistical differences (P < 0.05) were recorded for the extracts and the treatment doses of mushrooms stored in polythene and polypropylene packs. A significant linear correlation was confirmed between values for the total phenolic content and antioxidant activity of mushroom extracts. The high contents of phenolic compounds indicated that these compounds contribute to high antioxidant activity. Pleurotus ostreatus can be regarded as a promising candidate for natural mushroom sources of antioxidants with high value. The use of low dose gamma radiation by the local food industry could improve the hygienic quality, extend shelf-life, and preserve nutrients and antinutrients.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Afrizal Itam ◽  
Mutia Siska Wati ◽  
Vina Agustin ◽  
Nursal Sabri ◽  
Rafika Aris Jumanah ◽  
...  

Syzygium aqueum, consisting of various fruit colors, is one of the plants that have been used as traditional medicine. This study aims to evaluate and compare phytochemical, antioxidant, and cytotoxic activities and total phenolic content of leaves and stem bark extracts of S. aqueum with pink and red fruits, in order to identify the best extract that can be used as a natural antioxidant. Phytochemical constituents were evaluated qualitatively using chemicals, while cytotoxic activities were identified using the brine shrimp lethality test. Total phenolic content was determined via the Folin–Ciocalteu method. Leaves and stem bark of S. aqueum contained flavonoids, phenolics, and triterpenoids, but the stem bark also contained saponins and alkaloids. Methanol and ethyl acetate extracts of leaves and stem bark were categorized as very powerful antioxidants to DPPH (IC50 9.71–38.69 μg/mL) and hydrogen peroxide (IC50 16.44–44.02 μg/mL), while hexane extracts were inactive. Methanol, ethyl acetate, and hexane extracts of leaves and stem bark were categorized as moderately cytotoxic to A. salina larvae (LC50 104.04–440.65 μg/mL). Comparing leaves and stem barks, antioxidant and cytotoxic activities of stem bark extracts were higher than those of leaves extracts. Total phenolic content of leaves extracts was higher than that of stem bark extracts where the order of total phenolic content progressed from methanol extracts > ethyl acetate extracts > hexane extracts. Therefore, the stem bark of S. aqueum was identified as the better source of natural antioxidant compared with the leaves.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Emmanuel M. Halilu ◽  
Abdullahi M. Abdurrahman ◽  
Sylvester N. Mathias ◽  
Chinenye J. Ugwah-Oguejiofor ◽  
Muntaka Abdulrahman ◽  
...  

Abstract Cadaba farinosa is used in traditional medicine for treatment of cancer, diabetes, and rheumatism. The research was aimed at evaluating the phytochemical and antioxidant activity of the extracts. The powdered stem bark was extracted successively with the aid of Soxhlet extractor using n-hexane, ethyl acetate, and methanol. The resulting extracts were concentrated on rotary evaporator and the percentage yields were calculated. The phytochemical and TLC profiles of the extracts were studied. The antioxidant activity of the extracts and ascorbic acid (standard) were determined using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical assay. The total phenolic content of the extracts and tannic acid (standard) were evaluated using Folin–Ciocalteu reagent. The percentage yields of n-hexane, ethyl acetate, and methanol extracts were found to be 1.19, 1.37, and 13.93%, respectively. The phytochemical screening revealed the presence of tannins, flavonoids, saponins, cardiac glycosides, alkaloids, and triterpenoids. The TLC profiles of the extracts revealed the presence of compounds as evidenced from their R f values. The total phenolic content of ethyl acetate and methanol extracts were found to be 135 and 112 mg, respectively. The free radical scavenging activity demonstrated by the extracts was comparable to ascorbic acid. The ethyl acetate extract had higher phenolic content and demonstrated the highest free radical scavenging with IC50 31.07 mg/mL. The results of research have provided strong preliminary evidence of antioxidant activity which may be because of phenolic compounds in the extracts.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Nadia Hidar ◽  
Abdelhamid Noufid ◽  
Ayoub Mourjan ◽  
El Mustapha El Adnany ◽  
Safa Mghazli ◽  
...  

The effect of freeze-drying and gamma irradiation at 0.5, 1, and 2 kGy on the physicochemical composition (moisture, fat, ash, mineral, and chlorophyll contents), microstructure, total phenolic content, and antioxidant capacity of stevia leaves was investigated in the present study. The results obtained indicated that freeze-drying and gamma irradiation treatments caused significant reduction ( p  ≤ 0.05) of moisture and fat contents in comparison with those of commercial leaves, while ash content was not significantly affected. Mineral composition was analysed. Among the analysed elements, potassium and iron levels were higher in the freeze-dried and irradiated samples, respectively. The microstructure was analysed using a scanning electron microscope. Micrographs revealed that a higher porous size structure was obtained by freeze-drying, and degradation of cell wall structure was more clearly visualized by irradiation at 2 kGy. However, the main functional groups were stable as confirmed by Fourier transform infrared spectroscopy analysis. The effects on chlorophyll content, phenolic profile, and antioxidant properties were evaluated before and after ten months of storage. In terms of chlorophyll contents, the freeze-dried leaves exhibited the highest content. Chlorophylls a and b decreased when storage progressed for freeze-dried leaves as well as for gamma-irradiated leaves. Both preservation methods gave significant advantages in increasing the total phenolic content and DPPH scavenging activity. Moreover, a significant increase of bioactive compounds and antioxidant activity was observed as the gamma irradiation dose increased. In addition, the storage time increased the amounts of polyphenols and DPPH scavenging activity. After 10 months of storage, gamma-irradiated leaves had the highest total phenolic content as well as the DPPH scavenging activity followed by freeze-dried leaves. The results indicate that freeze-drying and gamma irradiation at the studied doses could be effective postharvest methods for preservation of stevia leaf quality.


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