Effects of lyophilization on colorimetric indices, phenolics content, and antioxidant activity of avocado (Persea americana) pulp

Food Control ◽  
2021 ◽  
pp. 108526
Author(s):  
Vanessa Dal-Bó ◽  
José Teixeira Freire
2019 ◽  
Vol 157 (04) ◽  
pp. 342-349
Author(s):  
A. Weil ◽  
C. Sofer-Arad ◽  
Y. Bar-Noy ◽  
O. Liran ◽  
L. Rubinovich

AbstractA major drawback of avocado (Persea americanaMill.) is susceptibility to frosts, which reduces yields and limits its geographic distribution and market growth. Whereas the frost-susceptible cultivar ‘Hass’ leads the global avocado market, cv. ‘Ettinger’, although commercially less important, is considered frost-tolerant. The mechanism behind the greater frost tolerance of ‘Ettinger’ has not yet been elucidated; therefore, the aim of the current study was to evaluate the differences between the frost responses of the two cultivars. The results showed that detached ‘Ettinger’ branches had greater tolerance than ‘Hass’ to controlled frost stress. Tissue browning caused by methyl viologen oxidative cell damage, superoxide accumulation in leaf discs following wounding and browning of cut surfaces in branches were much lower in ‘Ettinger’ than in ‘Hass’, suggesting greater antioxidant activity (AA) in the former. In leaf extracts, AA was significantly higher in ‘Ettinger’ than in ‘Hass’, but osmolarity was similar in the two cultivars. Total phenolics content was significantly higher in ‘Ettinger’ but addition of a protein mask did not significantly reduce AA in either cultivar. Interestingly, following the freezing treatment, AA increased in ‘Ettinger’ and remained almost unchanged in ‘Hass’, while osmolarity was unaffected in either cultivar. These results suggest that the greater frost-tolerance of ‘Ettinger’ than ‘Hass’ is due largely to its greater AA, which springs mainly from a non-enzymatic source, i.e. accumulation of phenolic compounds. Based on the current study, future applications may be developed to minimize frost damage in avocado orchards.


2015 ◽  
Vol 13 (1) ◽  
Author(s):  
Wojciech Koch ◽  
Tomasz Baj ◽  
Wirginia Kukula-Koch ◽  
Zbigniew Marzec

AbstractThe determination of phenolic acids’ and flavonoids’ content in daily food rations (DFRs) of a selected group of male and female students and the development of chromatographic conditions is the primary goal of the study. The presence of 7 phenolic components were confirmed in the prepared extracts from all diets reconstructed within a period of 3 years. The highest concentrations were determined for hesperidin (124 and 55.6 mg for women and men, respectively), naringin (47.6 mg in female and 37 mg in male diets) and chlorogenic acid (19.7 and 19.8 mg for women and men). The antioxidant potential of the daily food rations, measured with a DPPH test, was higher for women (range 47.1‒78.8%) than for men (range 34.5‒78.0%) and was found to strongly correlate with the total phenolics content of the samples (Folin-Ciocalteu test) (correlation coefficient 0.90).


2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Aleksandra Wilczyńska ◽  
Joanna Newerli-Guz ◽  
Piotr Szweda

Bee honey is nutritious and has numerous health benefits, but its taste is for many people too bland. Honey with addition of spices could be important to the food industry as a functional product with positive health image and interesting taste. Such product would definitely meet health-driven consumers’ expectations. Therefore, the aim of this study was to evaluate the effect of addition of selected spices on sensory, antimicrobial, and antioxidant properties of honey. Results showed that the addition of spices significantly affected the taste and the smell of honey (p<0,05) and that honey with the cinnamon was the most desired and easily accepted product by the consumers. The addition of spices had no significant effect on texture and appearance. All tested samples showed the ability to inhibit the growth of bacteria and, contrary to the assumptions, the addition of spices did not cause an increase of antimicrobial activity. The results also showed that the kind and amount of added spice significantly affected the antioxidant activity: ability to scavenge free radicals and total phenolics content. The highest antioxidant activity revealed the honey with cinnamon and the lowest revealed the honey with cardamom addition.


Author(s):  
Ade Chandra Iwansyah ◽  
Rizal M. Damanik ◽  
Lilik Kustiyah ◽  
Muhammad Hanafi

<p><strong>Objective: </strong>The objectives of this research were to evaluate and compare the antioxidant activity; phenolics and flavonoids contents; and chemical composition of some galactopoietic herbs used in Indonesia and to find a possible relationship between antioxidant activity; phenolics, flavonoids and chemical composition of these plants.</p><p><strong>Methods: </strong>A wide range of analytical parameters was studied, including yield; pH; water activity (a<sub>w</sub>); total color difference; phenolics and flavonoids content; moisture; ash; protein; fat; carbohydrate; fiber; calcium; zinc; magnesium; potassium; iron content; and the data were analyzed by partial least squares (PLS) regression analysis and principal component analysis (PCA) to evaluate the correlation between the parameters and classification of the plants. Folin–cioceltaeu assay, aluminum chloride assay and DPPH scavenging assay were used to evaluate of total phenolics content and free radical scavenging activity of the ethanolic extract of galactopoietic herbs.</p><p><strong>Results: </strong>All of the galactagogue herbs, <em>viz</em>. <em>Plectranthus amboinicus </em>(Lour.) (PA), <em>Sauropus androgynus</em> (SA), <em>Moringa oleifera</em> (MO), and <em>Carica papaya</em> leaves (CP) exhibited good results of TPC, TFC and antioxidant activity. MO contained the highest average of total phenolics content (53.89 mg GAE/g). SA with a ratio of total flavonoids to total phenolics (TF/TP) which is 1.59 contained the highest average of total flavonoids and antioxidant activity (IC<sub>50</sub>), 43.63 mg QE/g and 126.13 μg/ml, respectively, followed by MO&gt;CA&gt;PA. Based on PLS and PCA analysis, antioxidant activity correlated with fat, protein, phenolics content, flavonoids content and pH, but only the total flavonoids content correlated strongly with antioxidant activity.<strong></strong></p><p><strong>Conclusion: </strong>This provides useful data about the studied relationships and chemical patterns in some galactopoietic herbs used and provides a helpful tool for understanding much more about the interpretation of results from the experiments and the mechanism of biosynthesis in plants.</p>


2021 ◽  
Vol 12 ◽  
Author(s):  
Deepak Kasote ◽  
Rhowell N. Tiozon ◽  
Kristel June D. Sartagoda ◽  
Hameeda Itagi ◽  
Priyabrata Roy ◽  
...  

Cereal grains and products provide calories globally. The health benefits of cereals attributed to their diverse phenolic constituents have not been systematically explored. Post-harvest processing, such as drying, storing, and milling cereals, can alter the phenolic concentration and influence the antioxidant activity. Furthermore, cooking has been shown to degrade thermo-labile compounds. This review covers several methods for retaining and enhancing the phenolic content of cereals to develop functional foods. These include using bioprocesses such as germination, enzymatic, and fermentation treatments designed to enhance the phenolics in cereals. In addition, physical processes like extrusion, nixtamalization, and parboiling are discussed to improve the bioavailability of phenolics. Recent technologies utilizing ultrasound, micro- or nano-capsule polymers, and infrared utilizing processes are also evaluated for their effectiveness in improving the phenolics content and bio-accessibility. We also present contemporary products made from pigmented cereals that contain phenolics.


2020 ◽  
Vol 145 ◽  
pp. 01005
Author(s):  
Yanqiu Shen ◽  
Wanling Zhang ◽  
Xiaohan Wei ◽  
Guihong Zhou ◽  
Hui Xia ◽  
...  

The polyphenolic of grape skins, pulps and seeds are potential source of natural antioxidant, which are receiving increased attention. In the present work, the total phenolics content (TPC), total flavonoids content (TFC), total flavanols content (TFAC), total anthocyanins content (TMAC) and antioxidant activity (DPPH, ABTS and FRAP) in different tissues of 4 table grapes cultivated in Chengdu plain, south of China, were investigated. In present study, expect TMAC was not be detected in seeds, and our results showed that seeds were the highest in polyphenolic content and antioxidant activity followed by skins, and then pulp. Besides, ‘Fenghou’ is richer in polyphenolic content than other three cultivars. Hence, ‘Fenghou’ extracts possesses higher free radical scavenging ability.


Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4695
Author(s):  
Mónica Cunha ◽  
Ana Lourenço ◽  
Susana Barreiros ◽  
Alexandre Paiva ◽  
Pedro Simões

Granulated cork was submitted to subcritical water extraction/hydrolysis in a semi-continuous reactor at temperatures in the range of 120–200 °C and with a constant pressure of 100 bar. The influence of temperature on the composition of the cork extracts obtained was assessed—namely, their content of carbohydrates and phenolics. The extraction yield increased with the temperature, and this was associated with the decrease in the dielectric constant of water and the increase in its ionic product. Extracts composed of up to 36% phenolics were obtained at temperatures of up to 120 °C, with an antioxidant activity only two times lower than that of pure gallic acid, but in low amounts. Assays at higher temperatures generated extracts richer in carbohydrates and with a phenolics content of ca. 20 wt.% in comparatively far higher amounts. Neither the amount of suberin nor its structure were affected by the subcritical water treatment.


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