Green non-conventional techniques for the extraction of polyphenols from agricultural food by-products: A review

2021 ◽  
pp. 462295
Author(s):  
Imma Pagano ◽  
Luca Campone ◽  
Rita Celano ◽  
Anna Lisa Piccinelli ◽  
Luca Rastrelli
Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 357
Author(s):  
Jianjun Zhou ◽  
Beatriz Gullón ◽  
Min Wang ◽  
Patricia Gullón ◽  
José M. Lorenzo ◽  
...  

Food by-products contain a remarkable source of bioactive molecules with many benefits for humans; therefore, their exploitation can be an excellent opportunity for the food sector. Moreover, the revalorization of these by-products to produce value-added compounds is considered pivotal for sustainable growth based on a circular economy. Traditional extraction technologies have several drawbacks mainly related to the consumption of hazardous organic solvents, and the high temperatures maintained for long extraction periods which cause the degradation of thermolabile compounds as well as a low extraction efficiency of desired compounds. In this context, supercritical fluid extraction (SFE) has been explored as a suitable green technology for the recovery of a broad range of bioactive compounds from different types of agri-food wastes. This review describes the working principle and development of SFE technology to valorize by-products from different origin (marine, fruit, vegetable, nuts, and other plants). In addition, the potential effects of the extracted active substances on human health were also approached.


Author(s):  
Kusum Kumari

<p><em>After independence in 1947, the Government of India started organized plan for the development of the country. Visible impact was not felt during the 1<sup>st</sup> plan period. Regular famine, division of country created a situation where supply of food to country men was a major problem before the Government. According during the  second five year plan emphases  was given on the development of agriculture and animal husbandry sectors. The second five year plan started in 1956. An outlay of Rs 56 crores was provided by the Government of India for development of animal husbandry and dairying. The object of animal husbandry programme was to supply milk, meat and eggs in order to balance the customary Indian diets and to provide bullock power for agricultural operations.</em></p><p><em>           </em></p><p><em>In addition to by Products of agricultural food crops,  residuesgrazing areas had been the main stay for cattle. Increase in the requirements of agriculture land for food production for the human population, development of industries road &amp; buildings grazing areas have steadily diminished. Cattle raising had to undergo a basic change in the sense that its future would depend on mixed farming system. Most of the fodder have to be grown on the holding of the farmers.</em></p>


1997 ◽  
Vol 161 ◽  
pp. 179-187
Author(s):  
Clifford N. Matthews ◽  
Rose A. Pesce-Rodriguez ◽  
Shirley A. Liebman

AbstractHydrogen cyanide polymers – heterogeneous solids ranging in color from yellow to orange to brown to black – may be among the organic macromolecules most readily formed within the Solar System. The non-volatile black crust of comet Halley, for example, as well as the extensive orangebrown streaks in the atmosphere of Jupiter, might consist largely of such polymers synthesized from HCN formed by photolysis of methane and ammonia, the color observed depending on the concentration of HCN involved. Laboratory studies of these ubiquitous compounds point to the presence of polyamidine structures synthesized directly from hydrogen cyanide. These would be converted by water to polypeptides which can be further hydrolyzed to α-amino acids. Black polymers and multimers with conjugated ladder structures derived from HCN could also be formed and might well be the source of the many nitrogen heterocycles, adenine included, observed after pyrolysis. The dark brown color arising from the impacts of comet P/Shoemaker-Levy 9 on Jupiter might therefore be mainly caused by the presence of HCN polymers, whether originally present, deposited by the impactor or synthesized directly from HCN. Spectroscopic detection of these predicted macromolecules and their hydrolytic and pyrolytic by-products would strengthen significantly the hypothesis that cyanide polymerization is a preferred pathway for prebiotic and extraterrestrial chemistry.


Author(s):  
Sumio Iijima

We have developed a technique to prepare thin single crystal films of graphite for use as supporting films for high resolution electron microscopy. As we showed elsewhere (1), these films are completely noiseless and therefore can be used in the observation of phase objects by CTEM, such as single atoms or molecules as a means for overcoming the difficulties because of the background noise which appears with amorphous carbon supporting films, even though they are prepared so as to be less than 20Å thick. Since the graphite films are thinned by reaction with WO3 crystals under electron beam irradiation in the microscope, some small crystallites of WC or WC2 are inevitably left on the films as by-products. These particles are usually found to be over 10-20Å diameter but very fine particles are also formed on the film and these can serve as good test objects for studying the image formation of phase objects.


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