Effect of Ultrasound-Assisted Extraction of Moringa stenopetala Leaves on Bioactive Compounds and Their Antioxidant Activity

Moringa stenopetala je višenamjenska biljka s izraženim nutritivnim i terapeutskim svojstvima. Svrha je ovoga rada bila ispitati utjecaj vremena i temperature ekstrakcije potpomognute ultrazvukom na izdvajanje bioaktivnih spojeve i antioksidacijsku aktivnost ekstrakta lista biljke M. stenopetala. Ekstrakcija je provedena pri temperaturama od 30, 40 i 50 °C tijekom 10, 20 i 30 minuta. Ispitan je i međusobni utjecaj vremena i temperature ekstrakcije na ukupne udjele fenola i flavonoida, antioksidacijsku aktivnost (mjerenu pomoću ABTS, DPPH i FRAP metoda) i sposobnost keliranja Fe2+ iona. Nakon 20 min ekstrakcije pri 40 °C dobiven je najveći udjel ukupnih fenola u suhoj tvari, izražen kao ekvivalent galne kiseline, i to 46,6 mg/g, te najveći udjel ukupnih flavonoida u suhoj tvari, izražen kao ekvivalent katehina, i to 20,4 mg/g. Pri istim je uvjetima izmjerena najveća antioksidacijska aktivnost ekstrakata, izražena kao ekvivalent Troloxa u suhoj tvari, i to 336,5 mg/g prema DPPH metodi, 581 ,8 mg/g prema ABTS metodi i 1 33,3 mg/g prema FRAP metodi. Sposobnost keliranja, izražena u ekvivalentima EDTA u suhoj tvari, bila je 28,4 mg/g. Najmanje bioaktivnih spojeva i najmanja antioksidacijska aktivnost opaženi su u ekstraktima dobivenim nakon 30 min pri 50 °C, te nakon toga u ekstraktima dobivenim pri nižoj temperaturi (30 °C) i kraćem vremenu trajanja (10 min). Morfološka je analiza ostataka dobivenih nakon ekstrakcije pomoću pretražnog elektronskog mikroskopa pokazala veća oštećenja strukture uzorka pri duljem vremenu ekstrakcije. Stoga je zaključeno da su temperatura od 40 °C i vrijeme ekstrakcije od 20 min optimalni za izdvajanje bioaktivnih spojeva iz lišća biljke M. stenopetala.Moringa stenopetala is a multipurpose plant having high nutritional and medicinal values. The aim of this study is to evaluate the effect of time and temperature of ultrasound-assisted extraction on bioactive compounds and antioxidant activities of M. stenopetala leaf extract. The ultrasound-assisted extraction took place at each of 30, 40 and 50 °C for 10, 20 and 30 min. The study also included the analysis of the interaction effects of time and temperature on the total phenolic content, total flavonoid content, antioxidant activity (ABTS and DPPH assay), FRAP and chelating activity. The highest total phenolic content, expressed in mg gallic acid equivalents per g dry mass, was 46.6 and total flavonoid content, expressed in mg catechin equivalents per g dry mass, was 20.4 at 40 °C for 20 min. Under the same conditions, the highest antioxidant activities evaluated by DPPH, ABTS and FRAP, expressed in mg Trolox equivalents per g dry mass, were 336.5, 581.8 and 133.3 respectively, and chelating activity, expressed in mg EDTA equivalents per g dry mass, was 28.4. The lowest amounts of bioactive compounds and antioxidant activities were observable when the extraction occurred at 50 °C for 30 min, followed by the extraction at lower temperature (30 °C) for shorter time (10 min). The morphological analysis of the residues obtained after extraction using scanning electron microscope indicated that there was a higher ultrasonic destruction of the structural components of the sample at longer extraction time. Therefore, ultrasound-assisted extraction at a temperature of 40 °C for 20 min is the best time-temperature combination to extract bioactive compounds from M. stenopetala leaves

African <em>Moringa stenopetala</em> Plant: An Emerging Source of Novel Ingredients for Plant-Based Foods

Moringa stenopetala is a multi-purpose tropical plant native to East Africa. The plant is exceptionally rich in nutrients and health-promoting bioactive compounds. It is among the top plants that could potentially feed the world and alleviate nutritional deficiencies. Moringa stenopetala is a versatile plant because its various parts, including leaves, seeds, flowers, pods, bark, and roots are useful to humans. Especially, the leaves and seeds are high in protein with all the essential amino acids. Based on the FAO database, M. stenopetala seed protein with its essential amino acid content stands highest among all commercial plant protein sources. Though it is a high-value plant and extensively used for food and traditional medicine by the local people in its native place, it is underutilized elsewhere. This chapter reviews recent research efforts that aim to unlock the potential of the plant as a source of ingredients for food, cosmetic and nutraceutical industries

Antihyperglycemic, Vasodilator, and Diuretic Activities of Microencapsulated Bioactive Product from Moringa stenopetala Leaves Extract

Moringa stenopetala has nutritional and medicinal values, which is widely used by the local communities. The study aimed to evaluate the antihyperglycemic, vasodilator, and diuretic activities of the microencapsulated bioactive product from M. stenopetala leaves extract. Microencapsulation of the extract was done by spray drying technique using maltodextrin and pectin as coating materials with the core: coating ratio of 1 : 6. Then, the antihyperglycemic, diuretic, and vasodilator activities were evaluated after the product was administered to experimental animals at different doses and compared with the control groups. There were no observed physical, behavioral, and physiological changes on the mice during the acute toxicity test. The results also indicated no toxicity signs and death occurrence in the experimental animals up to 5000 mg/kg administered dose. Therefore, microencapsulated M. stenopetala leaves extract does not produce adverse effects in experimental mice. The study also showed that the microencapsulated bioactive product exhibited significant antihyperglycemic, vasodilator, and diuretic activities as the doses increase. Therefore, the study showed that microencapsulated bioactive product has significant medicinal values. Further detailed studies are recommended on chronic toxicity tests and to understand the possible mechanism of actions on the antihyperglycemic, vasodilator, and diuretic activities of the microencapsulated product