Storage stability of Jatropha curcas L. oil naturally rich in gamma-tocopherol

Abstract

29Jatropha curcas L. is an interesting tropical oil crop for biodiesel production. 30 However, seed conservation until oil extraction may be a problem under high 31 temperature and humidity. In this study, Jatropha curcas L. seeds grown in 32 Mozambique and presenting 160 mg/kg of gamma-tocopherol in their oil were 33 stored for 42 days, in dark, at 35ºC and 75 % or 92 % Relative Humidity (RH). 34Along storage, the oil was extracted and analysed in terms of fatty acid 35 composition, tocopherol content, acidity, initial and final oxidation products 36 (monitored by K232 and K270 values, respectively). 37Jatropha seeds presented an initial water content of 8.4 % and an oil content of 38 45.7 % (dry basis). The oil was rich in oleic (41.2 %) and linoleic (38.8 %) acids. 39Along 42 days of storage, the acidity increased from 0.8% to 7.4 % and 25.3 % 40 and K270 increased from 0.07 to 0.25 and 0.46 in oils from seeds stored at 75% 41 and 92% RH, respectively. Simultaneously, a decrease in gamma-tocopherol 42 content was observed, which was more pronounced at 92 % RH than at 75 % 43 RH (96 % decrease versus 57% decrease). Gamma-tocopherol showed to 44 protect the oil against oxidation principally during the second stage of oxidation. 45During the storage at 35ºC, the fatty acid composition of the oils from seeds 46 kept either at 75 % or 92 % of humidity, did not significantly vary throughout the 47 test. 48 49

Fatty acid profiles of species of Jatropha curcas L., Jatropha mollissima (Pohl) Baill. and Jatropha gossypiifolia L.

“…The results of fatty acids and oil content in J. curcas (Table 1) are similar to those disclosed in the literature (Rodríguez et al, 2011;Rodrigues et al, 2015). Earlier reports were not found for J. mollissima and J. gossypiifolia, which are non-breeding species adapted to semiarid environments.…”

Influence of HorseradishAmorica rusticanaL. and LovageLevisticum officinaleL. Extracts on the Stability of Rapeseed Oil

“…Unrefined rapeseed oil already contains compounds that are able to scavenge DPPH radicals. One of the most important scavenging compounds are tocopherols, found in most cold-pressed, fruit and nut oils, which act as a natural antioxidants and synergists (Rodrigues et al, 2015). The presence of these compounds may explain the high DPPH radical SA in the control sample at the beginning of the experiment.…”

Investigation of biologically active substances in horseradish and lovage = Mārrutku un lupstāju bioloģiski aktīvo vielu izpēte

“…Nerafinētas rapšu eļļas sastāvā jau ir savienojumi, kuri spēj saistīt DPPH radikāļus. Kā vienu no šādiem savienojumiem var minēt tokoferolu, kas ir sastopams lielākajā daļā auksti spiestu sēklu, augļu un riekstu eļļās, un tas var darboties kā dabīgais antioksidants, kura sinerģists visbiežāk ir askorbīnskābe (Rodrigues et al, 2015). Par tāda veida savienojumu klātbūtni varēja pārliecināties pētījuma gaitā, jo kontroles paraugam eksperimentu sākumā DPPH radikāļu sasaistīšanas aktivitāte bija 80,30% (3.22.…”