Influence of the physical structure of irradiated starches on their electron spin resonance spectra kinetics

The ESR spectroscopic features and kinetics of the radiation-induced free radicals in maize (Zea mays L.)

“…Radical II results from the action of gaseous oxygen on the radicals deriving from the break of the glycosidic link (Miyoshi, Matsui, & Washida, 1990;Raffi & Agnel, 1983). Radicals I and II are expected to exhibit hyperfine splitting due to the hydrogen atoms attached to C(2), C(4), C(1) and the OH proton.…”

“…Many research groups have reported the depolymerizing effects of gamma and electron irradiation on cereals and starches from different foodstuffs through post-irradiation study of radicals using ESR technique (Adem et al, 1993;Dadayli, S€ unnetc ßioglu, K€ oksal, & C ß elik, 1997;Duarte & Rupnow, 1993;Munoz, Adem, Burillo, Gleason, & Murrieta, 1994;Murrieta et al, 1996;Raffi & Agnel, 1983;Raffi, Agnel, & Kassis, 1987;Raffi, Agnel, Thiery, Frejaville, & Lebe, 1981). However, due to the complex nature of the phenomena, correct assignments and characterizations of these radicals are very difficult and, thus, the results given in the literature contain ambiguities.…”

“…However, due to the complex nature of the phenomena, correct assignments and characterizations of these radicals are very difficult and, thus, the results given in the literature contain ambiguities. Therefore, more detailed investigations, especially those related to stability of the radicals at different temperatures are needed, as the information on these properties is very limited in the literature (Adem et al, 1993;Munoz et al, 1994;Murrieta et al, 1996;Raffi & Agnel, 1983). In all these studies analyses were based on the signal intensity decay data at one or two different temperatures obtained for samples irradiated at room temperature without performing any spectrum simulation calculation yielding to the determination of spectroscopic features of the radical species involved in the formation of the experimental ESR spectra.…”

Analytical methods for post-irradiation dosimetry of foods (Technical Report)

“…Since the ultimate fate of the radicals depends on their ability to move into a position for bimolecular reaction, factors that alter their environment, such as water activity, predetermine the pathways for decay and hence, the lifetime. Indeed, the half life of free radicals produced in irradiated, solid foods decreased with an increase of the humidity in the system (Diehl 1972, Fritsch and Reymond 1970, O'Meara and Shaw 1957, Raffi and Agnel 1983, Uchiyama and Uchiyama 1979.…”

Análise físico-química e microbiológica por método moleular, de pratos prontos radapertizados para suprimentação alimentar de imunodeprimidos

“…A dispersão de íons e radicais livres é maior na forma líquida e menor em produtos secos ou congelados (RAFFI; AGNEL, 1983). Quando a água está congelada, radicais livres tendem a recombinar formando a substância original, porque a difusão é reduzida, limitando o seu acesso a outros componentes de alimentos (TAUB et al, 1978).…”