Effect of gamma irradiation and pyrolysis on indigestible fraction, physicochemical properties, and molecular structure of rice starch

Abstract

Processing starch into resistant starch has many benefits for human health and the food industry. It has been demonstrated that resistant starch (RS) is not hydrolyzed by the amylase enzyme, so it is not absorbed through the small intestine. This has contributed to significantly reducing energy supply to the body without increasing blood sugar. Therefore, the RS has been considered as an essential nutrient to human, especially for obesity, diabetes, and cardiovascular diseases (Homayouni et al., 2013;Cao et al., 2018). Moreover, RS, used as a staple ingredient in many diets and healthy foods exhibits an excellent dietary fiber with superior properties (Yangilar, 2013;Yang et al., 2020).As a proof of concept, resistant starch is classified into five types, in which resistant dextrin (RD) and resistant maltodextrin (RMD) reside to Type-4 as partly hydrolysed starch (Yangilar, 2013). RMD product such as Fibersol-2 or Nutriose has been commercially produced by two important steps: pyrolysis and enzymatic hydrolysis

Gamma radiation modification of cassava starch and its characterization

“…Figure 2 shows the AAC of the irradiated cassava starches as a function of radiation dose. Similar to rice starch in our previous study, [21] gamma irradiation significantly reduced AAC of cassava starch. The apparent amylose of about 21.69% in initial cassava starch decreased to 21.09% by irradiation at 1 kGy, the decrease F I G U R E 1 Scanning electron microscopy (SEM) images of initial cassava starch (A), and the starches irradiated at 1 (B), 2.5 (C), 5 (D), 7.5 (E), and 10 kGy (F) is higher at higher dose, that is, to 17.63% in the starch irradiated at 10 kGy.…”

“…However, the bands were not shifted to higher wavenumber as observed with rice starch as indicated in our previous study. [ 21 ]…”

“…However, the bands were not shifted to higher wavenumber as observed with rice starch as indicated in our previous study. [21] 3.7 | Thermal stability of the irradiated starch Pyrolysis processes of non-irradiated and irradiated starches were analyzed by thermogravimetric analysis (TGA) as the functions of heating temperature (Figure 9). All samples revealed an initial weight loss of about 10% under 130 C, due to loss of water.…”

“…For example, amylose and amylopectin molecules are broken into smaller fragments with low molecular weight, reduced viscosity, and improved solubility by radiation degradation. Gamma irradiation in the range of 5–50 kGy reduced the apparent amylose content (AAC) in rice starch, [ 21 ] while molecular weight distribution of amylose and amylopectin was significantly changed by both gamma and electron beam (EB) irradiation, specifically there was an increase in amylopectin‐like fractions as observed with corn starch. [ 22 ] However, the high dose irradiation may reduce the stability of starch paste, and promote its retrogradation.…”

Microbial Control in the Primary Packaging of Pills Using Ionizing Radiation and Its Effect on Characteristic Constituents for Quality Control in Irradiated Pills

“…Alcohols, including sugars, cause a hydrogen abstraction reaction by irradiation, which occurs at the carbon bearing hydroxyl group, and forms a hydroxylalkyl radical [27]. It has been reported that the main chain of polysaccharides, including cellulose or starches, is cleaved by ionizing radiation [28][29][30]. In the future, the physicochemical influence of additives by irradiation should be investigated, including disintegration tests for pills.…”