**Author details**

**5. Concluding remarks and future perspectives**

64 Applications of Modified Starches

a typical pattern behavior of a specific starch property.

tional properties of starch, mainly due to the degradation process.

The great volume of results published in the last decade indubitably proved that the ionizing radiation (gamma rays and electron beam) is able to produce changes in structural and func-

The radiation-induced effects are related to depolymerization of starch macromolecule followed by the reduction of molecular weight as well as the alteration of the double helix in the branched regions and crystalline structure, especially in the intrusion area of the amorphous region in the crystalline structure. Consequently, irradiation induces generally reconfiguration of starch molecules which lead to the reduction of crystallinity degree, shifts and decrease of spectral bands, and changes of thermal parameters. The general trend of decreasing for viscosity and swelling power concomitantly with the increasing of water solubility by irradiation makes the irradiated starches able to meet the specific needs in different new applications.

It is important to note that a number of factors related both to starch and ionizing radiation processing plays a major role in dictating the response of granular starch to ionizing radiation (**Table 4**). Taking into account this aspect, the comparison of properties among the irradiated starches should attentively be performed due to the differences in methodologies of ionizing radiation treatments and in composition and structure of starches. In other words, the random approaches of ionizing radiation processing of starch extracted from various botanical sources can lead to various results making difficult their comparison and the identification of

Further studies should systematically focus on the response (physicochemical and structural properties) of each type of starch having different moisture content exposed to ionizing radiation (gamma rays and/or electron beam) in a large range of irradiation dose rate and different gas atmospheres. Studies on the major starch components, amylose and amylopectin, extracted from different native starches and subsequently exposed to ionizing radiation can be useful to validate observations on starch, leading to advancements in this research area.

Another issue that must be carefully explored is related to the investigation of thermal properties by DSC since nowadays the available reports showed a large variability of results with-

It is also opportune to make deeper chromatographic studies on the molecular weight and mass distribution of irradiated starch, especially as the chromatographic technique has developed spectacularly in recent years. The comprehensive evaluation of the dynamics of molecular mass distribution of irradiated starch will provide new relevant knowledge, contributing to a better

out consistent correlations with other structural investigated properties of starch.

**Starch factors Ionizing radiation processing**

Type of starch (botanical source) Irradiation dose Variety of starch (cultivar) Dose rate

**Table 4.** Factors influencing the response of starch to ionizing radiation processing.

Water content Type of gas atmosphere

Mirela Brașoveanu and Monica-Roxana Nemțanu\*

\*Address all correspondence to: monica.nemtanu@inflpr.ro

National Institute for Lasers, Plasma and Radiation Physics, Electron Accelerators Laboratory, Bucharest-Măgurele, Romania
