Parboiled obtainment

Jayasekera and Freitas were the first to investigate the content of 24 chemical elements in rice grain and flour from Sri Lanka [19]. The purpose of their study was to compare the data obtained with the maximum permissible levels prescribed by international guidelines. Determinations were made by means of INAA with k0 standardization. The rice samples were collected from local markets and were representative of two major varieties, raw polished and parboiled rice. Prior to analysis, samples were freeze-dried and ground to fine powder. The CRM IAEA V-8 rye flour was used to check the accuracy of experimental... 

Sample Collection Ten rice samples of Italian origin (five of which were parboiled) and 11 samples from Asian countries were obtained from Italian retailers. The Asian samples were from China (three), Thailand (two), Bangladesh (two), Sri Lanka (one), India (one), Pakistan (one), and Philippines (one). 

For the essential elements, higher concentrations were found in Asian rices, even though, in both cases, their levels are comparable with those obtained in previous studies [10, 42]. The observed ranges of concentration for Asian and Italian samples, expressed in nanograms per gram, are respectively as follows Co, 4-26 and 4-14 Cu, 1015-3005 and 961-2291 Fe, 1893-9949 and 1363-3673 Mn, 5505-17,612 and 3544-11,371 Zn, 6762-20,337 and 5977-18,574. In more detail Mn and Zn levels in parboiled Italian rice (see Table 12.2, rice varieties 5 through 9) were lower than in Asian rice, which may be a consequence of... 

FIGURE 28.16 Pasting property of parboiled paddy obtained from conventional parboiled rice production process and that of parboiled paddy obtained from superheated steam drying process. (From Soponronnarit, S. et al.. Drying TechnoL, 24, 1457, 2006.)... 

White rice, in comparison to rough or brown rice, is low in vitamin content (cf. Table 15.38) and in minerals. A nutritionally improved product may be obtained by a parboiling process, orginally developed to facilitate seed coat removal. About 25% of the world s rice harvest is treated by the following process raw rice — steeping in... 

Rice hulls are rich in cellulose, lignin, and silica and have low nutritional value even for ruminants (Chapter 18). As a result, rice hulls are usually used for combustion-pyrolysis in rice mills and parboiling plants. The hulls are less efficient than coal in terms of energy released and produce more ash, which requires a more sophisticated grating system. Hulls are also used as poultry litter, although other litters are considered to be of better quality. The pure silica obtained from rice hulls is used to produce solar cells and microchips. 

Parboiled rice Rice obtained after parboiling and milling rough rice. The white parboiled kernels are harder and, upon cooking, produce less stickiness. 

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