Optimization of preconditioning process of pressure parboiled brown rice (unpolished) for microwave puffing and its comparison with hot sand bed puffing

Abstract

Puffing of pre‐conditioned brown rice using microwave energy replacing the traditional puffing of preconditioned polished rice on hot‐sand‐bed has higher nutritive value and produce required amount of puffed rice as per consumer's wish. Preconditioning temperatures (60, 70, 80, 90 °C) and salt contents (0, 2, 4, 6% [w/w]) have been chosen to puff brown rice using microwave energy, and quality aspects have been evaluated and compared with those obtained with hot‐sand‐bed puffing. Optimization of processing variables was carried out for maximizing puffing percentage, expansion ratio, whiteness index, overall sensory score, and minimizing the bulk density and hardness of puffed brown rice. The sensory analysis for the product was carried out using fuzzy logic technique to obtain overall sensory score. Optimum preconditioning temperature and salt content were found to be 76.74 C and 3.74% (w/w) in microwave and 76.16 C and 2.76% (w/w) in hot‐sand‐bed puffing, respectively. Practice applications Puffing of brown rice (unpolished rice) using microwave oven provides an option in obtaining nutritious, fresh and hygienic puffed product on instant demand. Puffing of brown rice eliminates the energy‐intensive polishing step of the rice milling process. Optimization of the process variables can be implemented for making preconditioned brown rice in obtaining desired quality of the puffed rice using microwave energy. The prepacked preconditioned rice can be directly put inside the domestic microwave oven to get required amount of puffed product.

Optimization of pressure parboiling conditions and pre-conditioned moisture content of brown rice (unpolished rice) for microwave puffing and its comparison with hot sand bed puffing

“…However, microwave puffing is a recent development in this aspect (Maisont & Narkrugsa, 2009). Puffed unpolished rice is receiving more interest than puffed polished parboiled rice because of the excellent health beneficial properties of the bran D Desirability (Mir, Bosco, Shah, & Mir, 2016;Swarnakar, Srivastav, & Das, 2019). Rice bran is a good source of vitamins, minerals, fibre, protein and fat (Gul, Yousuf, Singh, Singh, & Wani, 2015).…”

Sorption isotherms of ready‐to‐puff preconditioned brown rice: Development of classical models and artificial neural network approach

“…The three‐dimensional surface plots obtained by fitting experimental data in the second‐order model representing the interaction of MC– T , MC–SC, and SC– T are exhibited in Figure a–c. The third variables SC, T , and MC bore the values 2%, 25°C, and 11%, respectively (Joshi et al, ; Swarnakar et al, ). It can be inferred from the figures that a w of the samples are largely dependent on T .…”

“…MC is the major parameter that affects the final quality of puffed rice. The efficiency of puffing of rice depends on the MC, salt concentration (SC), nature of salt, and concentration of salts diffused into the kernel (Joshi, Mohapatra, Joshi, & Sutar, 2014;Swarnakar et al, 2019).…”

“…The three-dimensional surface plots obtained by fitting experimental data in the second-order model representing the interaction of MC-T, MC-SC, and SC-T are exhibited in Figure 4a-c. The third variables SC, T, and MC bore the values 2%, 25 C, and 11%, respectively (Joshi et al, 2014;Swarnakar et al, 2019). It can be inferred from the figures that a w of the samples are largely dependent on T. An increase in T leads to an increase in a w for given MC (Figure 4a), and this can be due to the excitation and mobility of water molecules caused by an increase in T. This F I G U R E 5 MSI curves obtained by fitting experimental data with different models at different SC at 20 C. MSI, moisture sorption isotherm; SC, salt concentration activation causes water molecules to break away from the waterbinding sites, thus lowering the EMC (Wani & Kumar, 2016).…”

“…Puffed rice is commonly used as ready‐to‐eat breakfast cereals, infant foods, and snack products. Preconditioning of rice is the most crucial factor for obtaining good quality puffed rice (Mir, Bosco, Shah, & Mir, ; Swarnakar, Srivastav, & Das, ). This preconditioning process comprises uniform and slow heating of moisture–salt‐conditioned parboiled rice with continuous turning until the optimum moisture content (MC) of puffing (11%) is attained.…”