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This research explored the impact of in-vivo oral processing on the bolus properties of three rice varieties [white ponni (WP), mappillai samba (MS), and basmati (B)] that were selected based on variations in the amylose content. The amylose and dry matter content of the WP, MS, and B were 4.67, 7.48, and 13.8(%) and 69.57, 60.09, and 70.47(%), respectively. Mastication features (bite-size, chewing time, and chew cycles), bolus properties (particle size distribution, bolus moisture content, rheology, and starch hydrolysis), time-dependent bolus features (rate of incorporation of saliva and saliva content) and, temporal dominance of sensation (TDS) of cooked rice were studied. Results confirmed the significance of oral processing on various bolus characteristics. Moreover, a pronounced correlation between the morphology of rice varieties and mastication features was observed. The structure and textural characteristics of the different rice varieties (MS, WP, B) showed considerable effects on the consumption time (25.7 s, 22.2 s, 17.8 s) and chewing cycles (34, 31, 23). Rate of saliva incorporation was relatively lesser for MS as compared with WP and B. Solid loss followed the trends WP > MS > B. The total starch content of cooked rice boluseswas WP (82.69 ± 0.01%), MS (79.49 ± 0.01%), and B (71.74 ± 0.01%). Further, texture – TDS and flavor – TDS of all varieties were found to be strongly dependent on textural attributes, composition, and oro-sensory perception. This study provides a significant understanding of the oral processing behavior of rice and its bolus, considering the effect of variations in amylose content, texture, and morphology.

The effect of open steaming (HS) and pressure (PP) parboiling on the physicochemical characteristics and glycemic index (GI) of five different Indian rice varieties with varying amylose contents was investigated. Results showed that the severity of processing had a significant effect on the physicochemical properties of rice. PP resulted in reduced whiteness (18.83 ± 0.66 to 26.03 ± 1.27%), increased transparency (1.64 ± 0.05 to 2.05 ± 0.08%), hardness (6.66 ± 0.63 to 7.82 ± 1.19 kg) and equilibrium moisture content (117.59 ± 11.37 to 183.69 ± 39.46%db). PP rice also showed higher cooking time (40.28 ± 0.35 to 59.31 ± 0.69 min), water absorption ratio (4.52 ± 0.06 to 5.23 ± 0.04), and sedimentation volume than HS and non-parboiled counterparts. An increase in parboiling temperature significantly affected the pasting profiles of rice flour. Among the treated samples, the degree of gelatinization was higher for PP rice (70.80 ± 6.83 – 85.24 ± 1.48%). Alkali spreading value explained the lower gelatinization temperature for parboiled rice as compared with the non-parboiled counterpart. Higher amylose content of rice was associated with lower GI values and parboiled rice had a significantly lesser GI. The findings of this study provide insights on rice parboiling methods, particularly for the diabetic population.

The effect of the physicochemical properties on the digestion behavior of rice was evaluated using the artificial stomach response kit (ARK®). Due to the presence of the external bran layer, brown rice (Rv3) showed delayed rates of gastric emptying, apart from a higher half emptying time (101.80 ± 1.20 min) than milled rice (Rv1 - 57.84 ± 7.49 min) and basmati rice (Rv2 - 77.93 ± 10.18 min). The bran layer of Rv3 inhibited the diffusion of the simulated gastric fluid and resulted in lesser particle breakdown and low glycemic index (GI). In comparison with the shaker digestion process, the mechanical force produced in the ARK® resulted in a higher degree of particle breakdown. An in silico approach successfully predicted the glucose response pattern of rice varieties with no statistical difference (at p< 0.05) with the human in vivo datasets using the output obtained from ARK®. The GI obtained from ARK® was validated with in vivo data using Bland Altmann’s statistical tool which showed good agreement. The morphology, dimensions, capacity of the stomach chamber in the ARK® also resembled in vivo observations. The ARK® is proposed as an improved alternative for in vitro digestion studies.

Rice is an important starchy staple food and generally, rice varieties are known to have a higher glycemic index (GI). Over the years, the significance of GI on human health is being better understood and is known to be associated with several lifestyle disorders. Apart from the intrinsic characteristics of rice, different food processing techniques are known to have implications on the GI of rice. This work details the effect of domestic and industrial-level processing techniques on the GI of rice by providing an understanding of the resulting physicochemical changes. An attempt has been made to relate the process-dependent digestion behavior, which in turn reflects on the GI. The role of food constituents is elaborated and the various in vitro and in vivo approaches that have been used to determine the GI of foods are summarized. Considering the broader perspective, the effect of cooking methods and additives is explained. Given the significance of the cereal grain, this work concludes with the challenges and key thrust areas for future research.

Globally, tea is the most consumed beverage; next only to water. Compared to black or oolong tea, various in vivo and in vitro studies have confirmed that green tea carries a rich profile of components responsible for antimutagenic, antidiabetic, antiinflammatory, antibacterial, and antiviral properties and the potential to lower the risk of cancer and cardiovascular diseases. However, most of these are polyphenols, including catechins are known to have poor stability to temperature, light, pH, and the presence of oxygen or metal ions. Micro- and nanoencapsulation of polyphenols can protect these valuable components from degradation. It also serves added benefits in terms of flavor-masking, controlled/targeted release and improving bioavailability of polyphenolic compounds. This chapter presents an elaborate note on various encapsulation techniques, with emphasis on nanoencapsulation. Though the basic idea involves entrapment of bioactive compounds within a protective shell of 10–200 nm diameter, there have been numerous research challenges and developments in this field. These are discussed in addition to techniques for the production of colloidal nanoparticle dispersions and suspensions. The scope of incorporating these encapsulated bioactive compounds in other food products is also presented.

Spray freeze drying is relatively a recent drying technique involving heterogeneous set of steps which includes droplet formation, freezing, and sublimation. It has proven benefits over other drying methods in terms of producing products with improved structural integrity, superior quality, and better shelf stability. With such merits, spray freeze drying has found numerous applications in the field of drug delivery. Spray freeze drying yields particles of sizes and densities that show higher stability in the lungs, nasal mucosa, intestine, and skin, as compared to other drying technologies. These particles also possess the vital trait of sustained release and specificity through various delivery routes as compared to conventional drying techniques. This drives the market for commercialization of spray freeze dried drugs. The focus of this paper is on manufacturing approaches of spray freeze dried powders, with emphasis on its application in drug delivery systems. An overview of other applications of spray freeze drying is also presented.