Satish Bal

Specific energy and quality aspects of infrared (IR) dried parboiled rice

Qualities of infrared (IR) dried parboiled rice in terms of head rice yield, colour, percent-gelatinized kernel and specific energy consumption have been evaluated using five levels of radiation intensity (5514, 4520, 3510, 2520 and 1509 W/m 2 ) and four levels of grain bed depths (3 mm (single kernel thickness), 6, 12 and 25 mm) in a vibratory IR dryer. Response surface methodology was followed to predict the effect of above mentioned independent parameters on quality variables and specific energy. The major factor in reduction of head yield was observed because of a marked increase in moisture removal rate with the increase in radiation intensity. The drop in percent head yield was about 6–8% for all the grain bed depths, when the intensity increased from 1509 to 5514 W/m 2 . Both grain bed depth and radiation intensity influenced the colour (Yellowness Index) of the milled rice at 1% level of significance. The Yellowness Index of the product was found to vary between 30.54 and 52.44. Radiation intensity and bed depth significantly changed the percent gelatinization of the kernels at the 1% level of significance. The percent of gelatinized kernels increased about 8% at maximum bed depth, and 4% at lower bed depths. The variation of specific energy consumption values was between 14.7 and 73.4 MJ/kg at 1% and 5% levels of significance with the increase in radiation intensity and bed depth, respectively. 2003 Elsevier Ltd. All rights reserved.

Functional and nutritional properties of tamarind (Tamarindus indica) kernel protein

Tamarind (Tamarindus indica) is one of the important tree legumes in tropical and sub-tropical countries. [The fruit consists of seed (33.9%), pulp (55.0%) and shell and fibre (11.1%). The seed, a by-product of the tamarind pulp industry, is underutilized.] Functional as well as nutritional properties of the meal and concentrate from tamarind kernels (raw and roasted) were determined. The concentrates were obtained by using the micellization process of protein isolation. Functional properties determined were the nitrogen-solubility index, water absorption capacity, emulsifying capacity, foaming capacity and foam stability. Nutritional properties estimated included in vitro protein digestibility and amino acid composition. The proteins were also fractionated according to their solubility in water, salt solution, ethanol and sodium hydroxide solution. The in vitro digestibility was 71.3; the kernel protein was rich in lysine, glutamic acid, aspartic acid, glycine and leucine but deficient in sulphur-containing amino acids.

Rheological behaviour of tamarind (Tamarindus indica) kernel powder (TKP) suspension.

The shear rate-shear stress data for tamarind (Tamarindus indica) kernel powder (TKP) suspensions were obtained using a concentric cylinder viscometer. The effects of concentration (2, 4, 6, 8 and 10% powder) on the flow behaviour index, consistency index, and apparent viscosity were investigated. The TKP suspensions were pseudoplastic in nature and exhibited yield stress. The Casson and Herschel-Bulkley models were applicable for the determination of yield stress (r2 ≥ 0·98, p ≤ 0·01) and for fitting the shear rate-shear stress data (r2 ≥ 0·98, p ≤ 0·01), respectively. The concentration of flour was found to have a pronounced effect on the rheological behaviour of the TKP suspensions.

A study on diffusion of water by the soybean grain during cold water soaking

Abstract Hydration behaviour by the soybean grain at ambient temperature showed that moisture imbibition is a diffusion-controlled phenomenon. The moisture content of grains increased rapidly during the initial stages of hydration. The saturation moisture content obtained was 138% d.b.

Some physical and engineering properties of tamarind (Tamarindus indica) seed

Abstract The chemical composition of tamarind ( Tamarindus indica ) seeds and kernels, as well as some industrially important physical and engineering properties, were determined. The kernel powder was rich in potassium. The shape of the whole tamarind seed did not conform to any of the standard shapes of seeds. The length, breadth, thickness, sphericity, roundness, surface area, average weight and volume per seed were also determined. The bulk density of raw, whole seed was slightly greater than that of roasted kernels. The surface area of seeds was linearly related to weight per seed (r ≥ 0·96, p ≤ 0·01). The angle of friction of the whole seeds was determined on rough, smooth, and very smooth surfaces. The angle of repose for roasted kernel (34–39°) was higher than that of the raw whole seeds (31–35°).

Production of low-fat grits from pearl millet

Pearl millet contains more fat, protein and minerals than soft grains such as rice and millets such as sorghum. In spite of being nutritive, it has no place in the regular diet of the Indian people. Storability of pearl millet is poor and of its flour is poorer still due to its high fat content. Pearling of pearl millet has been tried as a means of producing low-fat pearled grains. Conditioning of the pearl millet has been investigated with a view to obtain in milling, different size fractions having different fat contents. It was found that conditioning with water at the rate of 35 mL/kg of the pearl millet produces low-fat grits (69%) having a fat content of 2.4% and a fat-rich fraction (12%) with fat content of 10%.

Kinetics of tamarind seed hydration

The kinetics of hydrothermal behaviour of unpunched and punched tamarind (Tamarindus indica) seeds were determined at different temperatures (25–80 °C). The kinetic parameters determined were hydration rate constant, equilibrium moisture content, frequency factor and activation energy. Punching of seed increases the hydration rate constant and the equilibrium moisture content but reduces the activation energy compared to unpunched seeds. The hydration rate constant values for the unpunched seeds were 0.13, 0.16, 0.18, 0.31 and 0.38 h−1 at hydration temperatures of 25, 35, 50, 65 and 85 °C, respectively; the corresponding values for the punched seeds were 0.37, 0.40, 0.41, 0.43 and 0.52 h−1. Linear relationships (r ≥ 0.92, p ≤ 0.01) were obtained between the rate of moisture absorption and average moisture content. The equilibrium moisture content also increases linearly (r ≥ 0.95, p ≤ 0.01) with an increase in hydration temperature.

Optimization of the Vibration – Aided Infrared Heating Process Using Response Surface Methodology: An application to the drying and parboiling of high moisture paddy

The response surface methodology (RSM) was used to derive an optimum drying cum parboiling conditions for high moisture paddy using infrared energy. Considering less penetration power of the infrared radiation spectrum, a vibratory drying bed was used rather than a static bed to facilitate uniform exposure of grains to the radiation. A laboratory set-up capable of modulating both frequency and amplitude of vibration of the grain bed was developed to study the parboiling and drying characteristics of high moisture paddy. The experiments were conducted using five levels of radiation intensity (5514, 4520, 3510, 2520 and 1509 W/m2) and four levels of grain bed depths [3 mm (single kernel thickness), 6 mm, 12 mm and 25 mm]. The responses analyzed were head yield (HY), L-value, percent-gelatinized kernel (PK) and specific energy consumption (SE), which are important quality attributes of parboiling cum drying process. Analysis of variance (ANOVA) revealed that both the radiation intensity and the grain bed depth affected L-value, HY, PK and SE either at 1 or at 5% levels of significance. A contour plot for each of the response was used to generate an optimum area through superimposition. Optimum radiation intensity of 3100 to 4290 W/m2 and 12 to 16 mm grain bed depth is recommended in obtaining the maximum or minimum levels of response parameters.

Determination of Specific Heat and Gelatinization Temperature of Rice using Differential Scanning Calorimetry

Specific heat and gelatinization temperature of long-grain basmati rice were measured usingdifferential scanning calorimetry (DSC). The value of specific heat of brown rice sample ranged between 1.27to 4.83 kJ/kg K, with temperature varying from -10 to 150°C range, whereas the same varied from 1.23 to 4.34kJ/kg-K for paddy for moisture content of 13 % and 12.4 % (wb), respectively. The gelatinization temperaturerange of has been found to be between 73-77 °C for the powdered milled rice sample.