See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/327765023 MSc Project Presentation, TEZPUR UNIVERSITY MSc 4th Semester, 2017(January - May) Presentation · September 2018 CITATIONS READS 0 28 1 author: Ankurjyoti Bordoloi India Meteorological Department 3 PUBLICATIONS 1 CITATION SEE PROFILE Some of the authors of this publication are also working on these related projects: Investigation of the surface and reflectance properties of rice and its by-products View project A DETAILED STUDY ON OPTICAL AND PHYSICAL PROPERTIES OF RICE AND ITS BY-PRODUCTS View project All content following this page was uploaded by Ankurjyoti Bordoloi on 21 September 2019. The user has requested enhancement of the downloaded file.
A STUDY ON OPTICAL AND PHYSICAL PROPERTIES OF RICE AND ITS BY-PRODUCTS M.Sc. 4 th Semester Major Project By Supervisor Ankurjyoti Bordoloi Dr. Dambarudhar Mohanta M.Sc. 4 th Semester Associate Professor Roll No. PHY15009 Dept. of Physics
Rice is one of the most common food prevailing among us. It has lot of importance in terms of by-product and nutrition. There are varieties & different by-products of rice such as Glutinous Rice, Parboiled Rice, Puffed Rice, Flat Rice, Rice Noodles, Rice Bran Oil, Rice Crackers etc. The properties and nutritional values varies for different products. The study of optical and physical properties and their correlations of different products have been rarely studied and discussed.
Sa Samp mple les s tak aken en fo for ob obse servatio rvation The samples chosen for our work are: Glutinous Rice 1) Normal Rice 2) Flat Rice 3) Puffed Rice 4) The digital photographs of the samples are shown below: Fig: Normal Rice Fig: Flat Rice Fig: Glutinous Rice Fig: Puffed Rice
Physical Properties Glutinous Properties Normal Rice Flat rice Puffed rice Rice Long grained Long grained Flat light Long grained Appearance (Oval (Cylindrical dry (Oval shaped) Shaped) or Oval) flakes. White, Black, In general, In general Colour White Brown or White and Brown. Red. Brown. Mass (per 0.0187 gm 0.0172 gm 0.0139 gm 0.0155 gm grain) 0.3 0.83 gm/cm 3 0.77 gm/cm 3 0.096 gm/cm 3 Density gm/cm 3 Calories 97 130 258 402 (per 100gm) Length 8 cm 8 cm 13 cm 13 cm Very Dryness Medium High Very High High
Results and Discussions X-Ray Diffraction (XRD) Study • All the rice samples showed almost similar trend; but in case of Glutinous Rice, initial variations are observed. • For Glutinous Rice, peaks are observed at 23.1 o and 15.18 o which proves a C-type pattern. • For Normal Rice also C type patterns are observed (peaks at 18.1 o and 23.1 o ). • Puffed Rice and Flat Rice don’t show any special pattern as peaks are not similar to Fig: X-Ray Diffraction Patterns the theoretical value. Sample Crystallinity (%) • By products of rice shows lower crystallinity than normal rice. Glutinous 17.13% • Rice and its by products are mainly Rice macromolecular & amorphous nature, as Normal Rice 25.98% Puffed Rice 24.87% degree of crystallinity < 30% . Flat Rice 16.79%
Reflectance Properties through UV-Visible Spectroscopy • Reflectance of light is highest for Glutinous Rice. • Puffed Rice shows slightly different type of characteristics. • Peaks are observed at 310 nm & 380 nm for Glutinous Rice. • Puffed Rice and Flat Rice show almost equal reflectance. • Below 540 nm, reflectance from Flat Rice is greater than Puffed Rice; but after 540 nm, the reverse is observed. Fig: UV-Visible Spectra of all the Samples • Area under the curve from UV-vis spectroscopy plot Fig: Area Under the Curve
Microstructural Analysis through SEM 1) NORMAL RICE Fig: SEM images of Normal Rice at different magnifications 2) FLAT RICE Fig: SEM images of Flat Rice at different magnifications 3) PUFFED RICE Fig: SEM images of Puffed Rice different magnifications
From the SEM images for rice and its by-products, we find that the surface morphology is different for each of the samples. Sl. Normal Rice Flat Rice Puffed Rice No Void fraction low. Void fraction is high but Void fraction is highest as 1 due to the applied cellulose materials are pressure during expanded due to the applied manufacturing. heat during manufacturing process. 2 Holes are less observed Some holes are on the Holes are observed on the on the surface. surface. surface. 3 Reflectance is highest Reflectance is low as Due to micro voids, as roughness is low. roughness is high. roughness is highest, so reflectance is low. 4 Granules are less seen Starch granules have Starch granules have and different shape & different shape and size. different shape and size. size. 5 Dimension of granules Dimension of granules is Dimension of granules is in is small and in the in the range of 1-10µm. the range of 1-50µm. It is order of ~1µm. due to the expansion of cellulose material.
Res esults ults from m SEM EM images ages SURFACE PROPERTIES PLAY AN IMPORTANT ROLE IN THE OPTICAL PROPERTIES. ORDER OF EMPTY SPACE : RICE < FLAT RICE < PUFFED RICE. ROUGHNESS : RICE < FLAT RICE < PUFFED RICE. EXPANSION OF CELLULOSE MATERIAL IS OBSERVED IN PUFFED RICE. STRONG CORRELATION IS OBSERVED BETWEEN THE REFLECTANCE PROPERTIES AND MORPHOLOGICAL FEATURES.
Porosity Measurement Porosity gives us the void or empty space inside the grain; which also gives us the water holding capacity. P(%) = (V i - V f )/V s × 100 P = the porosity of the sample (%) V i = The combined volume of the sample + added water (mL) V f = The final volume of the sample + added water (mL) V s = The volume of the sample (mL) For Normal Rice, P = 66.67% For Glutinous Rice, P = 75% • Since Glutinous Rice is highly sticky in nature, it has the capacity to absorb more water than normal rice. • Surfaces of flat rice & puffed rice are damaged instantly with added water; so their porosity can’t be measured.
Rapid Visco Analyzer (RVA) analysis Steps of the experiment are shown in the block diagram Fig: Viscosity vs Time Curve
• Viscosity vs Temperature Curves: Fig: Viscosity vs Temperature Curve
RVA Profiles RVA Profile gives us an overview of Viscosity parameters from which we can analyse the sample in terms of its quality and suitability. Fig: RVA Profiles for all the four samples Data obtained from RVA Profile Pasting Temperature Peak Viscosity Hold Breakdown Setback Final Sample (degree C) (cP) Viscosity (cP) Viscosity (cP) Viscosity (cP) Viscosity (cP) Glutinous Rice 64.2 1678 1125 553 351 1476 Normal Rice 79.8 1177 - - 1476 2844 Puffed Rice 48.9 - - - 1993 1993 Flat Rice 48.8 - - - 1992 3144
Conclusions from RVA Analysis Low peak viscosity means rapid swelling. Normal rice thus swells rapidly compared to Glutinous Rice. Final Viscosity measures the ability of starch to form viscous paste . Glutinous Rice < Puffed Rice < Normal Rice < Flat Rice Amylopectin content - Flat Rice < Normal Rice < Puffed Rice < Glutinous Rice Low total setback viscosity indicates low rate of starch retro-gradation . The order of water holding capacity - Puffed Rice < Flat Rice < Normal Rice < Glutinous Rice Higher Pasting temperature indicates high resistance potential against swelling . Flat Rice < Puffed Rice < Glutinous Rice < Normal Rice Pasting temperature indicates the minimum temperature required to cook . Flat Rice < Puffed Rice < Glutinous Rice < Normal Rice
Measurement of Shear Rate All the samples show non Newtonian trend. Viscosity vs Shear Rate Curve gives us whether the fluid is shear-thinning or shear-thickening. Fig: Viscosity vs Shear Rate Curves for a) Glutinous Rice, b) Normal Rice, c) Puffed Rice, d) Flat Rice • Puffed Rice follows double exponential trend. • Shear thinning or pseudo-plastic behaviour is observed for all samples. • At initial stage, Glutinous Rice shows shear thickening behaviour. • Shear thickening behaviour leads to the stickiness property of Glutinous Rice.
Conclusions • Moderately loosely packed, helical, six fold crystalline structure for rice through XRD peaks (C type peaks). • The Glutinous Rice showed highest reflectance. • Surface structures of samples are different from each other in terms of roughness; which leads to the change in reflectance of light. • RVA data shows diverse Pasting Properties. Classification of rice cultivars based on RVA profiles enabled us a suitable selection of rice. • RVA data & shear rate measurement shows different behaviour of glutinous rice compared to others. • High porosity leads to high stickiness.
Future Scope Internal structure and chemical bonds i.e., shifting of bond, can be studied through NMR spectroscopy. Scope of studying the internal structure of food grains produced from same origin. Chemical composition can also be taken into account.
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