Modeling of product temperature in a supercritical fluid extrusion process through dimensional analysis Tina Ying Pan, Rajamanickam Gopirajah, Sugirtha Krishnamurthy, Syed S.H. Rizvi Journal of Food Process Engineering, 2020 A correlation model for predicting the maximum product temperature reached during a supercritical fluid extrusion (SCFX) process was developed using the Buckingham Pi method. Two dimensionless groups, Dref (ratio of screw diameter to screw length) and Eref (ratio of energy added to energy removed), were developed to model the maximum temperature of an SCFX process using dimensional analysis. The model was validated by comparing predicted and experimental values. Experiments were conducted using two feed formulations: 1. Milk protein concentrate (MPC) with rice flour (30%), and 2. MPC with grape pomace (15%). The average percent error was 2.57% for rice flour extrudate and 1.02% for grape pomace extrudate. Based on the results, the model could be used for prediction of maximum temperature in SCFX systems.Practical ApplicationsMaintaining the extruder temperature below 100°C remains a major challenge during the supercritical fluid extrusion (SCFX) process. The model developed determines the maximum temperature of a given SCFX system based on key extrusion parameters. Hence, the developed model can be used by manufacturers for determining the optimal operating conditions while scaling up an SCFX process.
Emulsifying properties of milk protein concentrate functionalized by supercritical fluid extrusion Rajamanickam Gopirajah, Poonam Singha, Sumera Javad, Syed S. H. Rizvi Journal of Food Processing and Preservation, 2020 Emulsifying properties of milk protein concentrate functionalized by supercritical CO2 extrusion process were studied. Three levels of oil (20, 40, and 60% w/w) and protein dispersions in water (1, 2, and 4% w/w) were employed to study the emulsifying properties of functionalized milk protein concentrate (f-MPC85) and compared with emulsions stabilized by unextruded commercial milk protein concentrate (c-MPC85) and commercial sodium caseinate (NaCas). High viscosity (35 Pa·s), shear-thinning emulsions were obtained having uniform droplet size distribution using 2% w/w f-MPC 85 and 60% w/w oil. The emulsion remained stable for 14 days at room temperature with no sign of syneresis. f-MPC85 stabilized emulsions showed rapid shear thinning behavior whereas emulsions containing NaCas showed a gradual decrease in viscosity with an increase in the shear rate. f-MPC85 showed good emulsifying property and emulsion stability compared to c-MPC85 and NaCas and it can be an excellent alternative to sodium caseinate in food applications. Practical applications This study highlights the enhanced emulsifying properties of MPC functionalized (f-MPC) by the supercritical CO2 extrusion process. The f-MPC showed better emulsion activity index, reduced creaming index, and comparable viscosity as compared to commercial sodium caseinate. The improved properties of f-MPC make it a promising product that can be commercialized as an alternative to non-dairy sodium caseinate.
Enhanced stability of emulsions made with super-critical carbon dioxide extruded whey protein concentrate Sumera Javad, Rajamanickam Gopirajah, Syed S. H. Rizvi Journal of Food Process Engineering, 2019 Supercritical fluid extrusion (SCFX) with carbon dioxide was used to enhance the functionality of whey protein concentrate containing 80% protein by weight (WPC80) at two (3.0 and 5.4) pH values. Different levels of oil (20, 40, 60, and 80% by weight) and functionalized whey protein (f‐WPC80; 1, 2, and 4% by weight) were used to make emulsions and quantify their characteristics such as emulsion activity index, creaming index, droplet size, and viscosity. Unextruded whey protein (c‐WPC80) and commercial sodium caseinate (NaCas) were used as controls. Results showed that gel‐like emulsions with uniform droplet size distributions were formed by f‐WPC80 (4% by weight) with 80% (by weight) oil which was stable over 3 months of storage at room temperature. Compared to emulsions formed by control c‐WPC80, the f‐WPC80 emulsions exhibited higher viscosity and shear thinning behavior. The minimum protein required for stable emulsion formation (with 80% oil) was found to be 2% by weight for f‐WPC80 and NaCas and 4% by weight in the case of c‐WPC80. The functionalized whey protein provided a better emulsion at low concentrations with good stability at room temperature and may be used as a replacement of sodium caseinate to make nutritionally superior products.Practical applicationsPresent study showed that functionalized Whey protein concentrate (80% protein) f‐WPC80 was produced by the process of Supercritical carbon dioxide assisted extrusion which changed the structure of native protein. Two functionalized products (with pH 3.0 and 5.4) were obtained in this way. These functionalized proteins formed better oil‐in‐water emulsions which were stable against creaming and sedimentation as compared to emulsions stabilized by native WPC80 and sodium caseinate at very small concentration of protein used. Therefore it is concluded that f‐WPC80 can cover a range of food emulsions where different pH values are required. Lesser amount of stabilizer will be used commercially for emulsions. These functionalized WPC80 products may be used as a replacement of sodium caseinate to make nutritionally superior products with pH 3.0 and 5.4.
Effect of extrusion process conditions on the physical properties of tef-oat healthy snack extrudates Rajamanickam Gopirajah, Kasiviswanathan Muthukumarappan Journal of Food Processing and Preservation, 2018 Tef with different oat blend ratio was processed in a single screw extruder and evaluated for optimum physical and protein quality. Effects of oat level (0–30%), feed moisture content (12–16%), extruder die temperature (DT) (80–140 °C), and screw speed (SS) (80–200 rpm) on the extrudate characteristics were investigated using Box–Behnken design. The addition of oat level above 15% increased the extrudate protein availability and water absorption capacity. DT greater than 110 °C and feed moistures greater than 14% results in a steep increase in expansion ratio. The pasting property of tef flour showed higher initial (56 cP) and final viscosity (102 cP) than oat flour with 48 cP initial viscosity and 56 cP final viscosity. In conclusion, tef with 29% oat blend, 16% feed moisture, 140 °C DT, and 80 rpm SS gave an optimum product with high desirability (>0.8). Practical applications The demand for healthy snack formulation with low glycemic index is increasing with the snack industry. Extrusion cooking provides control on minimising the nutrient loss with improved functional qualities. The study provides new experimental data of extrusion process parameters for teff and oat flour formulation. The effect of extrusion process conditions on the extrudate physical and protein quality was optimized using response surface methodology. The pasting profile and gelatinization temperature of tef-oat formulation indicated their potential application in food textural modifications. The results obtained will be of great significance for formulation and development of healthy snack with minimal loss of nutrients during processing.
Packaging of Dried Dairy Products R. Gopirajah, C. Anandharamakrishnan Handbook of Drying for Dairy Products, 2017 The packaging of dried milk powder is important because it has an impact on quality, safety, consumer acceptance and marketing. Milk powder is prone to lipid oxidation owing to its hygroscopicity and fat content, therefore milk powders should be packaged to prevent contact from moisture, light and oxygen. Recently, novel technologies such as active packaging, intelligent packaging and nanotechnology have been introduced to improve the function of a packaging material and enhance the quality of food. This includes addition of active ingredients to increase the shelf life of the packaged dairy product, use of indicators to detect spoilage and freshness, and improving barrier properties. This chapter discusses the packaging of dried milk products, including recent developments in combating lipid oxidation through active and intelligent packaging techniques. Developments in nanotechnology for the production of bio-degradable polymers with improved barrier properties are also discussed.
Development of extruded snacks using soy, sorghum, millet and rice blend - A response surface methodology approach Dibyakanta Seth, Gopirajah Rajamanickam International Journal of Food Science and Technology, 2012 SummaryResponse surface methodology (RSM) based on a five‐level‐three‐factor central composite rotatable design (CCRD) was employed for optimisation of formulation for production of a soy‐fortified millet‐based extruded snack. Effects of amount of ingredients such as ragi (40–50%), sorghum (10–20%) and soy (5–15%) on the physical properties like bulk density, expansion ratio, water absorption index and water solubility index of snacks were investigated. Significant regression models that explained the effects of different percentages of ragi, sorghum and soy on all response variables were determined. The coefficients of determination, R2, of all the response variables were higher than 0.90. Based on the given criteria for optimisation, the basic formulation for production of millet‐based extruded snack with desired sensory quality was obtained by incorporating with 42.03% ragi, 14.95% sorghum, 12.97% soy and 30% rice.
RECENT SCHOLAR PUBLICATIONS
High internal phase oil-in-water emulsions stabilized by supercritical carbon dioxide extruded whey protein concentrate S Javad, R Gopirajah, SSH Rizvi Food Chemistry 372, 131362 , 2022 2022 Citations: 10
Food biopolymers: Structural, functional and nutraceutical properties A Gani, BA Ashwar Springer International Publishing , 2021 2021 Citations: 30
Nutraceutical properties of lipids GJ Swamy, EP Natarajan, G Rajamanickam Food biopolymers: Structural, functional and nutraceutical properties, 413-428 , 2021 2021 Citations: 1
Lipids and oils: an overview S Asokapandian, S Sreelakshmi, G Rajamanickam Food biopolymers: Structural, functional and nutraceutical properties, 389-411 , 2021 2021 Citations: 32
Modeling of product temperature in a supercritical fluid extrusion process through dimensional analysis TY Pan, R Gopirajah, S Krishnamurthy, SSH Rizvi Journal of Food Process Engineering 43 (12), e13561 , 2020 2020 Citations: 5
Emulsifying properties of milk protein concentrate functionalized by supercritical fluid extrusion R Gopirajah, P Singha, S Javad, SSH Rizvi Journal of Food Processing and Preservation 44 (10), e14754 , 2020 2020 Citations: 26
Enhanced stability of emulsions made with super‐critical carbon dioxide extruded whey protein concentrate S Javad, R Gopirajah, SSH Rizvi Journal of Food Process Engineering 42 (6), e13183 , 2019 2019 Citations: 12
Characterization methods for nanoparticles R Gopirajah, C Anandharamakrishnan Food Nanotechnology, 375-396 , 2019 2019 Citations: 1
Effect of extrusion process conditions on the physical properties of tef‐oat healthy snack extrudates R Gopirajah, K Muthukumarappan Journal of Food Processing and Preservation 42 (3), e13559 , 2018 2018 Citations: 42
Computational modeling of dehydration of mushroom C dehydration of mushroom MOJ Food Processing & Technology 6 (3), 264-270 , 2018 2018 Citations: 11
Packaging of dried dairy products R Gopirajah, C Anandharamakrishnan Handbook of Drying for Dairy Products, 229-248 , 2017 2017 Citations: 5
Advancement of imaging and modeling techniques for understanding gastric physical forces on food R Gopirajah, C Anandharamakrishnan Food engineering reviews 8 (3), 323-335 , 2016 2016 Citations: 12
The glycemic response to fibre rich foods and their relationship with gastric emptying and motor functions: An MRI study R Gopirajah, KP Raichurkar, R Wadhwa, C Anandharamakrishnan Food & function 7 (9), 3964-3972 , 2016 2016 Citations: 43
Shrinkage and porosity effects on heat and mass transfer during potato drying J Aprajeeta, R Gopirajah, C Anandharamakrishnan Journal of Food Engineering 144, 119-128 , 2015 2015 Citations: 249
Methods Integrating Physical Mechanisms Underlying the Food Digestion and Release of Nutrients in Human... G Rajamanickam, A Chinnaswamy 2014
Methods integrating physical mechanisms underlying the food digestion and release of nutrients in human stomach R Gopirajah, C Anandharamakrishnan J Nutr Nutr Epidemiol 1, 1-13 , 2014 2014 Citations: 8
Development of extruded snacks using soy, sorghum, millet and rice blend–A response surface methodology approach D Seth, G Rajamanickam International Journal of Food Science and Technology 47 (7), 1526-1531 , 2012 2012 Citations: 133
Finite Element Modeling of Freezing of Coffee Solution R Gopirajah, N Chhanwal, C Anandharamakrishnan Comsol , 2011 2011 Citations: 2
MOST CITED SCHOLAR PUBLICATIONS
Shrinkage and porosity effects on heat and mass transfer during potato drying J Aprajeeta, R Gopirajah, C Anandharamakrishnan Journal of Food Engineering 144, 119-128 , 2015 2015 Citations: 249
Development of extruded snacks using soy, sorghum, millet and rice blend–A response surface methodology approach D Seth, G Rajamanickam International Journal of Food Science and Technology 47 (7), 1526-1531 , 2012 2012 Citations: 133
The glycemic response to fibre rich foods and their relationship with gastric emptying and motor functions: An MRI study R Gopirajah, KP Raichurkar, R Wadhwa, C Anandharamakrishnan Food & function 7 (9), 3964-3972 , 2016 2016 Citations: 43
Effect of extrusion process conditions on the physical properties of tef‐oat healthy snack extrudates R Gopirajah, K Muthukumarappan Journal of Food Processing and Preservation 42 (3), e13559 , 2018 2018 Citations: 42
Lipids and oils: an overview S Asokapandian, S Sreelakshmi, G Rajamanickam Food biopolymers: Structural, functional and nutraceutical properties, 389-411 , 2021 2021 Citations: 32
Food biopolymers: Structural, functional and nutraceutical properties A Gani, BA Ashwar Springer International Publishing , 2021 2021 Citations: 30
Emulsifying properties of milk protein concentrate functionalized by supercritical fluid extrusion R Gopirajah, P Singha, S Javad, SSH Rizvi Journal of Food Processing and Preservation 44 (10), e14754 , 2020 2020 Citations: 26
Enhanced stability of emulsions made with super‐critical carbon dioxide extruded whey protein concentrate S Javad, R Gopirajah, SSH Rizvi Journal of Food Process Engineering 42 (6), e13183 , 2019 2019 Citations: 12
Advancement of imaging and modeling techniques for understanding gastric physical forces on food R Gopirajah, C Anandharamakrishnan Food engineering reviews 8 (3), 323-335 , 2016 2016 Citations: 12
Computational modeling of dehydration of mushroom C dehydration of mushroom MOJ Food Processing & Technology 6 (3), 264-270 , 2018 2018 Citations: 11
High internal phase oil-in-water emulsions stabilized by supercritical carbon dioxide extruded whey protein concentrate S Javad, R Gopirajah, SSH Rizvi Food Chemistry 372, 131362 , 2022 2022 Citations: 10
Methods integrating physical mechanisms underlying the food digestion and release of nutrients in human stomach R Gopirajah, C Anandharamakrishnan J Nutr Nutr Epidemiol 1, 1-13 , 2014 2014 Citations: 8
Modeling of product temperature in a supercritical fluid extrusion process through dimensional analysis TY Pan, R Gopirajah, S Krishnamurthy, SSH Rizvi Journal of Food Process Engineering 43 (12), e13561 , 2020 2020 Citations: 5
Packaging of dried dairy products R Gopirajah, C Anandharamakrishnan Handbook of Drying for Dairy Products, 229-248 , 2017 2017 Citations: 5
Finite Element Modeling of Freezing of Coffee Solution R Gopirajah, N Chhanwal, C Anandharamakrishnan Comsol , 2011 2011 Citations: 2
Nutraceutical properties of lipids GJ Swamy, EP Natarajan, G Rajamanickam Food biopolymers: Structural, functional and nutraceutical properties, 413-428 , 2021 2021 Citations: 1
Characterization methods for nanoparticles R Gopirajah, C Anandharamakrishnan Food Nanotechnology, 375-396 , 2019 2019 Citations: 1
Methods Integrating Physical Mechanisms Underlying the Food Digestion and Release of Nutrients in Human... G Rajamanickam, A Chinnaswamy 2014
