Manikantan Ramarathinam - Academia.edu (original) (raw)

Papers by Manikantan Ramarathinam

Journal of Food Engineering, 2006

The moisture dependent physical properties of dried pomegranate seeds (anardana) in the moisture ... more The moisture dependent physical properties of dried pomegranate seeds (anardana) in the moisture range of 6-18.13% (w.b.) were determined. The size and mass increased from 3.5 mm to 4.4 mm and 28.98 g to 32.58 g, respectively, when the moisture content increased from 6% to 18.13%. The bulk density, true density and angle of repose increased, whereas the porosity decreased with the increase in moisture content. The angle of repose increased from 26.46°to 32.13°for the same moisture increase. The plywood surface offered more frictional resistance than the galvanized iron surface. The hardness and toughness of anardana decreased with increase in moisture content.

Packaging of foods in high barrier and strong materials is essential to attain food safety, and n... more Packaging of foods in high barrier and strong materials is essential to attain food safety, and nanocomposite technology leads in search of the above kind of packaging material. The effect of compatibilizer, nanoclay and thickness of film on morphology, oxygen transmission rate (OTR), water vapor transmission rate (WVTR), tensile strength and percent elongation of linear low density polyethylene (LLDPE)-based nanocomposite films are studied using response surface methodology. The maximum reduction in OTR and WVTR over the control (0% compatibilizaer, 0% nanoclay and 100 µm film thickness) is 24.7% and 64.9%, respectively in the treatment having 5% compatibilizer, 2% nanoclay and 100 µm thickness. The regression models are developed for the prediction of OTR and WVTR. The maximum increase in the tensile strength and percent elongation over the control (0% compatibilizaer, 0% nanoclay and 100 µm film thickness) is 54% and 7.64%, respectively. Treatment having 5% compatibilizer, 2% nanoclay and 100 µm thickness of nanocomposite films showed better morphological, barrier and strength characteristics than other treatments. This paper helps to design the packaging films according to the requirement of foods to be stored using the developed regression models.

Drying kinetics of milky mushroom slices (10 mm) in a fluidized bed dryer was studied at air temp... more Drying kinetics of milky mushroom slices (10 mm) in a fluidized bed dryer was studied at air temperatures of 50, 55 and 60°C. Drying of milky mushroom slices occurred in falling rate period. In order to select a suitable drying curve, eight thin layer-drying models were fitted to the experimental moisture ratio data. Among the mathematical models investigated, Wang and Singh model best described the drying behaviour of mushroom slices with high correlation coefficient (R 2) values. The effective moisture diffusivity (D eff) of mushroom increased as the drying air temperature increased. The moisture diffusivity in milky mushroom was found to increase from 1.55 to 4.02 x 10-9 m 2 s-1 during the initial stage of drying, and from 8.76 to 16.5 x 10-9 m 2 s-1 during the later stage of drying. Drying at temperature of 60°C required minimum activation energy to detach and move the water during the drying process. K e y w o r d s: milky mushroom, drying models, moisture ratio, diffusivity, activation energy MATERIALS AND METHODS Freshly harvested milky mushrooms (Calocybe indica) of uniform maturity were obtained from the Environment

Acta Alimentaria, 2015

Sunfl ower (PSH 569) was used to obtain textured defatted meal. Proximate analysis, water absorpt... more Sunfl ower (PSH 569) was used to obtain textured defatted meal. Proximate analysis, water absorption index (WAI), water solubility index (WSI), fat absorption capacities (FAC), foaming capacity (FC), and bulk density (BD) were determined. The objective of the study was the optimization of extrusion conditions for production of textured defatted sunfl ower meal using response surface methodology (RSM) by evaluating functional properties. It was dried, grinded, and sieved to eliminate hull and fi bre. Numerical optimization provided eight solutions with desirability value varying from 0.81 to 0.82. Range of predicted values of FAC (80.96-90.49), WHC (1.95-2.12), WSI (3.22-3.36), WAI (2.84-3.08), bulk density (0.31-0.36), and foaming capacity (14.39-16.30) were used for numerical optimization. Best extrusion conditions were 16.36% feed moisture, 300 r.p.m. screw speed, and 149.40 °C barrel temperature. Textured sunfl ower defatted meal was prepared using the above optimized conditions.

The machines and systems for processing and value addition of ragi are totally dependent on its p... more The machines and systems for processing and value addition of ragi are totally dependent on its postharvest engineering properties. These properties are further, greatly affected by the moisture content of the grains. As ragi processing and value addition requires different set of moisture contents, the present study was aimed at assesment of selceted postharvest engineering properties of ragi (cv. VL Mandua-315), grown in Himalayan regions of India as a function of its moisture content (8-40%, wb). The spatial dimensions, geometric mean diameter, thousand grain mass, angle of repose, sphericity, surface area and porosity increased with increasing moisture content of the grains. The bulk density and true density decreased linearly from 777.50 to 684.99 kg/m 3 and from 1270.44 kg/m 3 to 1236.48 kg/m 3 , respectively with the moisture content. The values of static coefficient of friction of ragi against plywood, mild steel, galvanized iron and glass increased from 0.57, 0.52, 0.35 and 0.30 to 0.83, 0.72, 0.79 and 0.70, respectively. The hardness decreased with moisture (67.95 N to 37.51 N) whereas toughness first increased from 5.17 Nmm (8% moisture) to 6.91 Nmm (24% moisture) followed by decrease to 3.97 Nmm at 40% moisture content.

Coconut kernel is a potent source of carbohydrate and rich source of plant protein with appreciab... more Coconut kernel is a potent source of carbohydrate and rich source of plant protein with appreciable amount of fiber. The dehydrated coconut chips are one of the important product of intermediate moisture coconut kernel. Intermediate moisture coconut kernel is the mature coconut kernel after removal of moisture content of the kernel, partially by osmotic dehydration. Using a new method of drying on the basis of osmosis, in which partial dehydration in sliced form is brought about by dipping the fresh kernel in sugar solution followed by hot air drying. This is claimed to result in product with better flavor than freeze drying method at comparatively lesser cost. Utilizing this technology, a process was developed for producing white color sweet coconut chips by osmotic dehydration followed by hot air drying. Experiments were carried out to produce beet root and carrot colored coconut chips. The coconut was subjected to dehusking, deshelling, testa removing, slicing, blanching and was ...

Physical properties of sunflower seeds were evaluated as a function of moisture content. Various ... more Physical properties of sunflower seeds were evaluated as a function of moisture content. Various physical properties of seeds and their fractions are dependent on moisture content and appear to be important in the design of handling and processing equipment. The geometric mean diameter and sphericity of the seed were 6.69 mm and 0.63 respectively. In the moisture range from 10-18% w.b., the bulk density of the rewetted seed decreased from 330.7 to 320.88 kg/m3, true density increased from 688.10 to 725.56 kg/m3, thousand kernel weight (TKW) increased from 75.31 to 78.86 g and porosity increased from 51.94 to 55.77 %. In the same moisture range the static coefficient of friction varied from 0.51 to 0.61 for seed different surfaces, while the angle of repose varied from 18.10 to 24.07 for seed. Hardness and initial cracking force for sunflower seed decreased with increase in moisture content.

African journal of microbiology research

Pre-dehulling treatments with some culture extracts of Aspergillus oryzae of various incubation p... more Pre-dehulling treatments with some culture extracts of Aspergillus oryzae of various incubation periods played an important role in improving the dehulling properties of pigeon pea (Cajanus cajan L.). Yield percent of dehulling grains and dehulling efficiency increased concurrently with increase of incubation period of culture extracts. Maximum dehulled grains were achieved by 12-day old culture extract to the tune of 73% with lease amount of undehulled kernels and fines (6.6 and 6.5% respectively). Pre-dehulling trials conducted on pigeon pea grain employing wheat bran and pigeon pea based culture extracts of A. oryzae showed dehulling efficiency of 73% for wheat bran (12-day incubation period) and pigeon pea husk (9 day incubation period) in comparison with uninoculated extract (control) in the range of 62.2-64.4%. Based on the results obtained, dehulling properties affected by pigeon pea husk based culture extract proved better than wheat bran culture extract.

Present study was carried out to develop quick cooking wheat dalia using wheat sprouted for 36 an... more Present study was carried out to develop quick cooking wheat dalia using wheat sprouted for 36 and 48 h, dried at 50oC, followed by milling. Recovery of dalia (particle size 1.41 to 2 mm) from unsprouted, 36 h and 48 h sprouted wheat was 75.1, 74.41 and 73.8%, respectively. Sprouting and particle size affected the physical properties and cooking quality of wheat dalia. Rehydration ratio and solid loss in cooking water of different dalia samples ranged from 3.15 to 3.39 and 10.26 to 13.34%, respectively. Cooking time of dalia samples (3.2 to 7.38 min) was reduced due to sprouting, but sprouting did not affect the sensory characteristics. Overall sensory acceptability scores for dalia samples ranged from 7.69 to 7.98 with better acceptability for dalia prepared from 36 h sprouted wheat. Protein, fat, minerals, crude fibre, calories, iron and calcium content in this dalia sample were 10.32%, 1.33%, 1.48%, 3.33%, 359 kcal, 1.18 and 44.67 mg/100 g, respectively. In vitro protein digestib...

An integrated dryer comprising three different air heating sources such as solar, biomass and ele... more An integrated dryer comprising three different air heating sources such as solar, biomass and electrical was developed for drying of paddy. Drying kinetics of paddy (long grain variety PR-ll8 procured from PAU, Ludhiana) in the dryer using single as well as combined heating sources was studied at different air temperatures. Drying of paddy occurred in falling rate period. It was observed that duration of drying of paddy from 22% to l3% moisture content (wet basis) was 5-9 hours depending upon the source of energy used. In order to select a suitable drying curve, six thin layer-drying models (Newton, Page, Modified Page, Henderson and Pabis, Logarithmic and Wang and Singh) were fitted to the experimental moisture ratio data. Among the mathematical models investigated, Wang and Singh model best described the drying behaviour of paddy using solar, biomass and combined heating sources with highest correlation coefficient (r2) values and least chi-square, (X2\, mean bias error (MBE) and ...

BioNanoScience, 2012

Pediocin is small antilisterial polypeptide bacteriocin. Direct addition of pediocin has been stu... more Pediocin is small antilisterial polypeptide bacteriocin. Direct addition of pediocin has been studied so far and is found to be effective only for a limited duration of time. The controlled release or slow release is an efficient method to prolong the effectiveness of pediocin and other such antimicrobials. Encapsulation is one of the numerous strategies that can be employed for achieving controlled release. Diverse wall materials such as phospholipids, proteins and carbohydrate polymers and combinations of these are used to encapsulate active ingredients. One of the aims of this study was to evaluate the effect of process parameters, viz. concentration of phospholipid (lecithin, phophatidylcholine) at the rate of 0.1, 0.2 and 0.3 % (w/v), amplitude for sonication (40, 50 and 60 %) and sonication time (3, 5 and 7 min), on size of nanoliposomes. There was an increase in liposome size with increase in concentration of phospholipids; however, there was decrease in size with increase in amplitude and duration of sonication. The main aim of the study was to compare the controlled release behaviour of pediocin loaded in delivery systems of different wall materials, viz. nanoliposomes (lecithin, phophatidylcholine), capsules of alginate plus guar gum and hybrid capsules of alginate plus guar gum incorporated with nanoliposomes. Encapsulated pediocin was found to be more effective in inhibiting bacterial growth than directly added pediocin. Hybrid capsules of alginate plus guar gum incorporated with pediocin-loaded nanoliposomes of phosphatidylcholine were found to be the best delivery system for controlled release of pediocin.

International Journal of Engineering Practical Research, 2014

Physical properties of wheat grains were evaluated

Agricultural Research, 2014

ABSTRACT A method of preparing microcapsules using two-ﬂuid glass nozzle was studied for microenc... more ABSTRACT A method of preparing microcapsules using two-ﬂuid glass nozzle was studied for microencapsulation of food ingredients. In this method, a solution of sodium alginate and starch was sprayed using a two-ﬂuid glass nozzle into a reaction vessel containing calcium chloride gelling bath. The aim of this work was to study the effect of some process variables on particle size of microcapsules. Response Surface Methodology by applying Box-Behnken design was used to optimize four independent variables viz., sodium alginate concentration (% w/v), starch concentration (% w/v), pressure (bar), and ﬂow rate (ml/min) for obtaining target particle size. The ANOVA of the regression model demonstrated that the model was highly signiﬁcant and adequate (p = 0.0054, R2 = 0.8837). The microcapsules produced have average particle size ranging from 104.56 to 734.69 lm. The results revealed that concentration of sodium alginate solution and air pressure used for atomization had signiﬁcant effect on particle size of microcapsules (p<0.01). The optimized formulation and experimental conditions (sodium alginate concentration (2 % w/v), starch concentration (3 % w/v), air pressure (0.75 bar), and ﬂow rate (80 ml/min) yielded microcapsules of particle size values very close to predicted particle size. The morphology of microcapsules confirmed the near spherical capsular structure; which indicated that two-ﬂuid glass nozzle can be used for production of spherical microcapsules.

Acta Alimentaria, 2014

Physical properties of maize were evaluated as a function of moisture content. The obtained data ... more Physical properties of maize were evaluated as a function of moisture content. The obtained data provide help in the designing of post-harvest handling machinery. In the moisture range of 10-18% wet basis (w.b.), the length of the rewetted grain increased from 10.01 to 10.65 mm, width increased from 8.57 to 8.70 mm, thickness ranged from 4.63 to 4.97 mm, geometric mean diameter (GMD) increased from 7.34 to 7.67 mm, sphericity increased from 0.72 to 0.73, thousand kernel weight (TKW) increased from 258.1 to 287.9 g, bulk density decreased from 591.6 to 554.2 kg m-3 , true density increased from 1194.9 to 1267.2 kg m-3 , porosity increased from 52.61 to 56.27%, hardness decreased from 293.75 to 228.04 N, initial cracking force decreased from 190.11 to 137.35 N and area ranges from 55.09 to 36.58 Nmm. In the same moisture range the angle of repose varied from 23.36 to 28.55 for grain. Lightness (L) of grain ranges from 62.82 to 59.26, a value (red-green axis) ranges from 13.97 to 8.96, b value (yellow-blue axis) ranges from 31.05 to 26.19 and hue angle (z%) decreased from 14.59 to 14.

International Agrophysics, 2014

The present study was carried out to investigate the compression loading behaviour of five Indian... more The present study was carried out to investigate the compression loading behaviour of five Indian sunflower varieties (NIRMAL-196, NIRMAL-303, CO-2, KBSH-41, and PSH- 996) under four different moisture levels (6-18% d.b). The initial cracking force, mean rupture force, and rupture energy were measured as a function of moisture content. The observed results showed that the initial cracking force decreased linearly with an increase in moisture content for all varieties. The mean rupture force also decreased linearly with an increase in moisture content. However, the rupture energy was found to be increasing linearly for seed and kernel with moisture content. NIRMAL-196 and PSH-996 had maximum and minimum values of all the attributes studied for both seed and kernel, respectively. The values of all the studied attributes were higher for seed than kernel of all the varieties at all moisture levels. There was a significant effect of moisture and variety on compression loading behaviour.

Packaging Technology and Science, 2011

Packaging of foods in high barrier and strong materials is essential to attain food safety, and n... more Packaging of foods in high barrier and strong materials is essential to attain food safety, and nanocomposite technology leads in search of the above kind of packaging material. The effect of compatibilizer (1.6, 5, 10, 15 and 18.4%), nanoclay (0.6, 2, 4, 6 and 7.4%) and thickness of film (35, 50, 75 100 and 120 mm) on oxygen transmission rate (OTR), water vapour transmission rate (WVTR), tensile strength and per cent elongation of polypropylene (PP)-based nanocomposite films was studied using response surface methodology. The maximum reduction in OTR of PP-based nanocomposite films over the control was 21.4% in treatment having 10% compatibilizer, 4% nanoclay and 120 mm thickness. A maximum of 28.1% reduction in WVTR for the treatment with 5% compatibilizer, 2% nanoclay and 100 mm thickness over the control was achieved. The regression models were developed for the prediction of OTR and WVTR of nanocomposite films. The maximum increase in the tensile strength of PP-based nanocomposite films over the corresponding control was 71.7%. The elongation percentage of nanocomposite films was less than the control and increased with increase of thickness of film and decrease of both nanoclay and compatibilizer. Treatment having 5% compatibilizer, 2% nanoclay and 100 mm thickness of nanocomposite films showed better barrier and strength characteristics than other treatments. This paper helps to design the packaging films according to the requirement of foods to be stored using the developed regression models.

Journal of Food Science and Technology, 2014

Drying characteristics of paddy (long grain variety PR-118 procured from PAU, Ludhiana) in an int... more Drying characteristics of paddy (long grain variety PR-118 procured from PAU, Ludhiana) in an integrated dryer using single as well as combined heating source was studied at different air temperatures. The integrated dryer comprises three different air heating sources such as solar, biomass and electrical. Drying of paddy occurred in falling rate period. It was observed that duration of drying of paddy from 22 to 13 % moisture content (w.b.) was 5-9 h depending upon the source of energy used. In order to select a suitable drying curve, six thin layer-drying models (Newton, Page, Modified Page, Henderson and Pabis, Logarithmic and Wang and Singh) were fitted to the experimental moisture ratio data. Among the mathematical models investigated, Wang and Singh model best described the drying behaviour of paddy using solar, biomass and combined heating sources with highest coefficient of determination (r 2) values and least chi-square, χ 2 , mean bias error (MBE) and root mean square error (RMSE) values. However, Page model adequately described the drying behavior of paddy using electrical heating source.

Journal of Food Engineering, 2006

Acta Alimentaria, 2015

African journal of microbiology research

BioNanoScience, 2012

International Journal of Engineering Practical Research, 2014

Physical properties of wheat grains were evaluated

Agricultural Research, 2014

Acta Alimentaria, 2014

International Agrophysics, 2014

Packaging Technology and Science, 2011

Packaging of foods in high barrier and strong materials is essential to attain food safety, and n... more Packaging of foods in high barrier and strong materials is essential to attain food safety, and nanocomposite technology leads in search of the above kind of packaging material. The effect of compatibilizer (1.6, 5, 10, 15 and 18.4%), nanoclay (0.6, 2, 4, 6 and 7.4%) and thickness of film (35, 50, 75 100 and 120 mm) on oxygen transmission rate (OTR), water vapour transmission rate (WVTR), tensile strength and per cent elongation of polypropylene (PP)-based nanocomposite films was studied using response surface methodology. The maximum reduction in OTR of PP-based nanocomposite films over the control was 21.4% in treatment having 10% compatibilizer, 4% nanoclay and 120 mm thickness. A maximum of 28.1% reduction in WVTR for the treatment with 5% compatibilizer, 2% nanoclay and 100 mm thickness over the control was achieved. The regression models were developed for the prediction of OTR and WVTR of nanocomposite films. The maximum increase in the tensile strength of PP-based nanocomposite films over the corresponding control was 71.7%. The elongation percentage of nanocomposite films was less than the control and increased with increase of thickness of film and decrease of both nanoclay and compatibilizer. Treatment having 5% compatibilizer, 2% nanoclay and 100 mm thickness of nanocomposite films showed better barrier and strength characteristics than other treatments. This paper helps to design the packaging films according to the requirement of foods to be stored using the developed regression models.

Journal of Food Science and Technology, 2014