Cornstarch, at 20% moisture content (dry basis, d.b.), was mixed with glycerol at 3:1 ratio to form the base material for extruded starch films. Stearic acid, sucrose and urea, at varying concentrations, were tested as secondary plasticizers for the starch-glycerol mixture. The ingredients were extruded at 110 and 1207C barrel temperatures to determine the effects of extrusion temperature, plasticizer type and their concentrations on the film-forming characteristics of starch, as well as their effects on selected physical and functional properties of the films. The physical and mechanical properties of the films were studied by scanning electron microscopy (SEM) and tensile testing, while the glass transition and gelatinization properties were analyzed using differential scanning calorimetry (DSC). The interactions between the functional groups of starch and plasticizers were investigated using Fourier-transform infrared (FTIR) spectroscopy. The water vapor permeability (WVP) properties of starch films were determined using ASTM standard E96-95. Scanning electron micrographs exhibited the presence of native and partially melted starch granules in the extruded films. The tensile stress, strain at break and Young's modulus of starch films ranged from 0.9 to 3.2 MPa, 26.9 to 56.2% and 4.5 to 67.7 MPa, respectively. DSC scans displayed two glass transitions in the temperature ranges of 0.1 to 17C and 9.6 to 127C. Multiple melting endotherms, including that of amylose-lipid complexes, were observed in the thermoplastic extrudates. The gelatinization enthalpies of the starch in the extruded films varied from 0 to 1.7 J/g, and were dependent largely on the extrusion temperature and plasticizer content. The shift in the FTIR spectral bands, as well as the appearance of doublepeaks, suggested strong hydrogen bonding interactions between the starch and plasticizers. The WVP of starch films ranged from 10.9 to 15.7 g mm h -1 m -2 kPa -1 , depending on the extrusion temperature and the type of plasticizer used.

Starch-based loose-fi ll packaging foams were made in a single-screw laboratoryscale extruder. Corn starch was blended with polystyrene in the ratio of 70 : 30 and extruded into foams using talc and polycarbonate as additives. Extrusions were carried out at moisture contents of 16, 18 and 20% (dry basis), and at barrel temperatures of 140 and 160ºC. The infl uences of extrusion temperature, moisture content of starch, talc and polycarbonate on the radial expansion and other selected physical properties of starch foams were investigated. The effects of moisture and talc contents on the radial expansion of foams were found to be critical, while the role of temperature was close to signifi cant. The expansion ratio increased when the moisture content was increased from 16 to 18%, and then decreased when moisture content was increased to 20%. In general, the expansion ratios of foams were higher at 160ºC as compared to 140ºC. Although polycarbonate mixed well with the starchpolystyrene melt, it was not effective as a structural and anti-shrinking agent, and it did not contribute to the radial expansion. In general, the bulk densities and unit densities of the starch foams decreased as the moisture content and extrusion temperature increased. Scanning electron microscope images showed that the addition of talc yielded foams with smaller-sized cells, with less expansion of the foam melt, and thus a higher density. X-ray diffractograms revealed that the crystallinity of starch foams increased post-extrusion, and there was adequate dispersion of the starch and polystyrene polymers to make the foam water-resistant.

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Casein and whey protein concentrate (WPC) films, plasticized with glycerol and sorbitol independently, were prepared by casting. The film thickness, water vapour and oxygen permeation and tensile and moisture sorption properties of the films were determined. The tensile strength (TS), tensile strain (TE) and elastic modulus (EM) of the films ranged from 0.71 to 4.58 MPa, 19.22 to 66.63 % and 2.05 to 6.93 MPa, respectively. The film properties were influenced by the type of biopolymer (casein and whey protein concentrate), plasticizer and its concentration. Increasing the plasticizer concentration, increased the film thickness, TE and water vapour permeability (WVP), but decreased the TS and EM. As the concentration of plasticizer increased to the highest level, the film thickness increased from 0.168 to 0.305 mm for glycerol-plasticized films and from 0.251 to 0.326 mm for sorbitol-plasticized films. The film thickness increased because the amount of plasticizer in the film network increased and the amount of biopolymer remained same. Casein films showed superior tensile properties as compared to WPC films. The WVP of both casein and WPC films lied between 3.87 and 13.97 g.mm./(m 2 .h.kPa). The moisture sorption isotherms of both films were typical of high-protein material, and were adequately described by the GAB model. The oxygen permeability of casein films was relatively lower than that of WPC films, regardless of the plasticizer used. The sensory data revealed that the organoleptic quality of Cheddar cheese was unaffected by milk-protein film packaging.

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Starch plasticized with water, glycerol, and stearic acid was extruded and sheeted into films 0.4–0.6 mm thick. The ingredients were extruded in a conical twin‐screw extruder at a temperature profile of 50–120–120–120°C and a screw speed of 45 rpm. The effects of glycerol, water, and stearic acid on selected physical and functional properties of the films were studied. The tensile strength, tensile strain at break, and Young's modulus were 0.23–2.91 MPa, 45.79–90.83%, and 2.89–37.94 MPa, respectively. Differential scanning calorimetry thermograms exhibited two glass transitions and multiple melting endotherms, including that of amylose‐lipid complexes formed during extrusion. The enthalpy of gelatinization of starch in the extruded films was 0.7–4.1 J/g and was dependent largely on the plasticizer content. Fourier‐transform infrared spectra revealed significant interactions between the starch and plasticizer but the peaks shifted to higher wave numbers with increasing glycerol content. During extrusion in the presence of glycerol, the A‐type crystalline structure of starch was transformed to B‐type. It also was observed that the Vh crystallinity increased with increase in glycerol content due to tight packing of starch chains. The water vapor permeabilities of the starch films were 12.3–19.9 g·mm/hr·m2·kPa.

The animal husbandry and livestock sectors play a major role in the rural economy, especially for the small and marginal farmers. India has the largest livestock population in the world and ranks first in the milk production. Mastitis is the most common and expensive infectious disease in dairy cattle. The global economic losses per year due to mastitis amounts to USD 35 billion and for Indian dairy industry ₹6000 crores per year. Early detection of mastitis is very important to reduce the economic loss to the dairy farmers and dairy industry. Automated methods for early and reliable detection of mastitis are currently in focus under precision dairying. Skin surface temperature is an important indicator for the diagnosis of cow’s illnesses and for the estimation of their physiological status. Infrared thermography (IRT) is a simple, effective, on-site, and noninvasive method that detects surface heat, which is emitted as infrared radiation and generates pictorial images without causing radiation exposure. In human and bovine medicine, IRT is used as a diagnostic tool for assessment of normal and physiological status.

A mathematical model to predict the shelf life of gulabjamun mix based on moisture‐induced spoilage by stickiness (caking) and nonenzymatic browning (NEB) was developed. The moisture adsorption isotherms of gulabjamun were determined at 10, 25 and 40C. The water vapor permeabilities of the packaging materials were also calculated. The critical moisture contents for stickiness and NEB to occur were determined and the moisture‐limiting shelf life was predicted. Validation of the prediction model was done by accelerated shelf life testing at 38C and 90% RH. At 4.8% moisture content, the experimental shelf life of gulabjamun mix based on stickiness and NEB was observed respectively as 41 and 54 days in low‐density polyethylene (LDPE) and 280 and >360 days in polyethylene terephthalate (PET)/Al foil/PET/LDPE pouches. The corresponding predicted values were 34 and 46 days in LDPE and 247 and 342 days in PET/Al foil/PET/LDPE, respectively. The simulation model was fairly accurate and reliable in predicting the shelf life of this product. Practical Applications Stickiness and nonenzymatic browning reactions, induced by moisture gain, affect the shelf life of gulabjamun mix. For dry powders like gulabjamun mix, having a regular shelf life of 6–12 months, accelerated shelf life testing (ASLT) is cumbersome and sometimes unfeasible. Simulation and mathematical modeling of shelf life is an alternative to long‐term ASLT. In this study, a model for predicting the shelf life of gulabjamun mix was developed, incorporating the water vapor permeability of the packaging material, the adsorption of moisture from headspace of the package and the weight of moisture in the product. The shelf life prediction will be useful to monitor the product quality and stability against deteriorative reactions. The model could also be used for shelf life estimation of new products in flexible packaging materials.