Aluminum-laminated Polyethylene Research Articles

Metabolite, volatile and antioxidant profiles of black garlic stored in different packaging materials

This study examined the levels of metabolites, volatile compounds and antioxidant activity of black garlic stored in polyethylene terephthalate bottles (PETB), Kraft paper bags (KPB) and aluminum-laminated polyethylene bags (ALPB) at 4 and 20 °C for 90 days. A total of 27 water-soluble and 96 volatile compounds were identified using NMR and GC-MS. Black garlic packaged with ALPB was markedly different from that packaged with PETB and KPB. ALPB decreased sulfur compounds and increased organic acids, heterocyclic compounds and glucose. The latter are the primary constituents of the roasted and sweet aromas of the garlic. In contrast, sucrose levels were greater for the PETB and KPB storage groups. The antioxidant activity of black garlic decreased in the order of ALPB, KPB and PETB at the same temperature. In general, storage at 20 °C promoted enzymatic hydrolysis and the Maillard reaction while storage at 4 °C maintained antioxidant activity.

Sorption behavior and storage stability of microencapsulated transglutaminase by ultrasonic spray–freeze–drying

Adsorption isotherms at 25 °C and 38 °C for microencapsulated microbial transglutaminase (mTG) powder produced by ultrasonic spray–freeze–drying (USFD), conventional spray drying (CSD), and conventional freeze–drying (CFD) methods and USFD–crude (without coating materials) were obtained using the standard static gravimetric method, and experimental data were fitted to the mathematical models. The sorption isotherms exhibited type III behavior, and the Ferro–Fontán model was selected as the best fit, having an R 2 of 0.920–0.995. The sorption isotherms of mTG powder depended on temperature and drying methods. The equilibrium moisture content decreased with increasing temperature, and the monolayer moisture content of the USFD sample was lower than other microencapsulated samples (M 0 = 0.133 kg/kg dry solids for 25 °C and M 0 = 0.080 kg/kg dry solids for 38 °C from Guggenheim–Anderson–deBoer model), followed by CFD and CSD. Furthermore, the storage stability of mTG powders produced by different methods in terms of quality parameters including enzyme activity, moisture content, water activity, color, density, porosity, flowability, and caking degree value was studied in aluminum-laminated polyethylene (ALPE) pouches under storage conditions of 25 °C, 50% relative humidity (RH) for 180 days and 38 °C, 90% RH for 90 days. Inactivation kinetics, the effect of drying methods, and application of the microencapsulation process were also examined on mTG powder during the storage period. The first-order kinetic reaction was successfully applied to the relative activity values of all samples for both storage conditions. Both the drying method and application of microencapsulation showed a significant effect on enzyme activity. When comparing the drying techniques, the USFD samples were the most stable, having 816 and 465 days of half-life times for both storage conditions, respectively. Storage at 25 °C, 50% RH increased the half-life twofold compared with that of the USFD samples kept at 38 °C, 90% RH. The physical properties of mTG powder obtained either USFD, USFD–crude, CFD, or CSD showed that moisture content and wettability values increased, while caking degree and enzyme activity values decreased during storage. USFD samples had the lowest moisture content (5.48%) and Hausner ratio (1.12) and the highest relative activity (86.2%) compared with other samples after 180 days storage at 25 °C, 50% RH. When all quality characteristics and enzyme stability were considered, the USFD method was superior to others, and it was determined to be the best method for the production of microencapsulated mTG powders. mTG powders stored at 25 °C, 50% RH exhibited a longer shelf life.

Effect of packaging materials and storage temperature on water status, mechanical and thermal properties of black garlic

Abstract We examined the effects of the packaging materials [polyethylene terephthalate bottles (PETB), Kraft paper bags (KPB) and aluminum-laminated polyethylene bags (ALPB)] and storage temperatures (4 and 20 °C) on the chemical composition, water status and mechanical and thermal properties of black garlic after 90 days of storage. We found that ALPB retained the highest levels of 5-hydroxymethylfurfural, total sugar and reducing sugars at the same temperature while PETB retained the textural properties of the garlic. Water loss and migration were serious defects in KPB and PETB at 20 ℃. The initial decomposition temperature was highest for KPB while the glass transition temperature was highest for ALPB. The samples stored in ALPB could easily be differentiated from the others using an orthogonal partial least squares-discriminant analysis model and this gave a high predictive power of 98.9 %. Taken together, low temperatures and ALPB most effectively maintained the integrity of the black garlic.

Influence of packaging materials, oxygen and storage temperature on quality of germinated parboiled rice

In this study, the effects of storage conditions of germinated parboiled rice (GPR) including packaging materials, oxygen, and temperature on its physicochemical qualities, bioactive compounds, antioxidant activity, sensory quality, and microbiological properties were investigated. GPR from purple rice (Oryza sativa var. ‘Hom Nil’) was packaged under vacuum and normal atmosphere in polyamide-polyethylene (PAPE) and aluminum-laminated polyethylene (ALPE) pouches and stored at 4 °C and 30 °C for 6 months. The results showed that storage at lower temperatures under vacuum in ALPE was effective in retarding the degradation of bioactive compounds, changes in physicochemical quality, and rancidity. Moisture content and water activity continuously declined during the storage in PAPE pouches at 30 °C while they were unchanged when stored in ALPE at 30 °C and under all conditions at 4 °C. At 30 °C, the gamma-aminobutyric acid and anthocyanins contents decreased as the storage time increased, however the contents in samples at 4 °C did not vary with time. Total phenolic content and antioxidant activities were also effectively retained under low temperature storage, especially in vacuum packaging. Rancidity of GPR determined using the thiobarbituric acid test, increased with storage time and showed a high correlation with sensory evaluation results (R2 = 0.9724). Storage at 4 °C also significantly conserved the color of GPR. In addition, bacterial count, yeast and mold count and aflatoxins content of the GPR did not exceed Thai standards under all tested conditions.

Impact of sprouting on the degradation kinetics of color and vitamin C of onion powder packaged in different packaging materials

The present investigation was engrossed to depict the feasibility of sprouting process as an efficient way to retain various quality attributes in sprouted onion powder packed in high-density polyethylene (HDPE) and aluminum-laminated polyethylene (ALP) under accelerated storage conditions (40°C ± 1°C temperature, 90% relative humidity). There was significant (p < 0.05) influence of both packaging material and storage period on the various analyzed parameters. The kinetics of color change (ΔE) and vitamin C degradation followed zero-order and first-order reaction, respectively, with the type of packaging material affecting the reaction rate constants. Sprouted onion powder was found to retain quality characteristics with lower moisture content, better flowability, less color, and vitamin C degradation in both HDPE and ALP throughout the storage period. The intensity of quality degradation suggested the application of sprouting as an efficient tool to enhance the storage stability of onion powder. Practical applications This research shows less degradation of color and vitamin C with maximum retention of quality index parameters in sprouted onion powder as compared to raw onion powder. The findings revealed that the process of sprouting can be used to enhance the storage life of onion products with improved quality parameters. The research is also valuable in terms of promoting exploitation of sprouted onions by preparing various products which can alleviate the problem of postharvest losses and environmental concerns arising as a result of sprouted onion disposal.

Moisture sorption isotherms and quality characteristics of onion powder during storage as affected by sprouting

The present investigation was carried out to study the impact of sprouting on the moisture sorption isotherm at 20, 30, 40 and 50 °C and storage study at 25 °C of onion powder developed from PRO-6 variety using a gravimetric technique. The sorption isotherms obtained were of typical type II sigmoidal curves according to BET classification. The experimental data obtained was fitted to mathematical models (GAB, BET, Oswin, Smith, Caurie, Iglesias and Chirife, and Halsey). A non-linear least square regression analysis was used to evaluate the model constants. The GAB model followed by BET, Oswin and Smith best fitted the experimental data. The effect of storage time on the physicochemical properties of onion powder packed in low-density polyethylene (LDPE), aluminum laminated polyethylene (ALP) and glass was evaluated at ambient temperature (25 °C) condition. Storage stability of onion powder in terms of moisture content, colour parameters, bulk density and flowability varied to a different extent during storage, in three different types of packaging materials. In all the types of packaging materials, sprouted onion powder showed minimum changes in all analyzed physicochemical properties as compared to raw onion powder during storage. The extent of the change in physicochemical composition suggested the use of sprouting process for long-term storage of onion powders in ALP and glass packaging.

Thermodynamics of sorption isotherms and storage stability of spray dried sweetened yoghurt powder.

Sorption isotherm is a quantitative approach to predict the shelf life of dried foods. Adsorption isotherms of spray dried sweetened yoghurt powder (SYP) were determined by static gravimetric technique at 20, 30, 40 and 50°C. The data obtained were fitted to eight different sorption models. A non-linear least square regression analysis was adopted to evaluate the model constants. The experimental sorption data were best fitted to four parameter Peleg model. The monolayer moisture contents found from GAB model were 4.88, 4.54, 3.86 and 3.52% at 20, 30, 40 and 50°C, respectively. The maximum net isosteric heat of sorption and sorption entropy of SYP were 9.399kJ/mol and 20.28J/molK, respectively. The Gibb's free energy change for sorption was in the range 3436.19-303.91J/mol. The storage stability in terms of moisture content, thiobarbituric acid, free fatty acid, hydroxymethyl furfural values and starter counts of SYP packed in aluminium laminated polyethylene (ALPE) and low density polyethylene (LDPE) were studied along with their change kinetics. The relationship between the water vapour permeability of packaging materials and adsorbed moisture (determined from GAB equation) in powder was used to predict the shelf life and was predicted as 28 and 44.44days in LDPE and ALPE pouches, respectively.

Storage stability, color kinetics and morphology of spray-dried soursop (Annona muricata L.) powder: effect of anticaking agents

ABSTRACTSoursop is a tropical fruit that undergoes postharvest deterioration rapidly. Conversion into powder is an ave nue to value-add the fruit as it helps to reduce postharvest losses. Although powder production is not complicated, studies have shown that caking is a common problem often associated with fruit powders. Thus, an addition of a food additive is needed to improve the storage stability of powders. In this study, soursop powder was produced by spray-drying an enzyme-liquefied soursop puree incorporated with either tricalcium phosphate (TCP) or calcium silicate (CS), at three different concentrations (0.5, 1.0, and 1.5% w/w). The control was considered powder without the addition of anticaking agent. Storage stability of the powder packed in aluminum-laminated polyethylene (ALP) pouches was examined at conventional (25 ± 1°C) and accelerated (38 ± 1°C) temperatures for 91 days until lumpiness was observed. Statistical analysis showed that the addition of anticaking agent significantly (p ≤ 0.05) improved the process yield of powder (7.2%). The moisture content, water activity, density, and water solubility index of the powder were significantly affected by storage time, storage temperature, and concentration of the anticaking agents. The critical moisture content, Xc, for control and powder incorporated with either TCP or CS was 0.07 g H2O/g ds. The total color difference (ΔE) of the powder increased throughout the storage period, followed by a zero-order kinetic reaction. Kinetics-derived Arrhenius model showed that the activation energy (Ea) of color change ranged between 6.5 and 17.3 kJ/mol. Scanning electron microscopy showed that the freshly spray-dried powder was composed of spherical particles with smooth surfaces but these particles tended to agglomerate and form liquid bridges after storage for 91 days. Overall, TCP and CS exhibited a protective effect by lowering moisture adsorption and improved the glass transition temperature of the powder.

Effect of packaging materials and storage on quality attributes of freeze dried pineapple lassi powder for defence applications

The study evaluates the effect of two different packaging materials on storage stabililty of and instant fruit-dairy functional beverage mix. Freeze dried Pineapple lassi (PL) powder was packaged in Aluminium Laminated Polyethylene (ALP) and Metallised Polyester (MP). Quality changes at elevated temperature conditions (38±1°C, 33 % relative humidity) were evaluated. Shelf life was calculated to be 44 and 62 days in MP and ALP pouches, respectively. Moisture, water activity, Vitamin C, Lactococci, TBA, colour change and Browning Index were studied in both packaging materials. ALP was found to be better than MP as samples kept in ALP preserved most of the antioxidant properties. The kinetics of Vitamin C degradation was of first order (K=-0.017 , R2= 0.99). Moisture content increased and l&lt;em&gt;actococci &lt;/em&gt; count decreased during storage

Effect of Nitrogen Gas Enriched Packing on Quality and Storage Life of Pearl Millet Based Fried Snack

Purpose: The storage life of pearl millet-based, deep fried, ready-to-eat snacks, packaged in aluminum-laminated polyethylene having a thickness of 50 μm (with and without nitrogen) was evaluated under storage conditions of 38±2°C and 90% RH. Methods: The moisture content, free fatty acids (FFA), peroxide value, and crispness of the snack were evaluated throughout the storage period. The moisture content, FFA, and peroxide value increased with an increase in storage period, but the increase was less in packages flushed with nitrogen gas. The crispness decreased with an increase in the storage period, for snacks both with and without nitrogen packages. However, the decrease was less in nitrogen-flushed packages. FFA and peroxide values were strongly correlated with the moisture content of the snack. The storage life of the snack was found to be 60 and 45 days in packages with and without nitrogen respectively. Conclusions: The snack`s predicted storage life, for snacks with and without nitrogen packages, was determined as 294 and 254 days respectively.

Quality assessment and shelf life prediction of spray dried tamarind pulp powder in accelerated environment using two different packaging materials

Tamarind pulp powder (TPP) was produced using optimum spray drying conditions, packed in two different packaging materials viz., aluminium laminated polyethylene (ALP) and 4-ply laminate pouches (polythene-aluminium-polythene-paper) and stored under accelerated conditions (40 ± 1 °C temperature, 90 % relative humidity). The powder was analyzed for various quality parameters (moisture content, color, acidity, and powder flowability) at an interval of 7 days upto 70 days of storage period. Both packaging material and storage period showed significant effect on the powder properties. Kinetic study of color change of tamarind pulp powder during storage revealed that color change followed zero order reaction kinetics with a rate constant of 0.495 and 0.369 for the powder packed in ALP and 4-ply laminate, respectively. The magnitude of quality changes of TPP measured during accelerated storage suggested that 4-ply laminate was better than ALP for long term storage of spray dried TPP. The shelf life of TPP under accelerated storage condition was predicted on the basis of flowability of the powder and was calculated to be 53 and 66 days in ALP and 4-ply laminate, respectively.

Shelf-life and kinetics of quality change of dried pomegranate arils in flexible packaging

• GAB model was found best fit between moisture content and water activity. • Shelf-life of dried arils was predicted 187 and 96 days in ALP and HDPP pouches, respectively. • Quality changes during storage of dried arils followed zero order kinetics. Pomegranate arils were dried by microwave-vacuum drying technique and later packaged in pouches of high density polypropylene (HDPP) and aluminum laminated polyethylene (ALP). The shelf-life of dried pomegranate arils was predicted on the basis of change in color of the product under accelerated storage conditions (38 ± 1 °C, 90 ± 1% relative humidity (RH)) which was estimated to be 96 and 187 days in HDPP and ALP, respectively. The changes in quality parameters such as anthocyanin, phenolics, total soluble solids (TSS) (°brix) and titrable acidity (TA) were studied in the selected packaging materials. The magnitude of quality change of dried pomegranate arils measured during storage suggested that ALP has better protective effect than the HDPP. The kinetics of quality parameter change was of zero order.

Shelf life and storage stability of spray-dried bovine colostrum powders under different storage conditions.

Spray dried bovine colostrum (SDBC) powders were packaged in aluminium-laminated polyethylene (ALPE) and polyethylene terephthalate (PET) pouches and then stored under different conditions (25°C and 50% relative humidity (RH), 4°C and 40-70% RH, 50°C and 20-50% RH). The shelf life of SDBC powder was evaluated as 425.5 and 86.5days in ALPE and PET pouches under 25°C and 50% RH, respectively. The storage stability of SDBC powder in terms of quality parameters including thiobarbituric acid (TBA), hydroxymethyl furfural (HMF), colour change, moisture content and IgG concentration was studied in both packaging materials under different storage conditions. Results showed that ALPE pouches were more suitable for packaging SDBC powder than PET pouches and storage condition of 4°C and 40-70% RH was relative suitable for keeping quality of SDBC powder. The glass transition concept was helpful for evaluating the chemical stability of SDBC powder during storage.

Storage stability of freeze-dried colostral whey powders with different additives.

Effects of different additives (sucrose and maltodextrin) on storage stability of colostral whey (CW) powders packaged in aluminium-laminated polyethylene pouches were investigated under different storage conditions (4℃ and 40%-70% relative humidity (RH), 25℃ and 50% RH, and 50℃ and 20%-60% RH). All the samples stored under 50℃ and 20%-60% RH showed the highest levels of lipid oxidation, Maillard reaction, proteolysis, and color difference, and the lowest immunoglobulin G (IgG) retention. Moisture contents showed an increase trend with increasing RH. Addition of sucrose into CW powders increased water adsorption capacity and Maillard reaction, whereas addition of maltodextrin showed the opposite effects. Maltodextrin as drying aids was suitable for keeping quality during storage. Sucrose did not clearly play any roles in protecting denaturation of IgG during 90-day storage. The low storage temperature and RH were helpful for keeping storage stability of CW powders with different additives.

Moisture Sorption Isotherms and Storage Stability of Spray-Dried Yogurt Powder

Moisture adsorption isotherms of spray-dried yogurt powder were determined at 10, 25, and 40°C using the standard, static-gravimetric method. Experimental data were fitted to five mathematical models (Guggenheim-Anderson-de Boer [GAB], Brunauer-Emmett-Teller [BET], Halsey, modified Oswin, and modified Henderson). A nonlinear regression analysis method was used to evaluate the constants of the sorption equations. The shelf-life of yogurt powder was predicted based on the relationship between permeability coefficient of the packaging material and moisture adsorbed by the powder determined by the GAB equation. Furthermore, the storage stability of spray-dried yogurt powder in terms of quality parameters including moisture content, water activity, color change, and thiobarbituric acid (TBA) value was studied in aluminum laminated polyethylene (ALPE) pouches under storage conditions of 25°C and 50% relative humidity (RH).

Storage stability of jackfruit ( Artocarpus heterophyllus) powder packaged in aluminium laminated polyethylene and metallized co-extruded biaxially oriented polypropylene during storage

Total colour difference (Δ E), rates of adsorbed moisture and sensory attributes of drum-dried jackfruit powder packaged in aluminium laminated polyethylene (ALP) and metallized co-extruded biaxially oriented polypropylene (BOPP/MCPP) pouches stored at accelerated storage (38 °C, with 50%, 75% and 90% relative humidity (RH)) were determined over 12 weeks period. The changes in total colour followed zero order reaction kinetics. Packaging materials, storage temperature and RH values significantly ( p < 0.05) influenced the rates of adsorbed moisture of jackfruit powder. There was a significant ( p < 0.05) decrease in the intensities of the fruity odour, taste and increase in the lumpiness of the jackfruit powder stored at 38 °C with 90% RH. The shelf life of jackfruit powder stored at 38 °C and 90% RH was limited by overall acceptability and the intensity of fruity odour, taste and lumpiness at week 8 of storage. Jackfruit powder stored at 28 °C remained stable and acceptable throughout the storage period for all RH values. The powder packaged in ALP significantly ( p < 0.05) reduced total colour change, rates of adsorbed moisture, lumpiness intensity of jackfruit powder and was rated higher in terms of overall acceptability over BOPP/MCPP. Results of this study suggested that ALP packaging with storage conditions of 28 °C and RH less than 75% was better suited for keeping jackfruit powder.

Toward Novel Flexible Display - Top-Emitting OLEDs on Al-Laminated PET Substrates

We developed a flexible organic LED (OLED) using a top-emitting OLED (TOLED) architecture. The concept of our flexible OLED design is based on integration of a TOLED structure on an aluminum-laminated polyethylene terephthalate (Al-PET) substrate. Microcavity TOLEDs were formed for color tuning and efficiency enhancement. For a flexible TOLED with a 110-nm-thick poly (p-phenylenevinylene) light-emitting layer, it exhibited a luminous efficiency of 4.6 cd/A at 10 V. The performance of a TOLED made on a plastic substrate is analyzed and compared with that of the identical device on a rigid glass substrate. It is demonstrated that the flexible TOLED on Al-PET foil can be bent to a substantial degree without breaking.

Flexible top-emitting electroluminescent devices on polyethylene terephthalate substrates

An aluminum-laminated polyethylene terephthalate (Al-PET) is used as the substrate for flexible organic light-emitting devices (OLEDs). The efficient flexible electroluminescent devices have a top-emitting OLED architecture. An acrylic layer is formed on the Al-PET surface to improve the surface morphology and also the adhesion between the substrate and the anode. Poly(styrene sulfonate)-doped poly(3,4-ethylene dioxythiophene) was used as hole transporting layer. The light-emitting polymer used is a phenyl-substituted poly(p-phenylenevinylene). Bilayer anodes of Ag∕CFX and Ag/indium-tin oxide and a semitransparent top cathode were used for the flexible polymer OLEDs. For a flexible polymer OLED with a 110-nm-thick light-emitting polymer, it exhibited superior electrical and optical characteristics with a luminous efficiency of 4.56cd∕A at an operating voltage of 7.5V.

Storage stability of mango soy fortified yoghurt powder in two different packaging materials: HDPP and ALP

Mango soy fortified yoghurt (MSFY) powder was obtained after recirculatory convective drying, conditioning and grinding and was packaged in pouches of high density polypropylene (HDPP) and pouches of aluminium laminated polyethylene (ALP) pouches. The shelf life of MSFY powder was predicted on the basis of free flowness of product under accelerated storage condition (38 ± 1 °C, 90% relative humidity) and was calculated to be 45 and 54 days in HDPP and ALP, respectively. The storage stability of MSFY powder in terms of quality parameters free fatty acid (FFA), thiobarbituric acid (TBA), hydroxymethyl furfural (HMF), starter counts and colour change was studied in both packaging materials. The magnitude of quality change of MSFY powder measured during storage suggests that ALP was better than HDPP. The kinetics of quality parameter change was of zero order.

An efficient top-emitting electroluminescent device on metal-laminated plastic substrate

ABSTRACTAn efficient flexible top-emitting organic light-emitting device (OLED) was fabricated on an aluminum-laminated polyethylene terephthalate substrate. A spin-coated light-emitting polymer layer was sandwiched between a silver anode and a multi-layered semitransparent cathode. The performance of polymer OLEDs was analyzed and compared with that of the devices having a conventional structure. An optical microcavity formed in the device enables to tune the emission color by varying the thickness of the active polymer layer. The OLEDs having a 110-nm-thick active polymer layer exhibited superior electroluminescence performance, with a turn-on voltage of 2.5V and a luminance efficiency of 4.56 cd/A at an operating voltage of 10V.