Clear Polyethylene Terephthalate Research Articles

Evaluation of Steady-State and Time-Resolved Fluorescence Spectroscopy as a Method for Assessing the Impact of Photo-Oxidation on Refined Soybean Oils.

The type of material used in packaging, lighting, and storage time can impact food quality during storage. This study aimed to investigate the progress of photosensitized oxidation in refined soybean oil using steady-state and time-resolved fluorescence spectroscopy. The experiment was conducted through accelerated photo-oxidation with Light-Emitting Diode (LED) in samples stored for ten days at room temperature (26.0 ± 2.0 °C) in clear polyethylene terephthalate (PET) packaging of different colors and different transmission spectra in the UV and visible range. Emission spectra were obtained with excitation at 373, 405, and 500 nm, resulting in two main emission peaks: the first with maximum emission between 430 and 555 nm and the second at around 660 nm. Fluorescence decay curves were obtained with excitation at 340 and 405 nm. The results indicated that transparent PET bottles are not effective in protecting soybean oil from photosensitized oxidation under the studied conditions. Strong correlations were observed between fluorescence parameters and peroxide and conjugated diene values, indicators of lipid oxidation progress. Fluorescence spectroscopy has several advantages over traditional methods as it is a simple, fast, low-cost, and low-waste technique.

Different methods for returning PET into the economic cycle: A review

Polyethylene terephthalate (PET) is a saturated polyester, which is widely utilized in the production of films, bottles, and fibers in terms of its excellent thermal stability, clarity, strength, and moldability. PET waste has increased as the manufacture and consumption of PET bottles have increased. Major environmental and financial problems have resulted from the disposal of PET bottle waste. Both clear PET bottles and colorful PET bottles are recycled using various methods. However, it is possible to recycle PET trash by chemically replicating the monomers, separating them, and creating new PET from them. Here, we review the synthesis, characterization, and different methods for PET recycling as well as the commercial exploitation associated with the recycling and re-use of them.

Circular economy for sustainable packaging

Circular economy for sustainable packaging

Insight into the Storage-Related Oxidative/Hydrolytic Degradation of Olive Oil Secoiridoids by Liquid Chromatography and High-Resolution Fourier Transform Mass Spectrometry.

The study of negative effects potentially exerted by the exposure to oxygen and/or light and, thus, also by the type of container on the quality of extra virgin olive oil (EVOO) during its prolonged storage requires an appropriate choice of analytical methods and components to be monitored. Here, reverse-phase liquid chromatography coupled to high-resolution/accuracy Fourier transform mass spectrometry with electrospray ionization was exploited to study oxidative/hydrolytic degradation processes occurring on the important bioactive components of EVOO known as secoiridoids, i.e., oleuropein and ligstroside aglycones, oleacin, and oleocanthal, during storage up to 6 months under controlled conditions. Specifically, isomeric oxidative byproducts resulting from the transformation of a carbonylic group of the original secoiridoids into a carboxylic group and compounds resulting from hydrolysis of the ester linkage of secoiridoids, i.e., elenolic and decarboxymethyl elenolic acids and tyrosol and 3-hydroxytyrosol, were monitored, along with their precursors. Data obtained from EVOO storage at room temperature in glass bottles with/without exposure to light and/or oxygen indicated that, although it was more relevant if a periodical exposure to oxygen was performed, a non-negligible oxidative degradation occurred on secoiridoids also when nitrogen was used to saturate the container headspace. In a parallel experiment, the effects of storage of the same EVOO (250 mL) for up to 6 months in containers manufactured with different materials/shapes were considered. In particular, a square dark glass bottle, a stainless-steel can, and a ceramic jar, typically used for EVOO commercialization, and a clear polyethylene terephthalate bottle, purposely chosen to prompt secoiridoid degradation through exposure to light and oxygen, were compared. Dark glass was found to provide the best combined protection of major secoiridoids from oxidative and hydrolytic degradation, yet the lowest levels of oxidized byproducts were observed when the stainless-steel can was used.

Characterization of Antimony Leaching from Polyethylene Terephthalate Bottles by X-Ray Photoelectron Spectroscopy

X-ray photoelectron spectroscopy (XPS) is a really specific and sensitive method for surface analysis. The monitoring of antimony concentrations in polyethylene terephthalate (PET) bottles by XPS analysis is a new method for the characterization of bottled water contamination by antimony which frequently comes into contact with food and drink. The elevation of Sb concentrations in bottled waters is mainly due to Sb2O3 being used as a catalyst in the manufacture of PET. In this study, using a sensitive XPS determination of Sb in PET bottle materials, we observed that the water became contaminated with Sb during storage. Because the color of PET material may have an impact on the leaching of antimony, clear and blue PET bottle materials were analyzed separately and the results were compared directly. The main difference between the previous analyses and this study is that we analyzed only bottle plastic material rather than the water itself.

Preharvest β-aminobutyric acid treatment alleviates postharvest deterioration of ‘Bluecrop’ highbush blueberry fruit during refrigerated storage

We examined the effect of preharvest β-aminobutyric acid (BABA) treatment on postharvest quality and the softening of ‘Bluecrop’ highbush blueberry fruit during postharvest refrigerated storage. Reddish purple-colored fruit on shrubs were treated with 20 mM BABA and harvested 7 days after treatment when they turned dark purple. The harvested fruit were stored in clear polyethylene terephthalate clamshells at 2 °C for up to 20 days. Preharvest BABA treatment significantly delayed color changes, enhanced individual soluble sugars and organic acids, and reduced decay incidence. BABA-treated fruit also retained higher skin firmness throughout the storage period. Cell wall materials, closely associated with fruit softening, were significantly higher in BABA-treated fruit than in control. Moreover, preharvest BABA treatment significantly enhanced fruit pectin content at harvest and reduced activities of polygalacturonase and endo-1,4-β-xylanase, although hemicellulose content was unchanged. These results suggest that preharvest BABA treatment alleviates the deterioration of postharvest quality in ‘Bluecrop’ highbush blueberry fruit including skin firmness during refrigerated storage.

Estimating the flow of recyclable items and potential revenue at a waste bank: the case in Malang City, Indonesia

In some Southeast Asian countries, there has been a new approach to waste recycling called “waste banks,” which aims to encourage community members to recycle and develop sustainable waste management. This study investigated the waste banks using Bank Sampah Malang (BSM) in Malang City, Indonesia, as a case study. The aim of this study was to determine the flow of recyclables and which recyclables should be separated by participants of waste banks to effectively earn revenue. The second aim was to estimate the potential revenue from recyclables in the waste bank system. Detailed data, such as weight by recyclable material type, were collected from January 2 to April 4, 2013. There were five groups that participated at BSM, one of which [communities (COM) consisting of a minimum of 20 households] contributed the majority of the recyclables that were submitted to the BSM (72%). In the case of COM, only 14 of the 70 categories, including waste paper, clear polyethylene terephthalate bottles, and polypropylene cups for drinking water, generated 80% of the profit and the other items should be eliminated from the list to avoid overwhelming the participants. This study found that households can earn an average of 322,000 Rp (23.2 USD) per year from waste reclamation. The managers of waste banks can emphasize that this amount is sufficient to by school supplies for children in campaigns promoting BSM.

A Compact Closed-Loop Optogenetics System Based on Artifact-Free Transparent Graphene Electrodes.

Electrophysiology is a decades-old technique widely used for monitoring activity of individual neurons and local field potentials. Optogenetics has revolutionized neuroscience studies by offering selective and fast control of targeted neurons and neuron populations. The combination of these two techniques is crucial for causal investigation of neural circuits and understanding their functional connectivity. However, electrical artifacts generated by light stimulation interfere with neural recordings and hinder the development of compact closed-loop systems for precise control of neural activity. Here, we demonstrate that transparent graphene micro-electrodes fabricated on a clear polyethylene terephthalate film eliminate the light-induced artifact problem and allow development of a compact battery-powered closed-loop optogenetics system. We extensively investigate light-induced artifacts for graphene electrodes in comparison to metal control electrodes. We then design optical stimulation module using micro-LED chips coupled to optical fibers to deliver light to intended depth for optogenetic stimulation. For artifact-free integration of graphene micro-electrode recordings with optogenetic stimulation, we design and develop a compact closed-loop system and validate it for different frequencies of interest for neural recordings. This compact closed-loop optogenetics system can be used for various applications involving optogenetic stimulation and electrophysiological recordings.

Retail lighting and packaging influence consumer acceptance of fluid milk

Little is known about the effect of retail light-emitting diode (LED) exposure on consumer acceptance of milk. The study objective was to determine effects of fluorescent and LED lighting under retail storage conditions on consumer acceptance of milk. Consumer acceptance of milk stored under retail conditions was determined through sensory evaluation (2 studies; n=150+ each) and analytical measures (dissolved oxygen, secondary oxidation products, riboflavin retention). Study 1 evaluated milk stored in high-density polyethylene (HDPE) packages for 4h under LED light (960 lx). Commercially available HDPE package treatments included translucent HDPE (most commonly used), white HDPE [low concentration (1.3%) TiO2], and yellow HDPE; in addition, HDPE with a higher TiO2 concentration (high white; 4.9% TiO2) and a foil-wrapped translucent HDPE (control) were tested. Translucent and control packages also were tested under fluorescent light. Study 2 evaluated polyethylene terephthalate (PET) packages for 4h under fluorescent and LED light (1,460 lx). The PET packaging included 2 treatments (medium, 4.0% TiO2; high, 6.6% TiO2) as well as translucent HDPE (exposed to fluorescent), clear PET (fluorescent and LED), and light-protected control. Overall mean acceptability of milk ranged from “like slightly” to “like moderately” with significantly lower acceptability for milk exposed to fluorescent light. Milk in HDPE and PET packages had comparable overall acceptability scores when exposed to LED light. Only the fluorescent light condition (both PET and HDPE) diminished overall acceptability. Fluorescent light exposure negatively influenced flavor with significant penalty (2.0–2.5 integers) to overall acceptability of milk in translucent HDPE and clear PET. The LED also diminished aftertaste of milk packaged in translucent HDPE. Changes in dissolved oxygen content, as an indication of oxidation, supported the observed differences in consumer acceptance of milk stored under fluorescent and LED light. Consumers like the flavor of fresh milk, which can be protected by selecting appropriate packaging that blocks detrimental light wavelengths.

Design of a reverse logistics network for recyclable collection in Nova Scotia using compaction trailers

ABSTRACTAs municipal and regional initiatives for the collection of recyclable products, such as plastic, metal, glass, paper, etc., are increasing across the globe, designing collection networks to minimize collection costs and reduce associated greenhouse gas emissions are becoming important. In this study, a two-phase mathematical decomposition model for the collection of multiple recyclable products using compaction trailers is presented. In the first phase of the decomposition, compaction trailer routes for each product type are generated by repeatedly solving instances of the route-generation subproblem. In the second phase, a mixed integer linear programming is formulated for route selection and solved to determine the optimal combination of scenarios generated in the first phase to minimize total collection costs. A case study was conducted in the Canadian province of Nova Scotia using this approach for the collection of clear polyethylene terephthalate and aluminium cans. Numerical results show that the proposed optimization methodology can reduce current collection costs by 53.7%. The route configuration corresponding to this solution uses compaction trailers to pick-up approximately 85.1% of the two recyclable products investigated in this study, with the remaining collected using conventional trailers.

Microbial and chemical safety of non-commercially packaged water stored for emergency use.

Water storage is one of the most important components of emergency preparedness. Potable water is needed for ensuring the survival and well-being of disaster victims. Consumers may store water in previously used beverage or other food-grade containers for emergency use; however, this practice poses potential safety risks. Water stored in various containers for emergency purposes in residences within the state of Utah was tested for various contaminants. Of 240 samples, seven contained coliforms and 14 samples had free chlorine levels over the Environmental Protection Agency (EPA) 4 parts per million limit. There was a negative correlation between chlorine levels and age of water. The probability that a container had free chlorine present decreased by 4% for each month of storage, suggesting the importance of preventing subsequent contamination of water during storage and use. Water in clear polyethylene terephthalate plastic soda bottles (n=16), even when stored for >18 months, did not exceed 0.3 parts per billion (ppb) antimony, a level significantly lower than the EPA limit of 6.0 ppb antimony. These results support the practice of utilizing previously used containers, when properly cleaned and chlorinated, for emergency water storage.

Effect of packaging material headspace, oxygen and light transmission, temperature and storage time on quality characteristics of extra virgin olive oil

The effect of packaging parameters (transmission to light and oxygen, headspace volume) and storage temperature on quality characteristics of extra virgin olive oil (EVOO) was studied as a function of storage time (0–12 months). Packaging materials tested included clear glass, clear polyethylene terephthalate (PET), clear PET + UV blocker, clear PET covered with aluminum foil and clear polypropylene (PP) bottles. Quality parameters monitored over the 12 month storage period included: acidity, peroxide value (PV), spectrophotometric indices ( K 232, K 270) and color. Results showed that the best packaging material for olive oil packaging was glass followed by PET. PP proved to be unsuitable for such an application. Exposure of olive oil samples to light, high storage temperatures (35 °C) and large headspace volumes caused substantial deterioration in product quality parameters. The most pronounced effect was that of temperature and light while the smallest effect was that of headspace volume and packaging material permeability to oxygen. Olive oil color was not substantially affected by storage conditions with the exception of storage of olive oil at 35 °C exposed to light for 12 months. Shelf life of extra virgin olive oil was 6 months packaged in clear glass in the dark at temperatures up to 22 °C; 3 months in clear PET in the dark at 22 °C and less than 3 months in clear PP in the dark at 22 °C. When exposed to light, shelf life of olive oil was 9 months when packaged in PET + aluminum foil; 3 months in PET + UV blocker and less than 3 months in clear PET at 22 °C. Product shelf life was less than 3 months at 35 °C. Finally oxygen in the headspace of olive oil resulted in deterioration of product quality. The relative contribution of parameters studied to the retention of olive oil quality was: temperature ≈ light > container headspace > packaging material oxygen permeability.

Depth profiling of coil coating using step-scan photoacoustic FTIR

Photoacoustic (PA) Fourier Transform Infrared Spectroscopy (FTIR) has been demonstrated to be very useful in the analysis of molecular distribution and/or degradation in polymeric materials in a non-destructive manner. Step-scan (SS) PA FTIR has been found to be especially suitable to depth profile multi-layered polymer coating/laminate systems. In this current study, the capability of SSPA-FTIR in assessing industrial coil coatings was evaluated. Two multi-layered model coil coating samples were prepared, one had a pigmented Polyvinylidene Fluoride (PVdF) top coat and the other had a clear Polyethylene Terephthalate (PET) laminate film on the surface; both were depth profiled by SSPA-FTIR. The signal magnitude and phase angle were used to obtain a modulation frequency and a phase angle resolved depth profile, respectively. The advantages and disadvantages of the technique were also investigated. Optical microscopy was used to determine the true thicknesses of the PET and PVdF layers from the sample cross-sections. The values were compared with those predicted by SSPA-FTIR. It was found that a precise depth profile was only obtained with the PET sample whereas in the high pigmented coating system, the predicted values were smaller than the true PVdF thickness, possibly due to the high thermal diffusivity of the inorganic pigment.

Effect of package light transmittance on the vitamin content of milk, part 3: Fortified UHT low‐fat milk

AbstractThis work is the third and last part of a milk study evaluating the effect of package light transmittance on the vitamin content of milk, in this case on fortified UHT low‐fat milk. The milk was stored under light with an intensity of 700 lux in polyethylene terephthalate (PET) bottles with varying light transmittance to monitor the changes in the vitamin A, B2 and D3 contents over a storage period of 12 weeks at 23°C. Milk packed in pigmented PET bottles with the lowest light transmittance, which was stored in the dark under the same experimental conditions, served as the ‘control’ sample. In clear PET bottles, a reduction of 93% of the initial content was observed for vitamin A and 66% for vitamin D3, while the vitamin B2 content was completely degraded. In all pigmented PET bottles, the vitamin retention was only slightly higher; the losses ranged between 70 and 90% for vitamin A, between 63 and 95% for vitamin B2, and between 35 and 65% for vitamin D3 depending on the pigmentation level. In the dark‐stored ‘control’ sample, a 16% loss could be observed for vitamin A, while the level of vitamins B2 and D3 remained almost stable. Copyright © 2008 John Wiley & Sons, Ltd.

Effect of package light transmittance on vitamin content of milk. Part 2: UHT whole milk

AbstractThis work is the second part of a milk study evaluating the effect of package light transmittance on the vitamin content of milk, in this case on UHT whole milk. The milk was stored at three different light intensities in polyethylene terephthalate (PET) bottles with varying light transmittance as described by Saffert et al. (2006). Changes in the vitamin A, B2 and D3 content were monitored over a storage period of 12 weeks at 23°C. Losses in vitamins A and B2 were most pronounced in completely transparent PET bottles exposed to the highest light intensity. In these bottles, a reduction of the light intensity reduced the vitamin A loss from 88 to 66%, while in the case of vitamin B2 the complete decomposition was just delayed from 4 to 8 weeks storage. The vitamin D3 losses in clear PET bottles were almost independent of the light intensity. For pigmented PET bottles, the impact of package light transmittance and light intensity differed for each vitamin. An increase in package light transmittance and light intensity was found to be most decisive for vitamin B2 stability. In the case of vitamin D3, only the increase in light intensity was found to be of relevance, whereas for vitamin A stability the influence of increased package light transmittance and light intensity could not be clearly observed. In dark‐stored ‘control’ samples, the analysed vitamins were almost stable. Copyright © 2007 John Wiley & Sons, Ltd.

Effect of package light transmittance on the vitamin content of pasteurized whole milk

Pasteurized whole milk (3% fat) was stored under fluorescent light at 8°C in clear 1 litre polyethylene terephthalate (PET) bottles and three variants of pigmented PET bottles with different light transmittance. Changes in the vitamin content were monitored over a period of 10 days. Milk packed in pigmented PET bottles with the lowest light transmittance, which was stored in the dark under the same experimental conditions, served as the ‘control’ sample. Data were obtained for vitamin A (retinol), vitamin B2 (riboflavin) and vitamin B12 (cobalamin) content. Standard plate counts were determined to ensure an acceptable microbiological status of the pasteurized milk during the sampling period. In clear PET bottles a reduction of 22% of the initial content was observed for vitamin A and 33% for vitamin B2, while the vitamin B12 content remained almost stable. In all pigmented PET bottles the vitamin retention was significantly higher; the losses were 0–6% for vitamin A and 11–20% for vitamin B2, depending on the pigmentation level, as compared to 6% for vitamin A and no significant loss for vitamin B2 in the ‘control’ sample. An impact of the package light transmittance on the vitamin B12 content could not be observed. Copyright © 2006 John Wiley & Sons, Ltd.

Effect of light transmittance and oxygen permeability of various packaging materials on keeping quality of low fat pasteurized milk: chemical and sensorial aspects

Abstract Chemical and sensory changes in low fat (15 g kg −1 ) pasteurized milk stored under fluorescent light at 4°C in 500 mL bottles made of (a) multilayer pigmented [HDPE (high-density polyethylene)+20 g kg −1 TiO 2 /HDPE+40 g kg −1 carbon black/HDPE+20 g kg −1 TiO 2 ], (b) monolayer pigmented [HDPE+20 g kg −1 TiO 2 ], (c) clear PET (polyethylene terephthalate) and (d) pigmented [PET+20 g kg −1 TiO 2 ] were monitored for a period of 7 days. Milk packaged in coated paperboard cartons and stored under the same experimental conditions served as the “control” sample. Data were obtained for lipid oxidation, vitamin A and riboflavin content, microbial growth and sensory attributes (odour and taste). Results showed good protection of milk packaged in all packaging materials with regard to microbiological and chemical parameters assessed over the 7-day test period. Vitamin A losses recorded were 11% for multilayer and monolayer pigmented HDPE and pigmented PET bottles vs. 16% for the paperboard cartons and 31% for the clear PET bottles after 7 days of storage. Respective losses for riboflavin were 28% for the multilayer pigmented HDPE bottle and the paperboard carton, 30% for the monolayer pigmented HDPE bottle, 33% for the pigmented PET bottle and 40% for the clear PET bottle. Based on sensory analysis the shelf life of low fat (15 g kg −1 ) pasteurized milk is approximately 5 days. The best overall protection for the product was provided by the multilayer followed by the monolayer TiO 2 -pigmented HDPE bottle. Such packaging materials are recently emerging in the fresh milk packaging market.

Stability of alprazolam, chloroquine phosphate, cisapride, enalapril maleate, and hydralazine hydrochloride in extemporaneously compounded oral liquids.

The stability of five drugs commonly prescribed for use in oral liquid dosage forms but not commercially available as such was studied. Alprazolam 1 mg/mL, chloroquine phosphate 15 mg/mL, cisapride 1 mg/mL, enalapril maleate 1 mg/mL, and hydralazine hydrochloride 4 mg/mL were each prepared in a 1:1 mixture of Ora-Sweet and Ora-Plus (Paddock Laboratories), a 1:1 mixture of Ora-Sweet SF and Ora-Plus, and cherry syrup and placed in 120-mL amber clear polyethylene terephthalate bottles. Three bottles of each liquid were stored at 5 degrees C and three at 25 degrees C, all in the dark. Samples were taken initially and at various times up to 60 days for analysis by high-performance liquid chromatography and assessment of appearance and odor; pH was measured. A mean of at least 91% of the initial drug concentration was retained for 60 days in the alprazolam, chloroquine phosphate, cisapride, and enalapril maleate liquids. The hydralazine hydrochloride liquids retained more than 90% of the initial concentration for only one day at 5 degrees C when prepared with Ora-Sweet-Ora-Plus and two days when prepared with Ora-Sweet SF-Ora-Plus and for less than a day in these preparations at 25 degrees C and in cherry syrup at 5 and 25 degrees C. No substantial changes in the appearance, odor, or pH of any liquid were observed. Alprazolam 1 mg/mL, chloroquine phosphate 15 mg/mL, cisapride 1 mg/mL, and enalapril maleate 1 mg/mL were stable in three extemporaneously compounded oral liquids for 60 days at 5 and 25 degrees C; hydralazine hydrochloride 4 mg/mL was stable at 5 degrees C for one day in Ora-Sweet-Ora Plus and for two days in Ora-Sweet SF-Ora-Plus.

Stability of bethanechol chloride, pyrazinamide, quinidine sulfate, rifampin, and tetracycline hydrochloride in extemporaneously compounded oral liquids.

The stability of five drugs commonly prescribed for use in oral liquids but not commercially available as such was studied. Bethanechol chloride 5 mg/mL, pyrazinamide 10 mg/mL, quinidine sulfate 10 mg/mL, rifampin 25 mg/mL, and tetracycline hydrochloride 25 mg/mL were each prepared in a 1:1 mixture of Ora-Sweet and Ora-Plus (Paddock Laboratories), a 1:1 mixture of Ora-Sweet SF and Ora-Plus, and cherry syrup and placed in 120-mL amber clear polyethylene terephthalate bottles. Three bottles of each liquid were stored at 5 degrees C and three at 25 degrees C, all in the dark. Samples were taken initially and at various times up to 60 days for analysis by high-performance liquid chromatography and assessment of appearance and odor; pH was measured. A mean of at least 90% of the initial drug concentration was retained for 60 days in the liquids containing bethanechol chloride, pyrazinamide, or quinidine sulfate and for 28 days in the rifampin-containing liquids and the mixture of tetracycline hydrochloride and Ora-Sweet-Ora-Plus at both 5 and 25 degrees C. Tetracycline hydrochloride concentrations of 90% or more of the initial concentration were retained in the liquids prepared with Ora-Sweet SF-Ora-Plus for 10 days at 5 degrees C and 7 days at 25 degrees C and in those prepared with cherry syrup for 7 days at 5 degrees C and 2 days at 25 degrees C. No substantial changes in the appearance, odor, or pH of any liquid were observed. At 5 and 25 degrees C, bethanechol chloride 5 mg/mL, pyrazinamide 10 mg/mL, and quinidine sulfate 10 mg/mL were stable in three extemporaneously compounded oral liquids for 60 days and rifampin 25 mg/mL was stable for 28 days. The stability of tetracycline hydrochloride 25 mg/mL varied with the vehicle.

Shelf-life of Milk Packaged in Plastic Containers With and Without Treatment to Reduce Light Transmission

The effect of prolonged light exposure on the chemical changes in milk stored at 4°C in clear polyethylene terephthalate (PET) bottles was compared with milk stored in green PET bottles, containers made from PET incorporating a UV blocker, PET containers with exterior labels and high-density polyethylene (HDPE) jugs and low-density polyethylene (LDPE) pouches stored under the same conditions. Data were obtained for lipid oxidation, vitamin A degradation, protein hydrolysis, lipolysis and microbial growth. The milk stored in green PET bottles experienced less lipid oxidation and vitamin A loss than milk stored in the clear PET bottles, or the LDPE pouches and jugs. In general, the milk stored in the clear PET bottles was not as well protected from the effects of light as milk stored in green bottles or LDPE pouches. However, during the first week of storage, only vitamin A loss showed a substantial difference between the milk stored in green PET bottles, clear PET bottles or LDPE pouches. The PET bottles with UV blockers slowed vitamin A degradation but had little effect on lipid oxidation. Blocking visible light with translucent labels helped to inhibit lipid oxidation and vitamin A degradation.