Influence of PET and PET/PEN Blend Packaging on Ascorbic Acid and Color in Juices Exposed to Fluorescent and UV Light

Abstract

ABSTRA ABSTRA ABSTRA ABSTRA ABSTRACT CT CT CT CT: A : A : A : A : Apple and or pple and or pple and or pple and or pple and orange juices packed in poly ange juices packed in poly ange juices packed in poly ange juices packed in poly ange juices packed in polyester bottles w ester bottles w ester bottles w ester bottles w ester bottles wer er er er ere stor e stor e stor e stor e stored in dar ed in dar ed in dar ed in dar ed in dark, intense fluor k, intense fluor k, intense fluor k, intense fluor k, intense fluorescent (1500 lux), escent (1500 lux), escent (1500 lux), escent (1500 lux), escent (1500 lux), and UV light conditions in temperature-controlled (22 °C) chambers and monitored more than 7 mo for ascorbic and UV light conditions in temperature-controlled (22 °C) chambers and monitored more than 7 mo for ascorbic and UV light conditions in temperature-controlled (22 °C) chambers and monitored more than 7 mo for ascorbic and UV light conditions in temperature-controlled (22 °C) chambers and monitored more than 7 mo for ascorbic and UV light conditions in temperature-controlled (22 °C) chambers and monitored more than 7 mo for ascorbic acid content and color changes acid content and color changes acid content and color changes acid content and color changes acid content and color changes. P . P . P . P . Poly oly oly oly olyester bev ester bev ester bev ester bev ester bever er er er erage bottles w age bottles w age bottles w age bottles w age bottles wer er er er ere made of poly e made of poly e made of poly e made of poly e made of polyethylene ter ethylene ter ethylene ter ethylene ter ethylene terephthalate (P ephthalate (P ephthalate (P ephthalate (P ephthalate (PET ET ET ET ET), or P ), or P ), or P ), or P ), or PET ET ET ET ET blended with 0.25%, 1%, and 4% polyethylene naphthalate (PEN). The cut-off wavelength ranged from 322 nm for blended with 0.25%, 1%, and 4% polyethylene naphthalate (PEN). The cut-off wavelength ranged from 322 nm for blended with 0.25%, 1%, and 4% polyethylene naphthalate (PEN). The cut-off wavelength ranged from 322 nm for blended with 0.25%, 1%, and 4% polyethylene naphthalate (PEN). The cut-off wavelength ranged from 322 nm for blended with 0.25%, 1%, and 4% polyethylene naphthalate (PEN). The cut-off wavelength ranged from 322 nm for P P P P PET to 373 nm for the 4% P ET to 373 nm for the 4% P ET to 373 nm for the 4% P ET to 373 nm for the 4% P ET to 373 nm for the 4% PEN/P EN/P EN/P EN/P EN/PET blend. S ET blend. S ET blend. S ET blend. S ET blend. Spectr pectr pectr pectr pectral irr al irr al irr al irr al irradiance adiance adiance adiance adiance, visible light intensity , visible light intensity , visible light intensity , visible light intensity , visible light intensity, and light distr , and light distr , and light distr , and light distr , and light distribution w ibution w ibution w ibution w ibution wer er er er ere e e e e evaluated in the light chambers and compared with supermarket display lighting and outdoor daylight conditions. evaluated in the light c...

Ascorbic acid, aroma compounds and browning of orange juices related to PET packaging materials and pH

“…8,9 Moreover, changes to ascorbic acid levels are influenced by the type of packaging used. 2 Today, PET is the most widely employed packaging for food products and the trend is now to use PET with oxygen scavengers, or PET complexed with nylon or polyethylene naphthalate, 10,11 which have better barrier properties against oxygen and may limit the aerobic degradation of ascorbic acid. However, most of the results obtained when testing various new plastic packaging materials have remained confidential.…”

Quality of orange juice in barrier packaging material

“…Solomon and others 9 did not observe any statistical differences (p < 0.05) between the vitamin C content of orange juice stored in glass at 8°C under artifi cial light (200 lux, three tubes of 40 W) or in darkness. More recently, Conrad and others, 10 with monolayer PET, also found no positive effect of orange juice storage in darkness when compared with storage under artifi cial light; losses of vitamin C being almost identical. For another food product, pasteurized milk, one of the main mechanisms of quality deterioration is light-induced vitamin deg- …”

“…Sattar and others 7 showed that artifi cial light (540-650 lux) increased the degradation of vitamin C in model orange juice stored in glass bottles at 25°C during 32 days. On the contrary, Mottar, 8 Solomon and others, 9 and Conrad and others 10 did not fi nd any difference between the vitamin C contents of juice stored under artifi cial light and in darkness.…”

Data on Specific Polymers

“…Blending 4% polyethylene naphthalate with PET helps to reduce UV radiation between 322 and 373 nm in storage environments thus helping to preserve color and vitamin C in juices exposed to fluorescent light. 344 Tinuvin 1577 was successfully used to protect surface degradation of PET. 346 The presence of UV absorber reduced formation of carboxyl end-groups.…”