Colorless Bottles Research Articles

Photostabilized LDPE Films with UV Absorber and HALS as Protection against the Light for Rosé Sparkling Wine

Rose sparkling wines are photosensitive products thus subject to degradation by photo-oxidation over time when they are exposed on shelves. Consequently, its color gradually loses the most vibrant hues coupled with changes in aroma and flavor. An alternative to increase the shelf life of sparkling wines is the usage of light stabilizers, such as UV Absorbers (UVA) and Hindered Amine Light Stabilizers (HALS), substances that, when added to the packaging used for sparkling wines has the purpose of stabilizing the material, protecting the product. The purpose of this study was to evaluate the quality of rose sparkling wines looking at the following properties: hue, colorimetric intensity, anthocyanins index and chemical characteristics using FTIR and visible-UV of Low Density Polyethylene films (LDPE) used as a protective layer for the exterior of colorless bottles. The stabilization system of LDPE films proposed in this study allowed the rose sparkling wine to retain its chromatic characteristics longer, allowing for extensive periods of exposure on shelves, accounting for 60.4% reduction in the anthocyanins index for films with combined UVA/HALS, and 77.8% for films without photoprotection.

Análise térmica e propriedades mecânicas de resíduos de polietileno de alta densidade (PEAD)

Resumo Embalagens de polietileno de alta densidade (PEAD) pós-consumo foram coletadas e moídas. Após processamento em extrusora de rosca dupla, o material definido como PEAD reciclado (mistura de embalagens brancas, marfins e incolores) foi injetado e as propriedades mecânicas de resistência à tração e resistência ao impacto foram avaliadas e comparadas com uma amostra de PEAD comercial. A análise térmica, através da calorimetria exploratória diferencial (DSC), a microscopia eletrônica de varredura (MEV) e a análise estatística dos resultados experimentais também foram conduzidas. Em relação à resistência à tração, a diferença entre as amostras de PEAD reciclado e PEAD comercial foram tão pouco expressivas que, dentro das condições experimentais adotadas, se pôde afirmar que o material reciclado é equivalente ao comercial. Por sua vez, o modelo cinético aplicado na análise térmica revelou que a amostra de PEAD comercial demonstra um processo de nucleação e crescimento dos cristais mais homogêneo e simples, embora a energia de ativação seja consideravelmente maior do que o das demais amostras de PEAD.

The Color Purple: Dating Solarized Amethyst Container Glass

From the late-19th century on, there was an increased production of colorless bottles for a wide variety of products. Producing colorless glass is not difficult if pure sand with a very low iron content is available. Iron in sand gives the glass a range of colors from light green to dark amber, depending on the amount of iron in the sand. To overcome this problem, some factories that used iron-bearing sands added manganese to their batch as a decolorizer. While this produces colorless glass, that glass will turn a light purple or amethyst color when it is exposed to sunlight. Dating of solarized glass by archaeologists has relied on information from a variety of sources, including books produced by bottle collectors. Some of this information is good and some of it, erroneous. The objective here is to provide a useful chronology of the development and use of manganese as a decolorizer and to dispel some of the myths that have crept into the literature.

Rate of degradation of alpha-tocopherol, squalene, phenolics, and polyunsaturated fatty acids in olive oil during different storage conditions.

Changes in the concentration of tocopherol, monophenols, o-diphenols, squalene, and polyunsaturated fatty acids in olive oil were evaluated during 1 year at various storage conditions. Samples of two different extra virgin olive oil (EOO), produced in Calabria (Italy), were stored in dark and in colorless bottles, filled up completely or to half, in order to simulate the domestic storage conditions. The extent of oxidation or photooxidation was monitored by periodic measurements of peroxide values and the rate of degradation of alpha-tocopherol, o-diphenols, squalene, and polyunsaturated fatty acids. The quantitative analysis of the constituents has been performed by HPLC-DAD, HPLC-MS, and GC-MS. The main changes in the concentrations of the analyzed compounds were associated with the major oxygen level in the half-empty glass bottles. alpha-Tocopherol was the first molecule to be oxidized (-20% after 2 months, -92% after 12 months). Squalene and o-diphenols were protected in the first months by the presence of alpha-tocopherol, and their content decreased significantly only after 6 and 8 months, respectively, in the half-empty bottles. The concentration of polyunsaturated fatty acids remained almost constant during 8 months for all four different storage conditions; their oxidation started when the level of the antioxidants decreased.

Changes in odour of bartlett pear brandy influenced by sunlight irradiation

Sensory evaluation of Bartlett pear brandy revealed differences in taste and smell between the brandy in colourless and green bottles. To determine the differences in chemical composition, headspace sampling with solid-phase microextraction combined with gas chromatography-mass spectrometry was applied. The major aroma components in pear brandy stored in green bottles were ethyl trans-2- cis-4-decadienoate (68 ppm), ethyl trans-2- trans-4-decadienoate (21 ppm) and methyl trans-2- cis-4-decadienoate (27 ppm). In pear brandy kept in colourless bottles, the concentration of trans-2- cis-4-isomeres was lower and the concentrations of other possible isomeres were higher. Results show a pronounced difference in the concentration ratios among isomeres of ethyl 2,4-decadienoate and methyl 2,4-decadienoate in both samples. Sunlight irradiation was found to be the reason for these changes. It was confirmed that trans-2- cis-4-isomere partly converts to the other three isomeres during UV irradiation.

The decomposition of hypobromite solutions

The stability of 10 −1–10 −3 N hypobromite solutions, stored in brown or colourless bottles at room temperature, has been investigated. A reaction mechanism of decomposition has been proposed and some practical conclusions have been drawn concerning the optimal method of preparation and the required frequency of control of hypobromite solutions used as an analytical reagent.