Shelf life, beer

However, there remain numerous end-use applications which require significant improvements in the properties PET has to offer. These include higher tensile strength and modulus for tyre reinforcement yams and monofilament applications, higher temperature resistance for hot-fill containers and films, and greater gaseous barrier for longer shelf-life requirements (e.g. fruit juice and beer markets). 

Rohrer, C. Majoni, S. Effects of Shelf-Life on Phytonutrients in Beer Beverages. Proceedings of the 233rd American Chemical Society National Meeting, Chicago, IL, March 25-29, 2007. 

Beer stability, dehned as the ability of beer to maintain its properties unchanged from bottling to the end of the estimated shelf life, has three distinct aspects biological stability, colloidal stability, and sensory stability. The sensory stability of beer is closely related to its biological and colloidal stability, and additionally can be affected by the presence of oxygen, which leads to oxidative processes that can alter the taste of beer. 

Other enzymes are required to obtain good quality beer with good shelf-life. The major use of non-malt enzymes is an enzyme that is added to fermented beer to chillproof the beer. Beer is fermented and aged under chilled conditions. Almost all packed beer is filtered while cold to achieve clarity. In spite of the filtration steps beer becomes cloudy after it is packed, distributed and chilled again for serving. The cloudiness that develops is caused by formation of haze particles called chill haze which are the result of the interaction between peptides and polyphenol compounds. 

Komarek, D., Schieberle, P. (2003) Changes in key beer aroma compounds during natural beer aging. In CadwaUader, K.R., Weenen, H. (eds.) Freshness and Shelf Life of Foods. ACS Symposium Series 836, pp. 70-79... 

Pediococcus Fermentation of cabbage to sauerkraut Lactic acid provides sour taste and extends shelf life Gives butterscotch aroma to some wines and beers Production of cheese and yogurt... 

Since wine and beer are fermentation products, shelf life will be limited unless all yeast are removed. Unless beer is kept very cold, a few surviving pedio-cocci, lactobacilli, or wild yeasts may grow and produce off-flavors in the beer. Though the juices are not fermentation products, they nevertheless provide the perfect media for bacteria growth. In all cases, it is important to produce a sealed sterile product. 

The packaging industry has been constantly looking to replace glass with polymeric materials and has recently focused on biobased polymers. However, for very delicate food products such as beer or coffee, there is a challenge to keep the freshness of the food that is related to the lowest increase of oxygen into the pack. Salame et al [207] presented the Table 8.6 and proposed a relationship that will allow a rough estimation of the shelf life t ... 

Amorphous carbon has also been used as a barrier coating. One of the major players is Sidel, with its Actis coating, which permits PET to be used for beer bottles, achieving up to a six month shelf life [2]. Mitsubishi also has a system for depositing an amorphous carbon coating, which they term DEC, diamond-like carbon [3]. 

In 1997, Coca Cola introduced a high-barrier 12-oz PET/EVOH coinjection stretch blow molded bottle that was reported to double the shelf life of the beverage in hot and humid conditions. It also permitted the use of post-consumer PET content in the center layer of the container. In 1998, Miller test-marketed a five-layer PET bottle with a nylon barrier layer in several U.S. cities. Anheuser-Busch also test-marketed plastic beer bottles. In 2000, Miller introduced plastic PET beer bottles in the 16- and 20-oz sizes on a wide scale, becoming the first U.S. brewer to do so [5]. In 2014, MillerCoors expanded use of plastic bottles to the 32- and 40-oz sizes, reportedly reducing the weight of each bottle by 1 lb [6]. However, beer in plastic bottles remains rare. 

A resonant cavity has been used to excite and provide power to a low pressure mercury vapor lamp to produce UV radiation with 154 mn and 180 nm wavelengths. The conversion efficiency of microwave power into UV light power is very efficient at 80 % (Lucas 2005). This UV is used for germicidal activity within the food and drinks industry. By irradiating food with UV before MAP packaging doubles the shelf life. Likewise, a similar effect has been obtained with Turkish beers (Boza)... 

Uses Tablet binder/disintegrant, excipient, suspension stabilizer in pharmaceuticals complexing agent detoxifier adsorbent in thin-iayer chromatography clarifier, filter aid, shelf life enhancer in beer, wine Regulatory FDA approved for implants, ophthalmics, orals, injectables, topicals NF, BP, EP compliance... 

The role of protein-polyphenol interactions with regard to the development of non-biological haze is discussed further in Chapter 22 together with the methods employed to inhibit these reactions and prolong the shelf-life of bottled beer. 

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