Life cycle analyses of novel food packaging materials do not often account for the environmental impact of a change in shelf-life, which can result in misleading comparisons. This paper established a methodology for comparative life cycle analyses, whereby the direct effects of the lidding films were compared whilst ensuring the indirect effects of the wasted food portion remained stable. Global warming potential and non-renewable energy use were analysed for a conventional (low-density polyethylene/ethylene vinyl alcohol) versus a biodegradable (polyhydroxyalkanoate/butenediol vinyl alcohol) multilayer lidding film for modified atmosphere packaging of minced beef. Two methodologies were investigated. The first (metric one) changed the barrier layer thickness in the biodegradable film to match the carbon dioxide transmission rate with that of a conventional film. The second (metric two) changed the barrier layer thickness to match a carbon dioxide transmission rate predicted by a mathematical model to ensure the same shelf-life as the conventional film. Using metric two over metric one resulted in 1) a thinner film 2) 2.3 times lower global warming potential. When using sugar beet as the biopolymer feedstock and the current UK disposal system, the biodegradable film had 135% higher global warming potential than the conventional film. By incorporating waste products and better farming practices, the global warming potential of the biodegradable film could be up to 92% lower than that of the conventional film. This work demonstrates how shelf-life can be incorporated into life cycle analyses and the importance of accounting for it, in particular when evaluating biodegradables which often have higher permeabilities.

新型食品包装材料的生命周期分析通常不考虑保质期变化对环境的影响，这可能会导致误导性比较。本文建立了一种比较生命周期分析的方法，其中比较了封盖薄膜的直接影响，同时确保浪费食物部分的间接影响保持稳定。分析了传统（低密度聚乙烯/乙烯乙烯醇）与可生物降解（聚羟基链烷酸酯/丁烯二醇乙烯醇）多层封盖薄膜的全球变暖潜能和不可再生能源使用情况，用于牛肉末的气调包装。研究了两种方法。第一个（公制的）改变了可生物降解薄膜中的阻隔层厚度，使二氧化碳传输率与传统薄膜相匹配。第二个（公制二）改变了阻挡层的厚度，以匹配数学模型预测的二氧化碳传输率，以确保与传统薄膜相同的保质期。使用公制二而不是公制一会导致 1) 薄膜更薄 2) 全球变暖潜势降低 2.3 倍。当使用甜菜作为生物聚合物原料和当前的英国处理系统时，可生物降解薄膜的全球变暖潜力比传统薄膜高 135%。通过结合废物和更好的耕作方法，可生物降解薄膜的全球变暖潜力可能比传统薄膜低 92%。