Abstract Powdered infant formula (PIF) and lactose-free PIF during secondary shelf-life (SSL) and under domestic practices was investigated to verify their stability up to the expiration date and under the label instructions for milk reconstitution. Particular attention was given to variations in Maillard reaction and lipid peroxidation products identified and quantified by HS-SPME-GC-MS. Two types of PIF: Type A based on bovine milk and Type B a lactose-free product based on glucose syrup were analysed. The PIF were analysed at regular time intervals beyond the labelled expiration date after opening, and reconstituted using water at 70 °C, 80 °C and 90 °C. A large number of volatile compounds were identified and significant statistically differences resulted during SSL and water temperature used for reconstitution that were correlated to the PIF composition. The study showed that water temperature for reconstitution of samples and the SSL has to be adapted to PIF composition.

中文翻译：

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婴儿配方奶粉二次保质期和国内实践的稳定性

摘要 婴儿配方奶粉 (PIF) 和无乳糖 PIF 在二级保质期 (SSL) 和国内惯例下进行了调查，以验证它们在有效期内的稳定性以及在牛奶复原标签说明下的稳定性。特别注意美拉德反应和脂质过氧化产物的变化，通过 HS-SPME-GC-MS 鉴定和量化。分析了两种类型的 PIF：基于牛乳的 A 型和基于葡萄糖浆的无乳糖产品 B 型。PIF 在开封后超过标示的有效期后定期进行分析，并使用 70 °C、80 °C 和 90 °C 的水重新配制。鉴定了大量挥发性化合物，并且在与 PIF 组成相关的 SSL 和用于重建的水温期间产生了显着的统计差异。研究表明，用于重建样品和 SSL 的水温必须适应 PIF 组成。