Abstract Little published information exists examining the effect of heating methods on nutrient retention in single-serve frozen meals, which can have instructions for conventional and microwave ovens. In peer-reviewed references, there are no recent studies that address this question. This work compares the effect of two reheating methods on nutrient retention of a frozen single-serve meal that has dual conventional and microwave reheating instructions. The meal has a full range of nutrients that are either thermally labile or thermally stable. We hypothesized there would be parity in nutrient amounts in the meal between the two reheating methods. Nutrient composition was assessed by averaging results from 10 samples after three treatments: conventional oven reheating, microwave oven reheating, and unheated controls. Meals were reheated to a minimum of 74 °C per the package instructions and analysed for carbohydrate, protein, fat, sodium, potassium, vitamin A, vitamin C, vitamin E, thiamine, riboflavin, and folic acid. Nutrient changes were uniformly affected by reheating conditions, except for vitamin C. On average, microwaved meals retained 3.8 more milligrams vitamin C than meals heated in a conventional oven. Consumers can be confident that microwave reheating of frozen meals can result in equal nutrient retention as conventional oven reheating, and microwave reheating may result in slightly greater retention of vitamin C.

中文翻译：

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比较使用微波与传统烤箱加热的市售单份膳食中的营养水平

摘要 很少有已发表的信息检查加热方法对单份冷冻食品中营养保留的影响，这些食品可以有传统和微波炉的说明。在同行评审的参考文献中，没有最近的研究解决这个问题。这项工作比较了两种重新加热方法对具有双重常规和微波重新加热指令的冷冻单份膳食的营养保留的影响。膳食含有各种热不稳定或热稳定的营养素。我们假设两种再加热方法之间膳食中的营养含量是相同的。通过对 10 个样品进行三种处理后的平均结果来评估营养成分：常规烤箱再加热、微波炉再加热和未加热对照。根据包装说明将餐食重新加热至最低 74 °C，并分析碳水化合物、蛋白质、脂肪、钠、钾、维生素 A、维生素 C、维生素 E、硫胺素、核黄素和叶酸。除了维生素 C 外，再加热条件对营养物质的变化产生了一致的影响。平均而言，微波食物比传统烤箱加热的食物多保留 3.8 毫克的维生素 C。消费者可以确信，冷冻食品的微波再加热可以导致与传统烤箱再加热相同的营养保留，而微波再加热可能会导致维生素 C 的保留略多。除了维生素 C 外，再加热条件对营养物质的变化产生了一致的影响。平均而言，微波食物比传统烤箱加热的食物多保留 3.8 毫克的维生素 C。消费者可以确信，冷冻食品的微波再加热可以导致与传统烤箱再加热相同的营养保留，而微波再加热可能会导致维生素 C 的保留略多。除了维生素 C 外，再加热条件对营养物质的变化产生了一致的影响。平均而言，微波食物比传统烤箱加热的食物多保留 3.8 毫克的维生素 C。消费者可以确信，冷冻食品的微波再加热可以导致与传统烤箱再加热相同的营养保留，而微波再加热可能会导致维生素 C 的保留略多。