Abstract The aim of this study is to survey the content of α-dicarbonyl compounds and 5-hydroxymethylfurfural in different processed fruit products. For this purpose, different commercial fruit products including dried fruits, fruit purees, puree concentrates, juices, and juice concentrates, as the examples of solid, semi-solid and liquid samples of sugar-rich and acidic food systems were analyzed. Among the α-dicarbonyl compounds, 3-deoxyglucosone, glucosone, 1-deoxyglucosone, 3-deoxypentosone, threosone, diacetyl, methylglyoxal, and glyoxal were monitored. 3-deoxyglucosone formation, which was the dominant dicarbonyl compound in fruit products, varied between 21.9–4117.0 mg/kg, was the highest in dried fruits. 5-hydroxymethylfurfural could not be detected in fruit puree concentrates, whereas the highest concentration of 5-hydroxymethylfurfural with the median level ranging between not detectable and 2136.5 mg/kg was found in dried fruits. The results confirmed that lower pH and moisture promoted the formation of 5-hydroxymethylfurfural in fruit products. Accordingly, the concentrations of dicarbonyl compounds were found significantly higher than the levels of 5-hydroxymethylfurfural in all types of fruit products.

中文翻译：

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干果、果汁、果泥和浓缩物中α-二羰基化合物和5-羟甲基糠醛的存在调查

摘要 本研究旨在调查不同水果加工产品中α-二羰基化合物和5-羟甲基糠醛的含量。为此，我们分析了不同的商业水果产品，包括干果、果泥、浓缩果泥、果汁和浓缩果汁，作为富含糖分和酸性食品系统的固体、半固体和液体样品的示例。在α-二羰基化合物中，监测了3-脱氧葡萄糖酮、葡萄糖酮、1-脱氧葡萄糖酮、3-脱氧戊酮、苏糖酮、二乙酰、甲基乙二醛和乙二醛。3-脱氧葡萄糖酮是水果产品中主要的二羰基化合物，在 21.9-4117.0 mg/kg 之间变化，在干果中最高。在浓缩果泥中未检测到 5-羟甲基糠醛，而在干果中发现最高浓度的 5-羟甲基糠醛，中值水平介于检测不到和 2136.5 毫克/公斤之间。结果证实，较低的pH值和水分促进了水果产品中5-羟甲基糠醛的形成。因此，在所有类型的水果产品中，二羰基化合物的浓度显着高于 5-羟甲基糠醛的浓度。