Center for Nuclear Energy in Agriculture, University of São Paulo, Piracicaba, São Paulo, Brazil.
State Center of Technological Education "Paula Souza", Technology College of Piracicaba "Dep. Roque Trevisan", Piracicaba, São Paulo, Brazil.
J Food Sci. 2023 Dec;88(12):5012-5025. doi: 10.1111/1750-3841.16807. Epub 2023 Oct 27.
Green coffee is the hulled coffee bean, rich in chemical compounds indicative of quality before roasting, making the classification special or traditional. This work aimed to determine compounds in green coffee beans and find the differentiation of green coffee beans into special or traditional ones through chemometrics. For that, the levels of phenolic compounds, reducing, nonreducing, and total sugars were quantified by spectrophotometry: caffeine, trigonelline, 5-hydroxymethylfurfural (5-HMF), 3-hydroxybenzoic, 4-hydroxybenzoic, chlorogenic, caffeic, and nicotinic acids (NAs) by high-performance liquid chromatography-UV-Vis; acetaldehyde, acetone, methanol, ethanol, and isoamyl by HS-GC-FID. Principal component analysis (PCA) was used to differentiate green coffee beans through the levels obtained in spectrophotometric and chromatographic analyses. Statistically, the contents of total phenolic compounds, caffeine, nonreducing sugars, total sugars, NA, 5-HMF, acetaldehyde, ethanol, and ethanol/methanol showed significant differences. The PCA made it possible to classify green coffee beans into special and traditional, in addition to understanding the attributes that influenced the differentiation between coffees. In addition, it was possible to classify green coffee beans into special and traditional, either using all parameters evaluated or only using spectrophotometric analyses. In this way, some advantages allow classification without using a trained and experienced evaluator as their previous experience can influence the results due to their expertise in a certain type of coffee, in addition to being faster and cheaper, especially regarding spectrophotometric analyses.
绿咖啡豆是带壳的咖啡豆，在烘焙前就富含可指示品质的化合物，这使得它可以被分类为特殊或传统咖啡。本工作旨在通过化学计量学确定绿咖啡豆中的化合物，并找到将绿咖啡豆区分成特殊或传统咖啡的方法。为此，通过分光光度法定量测定了绿咖啡豆中酚类化合物、还原糖、非还原糖和总糖的水平：通过高效液相色谱-紫外可见分光光度法测定了咖啡因、葫芦巴碱、5-羟甲基糠醛（5-HMF）、3-羟基苯甲酸、4-羟基苯甲酸、绿原酸、咖啡酸和烟酸（NAs）；通过 HS-GC-FID 测定了乙醛、丙酮、甲醇、乙醇和异戊醇。通过主成分分析（PCA），使用分光光度法和色谱分析法获得的水平来区分绿咖啡豆。统计学上，总酚类化合物、咖啡因、非还原糖、总糖、NA、5-HMF、乙醛、乙醇和乙醇/甲醇的含量存在显著差异。PCA 不仅可以将绿咖啡豆分为特殊和传统咖啡，还可以了解影响咖啡区分的属性。此外，无论是使用所有评估参数还是仅使用分光光度法分析，都可以将绿咖啡豆分为特殊和传统咖啡。这样，一些优势允许在不使用经过培训和经验丰富的评估师的情况下进行分类，因为他们的专业知识可能会影响结果，特别是在某种类型的咖啡方面，此外，这种方法还更快、更便宜，尤其是在分光光度法分析方面。
