Studies on nutritional and functional properties of various genotypes of Andean beans.

Andean bean group have a wide number of genotypes and are available as a source of nutrients and antioxidant compounds in a diet. Proteins, minerals, phenolic compounds, phytic acid, and antioxidant activity were evaluated in 14 white, red, and mottled seed coat genotypes. The Ca, Mg and Cu contents presented the greatest variability. The white seed coat genotypes presented lower phenolic compounds and antioxidant activity levels than the red and mottled seed coat genotypes. A strong correlation between phenolic compounds and antioxidant activity was observed, and hierarchical cluster analysis showed the formation of three groups (G1, G2 and G3). G1 and G2 can be recommended to individuals who want foods with a high content of antioxidant compounds, while any group can be consumed to meet the demand for a diet rich in minerals. G1 and G3 can be recommended to individuals who want a diet high in protein. Changes in eating habits are a barrier to incorporating new sources of nutrients into a traditional diet. However, Andean beans can easily be incorporated into the diets of those who already consume beans daily, as Andean beans can be prepared in the same manner as other beans. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13197-021-05157-7.

Physical characteristics of the paper filter and low cafestol content filter coffee brews.

The results found in the literature concerning the effect of consuming filter coffee brews on increasing the blood cholesterol levels due to the presence of diterpenes, are divergent. Thus the present research evaluated the diterpene (cafestol and kahweol) concentrations in filter coffee brews prepared with paper filters of different sizes, colors and origins (Brazil, Japan, The United States of America, Germany, France and the Netherlands), with and without micro perforations. This is the first study that reports the physical characteristics of paper filter and its importance to obtain filter coffee brew with low cafestol content. Thus, a sample of Catuai cultivar coffee with high cafestol content was roasted to a medium-light degree and used to prepare the brews in a 1:10 ratio (coffee powder to water). The diterpenes were extracted by direct saponification and quantified and identified by HPLC-DAD-MS/MS. The paper filters were physically characterized by measuring their grammage, and the fat permeation rate calculated in order to better understand the differences between the filters which allow one to obtain higher or lower diterpene contents. The cafestol and kahweol concentrations in the brews varied from 1.62 to 2.98 mg/L and from 0.73 to 1.96 mg/L, respectively. The highest cafestol and kahweol concentrations were obtained using paper filters with micro perforations, considering similar sized paper filters. The paper filters showed high fat permeability and grammages between 50.46 and 67.48 g/m2. The diterpene retention capacities of the filters produced in the different countries were similar. The results showed that the porosity of the paper filter and the particle size of the ground roasted coffee were determinant factors in obtaining filter coffee brews with lower cafestol contents.

Quantitative assessment of specific defects in roasted ground coffee via infrared-photoacoustic spectroscopy.

Chemical analyses and sensory evaluation are the most applied methods for quality control of roasted and ground coffee (RG). However, faster alternatives would be highly valuable. Here, we applied infrared-photoacoustic spectroscopy (FTIR-PAS) on RG powder. Mixtures of specific defective beans were blended with healthy (defect-free) Coffea arabica and Coffea canephora bases in specific ratios, forming different classes of blends. Principal Component Analysis allowed predicting the amount/fraction and nature of the defects in blends while partial Least Squares Discriminant Analysis revealed similarities between blends (=samples). A successful predictive model was obtained using six classes of blends. The model could classify 100% of the samples into four classes. The specificities were higher than 0.9. Application of FTIR-PAS on RG coffee to characterize and classify blends has shown to be an accurate, easy, quick and "green" alternative to current methods.

Is cafestol retained on the paper filter in the preparation of filter coffee?

Coffee brew presents sensory, stimulatory and antioxidant properties highly appreciated by consumers, despite being associated with an increase in the level of blood cholesterol due to the effects of the diterpenes, especially cafestol, present in the lipid fraction. Although it is believed that the paper filter retains the brew diterpenes, new studies have shown that sometimes coffee filtered through paper can also increase the blood cholesterol level, putting in doubt the efficiency of the paper filter in retaining the diterpenes. Thus the objective of the present study was to verify the distribution of cafestol between the paper filter, the spent coffee and the coffee brew itself, from two coffee samples containing high and low cafestol contents selected from 13 samples of different cultivars and from different locations. In addition, the effect of the roasting degree on the cafestol contents of the roasted coffee was evaluated and the relationship between particle size of the roasted coffee and the extraction of solids. The highest cafestol content was found in the lightly roasted coffee, and the coffee brew presented higher solids contents when the particle size of the coffee powder was below 500µm. The results showed that of the initial cafestol concentration present in the roasted coffee, the paper filter retained 12.41%, the spent coffee 87.45% and the brew 0.15%. Thus, one can conclude that the greater part of the coffee cafestol is retained by the spent coffee, due to the low extraction of the lipid fraction by the hot water.