Functional properties and sensory profile of coffee prepared by different brewing methods.

Coffee is one of the main sources of antioxidants in the diet of many countries. The purpose of this research was to assess the effect of different brewing methods, particle size, and coffee quality on the total phenolic content, antioxidant capacity (AC), and sensory profile of the beverage. The brewing methods yielded differences in taste with higher bitterness in immersion methods. However, the main factors that influenced coffee extraction and taste were particle size and coffee type. A finer particle size allowed for greater phenolic and caffeine (CA) extraction (2.82 mg GA/mL; 1.01 mg CA/mL), resulting in higher bitterness and astringency. Additionally, the type of coffee resulted in a higher CA content in commercial coffee (Specialty: 0.72 ± 0.10 mg CA/mL; Commercial: 1.13 ± 0.14 mg CA/mL). The results showed that using a ratio of 1:20 and 1:15 for commercial and specialty coffee, respectively, yielded differences in AC using the DPPH method (Specialty: 11.54 ± 1.12 µmol/mL; Commercial: 10.20 ± 1.88 µmol/mL) but not with the ABTS method (Specialty: 10.38 ± 1.23 µmol/mL; Commercial: 10.37 ± 1.13 µmol/mL). Similarly to the ABTS method, no differences in the total phenol content of the coffee cup were observed (Specialty: 2.52 ± 0.40 mg/mL; Commercial: 2.43 ± 0.28 mg/mL). Thus, the findings suggest that specialty coffee offers consumers a more balanced cup with less CA content. This allows for more coffee consumption without an excessive intake of CA. However, consumers can adjust the functionality, sensory profile, and CA content of a coffee cup by modifying the particle size and the brewing method used.

Impact of Peptidase Activities on Plant Protein Hydrolysates Regarding Bitter and Umami Taste.

The aim of this study was to investigate six food-grade peptidase preparations, namely, Flavourzyme 1000L, Protease P "Amano" 6SD, DeltazymAPS-M-FG, Promod278, ProteAX-K, and Peptidase R, regarding their use for the hydrolysis of soy, pea, and canola protein. The relationship between the specific peptidase activities and, first, the degree of hydrolysis, second, the free amino acid profiles of the hydrolysates, and, third, the corresponding taste of the hydrolysates was analyzed using a random forest model. The taste attributes bitter and umami were of special interest. The peptidase ProteAX-K was the biocatalyst most suited for the high umami and low bitter taste of the plant-based protein hydrolysates based on the experimental results and the random forest model.

Insights into the evolution of myosin light chain isoforms and its effect on sensory defects of dry-cured ham.

To better understand the contribution of myosin light chain (MLC) isoforms to sensory defects in Jinhua ham, dipeptidyl peptidase (DPP) activities, peptide fragments, cleavage sites and the potential of DPP to develop sensory defects of dry-cured ham were evaluated and discussed in normal and defective hams. Higher residual activities of DPP I were found in defective ham compared with normal ham; approximate 3-fold peptide fragments were identified in defective ham than in normal ham. These regions of positions 11-35 and 116-141 in MLC 1, 13-53 and 139-156 in MLC 2, and 18-50 in MLC 3 contributed to the intense generation of peptide fragments in defective ham. PLS-DA further revealed DPP I showing intense response to degrade peptides. Cleavage sites including Glu-128, Tyr-132 and Glu-133 were responsible for the intense release of dipeptides in defective ham. These cleavages could play key role in discriminating taste attributes between defective and normal hams.

Characterization of the Volatile Compounds and Taste Attributes of Sesame Pastes Processed at Different Temperatures.

Sesame paste is used as a condiment in many parts of the world because of its unique flavor. In the study, the volatile compounds and flavor characteristics of sesame pastes processed at different temperatures (140°C - 190°C) were analysed by application of solid phase microextraction - gas chromatography/mass spectrometry analysis, odor activity value evaluation and sensory evaluation. For all the sesame pastes processed at the different temperatures, the pyrazine group had the highest content. The amount of the volatiles increased by 4.15-fold when the roasting temperature increased from 140°C to 180°C, which was mainly attributed to the increase of pyrazines, alkenes, ketones, thiazoles and pentylfuran. And accordingly, sesame paste prepared at 180°C had the highest Odor Activity Value (OAV). Samples differed significantly in terms of aroma and total acceptability (p < 0.05). The sesame paste processed at 180°C had a moderate roasted and sweet aroma, and the highest acceptability, followed by that processed at 170°C. These results can be valuable for manufacturers to adjust the roasting process according to market demand for a particular flavor profile.