In this article, we will summarize and try to interpret the study on the characterization of bioactive, chemical and sensory compounds of coffees fermented with different yeast species. As we know, we can briefly define coffee fermentation as a process that occurs as a result of the microbial activation process by contacting coffee beans with various microorganisms. Many studies have shown that this process increases the biological activity of some compounds in coffee, while it can also cause some compounds to decrease. Coffee fermentation can generally be carried out using different types of microorganisms, but especially bacteria and yeasts. While coffee is fermented, it can be carried out by naturally occurring existing microorganisms or by adding them using specific yeast strains. While different yeast species such as Lactobacillus, Acetobacter and Leuconostoc can be used in coffee fermentation, different bacterial species such as Lactobacillus, Acetobacter and Leuconostoc can also be used. Let us also inform you that a very comprehensive, maximally simple and understandable article has been prepared regarding the fermentation process of coffee. As stated in the title of the study, fermentations made by different yeasts are the subject of the experiment. Yeast species are among the microorganisms frequently used in coffee fermentation, and the use of different yeast species can have an effect on the amount and type of bioactive compounds in coffee beans. Therefore, characterization of bioactive, chemical and sensory properties of coffee obtained after coffee fermentation using different yeast species is important. The results of this study may contribute to the development of higher quality and healthier coffee production methods for the coffee industry. In the series of experiments performed, 7 different yeast species, mainly Saccharomyces cerevisiae, Candida parapsilosis, Torulaspora delbrueckii , were used. As we have encountered in previous fermentation studies, DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)) methods were used for antioxidant activity determination. The Folin-Ciocalteu method, which blog readers are now familiar with, was used for the determination of total phenolic content. In addition to the determination of antioxidant activity and total phenolic content, sensory analyses were performed to evaluate properties such as odor and taste profiles, coffee aroma, bitterness, acidity and taste balance, unlike other studies that have been conducted.
If the tables and graphs in the research are to be interpreted,
The results showing the amount of chemical components of coffee beans fermented with different yeast species can be summarized as follows;
The amount of caffeine in coffee beans subjected to fermentation decreased compared to the control group.
When some yeast strains (e.g. S. cerevisiae) were used, an increase in trigonelline levels was observed.
When some yeast species (e.g. C. utilis) were used, an increase in the amount of chlorogenic acid and total phenolic compounds was observed.
When some yeast strains (e.g. K. marxianus) were used, an increase in the amount of caffeic acid and ferulic acid was observed.
These results indicate that coffee fermentation using different yeast species may have different effects on the chemical components in coffee beans. When the results regarding the effect of different yeast species on antioxidant activity are examined, it is seen that they create significant differences in antioxidant activity in coffee beans. In particular, some yeast species such as Candida utilis and Kluyveromyces marxianus caused a significant increase in antioxidant activity in coffee beans. These results indicate that different yeast species have the potential to increase antioxidant activity during coffee fermentation and that this method may help increase the health-beneficial components in coffee beans. However, the generalization of these results is of course limited and more research is needed on the subject. We said that there is a difference in this study compared to other studies, which is the analysis of sensory effects. The aroma, taste, acidity and general quality of coffee beans were evaluated with the use of various yeast species.
The study results showed that different yeast strains affect the taste and aroma profiles of coffee beans in different ways. For example, the use of Candida utilis resulted in a fruity aroma and a lower bitterness level. On the other hand, the use of Kluyveromyces marxianus resulted in a higher acidity level. These results show that different yeast strains can create significant differences in taste and aroma profiles during coffee fermentation. These results show that different yeast strains can create significant differences in taste and aroma profiles during coffee fermentation. This means that coffee producers can obtain different taste and aroma profiles by using different yeast strains. If another table is to be interpreted, it shows that different yeast strains increase the total phenolic content in coffee beans. Here, the increase in phenolic compounds in coffees subjected to fermentation processes, which we have mentioned in previous articles, is a common finding that is not surprising.
However, the study shows that in addition to the fermentation effect, it also varies between different yeast species, with some species providing higher increases. For example, the use of Candida utilis caused an increase of approximately 60% in the total phenolic content of coffee beans, while the use of Saccharomyces cerevisiae only caused an increase of approximately 25%. These results show that different yeast species can be effective in increasing the total phenolic content in coffee fermentation. The importance of increasing the total phenolic content, as we have mentioned in many previous studies, depends on the increase in antioxidant activity, which is an important component for coffee health. Therefore, increasing the total phenolic content during coffee fermentation using different yeast species is an important finding in terms of the beneficial effects of coffee on human health.
If the analyzes (taste, odor, acidity, bitterness, etc.) made on the sensory properties of coffee samples fermented using different yeast types and their scoring table are summarized; The results show that the use of different yeast types causes differences in the sensory properties of coffee samples. For example, it was observed that the samples fermented using Candida utilis had a higher aroma score. However, the use of Saccharomyces cerevisiae caused the samples to have a higher acidity. These results show that the use of different yeast types can affect the sensory properties of coffee samples and cause different tastes and aromas. Another difference in the study is that the sensory properties of coffee samples fermented using different yeast types were evaluated by a panel with the participation of the participants. As a result of this panel, the Sensory Description table emerged and this table listed the scores given by the panelists according to the sensory properties of the samples (e.g. aroma, taste, acidity, etc.). The table also includes statistical data such as the mean, standard deviation and variance of the scores given to each sample. These data showed that there were significant differences between the sensory properties of coffee with the use of different yeast species. For example, the use of some yeast species such as Candida utilis and Pichia fermentans caused an increase in the aroma, taste and acidity properties of coffee. The Sensory Description table was a tool used to measure these sensory differences and contributed greatly to the evaluation of the results of the study. In terms of interpretation of the findings of the study, this study examined the characterization of the biological, chemical and sensory properties of coffees subjected to fermentation using different yeast species. The results obtained showed that there were significant differences in the biological and chemical properties of coffee with the use of different yeast species. In particular, it was observed that the use of some yeast species such as Candida utilis and Pichia fermentans caused an increase in the antioxidant activity and phenolic compound content in coffee. In addition, it was observed that the sensory properties of coffee changed significantly with the use of different yeast species. The aroma, taste and acidity of coffee increased with the use of certain yeast species. As a result, the study shows that the use of different yeast species can significantly affect the biological, chemical and sensory properties of coffee. In the discussion section of the study, the results obtained are compared with other studies in the literature. For example, some studies have shown that different yeast species such as Saccharomyces cerevisiae increase the antioxidant activity in coffee. However, this study states that the use of different yeast species such as Candida utilis and Pichia fermentans increases the antioxidant activity in coffee. These different results show that different yeast species can affect the compounds in coffee in different ways. As a result, this study examined how the use of different yeast species in coffee fermentation affects the biological, chemical and sensory properties and the results showed that different yeast species can affect the compounds in coffee in different ways. This study has shown the potential of using different yeast species in coffee fermentation stories and has shed light by providing a broad perspective on new yeast-based fermentations.
DUYGU KURTULUŞ
Co-Founder / Chemist / Nanotechnology Engineer / Hazardous Chemical Consultant / Chemical Evaluation Specialist