The sense of bitter taste is one of the five fundamental taste senses (besides the taste of sweet, salty, sour taste and umami), which acts as a defence mechanism for the body to avoid consuming toxic and harmful foods to the body. A bitter taste is commonly found in coffee, carbonated drinks, dietary supplements, or other chemical active ingredients that have a bitter taste. This bitter taste is unpleasant. Some medications are also made in pill or tablet form to avoid bitter and unpleasant tastes. Type II receptors on the t2r gene are the receptors responsible for perceiving the sense of taste bitter. The level of sensitivity to the basic sense of taste also depends on food, health status, and the balance of energy in the body. In general, the perception of bitter taste is very high compared to the sense of taste sweet, especially in children. When the bitter taste molecules enter the mouth, the digestive tract system will receive a signal to work and stimulate the production of enzymes that can break down food molecules and start the process of movement in the digestive tract.
Coffee as one of the ingredients that stimulate bitter taste is one of the elements that have various benefits in health because there are various phenol components, such as phenolic acid and chlorogenic acid, which are neuroprotective which can prevent Alzheimer’s disease. One type of coffee (civet arabica coffee) is coffee that was discovered and originated from the islands of Java, Sumatra and Sulawesi and has become famous due to an exciting manufacturing process that utilizes the civet animal digestive system (Paradoxurusheermaphroditus)
The study used two groups of fourteen male Wistar rats (Rattus norvegicus) aged 12 months. The number 14 male Wistar rats were obtained through the sample size calculation formula Lemeshow. The first group Negative Control (K) is the untreated group given pellets and distilled water without coffee. The second group Positive (P) is the group treatment given pellets, distilled water, and coffee with a standard dose of 223 mg / ml / day for 30 days with the process coffee intake at 9:20 to 11:30. After the 31st day, the two groups (K and P) then performed decapitation using the anaesthetic drug Ketamine HCl (KTM-100) at a dose of 2 mg / kg (1 mg / lb) using intravenous injection and making paraffin blocks in the area. The posterior tongue, on the foliate papillae for further examination using immunohistochemical (IHC) techniques. The results of IHC examination on cells expressing rt2r in the control group were 0.03 ± 0.08a, and in the treatment group 1.49 ± 0.86. The letter indicates that there is a significant difference using the ANOVA statistical test.
This study aims to find differences in t2r expression as a marker of sensitivity to bitter taste in mice consuming coffee. In this study, foliate papillae were selected because the bitter taste receptors (t2r) were found in foliate papillae. The selection of Arabica civet coffee types is also based on research that the sense of taste bitter can felt many molecules compared to robusta coffee. Still, the caffeine content of Arabica civet coffee is less compared to robusta coffee, with caffeine content in Arabica civet coffee. is (0.94-1.59%) while for robusta coffee is 2.2-2.8%. Giving arabica civet coffee is carried out at 9:20 to 11:30 hours because at that time it is still quite early in the morning so that the level of cortisol in the body is still low compared to that at night. A dose of 223 mg / ml per day is reasonable, with the dose not exceeding 367 / mg / kg. Giving excessive doses for 30 days will cause a histologic appearance of chronic erosive gastritis.
Based on the research conducted, the expression of the type II receptor for bitter taste t2r in foliate papillae has been proven. Type II receptor cells are sensory cells responsible for the taste senses of sweet, bitter, and umami which are transduced by G protein (G protein-coupled receptor). The proposed mechanism is that Arabica civet coffee will be perceived by tastants and captured by the tip of the type II responder cells on the taste buds, thereby activating protein G and phospholipase C-β2 (PLC-β2). Activation of protein G and PLC-β2 results in the production of InsP3 (IP3) and diacylglycerol (DAG). IP3 will bind to the InsP3 type 3 receptor, which triggers the release of Caions2+ from the endoplasmic reticulum. Increased release of Caions2+ activates the transient receptor potential cation channer subfamily M member 5 (TRPM5) which depolarizes the membrane, triggering an action potential of Naions+ which activate the calcium homeostasis modulator (CALHM) to release ATP. The released ATP binds to the P2X2/3receptors on the afferent nerve fibres that transmit a bitter taste to the primary gustatory cortex, resulting in the perception of bitter taste.
Author: Prof. Dr. Jenny Sunariani, drg., MS., AIFM., PBO
Link: http://www.sysrevpharm.org//fulltext/196-1602221156.pdf?1602456558
Intan Nadzirah, Ari Trihwardhani, Hans Lesmana, Aqsa Syuhada Okky, Hendrik Setia Budi, Jenny Sunariani [2020] The differences of T2RS expression as a sensitivity marker of bitter taste in consumed coffee. Systematic Reviews in Pharmacy (Sys Rev Pharm) Vol. 11 No. 11, pp: 182-185
