Creating a Better Grapefruit
Read Creating a Better Grapefruit and check the IELTS Reading answers. There is a reason why grapefruit juice is served in little glasses. Most people don't want to drink more than a few ounces at a time. This is because a natural chemical compound found in grapefruit, naringin, has a bitter taste.…
Passage preview
There is a reason why grapefruit juice is served in little glasses. Most people don't want to drink more than a few ounces at a time. This is because a natural chemical compound found in grapefruit, naringin, has a bitter taste. Some people like that bitterness in small doses and believe it enhances the general flavour, but others would rather avoid it altogether. So juice packagers often select grapefruit with low naringin content, even though the compound has antioxidant properties that some nutritionists contend may help prevent many serious diseases.
Vocabulary from this passage
11 words worth learning before you sit the test, each with the sentence it appears in.
- antioxidant properties noun
Characteristics of substances that inhibit oxidation, potentially protecting cells from damage caused by free radicals
Naringin has antioxidant properties that some nutritionists contend may help prevent many serious diseases.
- averse adjective
Having a strong dislike of or opposition to something; showing a clear tendency to avoid a stimulus
Most animal species are naturally averse to bitter tastes because they often signal the presence of poison.
- contend verb
To assert or maintain a particular position or claim firmly, especially as part of an academic argument
Many researchers contend that certain chemical compounds in fruit provide significant health benefits to humans.
- dampen verb
To make a feeling, reaction, or physical sensation less strong or intense; to moderate the impact
New chemical compounds might be used in children's cough syrups to dampen the unpleasant bitterness of medicine.
- delving verb
To carry out intensive research or make thorough inquiries into a subject to uncover complex information
Scientists are currently delving into the five basic tastes to better understand human dietary preferences.
- interfere verb
To prevent a process or activity from continuing or being carried out as intended by becoming involved
Once researchers understood the taste mechanism, they began to think of ways to interfere with bitter signals.
- naringin noun
A chemical compound found in grapefruit that provides a bitter taste and possesses various biological properties
Juice packagers often select grapefruit with a low naringin content to reduce the natural bitterness of the drink.
- palatable adjective
Pleasant or acceptable to the taste; also used to describe an idea or action that is satisfactory
Bitter blockers could make a whole range of foods, drinks, and medicines more palatable for consumers.
- palate noun
A person's appreciation of taste and flavor, often referring to the sensitivity and range of taste buds
Testers cleansed their palates with water and crackers before sampling the different types of grapefruit juice.
- perception noun
The way in which something is regarded, understood, or interpreted through the use of the physical senses
The perception of bitterness and sweetness is triggered by a complex cascade of chemical reactions within cells.
- receptor noun
An organ or cell able to respond to external stimuli and transmit a signal to a sensory nerve
Taste receptors on the tongue capture molecules from food and relay signals directly to the brain.
Answers with explanations
- 27. B
Paragraph B contains detailed information regarding a **taste comparison test**. It describes how participants were given cups labeled 304 and 305 and were asked to drink from both to compare the presence of the bitter taste.
- 28. H
Paragraph H lists several **examples of medications**—such as children's cough syrups, antihistamines, and antibiotics—that could have their harsh tastes improved by using bitter blockers. This directly answers the prompt.
- 29. E
Paragraph E outlines the **biological reason** behind taste aversion by stating that people have differing sensitivities due to **genetics**. It further explains that some possess a biologically high number of taste buds, making them sensitive 'supertasters'.
- 30. F
Paragraph F breaks down the mechanics of the **taste process**. It explains how receptors on taste buds capture molecules and use G proteins to trigger chemical reactions that ultimately send a signal to the brain.
- 31. C
Paragraph C states that the food industry has a **commercial interest** ('special interest to the food industry') in bitterness specifically because it is so widespread in various types of food, requiring management.
- 32. H
Paragraph H describes how a bitter blocker like AMP could allow food manufacturers to use healthier potassium chloride instead of unhealthy sodium chloride. This is a clear **example** of an **indirect health benefit** provided by reducing bitterness.
- 33. D
Paragraph D discusses the fundamental difference in **taste preferences** between humans and other animals. While animals avoid bitterness because it signals danger, humans have culturally **learned to enjoy** certain bitter flavours, such as coffee.
- 34. naringin
The text states that juice packagers prefer grapefruit with a **low** (smaller amount) content of a specific substance to reduce bitterness. The name of this substance is **naringin**.
- 35. poisonous
The passage explains that thousands of bitter compounds exist in nature to warn **animals** away from plants that might be dangerous. Therefore, animals associate bitterness with **poisonous** plants.
- 36. genetic
According to the passage, the primary reason why humans have **varying capacities** (degrees of sensitivity) to taste bitterness is biological. The text explicitly states that these differences appear to be **genetic**.
- 37. supertasters
The text identifies a specific group of people who are **especially sensitive** (extremely aware) to bitter compounds because they possess a high number of taste buds. These individuals are called **supertasters**.
- 38. taste buds
The text explains that the **receptors** responsible for capturing taste molecules are located inside structures on the tongue. These elongated cell structures are identified in the text as **taste buds**.
- 39. A
The passage states that the **G protein** identified by Robert Margolskee is involved in the perception of taste. When activated, it triggers chemical reactions that ultimately **deliver a signal to the brain** registering as bitter, making option A the correct answer. The other options misrepresent the scientific process described.
- 40. C
The text notes that while **AMP** is highly effective as a bitter blocker, it **may not be able to dampen every type** of bitter taste. This directly implies that its function is to **reduce some bitter tastes** (but not all), which accurately reflects the phrasing in option C.