You will hear part of a food science lecture about changing fashions in food.
First, you have some time to look at questions 31 to 40.
Now listen carefully and answer questions 31 to 40.
Food goes in and out of fashion in much the same way as clothes do.
Public enthusiasm for new food trends began rising quickly with the arrival of smartphones.
That was when people started photographing their meals and immediately sending the images to friends online.
The food business in the UK is especially keen to identify the next major craze and make the most of it.
Marketing teams try to generate enormous demand for an item that consumers may not previously have known about or even felt they needed.
One particularly powerful method is to turn social media influences into ambassadors for a brand.
Many will publish posts in exchange for complementary products while those with audiences numbering in the hundreds of thousands may charge substantial fees.
Firms producing vegan goods were among the first to show just how rapidly this approach could drive up sales.
Of course, no food can become widely popular unless people can buy it easily, so supermarkets also help shape new trends.
Their specialist teams monitor which products and ingredients are gaining attention online.
They pay especially close attention to the dishes that famous chefs are adding to their menus.
Let me now consider several campaigns that were extremely effective in turning particular foods into major trends.
I'll begin with the avocado in the 1990s.
A public relations agency in Britain was employed to make the fruit better known and increase demand.
The agency paid for a group of journalists to visit South Africa and meet avocado growers.
The reports produced after the trip taught British consumers more about the fruit, which was far from being an everyday food at that point.
The advertisements presented avocado as a nutrient-rich superfood and stressed its benefits for health.
The fruit soon became highly fashionable.
Within a few years, annual UK sales rose from £13 million to roughly £150 million, making this one of the country's most successful campaigns for fresh produce.
Oat milk provides a more recent example of a product that became fashionable in a very short time.
Although many versions are sold now, the Swedish company Oatly was one of the brands that succeeded early.
It drew widespread notice by deliberately using provocation in its media campaign.
Irritating producers of dairy milk was actually helpful because the controversy gave oat milk a fashionable image.
In the United States, the company chose not to begin with a large retail launch.
Instead, it supplied coffee chains, which meant it did not need a huge advertising budget.
This worked much better than handing out samples in supermarkets.
Oat milk also had an edge over other substitutes such as almond milk.
Many customers chose it because it caused less damage to the environment.
It takes considerably less water to make and has a comparatively small carbon footprint.
Another case is Norwegian Scray, a seasonal delicacy also called Arctic Cod, and available for only a limited period.
It now appears on menus in Michelin-starred restaurants across Europe.
A food marketing organisation has used demand for Scree to improve the reputation of Norway's fisheries more generally.
Consumer research indicates that many shoppers now connect Norway with seafood of excellent quality.
In certain respects, food fashions can be beneficial, particularly because farmers and other producers may gain considerably.
They can also persuade the public to purchase foods made in more sustainable ways.
However, a sudden rise in demand can also create ethical problems.
Quinoa is a well-known example.
The crop originated in Peru, and when demand reached its height several years ago, its price shot up.
Local people could no longer afford to buy it.
Quinoa's popularity did improve farmers' incomes, but it brought harmful effects as well.
To increase output, farmers began planting the crop throughout the year.
As a result, the fertility of the soil fell dramatically.
And in some places, this may eventually cause desertification.
A further example would be the case of...
That is the end of part four.
You now have one minute to check your answers to part four.
That is the end of the listening test.
In the IELTS test, you would now have ten minutes to transfer your answers to the listening answer sheet.
