Part 1
A Brief History of Canned Food
A Brief History of Canned Food
In 1795, the French government had a problem: they faced the fact that it is not easy to win battles abroad when your soldiers are hungry and malnourished. That year they established a 12,000-franc prize for whoever could find a way to preserve food -- from milk and meat to fruits and vegetables. French chef Nicolas Appert took more than a decade to develop a process that involved cooking food in glass jars and then using seals made of cork to make them airtight. In 1810, he published a book whose title translates as "The art of preserving all animal and vegetable substances for several years", and collected his prize money. Appert’s achievement didn’t escape the notice of British merchant and inventor Peter Durand, who applied for a British patent later that year. Durand used techniques similar to Appert’s, although he adapted the model to include the use of tin vessels as well as glass jars.
Following these discoveries, canned food was initially produced for soldiers and explorers. But even after people became aware of the existence of bacteria in the late 19th century, canning companies couldn’t work out exactly why some of their products turned bad. And even into the 20th century, newspapers were full of accounts not only of food poisoning but also of cases of the fatal disease botulism resulting from people eating canned food. For that reason, many continued to look upon canned food with suspicion and fear.
The US food manufacturer, The Heinz Company, realized bad cans were bad for business. From the 1890s to the 1920s, the company insisted on weekly manicures for its canning-factory workers to ensure that any bacteria beneath employees’ fingernails stayed out of the food. Heinz employees were required to shower and change their clothing regularly. In an era when food-factory hygiene was not universally adopted, what might have been considered a nuisance by workers was at least good for consumers.
Some canning companies killed bacteria with chemical additives such as sodium benzoate, which is still used today in canned food, and formaldehyde, which is now known to cause cancer. Some of the larger canning companies, such as Heinz, Libby, and Campbell’s, installed expensive steam-retort technology developed in the 1870s. Steam retorts worked like steam engines, using pressure to raise canning temperatures high enough to make food safe. Yet some batches of cans, even when made with this advanced technique, would explode after months on the shelf, while the contents of other cans might mysteriously sour. Smaller canning manufacturers relied on the open kettle method* and they had even less consistent results.
US canning companies eventually banded together to discover the scientific principles affecting the canning process. In 1913, they launched the Research Laboratory of the National Canners Association in order to look into the elusive bacteriology responsible for all manner of spoiled canned food. The research done by the laboratory in the decades that followed helped resolve the problem of spoiled food and led to improved flavor, color, nutritional value, and texture.
Before this time, canning companies had discovered through trial and error that the best way to avoid bad cans was to cook food at high temperatures for long periods, an approach that sacrificed flavor. ‘Food safety and palatability were often at cross-purposes,’ remarks food historian Gabriella Petrick. For string beans, for instance, long cooking times in hot water leach out the green color, creating an unattractive grayish-toned bean. The addition of salt was one technique employed in the early 20th century to prevent this happening, thereby maintaining the visual appeal of the product and restoring a certain amount of taste.
One of the major canning innovations of the 20th century was the development of aseptic processing. This technique, which involves sterilizing the container separately from the food, was invented in Switzerland in the 1960s for processing milk, but is now used widely for canned tomatoes and many juices. Small volumes of food are heated to a precise temperature and for a precise time in order to avoid overcooking and preserve color and nutrients, explains food scientist Philip Nelson, who won the 2007 World Food Prize in recognition of his research on making aseptic processing workable on a large industrial scale.
Today, despite all the modern alternatives, Appert’s technology still reigns supreme for long-term storage. More than two centuries on, the simple can is still the best solution for the safe and effective preservation of a wide range of foodstuffs worldwide.
*open kettle method: food is cooked in a covered container and then poured while hot into sterile jars
Questions 1--8
Complete the notes below.
Choose ONE WORD ONLY from the passage for each answer.
Solving Problems in the Preservation of Food
Early inventions
1795
• French government needs a supply of preserved food to feed the nation’s 1.
Early 1810
• Appert preserves food in glass jars -- using 2.
• Durand adapts Appert’s process for containers made of 3.
Dealing with problems of canned food going bad
1870s
• development of steam-retort technology in which 4 helps achieve high temperatures
1890s
• Heinz Company introduces regulations to reduce the risk of 5 entering the product
1913
• companies from across the US set up an organisation for the purpose of 6 into bacteriology
1960s
• technology developed for use with 7 is adapted for the sterilisation of cans
Preserving the appearance of food
• 8 was used in the 20th century to avoid loss of colour during the cooking process
Questions 9--13
Do the following statements agree with the information given in Reading Passage 1?
TRUE if the statement agrees with the information
FALSE if the statement contradicts the information
NOT GIVEN if there is no information on this
9. Peter Durand based his food preservation methods on a process that had recently won a cash prize from the French government.
10. The first canned food products were aimed at the general public.
11. Canned food producers often denied responsibility for cases of food poisoning.
12. The Heinz Company’s regulations regarding employees’ personal hygiene led to an increase in sales of its products.
13. The use of chemical additives was abandoned following the adoption of steam techniques.
Part 2
Viking Ireland
Viking Ireland
A When Irish archaeologists working under Dublin’s South Great George’s Street unearthed the remains of four young men buried with fragments of Viking shields, daggers and personal ornaments, the excavation appeared to be simply more evidence of the Viking presence in Ireland. At least 77 Viking burial sites have been identified across Ireland on the basis of the artefacts that accompanied them, and the South Great George’s Street burials seemed to be further examples. Yet when archaeologist Linzi Simpson sent the remains for analysis, the tests showed that the men had been buried in Irish soil years, or even decades, before the accepted date for the establishment of the first year-round Viking settlement in Dublin.
B Simpson’s findings are now adding new weight to an idea gaining growing acceptance -- that instead of a sudden, calamitous invasion, the arrival of the Vikings in Ireland started with small-scale settlements and trade links that connected Ireland with northern Europe. And, further, that those trading contacts may have occurred generations before the violent raids described in contemporary texts, works written by monks living in isolated monasteries. These were often the only places where literate people lived and were especially targeted by Viking raiders for their food supplies and treasures. Scholars are continuing to examine the texts written by monks, but are also considering the limitations of using them. ‘Most researchers now accept that the raids were not the first contact, as the old texts suggest,’ says Viking expert Gareth Williams. ‘How did the Vikings know where all those monasteries were? It’s because there was already contact. They were already trading before those raids happened.'
C Although the earlier dates for a Viking presence in Dublin that have been identified by Simpson and independent archaeologists differ from the later dates by only a few decades, when combined with other evidence, they are challenging the chronology of Viking settlement in Ireland. Since the 1960s, archaeologists have been gathering information about the mid-ninth-century settlement that lay under the sidewalks of Fishamble Street in Dublin. According to archaeologist Ruth Johnson, the Vikings started with sporadic summer raids, but after some years of profitable plunder, they decided to stay, and built settlements for the winter.
D Carbon dating, which measures the age of organic materials based on the amount of radioactive carbon 14 remaining in a specimen, usually gives a range of likely dates for the time of death. The older the material, the wider the range. In the case of the four individuals excavated at the South Great George’s Street site, Simpson found that two of them had a 95 per cent probability of having died between 670 and 880, with a 68 per cent probability of death occurring between 690 and 790. Thus, the entire most likely range was before the first documented arrival of Vikings in 795. A third individual lived slightly later, with a 95 per cent probability of having died between 680 and 882. The dates were not what Simpson had thought they would be. ‘These dates seem impossibly early and difficult to reconcile with the available historical and archaeological sources,’ she says.
E The fourth individual excavated at South Great George’s Street was the most intact of the group, and revealed the most about the lives and hardships of Vikings at this time. A powerfully built man in his late teens or early 20s, he was approximately 1.70 m tall by the standards of the day, with the muscular torso and upper limbs that would have come from hard, ocean-going rowing. His bones showed stresses associated with heavy lifting beginning in childhood. Unlike the three other men, he was not buried with weapons. Like one of the other men found at the site, he had a congenital deformity at the base of his spine, perhaps indicating they were relatives. Carbon dating gave a wider range for his lifetime, showing a 95 per cent probability that he died between 786 and 955.
F Tests were also carried out on the isotopic oxygen levels of the four South Great George’s Street men. Such tests indicate where a person spent their childhood based on a chemical signature left by groundwater in developing teeth. The results showed that the two men with the spinal deformity had spent their childhood in Scandinavia. However, the other two had spent their childhoods in Ireland or Scotland, another sign of permanent settlement by Viking families and not just summertime raids by warriors.
G The evidence of an earlier-than-expected Viking presence in Ireland, based as it is on forensic tests conducted on a handful of burials, may seem slight. But seemingly small pieces of evidence can overturn well-established conventions in archaeology. Both Simpson and Johnson stress that more excavations and tests will be needed before anyone can rewrite the history of Viking settlement, and such work is years away. Williams adds, ‘There are two possibilities raised by Simpson’s work. Either there was Viking activity earlier than we’ve realized in Ireland, or there is something in the water or soil in Dublin skewing the data, and both possibilities need further research.’ Nevertheless, Williams agrees with Simpson and others that the chronology of the Viking presence in Ireland is uncertain, and that they were possibly trading or raiding in Ireland before 795. ‘It’s a poorly documented part of history,’ says Williams. ‘But before there was Viking settlement, there was this big trading zone in the North Sea. Did it extend to the Irish Sea? We don’t have any evidence to say that, but it could be just a question of time.'
Questions 14--19
Reading Passage 2 has seven sections, A--G.
Choose the correct heading for Sections B--G from the list of headings below.
* Drag a heading and drop it into the blank space.
Questions 20--23
Look at the following statements and the list of experts below.
Match each statement with the correct expert, A, B or C.
NB You may use any letter more than once.
20. The Vikings were aware of the financial benefits of staying in Ireland.
20
21. Written accounts reporting when the Vikings arrived in Ireland may not be accurate.
21
22. The inconsistency in sets of data came as a surprise.
22
23. It may be the case that the archaeological evidence gathered so far is being affected by geological factors.
23
Questions 24--26
Complete the summary below.
Choose ONE WORD ONLY from the passage for each answer.
The Fourth Viking of South Great George’s Street
When the remains of the fourth Viking were excavated at South Great George’s Street, it became clear that they were the remains of a male who was tall by 24 of that time. Due to strenuous physical activity, his 25, as well as his arms, was well developed, but several of his bones indicated stresses that would have dated from his 26.
Part 3
Sea Change for Salinity
Sea Change for Salinity
A Beneath the flat, impassive surface of Australia lie hidden mountains, valleys and gorges -- ancient traps and channels for the deadly salt that is stealthily killing so much of the Australian landscape. The war on salt is calling forth new weapons. A suite of high technologies used by geologists to see underground and prospect for gold and minerals is now being used to pinpoint the presence of salt beneath the landscape and predict where it might move.
B Unless this process is clearly understood, warns Chief of Exploration and Mining Dr Neil Phillips, the hard work now underway of planning and tree-planting on the surface may be rendered ineffective: salt can still sneak past and erupt, following one of the ancient river channels formed millions of years ago. The use of airborne electromagnetic technology to detect salt hidden beneath the landscape has been around for a decade, but the past two years have seen a major development in its precision and powers of detection. Like the use of radar in battles, it has the potential to turn the tide of the struggle in favour of the defence by helping to pinpoint, plot and predict the movements of the foe.
C Angus Howell, who farms near Warrenbayne, in Southeast Australia, saw his first outbreak of salt in 1948. Over the ensuing decades, the patches spread and multiplied until they consumed almost 100 hectares. By the late 1970s, Howell and his fellow farmers had decided it was time for action and established a government-funded "Landcare" group in a bid to save Australia’s farmland. But despite a mounting effort by scientists, farmers and governments, the ‘white death’ continued to encroach. Small successes were eclipsed by larger defeats and fresh outbreaks.
D ‘The technical solutions just aren’t there yet for dealing with broadacre salinity, nor are the social and economic solutions. How do you introduce the land-use changes that are needed when people still need to make a living?’ Howell asks. There is no satisfactory solution yet. Part of the problem has lain in salt’s ability to mount ambushes, emerging somewhere new, sometimes unexpectedly and inexplicably, beating plans to intercept it. Only now are scientists starting to really disclose its secret subterranean stores and passages.
E The need for such knowledge is pressing. Salt has already afflicted six million hectares of once-productive country. At present rates, it is predicted that, by 2050, it will have sterilised a total of 17 million hectares and the waters of Australia’s Murray River will regularly exceed the World Health Organization’s salt limits for drinking water. Defeating this assault may take centuries, not decades.
F Electromagnetic surveys measure the electrical conductivity of soil to reveal the distribution of salt and the nature and variability of the regolith -- the weathered rock and sediment that may lie above the bedrock. Magnetic surveys measure small differences in the Earth’s magnetic field, enabling scientists to probe the deep past and reconstruct ancient landscapes -- rivers, basins and faults now buried under tens of metres of sediments. These features help to reveal where groundwater is stored, dictate the direction of groundwater movement, and are critical to predicting or ruling out salinity hot-spots.
G Radiometric analysis is based on the detection of radiation emitted by elements contained in rocks and soils, allowing scientists to delineate landforms. These factors influence the mobility of salt through the soil profile and help determine where to plant particular crop species to tackle the problem. Using data from the Murray River region, scientists have revealed a network of ancient drainage channels buried metres beneath the current landscape. These buried channels may carry salt and sometimes run at right angles to channels on the surface. This implies that the salt could move underground in quite a different direction from what one would expect by looking at surface slope and drainage.
H One of the biggest advances in detection, says Professor Neil Phillips, has come with the integration of different techniques such as magnetics, electromagnetics, radiomagnetics and ground mapping. Individually, these technologies only gave clues to what was going on underground. Together, they provide a far more revealing picture of the subsurface landscape, several hundred metres deep. Advanced airborne electromagnetics, in particular, enables scientists to take ‘slices’ of the landscape at depths of five metres, ten metres, fifteen metres and so on, to determine where salt may be stored at depth. This is building up a four-dimensional picture of the subsurface landscape, enabling researchers to understand movements of salt in width, depth, breadth and time. From such technologies, it will be possible to locate salt stores, identify how saline they are, look at man-made and natural changes to the landscape that may cause it to mobilise, and then predict where it will head to and over what time span. This, in turn, will give the salt warriors time to model various ways of containing or curbing the menace, see what works best and then try it out on the ground.
Questions 27--33
Reading Passage 3 has eight sections, A--H.
Which section contains the following information?
NB You may use any letter more than once.
| A | B | C | D | E | F | G | H | |
|---|---|---|---|---|---|---|---|---|
| 27. a prediction of the future risk of salt to water supplies | ||||||||
| 28. the reason why technologies must be combined to be effective | ||||||||
| 29. a reference to recent improvements in the accuracy of airborne electromagnetics | ||||||||
| 30. the organisation of concerned farmers into an official body | ||||||||
| 31. the estimated length of time salinity is likely to be a problem | ||||||||
| 32. a summary of stages in a proposed plan of action to combat the salt problem | ||||||||
| 33. the possibility that current re-vegetation practices are a waste of time |
Questions 34--36
Match each technique with the correct use, A--D.
34. Electromagnetic surveys
34
35. Radiometric analysis
35
36. Airborne electromagnetics
36
Questions 37--40
Choose the correct letter, A, B, C or D.
37. What link does the writer make between salt and gold?
38. What is the ‘process’ referred to in Section B?
39. According to Angus Howell, one problem in the fight against salinity is that
40. Which of the following best describes the writer’s view of the salinity problem in Australia?
