Posts Tagged ‘ Sydney ’

Issue 110: Feeding Sydney

January/February 2010
Author: Christine Paul

The University of Western Sydney, in association with the UWS Hawkesbury Foundation, recently held its inaugural Hawkesbury Conference where the focus was on challenges that major world population hubs like Sydney face. Against a background of dwindling agricultural land and water supplies, increasing pressure is also being placed on farming systems – what, if any, are the solutions?

Recently, the NSW Government announced the release of 800 hectares of employment land in Western Sydney to create the Western Sydney Employment Area with a capacity for up to 16,500 jobs and expected to eventually accommodate some 40,000 workers. The initiative is touted as a great benefit for people living in Western Sydney and the north-west and south-west growth centres.

However, not all reaction to the news has been positive with critics claiming that the initiative will result in even more pressure on Sydney Basin’s capacity by taking away already diminishing agricultural resources.

‘Feeding Sydney’ was the topic of talks at the recent one-day interactive conference, held at the Hawkesbury campus of the University of Western Sydney (UWS).

Held at the University of Western Sydney, the conference attracted attendees from a wide range of academic and industry backgrounds.

Talks at the conference focused on the issues and challenges facing major population hubs around the world at a time when available agricultural land and water supplies are declining and there is increasing pressure regarding sustainability of farming systems.

A mix of academic and industry professionals also explored possible alternative food supply options together with issues of food security.

Professor Phillip O’Neill (L), Director of UWS Urban Research Centre spoke at the conference as did Dr Gavin Ramsay from UWS Hawkesbury Foundation.

Speakers at the conference included National Water Commissioner Chris Davis (centre) advisor to Federal Minister for Climate Change, Penny Wong.

Professor Bill Bellotti, Vincent Fairfax Chair in Sustainable Agriculture and Rural Development UWS spoke at the conference, agreeing with Professor O’Neill that, based on food alone, it might be reasonable to conclude that agriculture in the Sydney Basin is insignificant.

Speakers included Professor Bill Bellotti, Vincent Fairfax Chair in Sustainable Agriculture and Rural Development UWS; Chris Davis, Commissioner of the National Water Commission; Professor Phillip O’Neill , Director Urban Research Centre UWS; Tristan Harris, G.M. Buying and Marketing, Harris Farm Markets; Mark Kable, Agricultural Director, Harvest Moon, Tasmania’s fresh vegetable specialists; John Webster, National Chief Executive, Foodbank Australia; and Dr Gavin Ramsay, Associate Head, School of Natural Sciences and Senior Lecturer in Rural Systems and Development UWS.

A grower’s and supplier’s panel discussion also provided a real world insight into the issues associated with the supply side of the equation.

Food security
Food security is determined by the food supply in a community, and whether people have adequate resources and skills to acquire and use (access) that food (NSW Health, 2003).

In the first plenary at the conference, Dr Gavin Ramsay gave a sobering overview of a possible future global scenario in his paper – Feeding the world: Pipe Dream or Possibility?

“The head of the international Monetary Fund (IMF) has warned that if food prices remain high, there will be war and other dire consequence for people in many developing countries,” Dr Ramsay said.

He added that the problem could also create trade imbalances that would impact major advanced economies, so it is not only a humanitarian question.

“The issue of food security is growing. China is eyeing overseas land in a push to secure more growing areas for food. Chinese companies will be encouraged to buy farmland abroad, particularly in Africa and South America to help guarantee food security, under a plan being considered by Beijing,” Dr Ramsay said.

“Saudi Arabia is doing a similar thing. According to information from Pakistan Ministry of Agriculture, currently Saudi Arabia is in talks with Pakistan to lease an area of farmland nearly twice the size of Hong Kong in a bid to ensure food security.”

Dr Ramsay also pointed out that Gulf Arab states are heavily reliant on food imports and, spurred on by a spike in prices of basic commodities, have raced to buy farmland in developing nations to guarantee supplies.

In his paper at the conference – Feeding Sydney: A Secure Future for Food? – Professor Bill Bellotti also talked of the “unprecedented uncertainty and complexity surrounding our agrifood systems.”

“The future challenge will be to produce more food from a shrinking resource base with less GHG emissions. But can we do it?” he asked.

“Food security is becoming a huge issue across the globe, including here in Australia. A recent study revealed that 22% of households in disadvantaged localities in Sydney experienced times when they ran out of food and the money to purchase more. Also according to figures from Foodbank Australia, a million children don’t get enough to eat so this is an alarming food security issue right here,” Professor Bellotti said.

Dr Ramsay explored the question of why food is such “a big deal”.

“The world’s population is growing, people are eating more food and often more expensive food (especially animal products). More expensive food uses more resources to produce,” he said.

“We also have to look at the nature of food. More than nutrition, it’s also about vitality and health. It’s also an incredibly important element in social activity. Then of course, it’s also very important for social status, for example, dining in an expensive restaurant shows others you can afford to.

“Also another important element is equity. In western society we eat differently from other parts of the world. We eat, for example, much more processed food and have much more resources available to us than in other parts of the world, particularly in Third World Countries so we’re talking about equity here,” he said.

Dr Ramsay cited several influencing factors responsible for the current world food crisis.

“Firstly, the climate seems to be changing. We are also running out of oil and are turning to biofuel production, effectively turning food producing land into land for houses,” he said.

“We are also destroying agricultural land due to inappropriate practices and we are running short of fresh water.”

In his paper Dr Ramsay also outlined the controlling factors behind the current international food system.

“Features of the system are that it is controlled by both public and private interests and a limited number of companies. It is controlled by the wealthy and is very production focused,” he said.

“Most of world’s population growth is occurring in urban areas of poor countries. These people are very food insecure – they can’t grow their own food. On top of this we are seeing huge changes in the patterns of food consumption, with a massive increase in the consumption of meat.”

Poor get poorer
“Many poorer countries are moving to become net importers of food not exporters. The number of food emergencies is also increasing from 14% to 27% in 2008. Resultant effects of these factors are that the poor and the vulnerable are hit even harder. In the areas I’ve worked in South Africa over 60% of the head of households were girls age 12. Most of this is due to the effects of HIV,” Dr Ramsay said.

“By 2050 there will be 9 billion people on the planet. What then are the implications for feeding tomorrow’s populations?

“All countries cannot be net importers of food. In fact, there are more countries than ever changing from being net exporters to net importers of food, therefore there will be an uneven distribution of food. Some will have too much, some too little.

“Those with too little will generally live in countries with poor governance and this has political ramifications as hungry, dissatisfied people are more vulnerable to political pressures and this will lead to a series of civil disturbances etc,” he said.

“If we cannot distribute food according to our needs now, will we be able to in 2050?

“In terms of food security, rich people (countries) who control resources (and manage them appropriately) are more likely to be food secure – but it is not guaranteed if they need to import food. However, poor people (especially the urban poor), will simply have no food security,” he said.

In his closing remarks, Dr Ramsay addressed his opening question of whether or not we can feed the world.

“It’s a possibility but it’s very much in the pipedream category,” he concluded.

Sydney’s food value chain
According to recent statistics, Sydney will grow from 4.2 million to 5.3 million people by 2030. These extra 1.1 million people will require 640,000 new dwellings with 160,000 of these to be built in the new north-west and south-west growth centres. Outside the growth centres another 60,000 dwellings will be constructed on greenfields lands. Then there is land needed for employment, which involves another 7,500 hectares.

In short, urban growth in Sydney has a large footprint.

“Beyond 2031 we know Sydney will continue to grow. Another million people by 2050 will mean a city in excess of 6 million people, which is large by developed world standards. And there may well be more after that. But these uncertain numbers are pretty much irrelevant,” said Professor Phillip O’Neill who presented his talk – Sydney’s food value chain: A discussion paper – to the Hawkesbury Foundation Conference.

Head of the Urban Research Centre (URC) at UWS, Professor O’Neill said the purpose of his paper at the conference was to “explore what we know about Sydney’s food value chain”.

“While some implications are drawn, its main purpose is to provide a knowledge base for further discussion and analysis,” he said.

“What we know is that Sydney’s food supply system and the basin’s agricultural lands are currently in crisis. The problem is that we know little detail about the crisis, its dimensions, its stakeholders, its impacts and its consequences. What we do know, however, is that there is alarming inattention by governments to the issue, let alone there being policies in the public domain for us to engage with.”

Professor O’Neill said that the task had been hampered by a marked lack of available data on the subject.

“We know little about Sydney’s food supply system. The Urban Research Centre has systematically tried to assemble the story of the task of feeding 4.2 million Sydneysiders. But it has proved difficult,” he said.

“The pertinent question for us to ask today is why was this task left to a group like ours to undertake without funding for labour or data? This neglect by government of basic information gathering is inexcusable.”

Agriculture
According to Professor O’Neill, in 2006, there were just 6,300 agricultural jobs in the Sydney Basin.

“They are located where you would expect, on Sydney’s NW and SW plains and along the orchard and poultry districts of the Central Coast,” he said. “The NSW Department of Agriculture estimates there are about 1,000 vegetable farms left in the basin. The ABS estimates these produce 43% of NSW vegetable production (by value). Poultry producers are also significant, contributing 42% of NSW poultry meat output and 48% of its eggs. Mushroom growers are responsible for close to 100% of NSW fungi supplies.

“But that’s about it. In total, Sydney’s agricultural output is just 8.5% of the value of our state’s total agricultural output, and under 2% of the nation’s total. In other words, aside from selected higher value fresh vegetables, and poultry and mushrooms, the Sydney Basin’s contribution to Sydney’s food needs is as meagre as it could be before you would describe it as insignificant,” he said.

“When the growth centres and other greenfields lands are transferred to urban uses, the NSW Department of Agriculture surveys show that 52% of the basin’s remaining vegetable farms will be eliminated. When this happens, then the basin’s agricultural significance – at least in its present format – will be lost forever, after just 221 years of white man’s custodianship.”

During his talk – Feeding Sydney: A Secure Future? – Professor Bill Bellotti gave an illustration of the farm gate value of agriculture in the Sydney Basin.

“As we can see the farm gate value of agriculture is around $1m with poultry, vegetables and cut flowers accounting for the top production values in the area,” he said.

“Sydney imports more than 85% of its vegetable requirements,” Professor Bellotti said. “And only 3-5 % of our average food energy consumption is produced in the Sydney Basin.”

Professor Bellotti agreed with Professor O’Neill that, based on food alone, it might be reasonable to conclude that agriculture in the Sydney Basin is insignificant.

“However, this does not account for environmental, aesthetic, recreational, and educational values, which are important.

“When community development benefits are valued, a different answer emerges,” he said.

“In terms of irrigation in the Sydney Basin (around 8000 hectares plus) there are competing claims on land and water where farmers are shifting to non-food options, which are more profitable and carry less risk,” Professor Bellotti said.

Freshwater consumption in NSW 2004-05

“Water for irrigation is already scarce, and will become scarcer in the future. So the question is should we prioritise allocation of land and water resources to food?”

In his paper – Feeding Sydney: the Water Question, Commissioner of the National Water Commission, Chris Davies, told the conference that it’s probably going to get drier, and water for irrigation is going to be hotly contested.

He made several recommendations as to the best future management of Sydney’s water resources.

“In the case of irrigation for agriculture in and around Sydney, river and dam allocations will be resolved through WSPs,” he said.

“Recycled water has to be used close to its source, nutrients should be left in water, where possible and urine separation is worth looking at.

“Small-scale irrigated agriculture is possible where sewer mining is permitted from decentralised schemes. Also opportunistically, rainwater or stormwater can be collected,” he said.

Despite the challenges for agriculture in the Sydney Basin, in food and beverage manufacturing, Professor O’Neill said that the food value chain is looking very healthy.

“Here we find over 30,000 jobs, 4000 in beverages (juices, soft drinks and beer mostly) and 25,600 in food manufacturing,” he said.

Food retail
Turning to the food retail sector, Professor O’Neill gave an overview of the major factors at play.

“There are 57,000 food retail workers in Sydney. Retailing jobs follow the population, especially the suburbanised population, especially in the suburbanised malls in and among the suburbanised population, like at Castle Hill, Warringah, Miranda and Penrith. But everywhere else too,” he said.

“Four sub-sectors account for 93.000 jobs, exactly one half of all Sydney’s food jobs: growing food, manufacturing food and drink, and retailing. Remember, just 6,300 of these jobs are in agriculture, producing less than 3% of the value added along Sydney’s food chain.”

Household consumption
“The concentration of employment in food services is reflected in what Sydney households spend their food money on. The standout spending category for Sydney households is meals eaten out and take away food. The next largest spending category is alcoholic beverages. Together these two categories constitute 38% of total household food and beverage consumption, or about 36 times what Sydney spends on its own fresh vegetable output,” Professor O’Neill said.

One implication of our spending so heavily on the higher value added food products and services – that is, where the actual food content makes us an increasingly small portion of what you buy – is that for the overwhelming majority of Sydney households, consuming fresh vegetables grown in Sydney is not an affordability issue. Rather, we choose, or are led, to buy food in other forms.

Summary
Professor O’Neill summed up his presentation, emphasising some major points:

“Clearly, Sydney-sourced fresh food attracts a meagre share of value flows in Sydney’s food economy. Sydney’s fresh food agriculture is threatened not only from diminished access to land and water resources, but also from its poor leverage over food industry value creation and distribution and poor leverage over Sydney households’ food spending patterns,” he said.

“Secondly, in the food market, agriculture has little market power and little capacity for competitive returns. But in the residential land market the food agriculturalist has significant market power and enormous capacity for high returns. Locked out of the food value chain, land-owning farmers instead choose, or are led, to the extraordinary gains available from selling rural lands to those who convert them to urban use.

“Much can be gained in understanding by analysing the food chain in terms of it being a competition between powerful players for the substantial consumer dollars on offer”, he said.

“That said, there is also much to be gained in understanding the food chain by analysing household consumption expenditure and householder food consumption habits. Sydney households in general are not poor. Their potential market power is enormous.”

Future scenarios
Professor Bellotti outlined three strategies for meeting future demands of population growth on Sydney’s food supply.

“The first scenario is the “Passive: Go with the Metro Strategy”. Following this strategy would lead to a further concentration of our food supply chains into a few major corporates and a loss of connection between food consumers and food producers,” he explained.

“Producers would also be forced into a global or national market, receiving low profit margins.

“The second is what I term the “Activist” strategy, which covers many different grassroots community movements,” he said.

“Basically, an activist rejects conventional agriculture, often striving for a high degree of food self-sufficiency.”

A third future scenario is the “Deliberate” strategy.

“This is where food security is taken seriously,” Professor Bellotti said. “It would involve a nationwide coordinated response to the challenge of food security.

“This strategy requires actions at all levels of society from national, state, local government levels to corporate Australia, communities and individuals,” he said.

Of the three strategies outlined, this one provides the best solutions to creating a healthy environment, farms, food and people and is underpinned by an integrated policy, science and practice.

“Food is the great integrator – healthy ecosystems are linked with healthy farms, healthy food and healthy people,” Professor Bellotti said.

“Government at all levels will focus on future food security (supply, access, affordability) while food consumers will be a driving force for change.

“We need to shift from being passive to becoming active food citizens – a citizen who not only has a voice in how their food is produced, but who also may be active in producing, purchasing and preparing their food,” he said.

“Part of this shift would see a strengthening of the relationship between food consumers and food producers, more direct food supply chains and a greater recognition by urban populations of their dependence on rural communities to supply their food needs.”

Issue 84: Current Consumer Attitudes Towards Tomatoes

September/October -2005
Author: Dr Sophie Parks & Dr Suzie Newman

How do Australians currently perceive tomatoes in the market place? This is an important question for the greenhouse industry at this point in time because hydroponic tomato products now have a strong presence in the market place. Understanding tomatoes is one way of identifying areas for industry improvement. To attempt to quantify consumer attitudes towards available tomato types, researchers from NSW DPI recently carried out a consumer survey in Sydney. Significant findings from this work are reported here.

About the survey
The survey was carried out over four days in June this year. Four supermarkets and four fruit and vegetable stores were randomly selected from the North Shore of Sydney. Twenty-five shoppers were interviewed in each store, near the tomato section, providing 200 respondents in total. Twenty questions were asked and the questionnaire took between 3 and 5 minutes to complete. The questions asked were designed to identify purchasing behaviour, use and storage of tomatoes, and the level of satisfaction with tomato quality. For this survey, five types of tomatoes found in the market place were defined: standard/gourmet, roma, truss/vine ripened, hydroponic and cherry/grape.

Purchasing behaviour
Fruit and vegetable stores were slightly favoured over supermarkets for tomato purchases. Although 50% were interviewed in a supermarket, only 32% bought tomatoes exclusively from the supermarket. Most of those interviewed in a fruit and vegetable store (46%) exclusively bought tomatoes there. The remaining 16% shopped at both supermarkets and fruit and vegetable stores, and 6% shopped elsewhere such as growers markets or at an organic store. Most people shopped weekly (66%) buying either 3-5 tomatoes (37%) or 1 kg (40%). Over 10% of people bought 1-2 punnets of cherry or grape tomatoes instead of, or in addition to, other tomatoes. Consumers were asked about the two types of tomatoes that they most frequently bought. Standard tomatoes were the most purchased (67%) and hydroponic tomatoes the least purchased (18%) (Figure 1). Over 35% of shoppers bought truss and cherry types, and over 40% bought roma tomatoes.

Figure 1. The proportion of consumers that bought each tomato type. This was based on the two tomato types that consumers usually purchased. First type – light green; second type – dark green.

The importance of flavour and quality in tomatoes
In terms of quality characteristics, flavour is the king tomato quality. Almost 30% of respondents were concerned about flavour, more than any other quality, when they had been disappointed with a tomato purchase (Figure 2). Firmness was the next quality of concern (16%), followed by ripeness (12%). Flavour was a key reason for buying tomatoes but this differed among tomato types. For example, over 80% of those that bought truss tomatoes did so for reasons of flavour, whereas only 20% of those that bought field tomatoes bought them for flavour (Figure 3). When it came to the question of the most flavoursome tomato, the largest group of consumers identified truss as having the most flavour (Figure 4).


Figure 2. Consumer reasons for being dissatisfied with a tomato purchase.

Figure 3. The reasons for buying a particular tomato type.

Figure 4. The tomato type considered as having the most flavour.

A significant proportion of consumers are not very excited about tomato flavour in the market place. When asked to rate tomato flavour, generally, 57% felt that tomato flavour was poor, not as good as it used to be, or average, and 43% felt that tomato flavour was good to very good. Consumers were asked to score the different tomato types for a number of quality characteristics. These included value for money, colour and appearance, firmness, sweetness, flavour, keeping and overall satisfaction. Combining these scores did not reveal significant differences among tomato types. However, generally speaking, cherry/grape tomatoes scored highest followed by truss, roma, hydroponic and lastly field tomatoes with the lowest quality score. Some consumers commented on how they usually pick out the best tomatoes from a poor batch of field tomatoes. This reflects the lower quality score for this tomato type.

The importance of use and versatility
People buy tomatoes for different uses. At the time of the survey (winter) almost 80% of respondents used tomatoes in salads. Over 35% also used tomatoes in sandwiches and for cooking. Versatility emerged as an important factor in buying tomatoes. It was the most important reason for buying cherry/grape tomatoes and the least important reason for buying any other tomato type (Figure 3). Consumers commented that cherry/grape tomatoes are very easy to use. Cherry/grape tomatoes are ideal as a snack, good for lunch boxes, well liked by kids, easy in salads, sandwiches and on crackers. Some mentioned that waste was reduced compared to other tomato types. Evidently, cherry/grape tomatoes have very successfully captured a niche in the tomato market.

The importance of price
Standard tomatoes were not considered the most flavoursome, or of a particularly high quality, but they were the most popular purchase. One would assume from this result that consumers are price sensitive when buying tomatoes. When asked why they bought field tomatoes, people were more likely to state price than flavour as a reason for buying this tomato type (Figure 3). However, price was not the main reason for buying any of the other tomato types. For truss, roma, and hydroponic tomatoes, flavour was the main factor prompting the purchase of these types. Versatility was the main factor prompting cherry/grape tomatoes, as previously mentioned. Also, price was not an important reason for being dissatisfied with a tomato purchase. In this case, only 2.5% of respondents reported price as being the significant issue.

Consumer comments were revealing about tomato price. Some consumers stated that they were not prepared to pay for more expensive types after having been disappointed with several purchases. Others stated that price was not an issue when entertaining, or when fresh tomato flavour was an important part of the meal, but bought cheaper tomatoes at other times.

Is there a problem with the ‘hydroponic’ tomato?
It is of concern that in this survey hydroponic tomatoes were the least purchased tomato type and were only considered the most flavoursome tomato type by 13% of consumers. However, of those that bought hydroponic tomatoes, 65% buy them for their flavour. Additionally, hydroponic tomato consumers are more likely than other consumers to think of tomato flavour in the market place as generally good.

It would appear that quality is not the reason for hydroponic tomatoes being one of the least popular tomato types in this survey. Perhaps the answer lies in marketing of the hydroponic tomato. In any case, this issue provides an opportunity for the hydroponic tomato industry to explore new ways of gaining a larger piece of the tomato market pie.

Storing tomatoes at home
Knowing how consumers store tomatoes at home can indicate whether or not tomatoes are getting the conditions that encourage full ripeness and flavour. From this survey it appears that there is room to educate consumers about how to best store tomatoes at home.

The majority of consumers store tomatoes in the fridge for 4-7 days. Some people were willing to admit that they kept tomatoes for up to 3 weeks! Ideally, tomatoes should be ripened at room temperature to obtain the best flavour. Once fully ripened they can be placed in the fridge if necessary. Only 30% of people in this survey stored tomatoes at room temperature (Figure 5). Given the importance placed by these consumers on flavour, providing information on correct storage conditions may reduce the dissatisfaction many have with tomato purchases.

Figure 5. Storage of tomatoes at home: Fridge – in the fridge; Open – at room temperature; F+O – at room temperature then in the fridge.

About the consumers
In any survey it is important to know a bit about the people participating so that effects, such as gender preferences, can be identified. In this survey all the respondents were interviewed on the North Shore of Sydney. The North Shore was chosen with the assumption that people in this higher socio/economic area would be more prepared to pay for expensive tomato types. This was important as one of the aims of the survey was to obtain information from consumers about a range of tomato types. If the survey Reels rotate once to release short had been carried out in another region, or at Disposable reels with 25metre twine another time of day or year, we may have obtained a different picture of consumer attitudes towards tomatoes.

Nylon hanger for strength and durability obtained a different picture of consumer Long lengths quickly and easily unwound attitudes towards tomatoes. Hangers will not spin off the crop wire Proven over 5 years in NZ and Australia Two hundred consumers were interviewed in total. There were more females (73%) than males (27%). Over a third had children living at home (38%). Just under a third of people were born overseas (30%). Income was approximately evenly split among four income levels: $0-25 000, $25 000-65 000, $65 000-100 000, >$100 000. Almost half of people were over 50 years of age, 35% were 36-50, 16% were 25-35, and 1% of the respondents were under 25 years of age.

With few exceptions, gender, age, income and place of birth did not influence the way consumers answered the questionnaire. The exception was that 25-35-year-olds were less likely to rate tomato flavour as poor and more likely to rate tomato flavour as good compared with other age groups. This could be interpreted in two ways. Younger taste buds are known to function better than older taste buds; hence this age group has not suffered any loss of tasting capability. Alternatively, tomatoes really good as they used to, with this age group being too young to have ever tried a tasty tomato!

Conclusions
There is a lot to be gained by looking at tomatoes from the consumer perspective. Most consumers buy more than one type of tomato and they are passionate about flavour. Flavour is the main impetus for buying tomatoes, and flavour, firmness and ripeness are perceived to be the biggest problems with tomatoes. Given the emphasis placed on these qualities, consumers would probably benefit with more information on appropriate storage and ripening conditions for tomatoes. As for tomatoes sold as are not as popular as other types and are not readily perceived to be flavoursome, except by those that buy them. The industry needs to address these issues.

About the authors
Dr Sophie Parks is a plant physiologist focused on greenhouse and hydroponic production. Dr Suzie Newman is a postharvest physiologist focused on postharvest and market access issues. They are both based at NSW Department of Primary Industries at Gosford, NSW.

For further information contact:
NSW DPI, Locked Bag 26,
Gosford NSW 2250 Ph:
Email: sophie.parks@dpi.nsw.gov.au or suzie.newman@dpi.nsw.gov.au

What is tomato flavour?
The organoleptic (taste or flavour) properties of tomato fruits are determined largely by the amounts of solids, particularly sugars and organic acids, and the volatile compound composition (Stevens, 1972). Some 95% of a typical ripe tomato fruit is water, so the tomato quality is therefore determined by a very small amount of solid matter. About 8% of this dry matter is minerals, the rest consisting of various carbon compounds, half of which are sugars as glucose and fructose, and an eighth organic acids. These are the factors which contribute to the typical sweet/sour taste of a tomato.

Sugars and acids not only contribute to the sweetness and sourness of tomatoes, but are also major factors influencing flavour intensity (Stevens et al., 1979). Hobson and Bedford (1989) stated that consumers preferred fruit with a balanced high sugar content, the taste is sweet but, to most people, insipid. With high quality acidity and low sugar content, the taste is rather sharp and thin. When both acidity and sugar content are low, the taste is watery and unattractive (Winsor, 1966). Tomato flavour changes dramatically during the process of ripening. The sugar content of both the seed and pulp increases rapidly during the first appearance of yellow and orange colouration, and then to a lesser extent up to the fully ripe condition (Winsor, 1966). The acidity of juices is relatively high at the mature green stage, but decreases markedly throughout the ripening process from the green or green-yellow stages onwards. The flavour of the fruit is thus best at about the orange-red stage, when sugar content is high and before overall acidity becomes too low.

References
The composition of cherry tomatoes and its relation to consumer acceptability.
J.Hort.Sci., 64(3): 324-329, Hobson, G.E. and Bedford, 1989.

Components contributing to quality variation among tomato lines
J.Amer.Soc.Hort.Sci., 97(1): 70-73.

Potential for increasing tomato flavour via increased sugar and acid content. 1979.
J.Amer.Soc.Hort.Sci., 104(1): 40-42

The composition, flavour and firmness of tomatoes
Scientific Hort., 18: 27-35.

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