Judging a fruit by the colour Package label 'senses' when pears are ripe  Colour change indicates fruit is ready to eat Nov. 16, 2005. 08:06 AM DANA FLAVELLE BUSINESS REPORTER Think of it as a mood ring for fruit. Canadian consumers can now buy pears packaged with a label that senses when the fruit is ripe. The label changes colour as the fruit ripens: Red means firm, orange means crisp and yellow means juicy, according RipeSense, the company that makes the label.  Developed in New Zealand, the label makes fresh fruit more competitive with other convenience foods and packaged snacks, according to RipeSense Ltd. Consumers can now choose the fruit at just the right moment of ripeness and eat it without fear of biting into something hard or tasteless, company spokeswoman Katie McInness explained.  McInness says the label works by sensing the aroma of the fruit much as you would smell the difference with your nose as a pear ripens.  But food scientists say the label is reacting to the ethylene gas the fruit emits as it ripens.  Ethylene is a naturally occurring hormone in fruit that triggers the ripening process, said Jennifer DeEll, head of fresh market quality for the Ontario Ministry of Agriculture and Food.  Fruit picked too early or left in storage too long can sometimes miss this stage and become dry and flavourless.  But fruit can also be tricked into ripening by exposing it to ethylene gas after it's been picked, DeEll explained.  This is particularly attractive to growers of tender fruit that may bruise or ripen prematurely while being transported over long distances. To extend their shelf life, pears are `put to sleep' and then exposed to ethylene before shipping  The pears in Canadian supermarkets that have the RipeSense label are being imported from the states of Washington and Oregon, McInness said.  Local growers also sometimes add ethylene to extend the season.  For the first time this year, locally grown Bosc pears will be available as late as January, said Adrian Huisman, general manager of the Ontario Tender Fruit Producers Association.  To extend their shelf life, the pears are being put to sleep in special climate-controlled warehouses until they're needed, he said. Then, they'll be exposed to ethylene before they're shipped to ensure they're ripe.  After the local supply runs out, supermarkets will begin importing the fruit from more southern climes, he said, giving consumers fresh pears year round. It's a good thing, Huisman said.  For now, the RipeSense label is limited to pears, but new versions are being developed for avocados, melons, kiwi fruit and the stone fruits, such as peaches and pears, said McInness.  The pears are sold in packages of four in recyclable plastic clamshells that reduce bruising and improve hygiene, the company also noted. Consumers aren't buying fruit that has been squeezed by other shoppers.  Of course, all this technology comes at a price. A package of four RipeSense Anjou pears ‹ about a kilogram ‹ costs $3.99. (Cdn.) In comparison, Sobeys is selling Anjous for $2.18 (Cdn.)a kilogram. The RipeSense label was developed at HortResearch, the government-owned agricultural laboratories in New Zealand, in co-operation with the Jenkins Group, specialists in food labelling and packaging.  Invented in 2003, the world's first intelligent label was initially test marketed in the U.S. last year, the company says.