Maple syrup
![](http://upload.wikimedia.org/wikipedia/commons/thumb/1/18/Maple_syrup.jpg/150px-Maple_syrup.jpg)
Maple syrup is a syrup usually made from the xylem sap of sugar maple, red maple or black maple trees, although syrup can also be made from other maple species such as the Bigleaf Maple. In cold climates, these trees store starch in their stems and roots before the winter; the starch is then converted to sugar and rises in the sap in the spring. Maple trees can be tapped and the exuded sap collected and concentrated by heating to evaporate the water and form syrup. Quebec, Canada is the world's largest producer.
Maple syrup was first collected and used by First Nations and Native Americans. The practice of maple syrup production was adopted by European settlers, who gradually improved production methods. Technological improvements in the 1970s further refined syrup processing. Maple syrup is most often eaten with waffles, pancakes, oatmeal (porridge), and French toast. It is also used as an ingredient in baking, or as a sweetener and flavouring agent. Sucrose is its most prevalent sugar.
The syrup is graded according to the Canada, US or Vermont scales based on its density and translucency. Syrups must be at least 66 percent sugar to qualify as "maple syrup" in Canada; in the US, any syrup not made almost entirely from maple sap cannot be labelled as "maple". Maple syrup and the sugar maple tree are symbols of Canada and several US states, particularly Vermont.
History
Native Americans
![](http://upload.wikimedia.org/wikipedia/commons/thumb/9/99/Sugar-Making_Among_the_Indians_in_the_North.gif/200px-Sugar-Making_Among_the_Indians_in_the_North.gif)
Aboriginal peoples living in the northeastern part of North America were the first people known to have produced maple syrup and maple sugar. According to their oral traditions, as well as archaeological evidence, maple tree sap, which they called "sweet water" or "Sinzibuckwud" (literally "drawn from trees"),[1] was being processed for its sugar content long before Europeans arrived in the region.[2] However, there are no authenticated accounts of maple syrup production and consumption among early aboriginal groups.[3] Various legends exist as to the origins of maple syrup production; one of the most popular involves maple sap being used to cook venison served to a chief.[1] Many aboriginal dishes replaced the salt traditional in Europe with maple sugar or syrup.[1]
The Algonquins recognized the sap as a source of energy and nutrition. At the beginning of the spring thaw, they used stone tools to make V-shaped incisions in tree trunks; they then inserted reeds or concave pieces of bark to run the sap into buckets, which were often made from birch bark.[3] The maple sap was concentrated either by dropping hot cooking stones into the buckets,[4] or by leaving them exposed to the cold temperatures overnight and disposing of the layer of ice which formed on top.[3] Production of maple syrup is one of only a few agricultural processes in North America that is not a European colonial import.[3]
Europeans
![](http://upload.wikimedia.org/wikipedia/commons/thumb/0/0f/Maple_syrup_bucket.jpg/200px-Maple_syrup_bucket.jpg)
In the early stages of European colonization in north-eastern North America, native peoples showed the arriving colonists how to tap the trunks of certain types of maples during the early-spring thaw to harvest the sap.[2] By 1680, European settlers and fur traders were involved in harvesting maple products.[2] During the 17th and 18th centuries, processed maple sap was used primarily a source of concentrated sugar, in both liquid and crystallized-solid form.[3]
Typically, maple sugaring parties began to operate at the start of the spring thaw in regions of woodland known to contain sufficiently large numbers of maples.[2] They first bored holes in the trunks of the maples, usually more than one hole per large tree, inserted home-made wooden spouts into the holes, and then hung a wooden bucket from the protruding end of each spout to collect the sap. The buckets were commonly made by cutting cylindrical segments from a large tree-trunk and then hollowing out each segment's core from one end of the cylinder, creating a seamless watertight container.[3] Sap slowly filled the buckets; members of the sugaring party periodically returned to retrieve the sap that had accumulated. It was then either transferred to larger holding vessels (barrels, large pots, or hollowed-out wooden logs), often mounted on sledges or wagons pulled by draft animals, or it was carried in buckets or other convenient containers.[2] The sap-collection buckets were returned to the spouts mounted on the trees, and the process was repeated for as long as the flow of sap remained "sweet". The specific weather conditions of the thaw period were, and still are, critical in determining the length of the "sugaring" season.[5] As the weather continues to warm, a maple tree's normal early spring biological process eventually alters the taste of the sap, making it unpalatable.[6]
![](http://upload.wikimedia.org/wikipedia/commons/thumb/8/8f/Sugar_house.jpg/200px-Sugar_house.jpg)
The boiling process was time-consuming. The harvested sap was transported back to the party's base camp, where it was then poured into large, usually metal vessels and boiled to achieve the desired consistency.[3] The sap was usually processed at a central collection point, either over a fire built out in the open or inside a shelter built for that purpose.[7] To protect themselves from the weather, sugaring parties built a small camp. By the 1850s, the "sugar shack" or "sugarhouse", the outdoor shack or building used to boil down the sap, had developed.[3] The sap was transported using large barrels pulled by horses or oxen and brought to the sugar shack for processing.[3]
Processing
Production methods have been streamlined since colonial days, yet remain basically the same. Sap must first be collected and boiled down carefully to obtain pure syrup without chemical agents or preservatives. Maple syrup is made by boiling between 20 to 50 litres (5.3 to 13.2 US gal)* of sap (depending on its concentration) over an open fire until 1 litre (0.26 US gal)* of syrup is obtained.[7] The finished syrup has a density of 66° or greater on the Brix scale (a hydrometric scale used to measure sugar solutions).[8] The syrup is then cooled and filtered to remove sugar sand, crystals made up largely of sugar and calcium malate, which form due to their reduced solubility at room temperature.[9]
Around the time of the American Civil War, syrup makers started using a large flat sheet metal pan as it was more efficient for boiling than a heavy rounded iron kettle, because it created a greater surface area for evaporation.[7] Around this time, cane sugar replaced maple sugar as the dominant sweetener in the US; as a result, producers focused their marketing efforts on maple syrup.[3] The first evaporator, used to heat and concentrate sap, was patented in 1858.[3] In 1872 an evaporator was developed that featured two pans and a metal arch or firebox, which greatly decreased boiling time.[3] Around 1900, producers bent the tin that formed the bottom of a pan into a series of flues which increased the heated surface area of the pan and again decreased boiling time.[7] Some producers also added a finishing pan, a separate batch evaporator, as a final stage in the evaporation process.[7]
![](http://upload.wikimedia.org/wikipedia/commons/thumb/5/5d/Sap_plastic_tubing.jpg/200px-Sap_plastic_tubing.jpg)
Buckets began to be replaced with plastic bags, which allowed people to see at a distance how much sap had been collected.[3] Syrup producers also began using tractors to haul vats of sap from the sugarbush to the evaporator. Some producers adopted motor-powered tappers and metal tubing systems to convey sap from the tree to a central collection container, but these techniques were not widely used.[3] Heating methods also diversified: modern producers use wood, oil, natural gas, propane, or steam to evaporate sap.[7] Modern filtration methods were perfected to prevent contamination of the syrup.[10]
During the 1970s, a large number of technological changes took place. Plastic tubing systems which had been experimented with since the early part of the century were perfected, and the sap came directly from the tree to the evaporator house.[2] Vacuum pumps were added to the tubing systems. Pre-heaters were developed to recycle heat lost in the steam. Reverse-osmosis machines were developed to take a portion of water out of the sap before it was boiled.[3]
Improvements in tubing, use of vacuum, new filtering techniques, "supercharged" preheaters, and better storage containers have since been developed. Research continues on pest control and improved woodlot management.[3] In 2009, researchers at the University of Vermont unveiled a new type of tap which prevents backflow of sap into the tree, reducing bacterial contamination and preventing the tree from attempting to heal the bore hole.[11]
Production
Maple syrup production is centred in northeastern North America; however, given the correct weather conditions, it can be made wherever maple trees grow. Usually, the maple species used are the sugar maple (Acer saccharum), the red maple (Acer rubrum) and the black maple (Acer nigrum),[12] because of the high sugar content in the sap – roughly two to five percent.[2] Red maple has a shorter season because it buds earlier than sugar and black maples, altering the flavor of the sap.[13] Silver maples and other maple species are occasionally also tapped.[6] A maple syrup production farm is called a "sugar bush" or "sugarwood". Sap is often boiled in a "sugar house" (also known as a "sugar shack", "sugar shanty" or cabane à sucre), a building which is louvered at the top to vent the steam from the boiling sap.[14]
Maples are usually tapped beginning between 30 and 40 years of age. Each tree can support between one and three taps, depending on its trunk diameter. The average maple tree will produce between 35 to 50 litres (9.2 to 13.2 US gal)* of sap per season, up to 12 litres (3.2 US gal)* per day.[2] This is roughly equal to 7 percent of its total sap. Seasons last for four to eight weeks, depending on the weather.[15] During the day, starch stored in the roots for the winter rises through the trunk as sugary sap, allowing it to be tapped.[5] Sap is not tapped at night because the temperature drop inhibits sap flow, although taps are typically left in place overnight.[16] Some producers also tap in autumn, although this practice is less common. Maples can continue to be tapped for sap until they are over 100 years old.[2]
Commerce
![](http://upload.wikimedia.org/wikipedia/commons/thumb/9/95/MapleSyrupProduction.jpg/220px-MapleSyrupProduction.jpg)
Canada makes more than 80 percent of the world's maple syrup, producing about 26,500,000 litres (7,000,000 US gal)* in 2004.[17] The vast majority of this comes from Quebec: the province is the world's largest producer, with about 75 percent of the world production totalling 24,660,000 litres (6,510,000 US gal)* in 2005.[17] Production in Quebec is controlled through a supply-management system, with producers receiving quota allotments from the Fédération des producteurs acéricoles du Québec, which also maintains reserves of syrup.[18] Canada exports more than 9,418,680 litres (2,488,150 US gal)* of maple syrup per year, valuing over C$145 million.[19][20]
The provinces of Ontario, Nova Scotia, New Brunswick, and Prince Edward Island produce smaller amounts of syrup.[17] The provinces of Manitoba and Saskatchewan produce maple syrup using the sap of the Manitoba maple tree (Acer negundo or "box-elder").[21] Manitoba maple syrup has a slightly different flavor than sugar-maple syrup; because it contains less sugar and the sap flows more slowly. The Manitoba maple tree's yield is usually less than half that of a similar-sized maple tree.[22]
Vermont is the biggest US producer, with 3,369,016 litres (890,000 US gal) in 2010, followed by New York with 1,181,048 litres (312,000 US gal) and Maine with 1,173,477 litres (310,000 US gal). Wisconsin, Ohio, New Hampshire, Michigan, Pennsylvania, Massachusetts, and Connecticut all produced marketable quantities of maple syrup of less than 450,000 litres (120,000 US gal) each in 2009.[23]
Maple syrup has been produced on a small scale in some other countries, notably Japan and South Korea.[24] However, in South Korea in particular it is traditional to consume maple sap, called "gorosoe", instead of processing it into syrup.[25]
Off-flavors
Sometimes off-flavors are found in maple syrup, from a variety of causes. These include contaminants in the boiling apparatus, such as paint or cleanser; changes in the sap, such as fermentation when it has been left sitting too long; and changes in the tree, such as "buddy sap" late in the season when budding has begun.[26] In some circumstances it is possible to remove off-flavor through processing.[27]
Grades
In Canada, there are three grades containing several color classes, ranging from Canada #1, including Extra Light (sometimes known as AA), Light (A), and Medium (B); through #2 Amber (C); and finally #3 Dark (D).[2] In addition, Canada #2 Amber may be labelled Ontario Amber when produced and sold in that province only.[28] A typical year's yield will be about 25 to 30 percent of each of the #1 colours, 10 percent #2 Amber, and 2 percent #3 Dark.[8]
The United States uses somewhat different grading standards. Maple syrup is divided into two major grades: Grade A and Grade B. Grade A is further broken down into three sub-grades: Light Amber (sometimes known as Fancy), Medium Amber, and Dark Amber.[2] The Vermont Agency of Agriculture Food and Markets uses a similar grading system of colour and is roughly equivalent, especially for lighter syrups.[2] The Vermont grading system differs from the US system in maintaining a slightly higher standard of product density (measured on the Baumé scale). New Hampshire maintains a similar standard, but not a separate grading scale. The Vermont graded product has 0.9 percent more sugar and less water in its composition.[29] A non-table grade of syrup called commercial, or Grade C, is also produced under the Vermont system.[29]
Typically #1 Extra Light and Grade A has a milder flavor than #3 or Grade B, which is very dark with a sharp maple flavor.[29] The dark grades of syrup are primarily used for cooking and baking, although some specialty dark syrups are produced for table use.[30] The classification of maple syrup in the US ultimately depends on its translucence. US Grade A "Light Amber" has to be more than 75 percent translucent, US Grade A "Medium Amber" has to be 60.5 to 74.9 percent translucent, US Grade A "Dark Amber" has to be 44 to 60.4 percent translucent, and US Grade B has to be less than 43.9 percent translucent.[10]
Food and nutrition
Nutritional value per 100 g (3.5 oz) | |||||||||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Energy | 1,093 kJ (261 kcal) | ||||||||||||||||||||||||||||||||||||
67.09 g | |||||||||||||||||||||||||||||||||||||
Sugars | 59.53 g | ||||||||||||||||||||||||||||||||||||
Dietary fiber | 0 g | ||||||||||||||||||||||||||||||||||||
0.20 g | |||||||||||||||||||||||||||||||||||||
0 g | |||||||||||||||||||||||||||||||||||||
| |||||||||||||||||||||||||||||||||||||
†Percentages estimated using US recommendations for adults,[31] except for potassium, which is estimated based on expert recommendation from the National Academies.[32] |
The basic ingredient in maple syrup is the sap from the xylem of the trees. It consists primarily of sucrose and water, with only small amounts of other sugars such as fructose and glucose. Organic acids, most notably malic acid, make the syrup slightly acidic.[33] Maple syrup has a relatively low mineral content. Potassium and calcium make up most of this mineral content, but maple syrup also contains nutritionally significant amounts of zinc and manganese. Maple syrup contains trace amounts of amino acids, which may contribute to the "buddy" flavor of syrup produced late in the season, as the amino acid content of sap increases at this time.[33] Additionally, maple syrup contains a wide variety of volatile organic compounds, including vanillin, hydroxybutanone, and propionaldehyde. It is not yet known exactly which compounds are primarily responsible for maple syrup's flavor.[9]
Maple syrup is similar to sugar calorie-wise, but is a source of manganese, with 13.33 grams (0.470 oz) containing about 0.44 milligrams (1.6×10−5 oz) or 22 percent of the U.S. Food and Drug Administration Daily Value (DV%) of 2 milligrams (7.1×10−5 oz).[34] It is also a source of zinc with 13.33 grams (0.470 oz) containing 0.55 milligrams (1.9×10−5 oz) or 3.7 percent of the FDA Daily Value (DV%) of 15 milligrams (0.00053 oz).[35][34] Compared to honey, maple syrup has 15 times more calcium and 1/10 as much sodium.[16]
British culinary expert Delia Smith described maple syrup as "a unique ingredient, smooth and silky textured, with a sweet, distinctive flavour - hints of caramel with overtones of toffee will not do - and a rare colour, amber set alight. Maple flavour is, well, maple flavour, uniquely different from any other."[16] Maple syrup and its artificial imitations are used as toppings for pancakes, waffles, and French toast in North America. It is used to create specialty products like maple syrup cream and candies. Maple syrup can also be used to flavor a variety of foods, including: biscuits, fritters, ice cream, hot cereal, and fresh fruit. It is also used as sweetener for applesauce, baked beans, candied sweet potatoes, winter squash, cakes, pies, breads, fudge and other candy, milkshakes, tea, coffee, and hot toddies. Maple syrup can also be used as a replacement for honey in wine (mead).[36]
Scientists have found that maple syrup's natural phenols – the beneficial antioxidant compounds – inhibit two carbohydrate hydrolyzing enzymes that are relevant to Type 2 diabetes. In the study 34 new beneficial compounds in pure maple syrup were discovered, five of which have never been seen in nature. Among the five new compounds discovered is quebecol, a compound created when the maple sap is boiled to create syrup. [37]
Imitation maple syrup
In the United States, "maple syrup" must be made almost entirely from maple sap; small amounts of substances such as salt may be added.[38] "Maple-flavoured" syrups contain maple, but also other less expensive ingredients.[39] "Pancake syrup", "waffle syrup", "table syrup", and similarly named syrups are substitutes, which are less expensive than maple syrup. In these syrups, the primary ingredient is most often high fructose corn syrup flavoured with sotolon; they have no genuine maple content, and are usually thickened far beyond the viscosity of maple syrup.[40] The fenugreek seed, a spice with high amounts of sotolon, can be prepared to have a maple syrup-like flavor, and is used to make a very strong commercial flavouring that is similar to maple syrup, but much less expensive.[41]
American labelling laws prohibit imitation syrups from having "maple" in their names.[42] In Canada, syrup must have a density of 66° on the Brix scale to be marketed as maple syrup.[8] Québécois sometimes refer to imitation maple syrup as sirop de poteau ("pole syrup"), a joke referring to the syrup as having been made by tapping telephone poles.[43]
Cultural significance
Maple syrup and maple sugar were used during the American Civil War and by abolitionists in the years prior to the war because most cane sugar and molasses was produced by Southern slaves.[44] During food rationing in World War II, people in the northeastern United States were encouraged to stretch their sugar rations by sweetening foods with maple syrup and maple sugar,[3] and recipe books were printed to help housewives employ this alternate source.[45]
The sugar maple's leaf has come to symbolize Canada, and is depicted on the country's flag.[46] Several US states, including New York and Vermont, have the sugar maple as their state tree.[47] A scene of sap collection is depicted on the Vermont state quarter.
See also
References
- ^ a b c "History". Michigan Maple Syrup Association. Retrieved 20 November 2010.
- ^ a b c d e f g h i j k l Ciesla, William M. (2002). Non-wood forest products from temperate broad-leaved trees. Food and Agriculture Organization of the United Nations. pp. 37–43, 103–113. ISBN 92-5-104855-X.
- ^ a b c d e f g h i j k l m n o p q Koelling, Melvin R.; Laing, Fred; Taylor, Fred (1996). "Chapter 2: History of Maple Syrup and Sugar Production". In Koelling, Melvin R.; Heiligmann, Randall B. (eds.). North American Maple Syrup Producers Manual. Bulletin. Vol. 856. Ohio State University. Archived from the original on 29 April 2006. Retrieved 20 September 2010.
- ^ Larkin, David (1998). Country Wild. Houghton Mifflin. pp. 146–147. ISBN 0395771900.
- ^ a b Heiligmann, Randall B. (1996). "Chapter 6: Maple Sap Production". In Koelling, Melvin R.; Heiligmann, Randall B. (eds.). North American Maple Syrup Producers Manual. Bulletin. Vol. 856. Ohio State University. Archived from the original on 29 April 2006. Retrieved 20 September 2010.
{{cite book}}
: Unknown parameter|coauthor=
ignored (|author=
suggested) (help) - ^ a b Heiligmann, Randall B. R.; Winch, Fred E. (1996). "Chapter 3: The Maple Resource". In Koelling, Melvin R.; Heiligmann, Randall B. (eds.). North American Maple Syrup Producers Manual. Bulletin. Vol. 856. Ohio State University. Archived from the original on 29 April 2006. Retrieved 20 September 2010.
- ^ a b c d e f Heiligmann, Randall B.; Staats, Lewis (1996). "Chapter 7: Maple Syrup Production". In Koelling, Melvin R.; Heiligmann, Randall B. (eds.). North American Maple Syrup Producers Manual. Bulletin. Vol. 856. Ohio State University. Archived from the original on 29 April 2006. Retrieved 20 September 2010.
- ^ a b c Eillot, Elaine (2006). Maple Syrup: recipes from Canada's best chefs. Formac Publishing Company. p. 12. ISBN 978-0-88780-697-1.
- ^ a b Ball, David (10 October 2007). "The Chemical Composition of Maple Syrup". Journal of Chemical Education. 84 (10): 1647–1650. doi:10.1021/ed084p1647. Retrieved 19 September 2010.
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(help) - ^ a b Koelling, Melvin R. (1996). "Chapter 8: Syrup Filtration, Grading, Packing, and Handling". In Koelling, Melvin R.; Heiligmann, Randall B. (eds.). North American Maple Syrup Producers Manual. Bulletin. Vol. 856. Ohio State University. Archived from the original on 29 April 2006. Retrieved 20 September 2010.
{{cite book}}
: Unknown parameter|coauthor=
ignored (|author=
suggested) (help) - ^ Perkins, Timothy D (2009). "Development and testing of the check-valve spout adapter" (PDF). Maple Digest. 21A: 21–29. Retrieved 21 September 2010.
{{cite journal}}
: Unknown parameter|month=
ignored (help) - ^ Eillot, Elaine (2006). Maple Syrup: recipes from Canada's best chefs. Formac Publishing Company. pp. 8–10. ISBN 978-0-88780-697-1.
- ^ Heilingmann, Randall B. "Hobby Maple Syrup Production". Ohio State University. Retrieved 20 September 2010.
- ^ Koelling, Melvin R.; Staats, Lewis (1996). "Appendix 1: Maple Production and Processing Facilities". In Koelling, Melvin R.; Heiligmann, Randall B. (eds.). North American Maple Syrup Producers Manual. Bulletin. Vol. 856. Ohio State University. Archived from the original on 29 April 2006. Retrieved 20 September 2010.
- ^ Koelling, Melvin R.; Davenport, Russell (1996). "Chapter 1: Introduction". In Koelling, Melvin R.; Heiligmann, Randall B. (eds.). North American Maple Syrup Producers Manual. Bulletin. Vol. 856. Ohio State University. Archived from the original on 29 April 2006. Retrieved 20 September 2010.
- ^ a b c Werner, Leo H. "Maple Sugar Industry". Canadian Encyclopedia. Historica-Dominion Institute. Retrieved 20 September 2010.
- ^ a b c "Production, Price, & Value, 2002-2004, U.S. & Canadian Provinces" (PDF). Maple Syrup. United States Department of Agriculture. p. 12. Retrieved 19 September 2010.
- ^ "Actions de la FPAQ" (in French). Fédération des producteurs acéricoles du Québec. Retrieved 22 September 2010.
- ^ Eillot, Elaine (2006). Maple Syrup: recipes from Canada's best chefs. Formac Publishing Company. p. 13. ISBN 978-0-88780-697-1.
- ^ "Sap and Resin". Non-wood forest products from temperate broad-leaved trees. Food and Agricultural Organization of the United Nations. Retrieved 14 July 2011.
- ^ Ehman, Amy Jo (April 25, 2011). "Sask. sap too sweet to waste". The StarPhoenix. Postmedia Network. Retrieved 2011-04-25.
- ^ Kendrick, Jenny. "Tapping the Manitoba Maple" (PDF). Statistics Canada. Retrieved 19 September 2010.
- ^ "Maple Syrup Production Down 19 Percent Nationwide" (PDF). Maple Syrup 2010. United States Department of Agriculture. 15 June 2010. Retrieved 19 September 2010.
- ^ Watanabe, Toshiyuki (1962). "On the Sugar Composition of Maple Syrup". Tohoku Journal of Agricultural Research. 13 (2): 175–181.
{{cite journal}}
: Unknown parameter|coauthors=
ignored (|author=
suggested) (help) - ^ Sang-Hun, Choe (5 March 2009). "In South Korea, drinks are on the maple tree". Hadong Journal. Retrieved 21 September 2010.
- ^ Childs, Stephen. "Maple Flavors and Syrup Grading". Cornell University. Retrieved 19 September 2010.
- ^ van den Berg, Abby K. (2009). "Metabolism Off-Flavor in Maple Syrup". Maple Digest. 21A: 11–18.
{{cite journal}}
: Unknown parameter|coauthors=
ignored (|author=
suggested) (help); Unknown parameter|month=
ignored (help) - ^ "Maple Syrup Grades". Ontario Maple Syrup Producers Association. Retrieved 19 September 2010.
- ^ a b c "Frequently Asked Questions". Cornell University. Retrieved 22 September 2010.
- ^ McGee, Harold (2004). On food and cooking: the science and lore of the kitchen (2nd ed.). Simon & Schuster. pp. 668–669.
- ^ United States Food and Drug Administration (2024). "Daily Value on the Nutrition and Supplement Facts Labels". FDA. Archived from the original on 2024-03-27. Retrieved 2024-03-28.
- ^ National Academies of Sciences, Engineering, and Medicine; Health and Medicine Division; Food and Nutrition Board; Committee to Review the Dietary Reference Intakes for Sodium and Potassium (2019). Oria, Maria; Harrison, Meghan; Stallings, Virginia A. (eds.). Dietary Reference Intakes for Sodium and Potassium. The National Academies Collection: Reports funded by National Institutes of Health. Washington, DC: National Academies Press (US). ISBN 978-0-309-48834-1. PMID 30844154. Archived from the original on 2024-05-09. Retrieved 2024-06-21.
- ^ a b Morselli, Mariafranca; Whalen, M. Lynn (1996). "Appendix 2: Maple Chemistry and Quality". In Koelling, Melvin R.; Heiligmann, Randall B. (eds.). North American Maple Syrup Producers Manual. Bulletin. Vol. 856. Ohio State University. Archived from the original on 29 April 2006. Retrieved 20 September 2010.
- ^ a b "Maple Syrup". National Nutrient Database. United States Department of Agriculture. Retrieved 19 September 2010.
- ^ "Syrups, Maple". Self Nutrition Data. Self. Retrieved 20 September 2010.
- ^ Eillot, Elaine (2006). Maple Syrup: recipes from Canada's best chefs. Formac Publishing Company. ISBN 978-0-88780-697-1.
- ^ "Maple Syrup May Help Treat Diabetes". Retrieved 14 April 2011.
- ^ E.g., 21 CFR §168.140 (USA).
- ^ E.g., 21 CFR §168.180 (USA).
- ^ Harris, N.E. (1975). Replacement of Sugar Syrup with High-Fructose Syrup in Imitation Maple Syrup. Defense Technical Information Center. pp. 1–13.
{{cite book}}
: Unknown parameter|coauthors=
ignored (|author=
suggested) (help) - ^ Wilhelm, Honor L. (1908). The Coast. Vol. 16. The Coast Pub. Co. p. 57.
- ^ 21 CFR §§168.140(a), 168.180(c) (USA).
- ^ MacInnis, Craig (6 July 2008). "Not just for breakfast anymore". The Ottawa Citizen. Retrieved 19 September 2010.
- ^ Gellmann, D. (2001). "Pirates, Sugar, Debtors, and Slaves: Political Economy and the case for Gradual Abolition in New York". Slavery & Abolition: A Journal of Slave and Post-Slave Studies. 22 (2): 51–68. doi:10.1080/714005193.
- ^ Driver, Elizabeth (2008). Culinary landmarks: a bibliography of Canadian cookbooks, 1825-1949. University of Toronto Press. p. 1070. ISBN 978-0-8020-4790-8.
- ^ "The maple leaf". Canadian Heritage. Retrieved 18 November 2010.
- ^ "State Trees & State Flowers". United States National Arboretum. Retrieved 18 November 2010.
Further reading
Nearing, Helen; Nearing, Scott (2000). The maple sugar book (50th anniversary ed.). White River Junction, Vt: Chelsea Green Pub. ISBN 1890132632.
External links
![](http://upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/30px-Commons-logo.svg.png)
![](http://upload.wikimedia.org/wikipedia/commons/thumb/d/df/Wikibooks-logo-en-noslogan.svg/40px-Wikibooks-logo-en-noslogan.svg.png)
- "Maple Syrup Quality Control Manual", University of Maine
- "UVM Center for Digital Initiatives: The Maple Research Collection" by the Vermont Agricultural Experiment Station.
- FDA description of table syrup