英文條目：https://en.wikipedia.org/wiki/Sugar
中文條目：https://zh.wikipedia.org/wiki/%E9%A3%9F%E7%B3%96
Sugar is the generalized name for sweet, short-chain, soluble carbohydrates, many of which are used in food. They arecarbohydrates(糖类), composed of carbon, hydrogen, and oxygen. There are various types of sugar derived from different sources. Simple sugars are called monosaccharides(單醣) and include glucose(葡萄糖) (also known as dextrose), fructose(果糖) and galactose(半乳糖). The table or granulated sugar most customarily used as food issucrose(蔗糖), a disaccharide(雙醣). (In the body, sucrose hydrolyses into fructose and glucose.) Other disaccharides include maltose(麥芽糖) and lactose(乳糖). Longer chains of sugars are called oligosaccharides(寡醣). Chemically-different substances may also have a sweet taste, but are not classified as sugars. Some are used as lower-calorie food substitutes for sugar described as artificial sweeteners(甜味剂).
糖是一個有[[甜]]味、短鏈、可溶於水的[[有機化合物]]，許多會用在食品中。糖在有機化學中屬於[[醣類]]，由碳、氫及氧三種原子組成。[[單醣]]是結構較簡單的糖，包括[[葡萄糖]]、[[果糖]]及[[半乳糖]]。日常用的[[蔗糖]]則屬於[[雙醣]]，在人體中會分解成葡萄糖及果糖。其他的雙醣有[[麥芽糖]]及乳糖]]。較長鏈的糖稱為[[寡醣]]。有些化學結構不同的物質也有甜味，但不會歸類為糖，有些會用來代替食物中的糖，稱為[[甜味劑]]。
Sugars are found in the tissues of most plants, but are present in sufficient concentrations for efficient extraction only insugarcane and sugar beet(糖用甜菜).[citation needed] Sugarcane refers to any of several species of giant grass in the genus Saccharum(甘蔗) that have been cultivated in tropical climates in South Asia(南亚) and Southeast Asia(东南亚)since ancient times. A great expansion in its production took place in the 18th century with the establishment of sugar plantations in the West Indies and Americas. This was the first time that sugar became available to the common people, who had previously had to rely on honey to sweeten foods. Sugar beet, a cultivated variety(栽培品种) of Beta vulgaris(甜菜), is grown as a root crop in cooler climates and became a major source of sugar in the 19th century when methods for extracting the sugar became available. Sugar production and trade have changed the course of human history in many ways, influencing the formation of colonies, the perpetuation of slavery(奴隶制度), the transition to indentured labour, the migration of peoples, wars between sugar-trade–controlling nations in the 19th century, and the ethnic composition and political structure of the New World(新大陸).
大部份植物的組織中都有糖份，但只有在[[甘蔗]]及[[糖用甜菜]]中才有夠高的濃度。自古在南亞及東南亞等熱帶氣候地區都有種植甘蔗，在18世紀在西印度群島及美洲開始開設製糖工廠，其產量大幅增加。這是首次一般人可以接觸到糖，之前只能靠蜂蜜使食物有甜味。糖用甜菜是[[甜菜]]的一個栽培品种，在較寒冷的氣候中成長，在十九世紀發現萃取糖的技術後，也成為糖的主要來源。糖的生產及交易在許多方面都改變了人類歷史，包括殖民的形成、[[奴隶制度]]的出現、契約勞工的產生、19世紀時因為糖交易控制國家而產生的人民遷徒及戰爭，以及[[新大陸]]的民族組成及政治結構。
The world produced about 168 million tonnes of sugar in 2011. The average person consumes about 24 kilograms (53 lb) of sugar each year (33.1 kg in industrialised countries), equivalent to over 260 food calories per person, per day.
Since the latter part of the twentieth century, it has been questioned whether a diet high in sugars, especially refined sugars, is good for human health. Sugar has been linked to obesity, and suspected of, or fully implicated as a cause in the occurrence of diabetes, cardiovascular disease, dementia, macular degeneration, and tooth decay. Numerous studies have been undertaken to try to clarify the position, but with varying results, mainly because of the difficulty of finding populations for use as controls that do not consume or are largely free of any sugar consumption.
全世界在2011年消耗了1.68億噸的糖，每人每年平均消耗24公斤的糖（若在工業化國家中，每人年均消耗量則為33.1公斤），相當每人每天從糖攝取了260卡路里。在二十世紀後期開始質疑高糖份（特別是精製糖份）的飲食到底對人類是否有益。食糖已確定和肥胖有關，也懷疑和糖尿病、心血管疾病、癡呆，黃斑變性及蛀牙有關。許多研究都試著找出其中的關係，但結果各有不同，原因是很難找到完全不攝取糖，或是幾乎不攝取糖的控制組族群。
The etymology(语源学) reflects the spread of the commodity. The English(英语) word "sugar"[1] originates from the Sanskrit(梵语) शर्कराśarkarā,[2] via Persian(波斯语) شکر shakkar. It most probably came to England by way of Italian merchants. The contemporary Italian word is zucchero, whereas the Spanish(西班牙语) and Portuguese(葡萄牙語) words, azúcar and açúcar respectively, have kept a trace of theArabic definite article. The Old French word is zuchre – contemporary French sucre. The earliest Greek(希腊语) word attested is σάκχαρις (sákkʰaris).[3][4] A satisfactory pedigree explaining the spread of the word has yet to be done. The English word jaggery(石蜜), a coarse brown sugar made from date palm sap or sugarcane juice, has a similar etymological origin; Portuguese xagara or jagara, from the Sanskrit śarkarā.[5]
[[语源学]]可以看出糖如何在各民族間擴展，英語的糖sugar [1]源自梵语的 शर्करा （śarkarā）[2]及[[波斯語]]شکر （shakkar），很可能是因為義大利商人而進入英國，當時義大利文的糖是zucchero，而[[西班牙语]]及[[葡萄牙語]]的糖（azúcar及açúcar），保留了阿拉伯人定冠詞的痕跡。古法文中的糖是zuchre，現代法文則是sucre，最早[[希腊语]]中的字是σάκχαρις（sákkʰaris）[3][4]，不過目前還沒有一個令人滿意的譜系詞傳播解釋<!--The English word jaggery(石蜜), a coarse brown sugar made from date palm sap or sugarcane juice, has a similar etymological origin; Portuguese xagara or jagara, from the Sanskrit śarkarā.[5]-->
Scientifically, sugar loosely refers to a number of carbohydrates, such as monosaccharides, disaccharides, oroligosaccharides(寡醣). Monosaccharides are also called "simple sugars," the most important being glucose. Almost all sugars have the formula CnH2nOn (n is between 3 and 7). Glucose(葡萄糖) has the molecular formula(化学式)C6H12O6. The names of typical sugars end with -ose, as in "glucose(葡萄糖)" and "fructose(果糖)". Sometimes such words may also refer to any types of carbohydrates(糖类) soluble in water(水). The acyclic mono- and disaccharides contain eitheraldehyde(醛) groups or ketone(酮) groups. These carbon-oxygen(羰基) double bonds (C=O) are the reactive centers. All saccharides with more than one ring in their structure result from two or more monosaccharides joined by glycosidic bonds(糖苷键) with the resultant loss of a molecule of water (H2O) per bond.[30]
Monosaccharides in a closed-chain form can form glycosidic bonds with other monosaccharides, creating disaccharides (such as sucrose) and polysaccharides (such as starch(淀粉)). Enzymes(酶) must hydrolyze or otherwise break these glycosidic bonds before such compounds become metabolized(代谢). After digestion and absorption the principal monosaccharides present in the blood and internal tissues include glucose, fructose, and galactose. Many pentoses and hexoses can form ring structures(杂环化合物). In these closed-chain forms, the aldehyde or ketone group remains non-free, so many of the reactions typical of these groups cannot occur. Glucose in solution exists mostly in the ring form at equilibrium(化学平衡), with less than 0.1% of the molecules in the open-chain form.[30]
Natural polymers of sugars
Biopolymers(生物聚合物) of sugars are common in nature. Through photosynthesis, plants produce glyceraldehyde-3-phosphate(甘油醛3-磷酸) (G3P), a phosphated 3-carbon sugar that is used by the cell to make monosaccharides such as glucose (C
6H
12O
6) or (as in cane and beet) sucrose (C
12H
22O
11). Monosaccharides may be further converted into structural polysaccharides(多糖) such as cellulose(纤维素) and pectin(果胶) for cell wall(細胞壁) construction or into energy reserves in the form of storage polysaccharides(多糖) such as starch or inulin(菊粉). Starch, consisting of two different polymers of glucose, is a readily degradable form of chemical energy(势能) stored by cells(细胞), and can be converted to other types of energy.[30] Another polymer of glucose is cellulose, which is a linear chain composed of several hundred or thousand glucose units. It is used by plants as a structural component in their cell walls. Humans can digest cellulose only to a very limited extent, though ruminants(反芻) can do so with the help of symbiotic(共生) bacteria in their gut.[31] DNA(脱氧核糖核酸) and RNA(核糖核酸) are built up of the monosaccharidesdeoxyribose(脱氧核糖) and ribose(核糖), respectively. Deoxyribose has the formula C5H10O4 and ribose the formula C5H10O5.[32]
Flammability
Sugars are organic substances that burn easily upon exposure to an open flame. Because of this, the handling of sugars presents a risk for dust explosion(粉尘爆炸). The 2008 Georgia sugar refinery explosion, which resulted in 14 deaths, 40 injured, and more than half of the facility’s destruction, was caused by the ignition of sugar dust.
Monosaccharides
Fructose, galactose, and glucose are all simple sugars, monosaccharides(單醣), with the general formula C6H12O6. They have five hydroxyl groups (−OH) and a carbonyl group (C=O) and are cyclic when dissolved in water. They each exist as several isomers(同分異構) with dextro- and laevo-rotatory forms that cause polarized light to diverge to the right or the left.[33]
Disaccharides
Lactose, maltose, and sucrose are all compound sugars, disaccharides(雙醣), with the general formula C12H22O11. They are formed by the combination of two monosaccharide molecules with the exclusion of a molecule of water.[33]
Rock candy crystallized out of a supersaturated sugar solution
Some studies involving the health impact of sugars are effectively inconclusive. The FAO meta studies and WHO(世界卫生组织) studies have shown directly contrasting impacts of sugar in refined and unrefined forms[64] and since most studies do not use a population that do not consume any "free sugars" at all, the baseline is effectively flawed. Hence, there are articles such as Consumer Reports on Health that stated in 2008, "Some of the supposed dietary dangers of sugar have been overblown. Many studies have debunked the idea that it causes hyperactivity, for example".[65]
Addiction
Sugar addiction is the term for the relationship between sugar and the various aspects of food addiction including "bingeing, withdrawal, craving and cross-sensitization". Some scientists assert that consumption of sweets(糖果) or sugar could have a heroin addiction-like effect.[66]
Alzheimer’s disease
Claims have been made of a sugar–Alzheimer’s disease(阿兹海默病) connection, but debate continues over whether cognitive decline is attributable to dietary fructose or to overall energy intake.[67][68]
Blood glucose levels
It used to be believed[when?(Wikipedia:格式手册/日期和数字)] that sugar raised blood glucose(血糖) levels more quickly than did starch(淀粉) because of its simpler chemical structure. However, it turned out that white bread or French fries(馬鈴薯條) have the same effect on blood sugar as pure glucose,[citation needed] while fructose, although a simple carbohydrate, has a minimal effect on blood sugar.[citation needed] As a result, as far as blood sugar is concerned, carbohydrates are classified according to their glycemic index(升糖指数), a system for measuring how quickly a food that is eaten raises blood sugar levels, and glycemic load(升糖负荷), which takes into account both the glycemic index and the amount of carbohydrate in the food.[69] This has led to carbohydrate counting, a method used by diabetics for planning their meals.[70]
Cardiovascular disease
Studies in animals have suggested that chronic consumption of refined sugars can contribute to metabolic and cardiovascular dysfunction(心血管疾病). Some experts have suggested that refined fructose is more damaging than refined glucose in terms of cardiovascular risk.[71] Cardiac performance has been shown to be impaired by switching from a carbohydrate diet including fiber to a high-carbohydrate diet.[72] Switching from saturated fatty acids(脂肪酸) to carbohydrates with high glycemic index(升糖指数) values shows a statistically-significant increase in the risk of myocardial infarction(心肌梗死).[73] Other studies have shown that the risk of developing coronary heart disease(冠狀動脈疾病) is decreased by adopting a diet high in polyunsaturated fatty acids but low in sugar, whereas a low-fat, high-carbohydrate diet brings no reduction. This suggests that consuming a diet with a high glycemic load(升糖负荷) typical of the "junk food(垃圾食品)" diet is strongly associated with an increased risk of developing coronary heart disease.[74]
The consumption of added sugars has been positively associated with multiple measures known to increase cardiovascular disease risk amongst adolescents as well as adults.[75] Studies are suggesting that the impact of refined carbohydrates or high glycemic load carbohydrates are more significant than the impact of saturated fatty acids on cardiovascular disease.[76][77] A high dietary intake of sugar (in this case, sucrose or disaccharide) can substantially increase the risk of heart and vascular diseases. According to a Swedish study of 4301 people undertaken by Lund University(隆德大学) and Malmö University College(马尔默大学), sugar was associated with higher levels of bad blood lipids(血脂), causing a high level of small and medium low-density lipoprotein(低密度脂蛋白) (LDL) and reduced high-density lipoprotein(高密度脂蛋白) (HDL). In contrast, the amount of fat eaten did not affect the level of blood fats. Incidentally quantities of alcohol(乙醇) and protein(蛋白质) were linked to an increase in the good HDL blood fat.[78]
Hyperactivity
There is a common notion that sugar leads to hyperactivity, in particular in children, but studies and meta-studies tend to disprove this.[65] Some articles and studies do refer to the increasing evidence supporting the links between refined sugar and hyperactivity.[79][80][81] The WHO FAO meta-study suggests that such inconclusive results are to be expected when some studies do not effectively segregate or control for free sugars as opposed to sugars still in their natural form (entirely unrefined) while others do.[64] One study followed thirty-five 5-to-7-year-old boys who were reported by their mothers to be behaviorally "sugar-sensitive." They were randomly assigned to experimental and control groups(實驗組). In the experimental group, mothers were told that their children were fed sugar, and, in the control group, mothers were told that their children received aplacebo(安慰劑效應). In fact, all children received the placebo, but mothers in the sugar expectancy condition rated their children as significantly more hyperactive.[82] This result suggests that the real effect of sugar is that it increases worrying among parents with preconceived notions.
Obesity and diabetes
Controlled trials have now shown unequivocally that consumption of sugar-sweetened beverages increases body weight and body fat, and that replacement of sugar by artificial sweeteners reduces weight.[83][84] Studies on the link between sugars and diabetes are inconclusive, with some suggesting that eating excessive amounts of sugar does not increase the risk of diabetes(糖尿病), although the extra calories from consuming large amounts of sugar can lead to obesity(肥胖症), which may itself increase the risk of developing this metabolic disease(代謝疾病).[85][86][87][88][89][90] Other studies show correlation between refined sugar (free sugar) consumption and the onset of diabetes, and negative correlation with the consumption of fiber(膳食纖維).[91][92][93][94] These included a 2010 meta-analysis of eleven studies involving 310,819 participants and 15,043 cases of type 2 diabetes(2型糖尿病).[95] This found that "SSBs (sugar-sweetened beverages) may increase the risk of metabolic syndrome(代謝症候群) and type 2 diabetes not only through obesity but also by increasing dietary glycemic load, leading to insulin resistance(胰岛素抵抗), β-cell dysfunction, and inflammation". As an overview to consumption related to chronic disease and obesity, the World Health Organization(世界卫生组织)’s independent meta-studies specifically distinguish free sugars ("all monosaccharides and disaccharides added to foods by the manufacturer, cook or consumer, plus sugars naturally present in honey, syrups and fruit juices") from sugars occurring naturally in food. The reports prior to 2000 set the limits for free sugars at a maximum of 10% of carbohydrate intake, measured by energy, rather than mass, and since 2002 have aimed for a level across the entire population of less than 10%.[64] The consultation committee recognized that this goal is "controversial. However, the Consultation considered that the studies showing no effect of free sugars on excess weight have limitations".[64]
Tooth decay
In regard to contributions to tooth decay(龋齿), the role of free sugars is also recommended to be below an absolute maximum of 10% of energy intake, with a minimum of zero. There is "convincing evidence from human intervention studies, epidemiological studies, animal studies and experimental studies, for an association between the amount and frequency of free sugars intake and dental caries" while other sugars (complex carbohydrate) consumption is normally associated with a lower rate of dental caries.[96] Lower rates of tooth decay have been seen in individuals with hereditary fructose intolerance(遺傳性果糖不耐症).[97]
Also, studies have shown that the consumption of sugar and starch have different impacts on oral health with the ingestion of starchy foods and fresh fruit being associated with low levels of dental caries.[96]
The World Health Organization (WHO)(世界卫生组织) recommends [98] that both adults and children reduce the intake of free sugars to less than 10% of total energy intake. A reduction to below 5% of total energy intake brings additional health benefits, especially in what regards dental caries. These recommendations were based on the totality of available evidence reviewed regarding the relationship between free sugars intake and body weight and dental caries.
Free sugars include monosaccharides and disaccharides added to foods and beverages by the manufacturer, cook or consumer, and sugars naturally present in honey, syrups, fruit juices and fruit juice concentrates.[98]
[[世界衛生組織]]建議[98]不論大人及小孩，每日攝取食物的能量中，游離糖份不能超過10%。若可以降到每天食物能量的5%以下，對身體更有幫助，尤其是在齲齒防治上有益。此建議是根據評估所有有關游離糖份和體重及齲齒的證據後所得的結果。
游離糖份包括食物及飲料中由製造商、廚師或是消費者加入的單糖及雙糖，以及蜂蜜、糖漿、果糖及濃縮果汁中的天然糖份。
Various culinary sugars have different densities due to differences in particle size and inclusion of moisture.
Domino Sugar gives the following weight to volume conversions (in United States customary units(美制单位)):[99]
The "Engineering Resources – Bulk Density Chart" published in Powder and Bulk gives different values for the bulk densities:[100]
一般烹飪糖因為顆粒大小不同，加上濕氣的因素，其密度會有所不同。
{{le|Domino食品|Domino Foods}}提供了以下重量和體積之間的換算關係，單位用[[美制单位]][99]：
*緊包裝的紅糖：一[[磅]]約2.5{{le|杯 (單位)|Cup (unit)}}（或每公斤1.3公升，每公升0.77公斤）
*砂糖：一[[磅]]約2.25{{le|杯 (單位)|Cup (unit)}}（或每公斤1.17公升，每公升0.85公斤）
*未篩分糖粉：一[[磅]]約3.75{{le|杯 (單位)|Cup (unit)}}（或每公斤2.0公升，每公升0.5公斤）
Powder and Bulk出版的"Engineering Resources – Bulk Density Chart"有不同的資料，其密度如下[100]：