FUZHOU UNIVERS工TY FOOD CHEMISTRY 福州大学生物科学与工程学院 食品化学 第三章碳水化合物 Carbohydrates
食品化学 第三章 碳水化合物 Carbohydrates 福州大学生物科学与工程学院
FUZHOU UNIVERSITY FOOD CHEM工STRY Outline 概述 食品中的单糖 ·食品中的低聚糖 ·食品中的多糖
Outline • 概述 • 食品中的单糖 • 食品中的低聚糖 • 食品中的多糖
FUZHOU UNIVERS工TY FOOD CHEMISTRY 第一节概述 1.碳水化合物的分类 （1)按组成分 单糖(Monosaccharides): 不能再被水解的多羟基醛或酮，是碳水化合物的基本单位。 低聚糖（寡糖）(Oligasaccharides) 由2-20个单糖分子缩合而成，水解后生成单糖 多糖(Polysaccharides) 由许多单糖分子缩合而成 (2)按功能分 结构多糖 贮存多糖 抗原多糖 福
第一节 概述 1. 碳水化合物的分类 （1）按组成分 单糖（Monosaccharides）： 不能再被水解的多羟基醛或酮，是碳水化合物的基本单位。 低聚糖（寡糖）(Oligasaccharides) 由2-20个单糖分子缩合而成，水解后生成单糖 多糖(Polysaccharides) 由许多单糖分子缩合而成 （2）按功能分 结构多糖 贮存多糖 抗原多糖
FUZHOU UNIVERSITY FOOD CHEMISTRY Nomenclature Carbohydrates consist of single or multiple units known as monosaccharide or glycose units Categorized by chain length Category of Glycose Units Food Example Monosaccharide 1 Sugars Disaccharide 2 Sugars Oligosaccharide 2-20 Sugars (3-10) Polysaccharide >20(10) Starch,Gums
Nomenclature • Carbohydrates consist of single or multiple units known as monosaccharide or glycose units – Categorized by chain length Category # of Glycose Units Food Example Monosaccharide 1 Sugars Disaccharide 2 Sugars Oligosaccharide 2-20 （3-10） Sugars Polysaccharide >20（10） Starch, Gums
FUZHOU UNIVERSITY FOOD CHEMISTRY Sugars Naming: prefix=no.of C atoms suffix:“ose”-indicates carbohydrate Trioses Tetraoses Pentoses Hexoses Monosaccharides aldoses contain an aldehyde group ketoses contain a ketone group In food the major monosaccharide sugars of interest are: 1.The aldo pentoses and hexoses D-galactose and D-glucose (in fruits,honey) 2.The keto pentoses and hexoses D-fructose (fruits,honey and corn syrup)
Sugars Naming: prefix = no. of C atoms suffix: “ose” - indicates carbohydrate Trioses Tetraoses Pentoses Hexoses Monosaccharides : aldoses contain an aldehyde group ketoses contain a ketone group In food the major monosaccharide sugars of interest are: 1.The aldo pentoses and hexoses D - galactose and D - glucose (in fruits, honey) 2. The keto pentoses and hexoses D - fructose (fruits, honey and corn syrup)
FUZHOU UNIVERSITY FOOD CHEM工STRY 第一节概述 2.食品中的碳水化合物 碳水化合物占所有陆生植物和海藻干重 的3/4，它们广泛存在于所有的谷物、 蔬菜、水果以及其他人类能食用的植物 中。 最丰富的碳水化合物是纤维素，它们主 要存在于植物细胞壁中。 人类消费的主要食品碳水化合物是淀粉 和糖（葡萄糖、果糖、乳糖及蔗糖等） 淀粉是植物中最普遍贮藏能量的碳水化 合物，广泛分布在种子、根和块茎中
第一节 概述 2. 食品中的碳水化合物 • 碳水化合物占所有陆生植物和海藻干重 的3/4，它们广泛存在于所有的谷物、 蔬菜、水果以及其他人类能食用的植物 中。 • 最丰富的碳水化合物是纤维素，它们主 要存在于植物细胞壁中。 • 人类消费的主要食品碳水化合物是淀粉 和糖（葡萄糖、果糖、乳糖及蔗糖等） 。 • 淀粉是植物中最普遍贮藏能量的碳水化 合物，广泛分布在种子、根和块茎中
FUZHOU UNIVERS工TY FOOD CHEMISTRY Sugars in Fruits .Sugar of total fruit weight (Fennema,1985:Marcel Dekker) 20 ■glucose ■fructose e3ns %1M 86420 ☐sucrose ▣all 6 4 2 60 High in fructose;other sugars present also
• % Sugar of total fruit weight (Fennema, 1985; © Marcel Dekker) • High in fructose; other sugars present also 0 2 4 6 8 1 0 1 2 1 4 1 6 1 8 2 0 w t% sugar apple grape peach pear cherry straw - berry glucose fructose sucrose all Sugars in Fruits
FUZHOU UNIVERSITY FOOD CHEMISTRY Sugars in Vegetables .Sugar of total vegetable weight (Fennema,1985:Marcel Dekker) 10 9 口glucose ☐fructose ▣sucrose Iens %M 6 ▣all 54 2 1 0三 beet broc-onion spi-sweetsweet tomato lima pea coli nach corn potato beans Vegetables less sweet,higher in sucrose
Sugars in Vegetables • % Sugar of total vegetable weight (Fennema, 1985; © Marcel Dekker) • Vegetables less sweet, higher in sucrose beet broccoli onion spinach sweet corn sweet potato tomato lima beans pea 0 1 2 3 4 5 6 7 8 9 10 wt% sugar beet broccoli onion spinach sweet corn sweet potato tomato lima beans pea glucose fructose sucrose all
FUZHOU UNIVERSITY FOOD CHEMISTRY 2 History8amag那inks K四 How Cane Sugar is Made-the Basic Story Growing the Cane Sugar cane is a sub-tropical and tropical crop that prefers lots of sun and lots of water-provided that its roots are not waterlogged.It typically takes about 12 months to reach maturity although the time varies widely around the world from as short as six months in Louisiana to 24 months in some olaces.Where it differs from many crops is that it re-grows from the roots so the plant lasts many cycles [or 'ratoons'.a word derived from the Spanish to sprout]before it is worn out. More Detail The More Detail button will take you to the web sie of Kew Gardens in a separate window.You should retum here when you clse thet down again Harvesting Sugar cane is harvested by chopping down the stems but leaving the roots so that it re-grows in time for the next crop.Harvest times tend to be during the dry season and the length of the harvest ranges from as little as 2 months up to 11 months.The cane is taken to the factory.often by truck or rail w wagon but sometimes on acart pulled or a donkeyl More Detall Extraction The first stage of processing is the extraction of the cane juice.In many factories the cane is crushed in a series of large roller mills:similar to a mangle [wringer]which was used to squeeze the water out of clean washing a century ago.The sweet juice comes gushing out and the cane fibre is cared ay foruse in the boilers in other factories a diffuser is used asis described for beet sugar manufacture.Either way dirty the soil from the fields.some small fibres and the green extracts from the plant are all mixed in with the sugar
FUZHOU UNIVERSITY FOOD CHEMISTRY Sugars in Processed Foods .Sugar of total food weight 9007430 ▣Glucose ☒Glucose/Fructose Sucrose Lactose All sugars dnuppy wIopouue
Sugars in Processed Foods • % Sugar of total food weight