NFS 53 1st Edition Lecture 21Outline of Last Lecture I. Hispanics and their cultural foodII. Dietary Patterns over historyOutline of Current Lecture I. Sugars: cane sugar, honey, maple syrup, agave and morea. Sugarsb. Honeyc. Cane Sugard. Molassese. Agavef. Corn Syrupg. Sugar from TreesCurrent LectureI. Sugars: cane sugar, honey, maple syrup, agave and morea. Sugarsi. Sugars are mono- and disaccharidesii. Natural sugars are in solutioniii. Refined sugars are in crystalline formiv. Mono, oligo, poly-saccharidesv. As a chemical:These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.1. Sugars are crucial in two main capacities for living creatures:a. The most common unit of energy b. All living things use sugar as one of their main forms of energy storage and transfer2. Structural building blocks a. Plants, in particular, use sugars as the monomers in large molecules called polysaccharides, giving plants structure, Including cellulose, hemicellulose, and pectin.vi. Glucose1. The “prototypical” monosaccaharide2. “Pyranose” – six-membered ring structure3. The end product of photosynthesis4. Directly transformed into energy in our blood5. About 70% as sweet as sucrose6. Most often encountered in honey and corn syrupvii. Fructose1. “Furanose” – five-membered ring structure2. Less directly digestible by the human body3. About 120% as sweet as sucrose4. Extremely water-loving (hydrophilic/hygroscopic), and so gets verysticky5. Melts and caramelizes at very low temperatures (220 F)6. Has more conformational mobility than glucose, and different forms have different perceived sweetnessesviii. Sucrose1. Common or table sugar2. Disaccharide formed from sucrose and glucose3. Second-sweetest, with a slow build and clean finish4. Forms stable crystals5. Melts and caramelizes at relatively high temperatures (compared to glucose and fructose)ix. Lactose1. Disaccharide of glucose and galactose2. Much less sweet (40%) than table sugar3. Not very soluble in water4. Not digested well by both humans and others5. Humans – only Northern Europeans have a higher proportion of late-life lactase production6. Yeast – beer yeasts do not have enzymes that can break down lactose, hence milk stouts7. Used as a bulking agent in different formulations because of low sweetnessx. Crystalline forms1. Granulated sugar or sucrose - table sugar from sugar cane or sugarbeets (refined sugar) is processed by crushing, extraction, evaporation, and separation. 2. Other crystalline sugars - fructose, glucose, lactose, maltodextrins3. Powdered, confectioners – pulverized sucrose4. Brown-less refined sugar or more often refined sugar that has molasses syrup added to itxi. History1. Humans have an inborn taste for sugar2. Babies have a distinctive “pleased” reaction to basic sweetness3. Fruits and honey are both natural sources of intense sweetness, aswell as intense energy4. Sweetness seems to enhance perception of some (although not all) flavors5. One theory presented to explain this is that the brain focuses attention on sweet products because of their presumable caloric densityxii. Sugars in solution1. Corn syrupsa. Regularb. High fructose-cornstarch is treated with glucose isomerase enzyme and is converted to a syrup that is 42-55% fructoseand rest is glucose. Due to high sweetness, less is used thus costing less 2. Molassesa. Lightb. Blackstrap3. Sorghum Syrup or Molasses4. Maple syrup5. Honey 6. Agave Nectar-1.5 times sweeter than sugar. Highly processed glucose and fructoseb. Honeyi. The first sugar1. Honey is about 80% sugar2. Energy storage for bees3. Cave paintings from 10,000 years ago depict humans harvesting wild honey4. Bees have been domesticated for about 4,000 years5. Honey is a common metaphor for all kinds of abundance and sweetness in human language6. We essentially model our own sugar refining processes on honeyii. Plant nectar1. Honey is the storage form of plant nectar2. Nectar is sugary fluid produced by plants to attract pollinators3. It is mostly sugar, with different ratios of sucrose, fructose, glucose, and other minor sugars4. Some nectars have higher protein contents, leading to interestingly browned (Maillard!) honeys5. Chestnut, buckwheat are particularly notable for thisc. Sugar Canei. Refined sugar1. Originated in the South Pacific and ended up in Asia around 2600 years ago2. By 2400 years ago, in India cooks were pressing cane for juice, making confections from it, and even washing the boiled down solids to make “white sugar”3. By 600 CE, cane appears in the Middle East, and to Spain and Italy (under middle-eastern rule)4. Western Europe first encountered cane sugar around the crusades: 1100 CE.ii. Sugar Cane and the modern food system1. By 1550, the Spanish had brought sugar cane to the Caribbean2. It’s estimated that over 2/3 of the slaves brought from Africa to the New World were brought to the Caribbean, primarily to work in the sugar industry3. The decline of the Caribbean in sugar production4. Abolition and new technology with sugar beets5. Current production6. cane – mostly Brazil, US, India, Caribbean (minor)7. 30% beets – Europe, US8. Corn Syrup!iii. Sugar manufacture1. Primarily crystallized sugars from beet and cane2. Different from sugars in solution, honey or syrups, because in this case sugar must be refined from significant impuritiesiv. Stages of sugar manufacture1. Press the juicea. Entirely mechanical2. Clarify the juicea. Classically using egg whites, eisenglass, animal blood, or other coagulateb. Modern times: heat and lime (CaOH) will coagulate proteins and other impurities3. Boil down to a syrup to concentrate the sucrosea. Requires large amounts of fuelb. Responsible for the deforestation of much of the Caribbean c. In modern times, can be done efficiently using vacuum evaporation and multiple evaporation (which reuses the steam)4. Let syrup crystallize and drain impuritiesa. Used to be done through timeb. Modern methods involve seed crystals and centrifuges5. Wash crystalsa. Now done with various solvents (alcohol, water) and with charcoal to adsorb final, microscopic impuritiesv. Types of Cane sugar1. White sugarsa. Different sizes of granule for different purposesb. Small crystals are useful for icings and for baking cakes (for aerating batters)c. Larger crystals require higher purity sugar and produce extremely white products2.