Unformatted text preview: WORLD OF CHEM NOTES: UNIT 3 -‐ shorthand key: ppl = people, bc = because, btwn = between, assoc = associated Topic 8: Chocolate & Weight Control Lesson 1: Chocolate Video 1 -‐ Confectionary Assoc. of Canada Survey 1995 à “Do you prefer sex or chocolate?” -‐ 30% men & 38% women preferred chocolate -‐ in Quebec, 74% preferred chocolate -‐ in Nova Scotia, 20% preferred chocolate -‐ 500+ chemicals in chocolate à phenylacetic acid, dimethylsulfide, 2-‐methoxy-‐4-‐methylphenol -‐ melting point of cocoa fat is 36°C (1 degree below body temp (37°C) -‐ as soon as chocolate is put in mouth, it starts meltingà people enjoy that sensation -‐ theobroma cacao is the name of the cacao tree -‐ Theo = Greek god, so theobroma means “the food of the Gods” -‐ Aztecs in Mexico used cocoa drinks served in gold goblets to satisfy the gods in offerings -‐ supposedly the gold goblets could only be used once -‐ Aztec term is for cocoa is xocolatl (meaning “bitter”) -‐ cocoa is hard to dissolve; have to beat it for a long time so it disperses into liquid -‐ used cocoa as currency to trade with Spaniards -‐ Spaniards believed cocoa had aphrodisiac properties & sent it back to Spain -‐ became popular in Europe as a beverage mixed with sugar, vanilla, cinnamon -‐ for most of its history, chocolate was not eaten, but drunk as a beverage -‐ in Canada (2004) each person eats 4 kg (9 lbs) chocolate per year Video 2 -‐ cocoa flower belongs to same family as orchid & grows on cacao trees -‐ coca flower & pods grow throughout branches, not only at ends of branches -‐ grow throughout all seasons (no specific cocoa growing season) -‐ cocoa types: forastero, criollo, trinitero -‐ the best cocoa is criollo -‐ pods are split open; cocoa nibs have a white coating (shell) -‐ once split, the seeds start fermenting -‐ fermentation: sugarà alcoholàacetic acidàesters -‐ this adds flavour to the chocolate/cocoa -‐ after fermentation, cocoa seeds are left to dry in the sun -‐ after drying, they’re roasted (like coffee beans) -‐ roasting enhances the flavour à cocoa seeds become darker -‐ Maillard reaction takes place (reaction btwn amino acids in protein & sugar) -‐ gives tastes to toasted butter, beer, scotch & other foods -‐ cocoa beans are shelled to leave remaining cocoa nibs -‐ when cocoa nibs are crushed, chocolate liquor forms (but doesn’t actually contain alcohol) -‐ top cocoa producers 2011 -‐ Ivory Coast (1.51 million metric tons), Ghana (1.03), Indonesia (0.44) -‐ child labour used in Ivory Coast -‐ book “Bitter Chocolate” à describes the social costs of chocolate production -‐ can buy fair trade cocoa Activity: How is chocolate made? 1. Cocoa pods are picked and split open 2. Seeds begin to ferment (adding flavour) 3. Seeds are left to dry in the sun & then roasted (enhancing flavour) 4. Seeds are shelled and then crushed into ground nibs Video 3 -‐ baking chocolate is closest in taste to chocolate liquor à vey bitter & high in fat -‐ in early 19th century, Casparus van Houten improved upon chocolate -‐ used compressor to separate cocoa powder (in cocoas cakes) from the fat (in cocoa butter) -‐ cocoa butter has melting point close to body tempà used in cosmetics (lipsticks) & medicines -‐ cocoa cakes are compressed cocoa powder à very bitter & don’t dissolve well -‐ 1828, Conrad van Houten founded the Dutch Process -‐ treat cacao with an alkali to convert it into a powder with neutralized acid -‐ natural cacao is lighter in colour than Dutch Processed (increased solubility, decreased acidity) -‐ first edible chocolate developed by Englishman JS Fry (1847) -‐ blended the cocoa butter & powder components with sugar à result was marketed as Fry’s Chocolate -‐ Cadbury was also making chocolate -‐ Switzerland produces milk chocolate -‐ Daniel Peter had chocolate factory in Switzerland in 1876 -‐ wanted to cut down bitterness of chocolate by adding milk -‐ Henri Nestle had a process by which milk could be condensed -‐ Daniel Peter used condensed milk to form milk choc -‐ white chocolate is made only with cocoa butter & has a very faint taste of choc -‐ Fenster’s favourite choc is Lindt named after Rudolph Lindt (Swiss, 1890s) -‐ Lindt chocolate is known for texture & uses a method in which choc liquor is stirred for a long time (technique called “conching”) -‐ nougat added to Toblerone chocolate -‐ Theodore Tobler developed the shape after the Matterhorn mountain where he lived -‐ Consumption of Chocolate: -‐ Switzerland 2013= 12kg (26 lbs) (Same with Belgium) Video 4 -‐ Milton Hershey (1903) found ways to mechanize production of choc & make it available to more people -‐ manufactured Hershey kisses; 60 million kisses produced every day -‐ Hershey founded Hershey, Pennsylvania (where they produce Hershey chocolate) -‐ street names like “Chocolate Ave” & “Cocoa Avenue”; even the street lamps are shaped like kisses -‐ choc development during WWI; part of the GI ration bc choc is highly caloric -‐ the choc would melt & US army asked Hershey to make choc that would melt in mouth & not in hand (can’t pull trigger if hands covered in choc) -‐ “Tropical Chocolate” developedà American high command were concerned that GI’s would spend more time eating choc than fighting -‐ asked Hershey to ensure that choc only tasted a little better than a boiled potato à it wasn’t popular & ppl didn’t like it -‐ US army turned to Mars Company to produce better tasting choc -‐ coated choc in hard shell made of sugar -‐ when it was hot, choc expanded within coating & broke it -‐ Dr. Alfred Stern (1942) was a German Jewish refugee living in Montreal -‐ he blended air into the choc before coating it; as choc expanded, it crushed air bubble & not coating à M&M’s (claimed to be one of the reasons why the allies won the war!) -‐ starting in 1976, for 11 years, there were no red M&M’s -‐ Fenster’s made up story explaining red M&M’s à parents used to teach kids road safety using M&M’s (green = go) & they petitioned to have red re-‐introduced -‐ the true storyà red dye was a dye that people thought was carcinogenic (red dye #2), but the actual dye used was red dye #40 which was not carcinogenic -‐ red M&M’s brought back in 1987 -‐ The Rolling Stones demand to have only brown M&M’s in their dressing room -‐ Aerosmith want only green M&M’s à green M&M’s claimed to be aphrodisiac -‐ did this to ensure that the promoter read the full contract -‐ Proportions of M&M colours: 30% brown, 20% red, 20% yellow, 10% orange, 10% blue, 10% green -‐ used in school to teach about statistics -‐ gooey Cherry Blossom chocolateà cherry surrounded by sweet liquid in middle of chocolate -‐ contains no chocolate butter, just vegetable fat, palm oil, invertase -‐ cherry enrobed in sugar in presence of invertase (enzyme), sugar is converted into invert sugar (glucose + fructose) then combined with water -‐ invert sugar is more water soluble than regular sugar, so mixture around the cherry becomes gooey -‐ Godiva used to be a Belgian company & then bought my American Campbell’s -‐ Porcelana & Ocumare chocolate come from Venezuala -‐ Wispa Gold chocolate wrapped in gold is world’s most expensive (961.48 British pounds) Video 5 -‐ choc has become a “health food”, but idea that choc is healthy is not new -‐ British ad in 1800 shows a healthy man drinking cocoa (instead of gin!) -‐ myth that choc causes acne -‐ GERD (Gastro Esophageal Reflux Disorder) aka. “heartburn” -‐ valve at base of esophagus prevents acidic content in stomach from flowing up -‐ choc relaxes the valve & causes GERD -‐ choc is rich in sugar & S. mutans bacteria feeds on sugar, converting it to lactic acid, which attacks tooth enamel -‐ but choc contain antibacterial agents that can fight off S. mutans -‐ some ppl claim to get migraines after eating choc -‐ can suppress a cough bc it’s high in sugar (which eases throat irritation) -‐ theobromine is cough suppressant -‐ theobromine is poisonous to small animals bc they can’t metabolize it so it builds up -‐ choc is high in fat % Fat % Carbs Bitter 55 30 Sweet 35 60 Milk 30 60 Cocoa 15 55 Fat type % of fat in chocolate stearic acid 35 oleic acid 35 palmitic acid 25 linoleic acid 3 -‐ choc is high in saturated fat, but one type, stearic acid, does not increase blood cholesterol (has a neutral effect on blood cholesterol) -‐ HDL cholesterol is good, but LDL cholesterol is bad -‐ oxidized LDL cholesterol (the worst!) forms plaque in arteries -‐ choc has flavanols/flavanoids (antioxidants) which prevent oxidation of LDL cholesterol -‐ the darker the chocolate, the more antioxidants -‐ red wine has less antioxidants than dark & milk choc -‐ choc increases levels of nitric oxide (NO) which lowers blood pressure à beneficial -‐ Mars tried to develop choc products “CocoaVia” high in flavanols à didn’t do well commercially bc too expensive -‐ ChocPlus is choc with added calcium & probiotics -‐ claim that French have low rate of heart disease bc French ppl drink a lot of coffee (best source of antioxidants); in France, they always serve coffee w small piece of choc (added antioxidants) Video 6 -‐ Study: When older ppl eat choc, it improves blood flow in brain, improving cognitive abilities à but study funded by Mars Company -‐ Switzerland has both the highest choc consumption & highest per capita Nobel Prize winners -‐ beauty products based on choc -‐ Vaseline using cocoa butter -‐ cocoa bath at Hershey Spa where you’re coated in cocoa ($525!!) -‐ Chocolate Show where fashion is based on chocolate; hair coated in choc -‐ 15% men & 40% women say they’re addicted to choc -‐ choc has caffeine but there’s not enough to cause addiction -‐ choc has anandamide (ananda = bliss in Sanskrit) -‐ effect of anandamide is similar to effect of marijuana -‐ choc is associated w love; possible that it’s an aphrodisiac -‐ Casanova’s conquests would always give him some choc -‐ choc increases levels of nitric oxide which is a vassodilator -‐ Viagra also works by acting upon nitric oxide levels -‐ choc contain phenylethylamine (PEA) -‐ studies show that some ppl who addicted to love (or have a strong urge to be loved) produce a large amount of PEA -‐ PEA assoc w sensation of love; so that explains why choc is the gift of lovers -‐ PEA present in choc can’t penetrate the blood-‐brain barriers, so likely no effect Lesson 2: Weight Control 1 Video 1 -‐ Lewis Carroll wrote The Walrus and the Carpenter à “Wait a bit,” the oyster cried. “Before we have our chat. But all of us are fat.” -‐ a people are more sedentary now than ever(risk of obesity & heart disease) -‐ 1960, 166 lbs average for men; 144 lbs for women -‐ in 2919, 196 lbs for men; 166 lbs for women -‐ difference between actual weight increase & what people think the increase is -‐
people’s judgment of their weight is not accurate -‐
rate of diabetes is increasing -‐ rapid weight gain now in Asia where there was no problem with obesity in past -‐ they are adopting the American lifestyle -‐ concerns about weight gain in Ancient Greece -‐ Hippocrates: “Perform hard work before food; take their meals after exertion and while still panting from fatigue; eat only once a day, take no baths, sleep on hard bed; walk naked as long as possible” -‐ 1800’sà weight reducing soap -‐ todayà miracle herbs, fat-‐burning chocolate, cellulite dissolvers, fat-‐free food -‐ “miraculous diets” à cabbage soup diet; mustard diet; low-‐carb -‐ Dr. Robert Atkins (1930-‐2003) proponent of low-‐carb diet -‐ low-‐fat diet by Dr. Dean Ornish -‐ Dr. Phil recommends diets -‐ diets based on naturopathy are nonsense à “Eat Right for Your Type” requires you to eat according to your blood type à not scientifically proven -‐ The Imagination Dietà think of something that you would like to eat & your appetite is curbed -‐ risky teenage dietà eat cotton balls soaked in orange juice -‐ told to chew on iceà ice melts & melting ice required heat input -‐ you’ll be using calories to melt ice; but don’t need a significant amount of calories to melt ice -‐ supplement that melt fat & block it from being absorbed à don’t work Video 2 -‐ obesity is risk factor for heart disease, stroke, hypertension, cancer, diabetes -‐ BMI (body mass index) = weight (kg)/height (m2) -‐ if greater than 30 = obese -‐ but BMI doesn’t distinguish btwn fat & muscle -‐ can have a body builder w a very high BMI & not be obese à exception to the rule -‐ must also consider waist-‐hip ratio -‐ the greater the waist-‐hip ration, the larger the belly size, the greater the risk -‐ The Calorie: amount energy needed to raise the temp of 1 gram of water by 1 degree C -‐ no such thing as “empty calorie” -‐ calorie is a unit of measure of energy -‐ 1 Calorie = 1000 (calories) or 1 kilocalorie -‐ kilocalorie = energy needed to raise temp of 1 kilogram water by 1 degree -‐ calorimeter à burn food in supply of oxygen & see how much heat is produced -‐ calorie content is the amount of potential energy it has (amount energy that is released when burned) -‐ Wilbur Olin Atwater burned food in calorimeter & measured contents of fecal matter & urine -‐ urea in urine & food remnants in fecal matter -‐ by burning urine & fecal matter in calorimeter -‐ then subtract fecal/urine calories from food calories to obtain calories absorbed by body (the metabolizable energy) -‐ fat (9cal/gr), protein, (4cal/gram), carbs (4cal/gram), fibre (2cal/gram) -‐ fate of food in body not the same as in a calorimeter -‐ texture makes a difference -‐ white vs. brown bread -‐ components of food not broken down the same way -‐ takes more energy to digest brown bread because of fibre content Video 3 -‐ metabolizable energy -‐ 250 grams lasagna if burned in calorimeter, produces 400 calories -‐ but only 367 cal available to body because body has to use energy to break down the food -‐ cooked foods are more easily metabolized bc they have been “pre-‐digested” -‐ expend more calories to break down raw carrots than cooked carrots -‐ well done take provides more calories than raw meat (cooking process breaks down protein & fat) -‐ well-‐done steak provides more calories than raw meat -‐ Calories as determined by calorimeter: -‐ orange juice (1 cup) 108 calories -‐ fudge (1 square) 155 calories -‐ dynamite (1 gram) 155 calories -‐ calorie counts in restaurants are determined by calorimeter; so it roughly parallels the actual calories absorbed which depend on fibre, texture, amount of cooking -‐ since fast food restaurants have had to post calorie counts, the amount fast food eaten hasn’t decreased -‐ metabolism: energy consumption by biochemical processes -‐ basal metabolic rate (BMR): amount of energy expended in 24 hours if body is doing nothing -‐ the total calories needed to keep you alive -‐ can’t “burn” a calorie à can burn food to produce energy; we equate calorie content with food -‐ walking (5.6hm/h)à 4 cal/minute -‐ how is this determined? -‐ have ppl exercise in room & measure the temp increase -‐ or measure amount O2 inhaled & amount CO2 produced which is proportional to amount of calories burned -‐ food + oxygen = CO2 + water -‐ dancing (disco) à 5.5 cal/min -‐ bicycling 21 km/h à 8 cal/min -‐ Swimming à 11 cal/min -‐ Running 16 km/h (10 mph)à 16.5 -‐ very hard to burn calories with exercise -‐ apple pie = 300 cal; apple pie w ice cream = 500 cal -‐ 30 mins of running at 10 mph or bicycle at 20k for 1 hour -‐ BMR typically 1500-‐1700 calories; varies depending on body size, gender, lifestyle -‐ men (2200 calories); women (1800 calories) Video 4 -‐ 2 cars with equal sized gas tanks -‐ put same amount gasoline in each car, so there’s the same amount of expendable energy -‐ one car will run out of gas earlier than the other -‐ one car could be heavier, or have a flatter tire, or drivers may be different weights -‐ humans are biochemically individualà just like car, we don’t use the same amount of energy -‐ some ppl have more efficient metabolism & require fewer calories to keep their body functioning -‐ can take 2 ppl and put them on the same diet, but they won’t react the same way -‐ low carb diets work better for ppl with metabolic syndrome -‐ metabolic syndromeà more than 100cm waist -‐ triglycerides above 1.7 Mmol/L -‐ HDL (good) cholesterol under 1Mmol/L -‐ high blood pressure (>130 systolic/>85 diastolic) remember trick: D for diastolic like D for denominator -‐ blood glucose >61 Mmol -‐ linked to genetics -‐ the Pima Native American in Arizona & Mexico -‐ a large % of Pima who live in US are grossly overweight -‐ the Pima in Mexico are not overweight; have diff lifestyle eating more veggies & fewer fast foods à there’s a genetic propensity for overweight, but to bring it out, it requires a poor diet -‐ obesity linked to brown fat -‐ fat which appears brown under microscope -‐ brown fat is more adept at converting food components (carbs, fats, etc) & releasing energy than are other fat cells -‐ obese rodents have less brown fat -‐ if put obese rodents in fridge, they will shiver continuously -‐ if put skinny rodent in fridge it will at first shiver, then stop because brown fat quickly takes over to convert stored nutrients to energy/heat -‐ overweight animal doesn’t have enough brown fat cells à suggests that if you have more brown fat, your more likely to be lean -‐ exercise causes weight loss because it converts white fat into brown fat -‐ white fat-‐ brown fat distribution in body is likely genetically determined -‐ low BMR can predict future obesity -‐ BMR increases with body weight because as the body‘s mass increases, it expends more energy. But, this rate tends to settle down when the body reaches a certain weight called the set point Video 5 -‐ some people born w very efficient bodies à born with a low BMR (but not a good thing) -‐ if they eat the same amount of food as someone w high BMR, they will put on more weight bc not as much of the food is needed to provide energy -‐ BMR increase as weight is gained (because it becomes harder to run the body) -‐ BMR is similar in obese & non-‐obese -‐ ppl born w low BMR are pre-‐programmed to have to put on weight so they can match the BMR of ppl who tend to be lean -‐ set point theory: body has in mind the weight it is happy with -‐ BMR will increase until it is at an ideal level, but for those born w low BMR they have to put on weight -‐ body resists to cutting back on calories à short-‐term weight loss -‐ but long term, the body reduces the BMRà body notices not as many calories are available coming in, so it must reduce the amount of energy needed for body to function -‐ exercise increases BMR, but have to do a lot of exercise to burn up calories -‐ the real value of exercise is that it increases BMR even when you are not exercising -‐ exercise & reduced calorie intake works for weight loss -‐ Bob Adelman couldn’t get into his car so he decided to lose weight -‐ he cut calories and started to exercise; goal of running a marathon -‐ by 9 months, he looked lean & in a year he was muscular -‐ went 315 pounds to 195 pounds -‐ Bob has been able to keep it off with some yo-‐yo effect, but this is a rare case; most gain it back -‐ what is causing the rise in obesity Lesson 3: Weight Control 2 Video 1 -‐ N. American produces 3900 calories per person per day -‐ many calories in soft drinks very high in sugar -‐ in past, the emphasis was on fat -‐ sucrose is a disaccharide = glucose + fructose -‐ glucose + fructose can be used as source of energy, but glucose metabolized differently than fructose -‐ more of fructose is converted into fat which builds up in liver -‐ as corn sweetener (w high fructose content) beverages have increased, have seen an increase in obesity (doesn’t mean that one causes the other) Dr. Robert Lustig is a neuroendocrinologist à fructos...
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