Milk Chocolate Bars Research Articles

Lead in Cocoa Products: Where Does Contamination Come From?

Manufactured cocoa products frequently have higher lead concentrations than other foods, even though cocoa beans, the main ingredient, have some of the lowest reported lead levels for any natural food. In 2001 the Codex Alimentarius Commission, an international body based in Rome, proposed reducing the maximum permissible level of lead in cocoa products by half, to 100 nanograms per gram (ng/g) for cocoa butter and 1,000 ng/g for cocoa powder. At a March 2002 meeting in West Africa, where most of the world’s cocoa supply originates, producers agreed that to reduce lead in their products, they needed research to identify the source of contamination. Now a U.S.–Nigerian research team has uncovered some of the first clues about where the lead is coming from [EHP 113:1344–1348]. Lead contamination of candies has been recognized as a problem since 1820, when a British study found the poison widespread in London confectionary products. In recent years, documented lead content in candy has ranged from a mean concentration of 21 ng/g in milk chocolate bars in an Australian study to an average of 1,920 ng/g in chocolates seen in research in India. In Nigeria, a 1999 study found an average of 310 ng/g lead in cocoa powders. (For comparison, the mean U.S. lead concentration for apples is 20 ng/g, 200 ng/g for dry table wine, and 100 ng/g for canned pineapple.) Lead is known to cause anemia, muscle weakness, and brain damage, with children particularly susceptible to effects. In the current study, the researchers studied the lead isotopic compositions of cocoa beans and shells from six farms in Nigeria’s top three producing states to determine if soil or farm sources might be the cause of lead contamination. The team took bean and sediment samples and homogenized them to make composites for soil, beans, and cocoa bean shells for each farm. They analyzed lead concentrations using high-resolution inductively coupled plasma mass spectrometry to make preliminary isotopic measurements, followed by thermal ionization mass spectrometry measurements. The lead concentrations for cocoa beans ranged from less than 0.103 to 1.78 ng/g, averaging 0.512 ng/g—among the lowest lead concentrations reported for any food. The average concentrations found in the cocoa bean shells, however, was about 320-fold higher (160 ng/g). Soils showed a range of isotopic compositions overlapping those of the shells. The cocoa bean shells all had an extremely similar isotopic composition, indicating a singular source of contamination, perhaps leaded gasoline. The authors conclude that although the soil may have caused a small degree of the contamination, the narrower range of isotopic composition in the shells suggested the more singular source of contamination was the true culprit. According to the paper, cocoa bean shells are known to be very effective at removing lead from solutions. So, although they provide excellent protection of the bean inside, the shells may also serve to contaminate the cocoa beans during fermentation or drying. The team also compared the cocoa beans with finished cocoa products and found much higher lead concentrations and greater variability in the isotopic composition among the finished products. They therefore deduced that most of the contamination occurred after the cocoa left the farm stage. The researchers conclude that while cocoa bean shells may be one source of lead, most contamination occurs during shipping or processing of the beans and in manufacturing. Further research on those stages of the process will help to isolate the source.

Effects of a milk chocolate bar per day substituted for a high-carbohydrate snack in young men on an NCEP/AHA Step 1 Diet

This study compares the plasma cholesterol response with the isoenergetic substitution of a milk chocolate bar (46 g) given daily for a high-carbohydrate snack in healthy young men on a Step 1 Diet. Normocholesterolemic men (n = 42) were fed a Step 1 Diet for 21 d (run-in diet) followed by a 27-d experimental period during which they consumed the same diet plus either a milk chocolate bar or a high-carbohydrate snack; after this they consumed the run-in diet for 21 d followed by the other snack for 27 d. When subjects consumed a milk chocolate bar instead of the high-carbohydrate snack, high-density-lipoprotein (HDL) cholesterol was 0.08 +/- 0.03 mmol/L higher (P < 0.01) and plasma triglycerides were 0.06 +/- 0.03 mmol/L lower (P < 0.05). Substitution of a milk chocolate bar for a high-carbohydrate snack did not adversely affect the low-density-lipoprotein-(LDL) cholesterol response to a Step 1 Diet despite an increase in total fat and saturated fatty acid content of the diet. This response may be due to stearic acid.

Chocolate feeding studies: a novel approach for evaluating the plasma lipid effects of stearic acid

Milk chocolate does not adversely affect plasma lipids and lipoproteins despite its relatively high content of saturated fatty acids (SFAs). Evidence from well-controlled feeding studies indicates that this unique response is due to the high proportion of stearic acid in milk chocolate. In experimental diets containing very high amounts (eg, 280 g/d, or 10 oz/d) and more typical amounts (46.2 g, or 1.65 oz) of milk chocolate, plasma total- and low-density-lipoprotein-cholesterol concentrations are not elevated. Furthermore, isoenergetic substitution of one milk chocolate bar per day for a high-carbohydrate snack in a National Cholesterol Education Program/American Heart Association Step 1 Diet does not adversely affect the cholesterol-lowering response. These findings indicate that stearic acid is not hypercholesterolemic as are the other long-chain SFAs. Thus, as illustrated by the different results generated from the predictive equations that group all long-chain SFAs vs those that consider stearic acid separately, grouping stearic acid with other SFAs appears to misrepresent the actual blood cholesterol response.

Glycemic effect and satiating capacity of potato chips and milk chocolate bars in diabetic teenagers

(IDDM). Fourteen teenagers, four girls and ten boys, attending the diabetic clinic at our hospital participated in the study. All had passed the initial remission. They had a diabetes duration of > 1 y and an insulin dose of > 0.5 lU/kg body weight. The subjects were between 13 and 19 y old. Their mean diabetes duration was between 3 and 15 y (mean 8.6 y). Their glycosylated hemoglobin (HbAic) concentrations ranged from 6.3% to 9.4% (mean 7.9%, reference value < 5.6%) at the time of the tests. The teenagers were receiving three or four insulin doses/d, with a mean of 1.0

Effects of preexercise candy bar ingestion on glycemic response, substrate utilization, and performance.

This study examined the effects of preexercise candy bar ingestion on glycemic response, substrate utilization, and performance in 8 trained male cyclists. The cyclists randomly ingested one large milk chocolate bar (1CB), two large milk chocolate bars (2CB), or a placebo (P) 30 min prior to a 90-min cycle ride at 70% VO2max followed by a 33-W increase every 2 min until exhaustion (approximately 10 min). Glucose decreased after 15 min of exercise but returned to preexercise values by 30 min of exercise. Glucose concentration for 2CB was significantly higher than for P and 1CB at exhaustion. Insulin concentration increased in response to 1CB and 2CB and returned to preexercise values within 15 min of exercise. No significant differences were noted for free fatty acid (FFA) concentrations, lactate concentrations, respiratory exchange ratio, total carbohydrate oxidation, or estimated fat and carbohydrate oxidation rates. Time to exhaustion was similar among the groups. The results suggest that the transient lowering of blood glucose observed with preexercise milk chocolate bar ingestion 30 min prior to exercise may not cause major metabolic perturbations that impair athletic performance in trained athletes performing moderately intense cycle exercise.

Glycaemic effect and satiating capacity of potato chips and milk chocolate bar as snacks in teenagers with diabetes.

In 14 adolescents with diabetes, the postprandial blood glucose, after ingestion of two popular snacks, milk chocolate bar and potato chips, was compared to a prescribed mid-afternoon snack that was isocaloric with the comparison snacks. The prescribed diabetes snack consisted of wholemeal wheat bread, margarine, cheese and apple (1533 kJ/365 kcal): 14% protein, 32% fat and 54% carbohydrate. The milk chocolate bar and the potato chips contained 4% protein, 55% fat and 41% carbohydrate. The mean blood glucose peak was 4.7 (+/- 0.8) mmol/l after the regular diabetes snack, after the milk chocolate bar 2.9 (+/- 0.6) mmol/l, and 3.2 (+/- 0.6) mmol/l after the potato chips (P > 0.05). The mean incremental area under the blood glucose curve was 450.3 (+/- 105.5) mmol/l x 180 min for the regular diabetes snack, 269.5 (+/- 96.7) mmol/l x 180 min for the milk chocolate bar and 191.7 (+/- 95.0) mmol/l x 180 min for the potato chips (P > 0.05). We conclude that an occasional exchange of a regular diabetes afternoon snack for an isocaloric amount of milk chocolate bar or potato chips has no negative impact on the postprandial blood glucose.

Lack of Correlation Between Food Retention on the Human Dentition and Consumer Perception of Food Stickiness

When dental health professionals advise that sticky foods be avoided, it is left to the consumer to choose correctly among different foods. In this study, comparisons were made among consumer ratings of stickiness of 21 commercially available foods and objective measurements of tooth retention of each of the foods. No correlation was found between the two, and neither the rates of clearance of food particles from the teeth nor the rates of clearance of food-derived sugars from the saliva correlated with ratings of food stickiness. Cookies, crackers, and potato chips were most retentive, whereas caramels, jelly beans, raisins, and milk chocolate bars were among those poorly retained. Clearance rates appeared to vary inversely with initial retention. However, chocolate-caramel bars exhibited high initial retention and a very rapid rate of clearance from the teeth. The findings show that consumers cannot accurately assess the retentiveness of foods and, thus, the advise simply to avoid sticky ones is inadequate.

HOW SWEET IT WAS, 1894

Machine-made candy was invented by the Germans. But it was Milton S. Hershey, a Pennsylvania candyman with a flair for packaging, who gave the world a craving for what he called simply the Hershey Milk Chocolate Bar. Hershey, who had started in the candy business in 1876 making caramels by hand, purchased his first chocolate-making machine, a German model, in 1893. By the following year, his plant in Lancaster, PA, was turning out America's first mass-produced milk-chocolate bar and its cousin, the Hershey Almond Bar. Weighing 9/16th of an ounce each and divided into small squares easily broken off and eaten, the Hershey milk-chocolate bars were a novelty: Most candy then was sold in large, unwieldy chunks. Within a few years, Hershey introduced another innovation in candy packaging, enclosing each bar at the factory with a wrapper containing the company logo. The whole chocolate business got a big boost when America entered World War I. The Army issued chocolate bars to the troops as quick-energy food, and when the troops came home, they came with a sweet tooth. By 1918 there were 20,000 candy companies in the U.S. Hershey rode the boom and remained a leading U.S. chocolate maker even though the company avoided advertising - Milton Hershey always believed his product would sell itself - until the 1940's.

Responses of interproximal plaque pH to snack foods and effect of chewing sorbitol-containing gum

Interproximal wire-telemetric plaque pH data were obtained from five volunteers after they ate milk chocolate bars, raisins, chocolate wafer cookies with cream filling, cupcakes with icing and cream filling, and cherry pies. All the foods produced rapid decreases in plaque pH for extended periods. In a second set of test sessions, volunteers chewed sugarless gum for 10 minutes, starting 15 minutes after they ate the snack food. In all cases, the gum chewing caused a rapid increase in plaque pH. The pH remained at a level considered safe for teeth for 30 minutes after chewing the gum.

Postprandial glucose and Insulin responses to various snacks of equivalent carbohydrate content in normal subjects

To evaluate glucose and insulin responses after ingestion of snacks, we gave healthy, nondiabetic male subjects carbohydrate equivalent (25 g) snacks or isocaloric (265 kcal) snack meals in a random crossover design. Individual snacks composed of either a milk chocolate bar, granola bar, chocolate milk, peanut butter cups, yogurt, or potato chips produced similar glucose response curves. Plasma glucose concentrations were lower (p ≤ 0.05) at 30 and 60 min postprandially than after a corresponding oral glucose challenge. In contrast, insulin responses to the snacks exhibited a two-fold variation in peak values. Isocaloric snack meals of cereal-milk, cheese sandwich-milk, and peanut butter sandwich-chocolate milk produced glucose and insulin responses similar to individual snacks. Although glucose concentrations at 60 min fell somewhat below baseline values after each snack, clinical hypoglycemia was not evident These data clearly indicate a similarity in glycemic response among normal individuals consuming a variety of common snacks.

Ingested Carbohydrates and Blood Glucose in Diabetics-Reply

In Reply.— Ms Halford and Dr Weir address the important concept that not all forms of carbohydrate are absorbed equally. They further address the question that a 2.5-oz Hershey chocolate bar containing 39 g of sucrose might not produce the same glycemic response as 20 g of D-glucose. Unfortunately, the article that they quote to show the glycemic response to 25 g of carbohydrate taken as milk chocolate is not readily available. It is, therefore, very difficult to assess or comment on the results of that study. Obviously, the results would depend on the milk chocolate bars ingested, the patient population selected for testing, the insulin response of the patient population selected, and multiple other variables. In addition, we carefully pointed out several of the points alluded to by Ms Halford and Dr Weir. We state in our manuscript that the specific form of carbohydrate may be more important than

Ingested Carbohydrates and Blood Glucose in Diabetics

To the Editor.— The article entitled Treatment of Insulin Reactions in Diabetics 1 dealt with the use of different carbohydrate sources to alleviate hypoglycemia. Twenty grams of D-glucose was recommended to treat hypoglycemicreactions. A list of foodstuffs containing 20 g of D-glucose was given to be used in the absence of commercially available D-glucose preparations. This list of alternative glucose sources included a 2.5-oz Hershey milk chocolate bar. The choice of a chocolate bar perpetuates the misconception that glucose from different foodstuffs will produce similar glycemic excursions. Our calculations show the 2.5-oz (70-g) chocolate bar contains 39 g of sucrose. This supports the assumption that this candy bar contains 20 g of glucose. However, a look at studies published by Otto et al 2 in 1973 shows that the glycemic response to 25 g of carbohydrate taken as milk chocolate is approximately 30% of the response to glucose. We assume

A STUDY ON SURVIVAL OF Staphylococcus aureus IN DARK AND MILK CHOCOLATE

Dark and milk chocolate bars were inoculated with Staphylococcus aureus to establish an initial population of approximately 102, 104 and 106 cells per gram. Samples were stored at room temperature and examined for the survival of staphylococci at 2‐day intervals for the first 6 days and every 8 days thereafter. When samples were inoculated with 102 cells per gram, absence of staphylococci was observed after 2‐days in dark and 14 days of storage in milk chocolate. Bars with 104 cells per gram were free of cells after 38 days in dark and 86 days of storage in milk chocolate. Dark chocolate bars with 106 cells per gram, were staphylococci free after 86 days of storage; whereas the milk chocolate bars with same level of inoculation were shown to be staphylococci free after 110 days of storage