apple

NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE
Is High Fructose Corn Syrup Bad for the Apple Industry?
by
by
b
Jeff ri C. Bohlscheid, School of Food Science, University of Idaho, Moscow, ID
Part I - Demise of the Hives
Dad snapped shut his cell phone and his shoulders slumped. "Now we've got a real problem," he sighed.
Life as an apple farmer in Wenatchee, Washington, could be challenging, but Dad was looking particularly depressed.
"What is it now?" Bruce asked.
"Seems that the last beekeeper in the area has lost almost all of his hives," Bruce's dad replied.
After a semester of introductory entomology at Washington State University and a childhood spent in an apple
orchard, Bruce knew that this was bad. Bees were necessary to pollinate apple trees to produce the fruit. Th
ey
pollinated over 130 diff erent food crops, such as berries, beans, nuts, melons, and tree fruit. In fact, bees were
responsible for over $15 billion in agricultural products in the United States alone. Without bees, there would be none
of these foods. And that included apples--which were paying for Bruce's college education!
Bruce thought for a moment. "Can you call anyone from outside the area?" he asked.
"If we can fi nd someone--but, even if we could, it might be too late. We only have a window of a week for pollination,"
Bruce's dad answered. "With the loss of so many hives around here, beekeepers from outside the area might be
reluctant to come up here."
Bruce pondered this. Colony Collapse Disorder (CCD), the phrase used to describe the unexplained death or
disappearance of a hive, could have over 60 diff erent factors involved. Pesticides and herbicides used in the fi elds,
fungal infections, viruses, and gut-eating mites all had been implicated.
Dad looked perplexed. "Th
e thing is...this just happened over the last three weeks. Our local beekeepers' hives have
had a clean bill of health these last few years. I've got money invested with one keeper and there were no signs of
infections or chemicals. We've been watching this very closely."
"I'm going to run some errands," said dad. "I think I'll stop by the library and extension offi
ce and see if I can fi nd
anything out."
Dad came back much later in the day. "Bruce, what do you know about high fructose corn syrup? I found a research
article written by scientists at the U.S. Department of Agriculture that seems to say it could be involved with CCD.
Can you help me fi gure this thing out? Recently we have been feeding high fructose corn syrup to our hives."
Bruce had gone over a few scientifi c articles in school his senior year--hopefully that would help him analyze the data
in the article his father handed him. "Well, let's just give this a look," he said. Sitting down, Bruce pulled out a note
pad and began to read.
"Is High Fructose Corn Syrup Bad for the Apple Industry?" by Jeff ri C. Bohlscheid
Page 1

---

NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE
"So...what are your questions?" he asked his father.
Pulling out his own notes, Dad said, "Well, this could be pretty controversial and damaging stuff , so I really want to
understand what is going on."
Your Task
Read the following abstract of the scientifi c article* as well as the introduction section of the same article (which your
instructor will provide you) and then answer the questions that follow. To help you with your reading, a list of terms and
their defi nitions is included at the end of this section (next page).
Abstract
In the United States, high-fructose corn syrup (HFCS) has become a sucrose replacement for honey bees
and has widespread use as a sweetener in many processed foods and beverages for human consumption.
It is utilized by commercial beekeepers as a food for honey bees for several reasons: to promote brood
production, after bees have been moved for commercial pollination, and when fi eld-gathered nectar
sources are scarce. Hydroxymethylfurfural (HMF) is a heat-formed contaminant and is the most noted
toxin to honey bees. Currently, there are no rapid fi eld tests that would alert beekeepers of dangerous
levels of HMF in HFCS or honey. In this study, the initial levels and the rates of formation of HMF at four
temperatures were evaluated in U.S.-available HFCS samples. Diff erent HFCS brands were analyzed and
compared for acidity and metal ions by inductively coupled plasma mass spectroscopy. Levels of HMF in
eight HFCS products were evaluated over 35 days, and the data were fi t to polynomial and exponential
equations, with excellent correlations. The data can be used by beekeepers to predict HMF formation on
storage. Caged bee studies were conducted to evaluate the HMF dose-response eff ect on bee mortality.
Finally, commercial bases such as lime, potash, and caustic soda were added to neutralize hydronium ion
in HMF samples, and the rates of HMF formation were compared at 45 C.
Dad's Questions
1. What are the major issues that the authors are addressing in the article?
2. Why is acid added to the syrups? Are there consequences to this?
3. What are the hypothesis and objectives of the authors in this article? Is this relevant to our problem?
Bruce had his own questions after quickly scanning the introduction of the article.
Bruce's Questions
4. Who would be most interested in the results of this scientifi c study?
5. With what I know about the scientifi c method, what should the researchers' next steps be to test their hypothesis
and meet their objectives? How would I outline the experiments required to answer the researchers' questions?
6. How long do honey bees live?
"Dad, I think I'll get back to you in the morning."
* Th
e scientifi c article excerpts and fi gures presented in this case study are reprinted with permission from Blaise W. LeBlanc et al. (2009),
"Formation of Hydroxymethylfurfural in Domestic High-Fructose Corn Syrup and Its Toxicity to the Honey Bee (Apis mellifera)," Journal of
Agricultural and Food Chemistry. Copyright 2009 American Chemical Society.
"Is High Fructose Corn Syrup Bad for the Apple Industry?" by Jeff ri C. Bohlscheid
Page 2

---

NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE
Defi nitions of Terms
Codex Alimentarius Commission - organization within the United Nations and Food and Agriculture Organization that
develops international food standards to protect health and ensure fair trade.
Dissolved solids - material dissolved in water that can be recovered by drying. In HFCS these would primarily be sugars.

% dissolved solids = g dissolved material/100 mL of solution.
Dysentery - infl ammation of the intestinal tract that can lead to diarrhea and death.
Enzymes - specialized proteins that speed up chemical reactions (catalysts).
Fermentation - conversion of sugar into alcohol and other substances by microorganisms such as yeast. Th
ese
compounds can be toxic to bees.
Heavy metals - e.g., cadmium, mercury and lead.
Hydrolyze - to break a molecule apart chemically by the addition of water.
Invertase - enzyme that hydrolyzes sucrose into glucose and fructose (the mixture is called invert sugar).
Kinetics - the study of the rate of chemical reactions, commonly expressed as unit of product per time.
First order kinetics - the rate of a chemical reaction is proportional to the amount of the starting materials, i.e., the
sugars.
Mineral acids - acids that do not contain carbon, e.g., HCl (hydrochloric acid) and H SO (sulfuric acid); generally
2
4
much stronger acids compared to organic acids.
Organic acids - acids that contain carbon, e.g., citric acid (lemons), tartaric acid (cream of tartar), and lactic acid
(yogurt).
Pasteurization - a heat treatment given to foods to kill off pathogens (disease causing) microorganisms, but not all
microorganisms; much more mild than sterilization.
ppm - parts per million, unit of concentration, i.e., microgram/gram or milligram/kilogram.
Sucrose - table sugar, composed of chemically bonded glucose (blood sugar) and fructose (fruit sugar).
Th
ermal eff ect - the results of heating. Increased temperatures generally result in faster chemical reactions.
Transition metals - e.g., cobalt, copper, iron and manganese.
"Is H
"I
igh F
s H
r
igh F uctose Corn Sy
uctose Corn S r
y up Bad for the A
up B
pple I
ad for the A
ndustr
pple I
y?" by
y?" b J
y e
J ff
e ri C. Bohlscheid
ff
Page 3

---

NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE
Part II - Analysis of Commercial High Fructose Corn Syrup Samples
"Ok Dad, let's go through this paper. What are your questions?"
Dad pulled out his notes again, "So I was looking at Table 1 and I don't get it."
Your Task
Examine Table 1 from the article below, and then answer Dad's questions.
Table 1. Hydronium Ion Concentration, Hydroxymethylfurfural Concentration, and Elemental Analysis
of Domestically Produced High-Fructose Corn Syrup. (The D-blend sample was a HFCS-55-sucrose
syrup blend that is specifi cally formulated for beekeepers. The higher pH of this D-blend syrup is due
to its high sucrose concentration. Sucrose is less stable at pH values <8.3 and particularly at even lower
pH values (18).) Note: The HFCS samples were gifts from Roquette, Archer Daniels Midland, Mann Lake,
Inc. (Cargill HFCS), and Tate & Lyle. All of the HFCS samples were received in quart containers, with the
exception of Mann Lake, Inc. (Cargill HFCS), which were provided as 5 gal (18.5 L) samples.
HFCS
pH
% HCl
HMFo (g/g)
% Fructose
% C, H, N, S *
A-42
4.15 0.04
0.0104 0.0013
20.75 0.004
42
29.30 0.09, 5.55 0.08, 0.0, 0.0
B-42
3.86 0.02
0.0108 0.0007
3.07 0.002
42
29.50 0.06, 7.65 0.04, 0.0, 0.0
C-42
4.18 0.04
0.0092 0.0005
8.13 0.000
42
29.53 0.11, 7.55 0.04, 0.0, 0.0
A-55
4.86 0.17
0.0776 0.0004
28.65 0.005
55
31.72 0.14, 7.39 0.04, 0.0, 0.0
B-55
4.16 0.04
0.0092 0.0030
20.77 0.006
56
31.56 0.08, 7.42 0.0, 0.0, 0.0
C-55
5.02 0.02
0.0074 0.0004
7.89 0.004
56
31.69 0.13, 7.43 0.07, 0.0, 0.0
D-55
4.34 0.06
0.0085 0.0005
27.47 0.003
55
31.70 0.09, 7.41 0.01, 0.0, 0.0
D-50
6.09 0.06
0.0062 0.0008
4.05 0.001
50
32.79 0.05, 7.19 0.03, 0.0, 0.0
blend
* C - Carbon, H - Hydrogen, N - Nitrogen, and S - Sulfur
Dad's Questions
1. What do 42, 50, and 55 stand for?
2. What do A, B, C, and D indicate?
3. What does Table 1 tell us about the relationships between HFCS samples, HFCS composition, acidity, and
HMF content?
"Th
e table doesn't make much sense to me," Dad continued. "Is there another way to present the data that is more
meaningful?"
"Let's get some graph paper and see if there is a pattern," suggested Bruce.
Your Task
Graph the data in Table 1 using the graph paper that your instructor will give you. Each student should graph the data
individually; then compare your results with your group, after which we will discuss the data as a class.
Bruce constructed a graph of the data in Table 1 and handed it to his father. Not surprisingly, Dad had some questions
for Bruce about it.
"Is High Fructose Corn Syrup Bad for the Apple Industry?" by Jeff ri C. Bohlscheid
Page 4

---

NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE
Dad's Questions
4. Explain why you chose the particular axes on the graph.
5. What are the dependent and independent variables?
6. What conclusions can you draw from the resulting graph?
After answering Dad's questions, Bruce moved on to the fi gures in the article. "Well it seems that the scientists looked
at how heat aff ected HMF production in the syrups," he noted.
"Is High Fructose Corn Syrup Bad for the Apple Industry?" by Jeff ri C. Bohlscheid
Page 5

---

NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE
Part III - Formation of Hydroxymethylfurfural in High Fructose Corn Syrup
Looking at Figure 2 from the article, Bruce began to consider the ways in which the specifi c graphs were similar and
diff erent.
Your Task
Examine the graphs below, and then answer Bruce's and Dad's questions.
From LeBlanc et al. 2009. Ccopyright American Chemical Society.
Bruce's Questions
1. What are the overall trends?
2. How are the graphs similar?
3. How are the graphs diff erent?
4. How are the axes diff erent and what are the implications?
"Ok Bruce, my turn to ask some questions."
"Is High Fructose Corn Syrup Bad for the Apple Industry?" by Jeff ri C. Bohlscheid
Page 6

---

NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE
Dad's Questions
5. Why did the researchers select these times and temperatures?
6. What do the temperatures 40C and 49C equal in F?
7. What can we conclude from these graphs?"
Bruce was really getting intrigued by the study.
Bruce's Question
8. Given the hypothesis I developed earlier, what as a researcher would I want to test next to determine if HMF is
an issue in HFCS?
"Is High Fructose Corn Syrup Bad for the Apple Industry?" by Jeff ri C. Bohlscheid
Page 7

---

NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE
Part IV - Caged Bee Studies
"Well, it seems that heat can really infl uence the rate of HMF formation," Dad concluded. He started reading the next
section of the article, titled "Materials and Methods," which was associated with Figures 3 and 4 in the article.
Caged Honey Bee Experiments
As previously reported, a caged bee method was used (17). Approximately 100 freshly emerged
Italian honey bees were placed into the cage for each caged bee trial (conducted in triplicate). Current
research laws use committee approval for honey bee research. The caged trials were recorded in mul-
tiples of four, so that average and standard deviation counts can be reported. For all trials, the bees
were fed water, ad libitum, and a plug of pollen-sugar. For the HFCS syrup formulation, we used A-55,
which was determined to have 57 ppm HMF. For the higher HMF concentration solutions (100, 150,
200, and 250 ppm), pure HMF was added to the 57 ppm HFCS to obtain the desired concentrations.
"What does ad libitum mean?" asked Dad.
"I think it means that they could eat as much as they like," Bruce suggested.
"Okay, but I have some other questions about these fi gures," Dad continued.
Your Task
Examine the fi gures below, and then answer Dad's questions.
Figure 3. Consumption of HFMS in mlligrams of HFCS per bee at 3 days (A) and over 27 days (B). Diff erent letters in the bar
graph indicate signifi cant diff erences in mortality between diff erent HMF dosages, ANOVA, Dunnet two-sided (P < 0.005).
From LeBlanc et al. 2009. Ccopyright American Chemical Society.
"Is High Fructose Corn Syrup Bad for the Apple Industry?" by Jeff ri C. Bohlscheid
Page 8

---

NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE
From LeBlanc et al. 2009. Ccopyright American Chemical Society.
Dad's Questions
1. What is the purpose of the sucrose (table sugar) in Figure 4A?
2. Why did the researchers choose % survival at 26 days?
3. Why were these levels of HMF selected?
4. What do these graphs tell us?!?
"Whoa, slow down," said Bruce.
"Is High Fructose Corn Syrup Bad for the Apple Industry?" by Jeff ri C. Bohlscheid
Page 9

---

NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE
Part V - Industry Response
"So Bruce, do we have a problem here?" asked Dad.
Bruce thought to himself:
1. Given all of the results presented, what overall conclusions can I draw from this study?
2. Did the researchers meet their objectives and demonstrate enough evidence to support their hypothesis?
a. If not, what other studies may need to be done?
b. Would these assist in answering the most important questions facing Dad, or just be of interest?
Dad came back into the room after being on the internet. "Seems the high fructose corn syrup producers were not that
happy with this article. I found a response by the HFCS manufacturers."
Humans, bees not at risk from heated HFCS, says CRA
by Jess Halliday, 01-Sep-2009
Storage standards and temperature control for HFCS mean human health is not at risk from the formation of
hydroxymethylfurfural (HMF), the Corn Refi ners Association asserts, which also refutes suggestions that the
toxin could be a factor in honeybee colony collapse disorder.
In a new study by published in the Journal of Agriculture and Food Chemistry, USDA researchers measured HMF
levels in samples of HFCS over a 35 day time frame, at temperatures of 31.5, 40.0, 49.0 and 68.8C.
Study leader LeBlanc and team saw that HMF levels increased steadily with temperature, and that there was
a dramatic jump at 49 C--a fi nding they said is important for commercial beekeepers, for manufacturers of
HFCS, and for purposes of food storage.
But the CRA has called the study "fl awed", and emphasized that its members have safety measures and best
practices in place.
Dr John White of White Technical Research, a consultant whose clients include the CRA, told FoodNavigator.
com that there are well-established and widely-available industry storage standards for HFCS: for HFCS 55 the
temperature standard is between 75 F and 86 F (23.9 C to 30 C), and for HFCS 42 between 95 F and
106 F (35 C to 41.1 C).
Moreover, the standards specify use of containers made with stainless steel or mild steel coated with stainless
steel material.
"Clearly LeBlanc used extreme conditions aimed at maximizing HMF formation which contradicted both
temperature and vessel composition specifi cations. It should be noted that any syrup source subjected to such
harsh treatment would produce elevated levels of HMF," White said, on behalf of the Corn Refi ners Association.
No danger to bees or humans
Th
e CRA and White say the risk of HMF to humans presented by the new study are also over-egged. Th
ey say
that a 2000 study by Janzowski et al. discounts HMF as posing a serious health risk to humans.
"Is High Fructose Corn Syrup Bad for the Apple Industry?" by Jeff ri C. Bohlscheid
Page 10

---