Text 2945, 153 rader
Skriven 2006-07-06 16:21:17 av mark lewis (1:3634/12.0)
     Kommentar till en text av Glen Jamieson
Ärende: HFCS [was: TASTES 875  60629]
=====================================
re: high fructose corn syrup

 GJ> Is it digested by the body and converted to fat the same as real
 GJ> sugar and other carbs?  I presume corn syrup is produced by enzymic
 GJ> action on maize, which could introduce the chemical taste you
 GJ> mention. 

here's what wikipedia has to say about it...

===== quote http://en.wikipedia.org/wiki/High_fructose_corn_syrup =====

Introduction
============
Like ordinary corn syrup, the high fructose variety is made from corn starch
using enzymes. The production process of HFCS was developed by Japanese
researchers in the 1970s. HFCS was rapidly introduced in many processed foods
and soda drinks in the US over the period of about 1975-1985, and usage
continues to increase as sugar use decreases at a nearly one to one level
(Bray, 2004 & U.S. Department of Agriculture, Economic Research Service, Sugar
and Sweetener Yearbook series, Tables 50-52.).

By increasing fructose content of corn syrup (glucose), the syrup is more
comparable to table sugar (sucrose). This makes it useful to manufacturers as a
possible substitute for sugar in soft drinks and other processed foods. Unlike
sucrose, HFCS consists of a mixture of glucose and fructose, which doesn't
require an enzymatic step to break it down before absorption in the intestine.

Through enzymatic processing, the fructose content of corn syrup can be
increased to yield a product with similar properties to table sugar. Common
commercial grades of high fructose corn syrup include fructose contents of 42%,
55%, or 90%. The 55% grade is most commonly used in soft drinks and equivalent
to caster sugar.


Comparison to other sugars
==========================
Sucrose (table sugar) is a disaccharide composed of one unit each of fructose
and glucose linked together. Sucrose is 50% fructose, so HFCS may have a higher
or lower fructose content than sucrose, with a corresponding change in
sweetness. Sucrose is broken down during digestion into fructose and glucose
through hydrolysis by the enzyme sucrase.

Honey is another product that is a mixture of different types of sugars, water,
and small amounts of other compounds. Honey typically has a fructose/glucose
ratio similar to HFCS, as well as containing some sucrose and other sugars.



Sweetener consumption patterns
==============================

In the United States
====================
US sweetener consumption, 1966-2004 (cane and beet sugar are both pure sucrose)

The accompanying graph shows the consumption of sweeteners per capita in the
United States since 1966. Since HFCS and sucrose (cane and beet sugars) provide
almost identical proportions of fructose and glucose, no metabolic changes
would be expected from substituting one for the other. However, it is apparent
from this graph that overall sweetener consumption, and in particular
glucose-fructose mixtures, has increased since the introduction of HFCS. Thus,
the proportion of fructose as a component of overall sweetener intake in the
United States has increased since the early 1980s. This would be true whether
the added sweetener was HFCS, table sugar, or any other glucose-fructose
mixture.


International markets
=====================
Currently, HFCS remains an almost uniquely American phenomenon.

In Europe, whilst HFCS is not specifically banned, the greater availability of
cane sugar over maize would make it uneconomical to produce it there.



Health effect controversy
=========================

Overview
========
The average American consumed approximately 42.3 lb of HFCS versus 44.0 lb of
sugar in 2004. By contrast, where HFCS is not used or rarely used (EU, Brazil,
Australia), the sugar consumption per person is nearly double or more than the
USA.

One study concluded that fructose "produced significantly higher fasting plasma
triacylglycerol values than did the glucose diet in men". The research, led by
J.P Bantle, concluded that "if plasma triacylglycerols are a risk factor for
cardiovascular disease, then diets high in fructose may be undesirable" (Bantle
et al., 2000). However, this study looked at the effects of fructose
independently. As noted by the U.S. Food and Drug Administration in 1996, the
saccharide composition (glucose to fructose ratio) of HFCS is approximately the
same as that of honey, invert sugar and the disaccharide sucrose (or table
sugar).

A more recent study by Dr. George Bray and others (2004) found a link exists
between obesity and high HFCS consumption, especially from soft drinks. On the
other hand, University of California, Davis nutrition researcher Peter Havel
pointed out that while there are likely differences between sweeteners, "the
increased consumption of fat, the increased consumption of all sugars, and
inactivity are all to blame for the obesity epidemic." (See External link on
HFCS and Obesity)


Labeling restrictions
=====================
In May 2006, the Center for Science in the Public Interest (CSPI) threatened[1]
to file a lawsuit against Cadbury Schweppes for labeling 7UP as "All Natural"
despite containing high fructose corn syrup. While the FDA has no definition of
"Natural", CSPI claims that HFCS is not a "natural" ingredient due to the high
level of processing required to produce it.


Production
==========
High-fructose corn syrup (HFCS) is produced by processing corn starch to yield
glucose, and then processing the glucose to produce a syrup with a higher
percentage of fructose.

First, cornstarch is treated with alpha-amylase to produce shorter chains of
sugars called oligosaccharides.

Next, an enzyme called glucoamylase breaks the sugar chains down even further
to yield the simple sugar glucose.

The third enzyme, glucose-isomerase, converts glucose to a mixture of about 42%
fructose and 50-52% glucose with some other sugars mixed in. While
alpha-amylase and glucoamylase are added directly to the slurry,
glucose-isomerase is packed into columns and the sugar mixture is then passed
over it. This 42-43% fructose glucose mixture is then subjected to a liquid
chromatography step where the fructose is enriched to approximately 90%. The
90% fructose is then back-blended with 42% fructose to achieve a 55% fructose
final product. Numerous ion-exchange and evaporation steps are also part of the
overall process.


References
==========
* Bantle, John P., Susan K. Raatz, William Thomas and Angeliki Georgopoulos
(November 2000). "Effects of dietary fructose on plasma lipids in healthy
subjects". American Journal of Clinical Nutrition 72 (5): 1128-1134.

* Bray, George A., Samara Joy Nielsen and Barry M. Popkin (April 2004).
"Consumption of high-fructose corn syrup in beverages may play a role in the
epidemic of obesity". American Journal of Clinical Nutrition 79 (4): 537-543.


===== end quote =====

)\/(ark

 * Origin:  (1:3634/12)