Today’s molecule – furan

I don’t need ANY bad news about my espresso coffee!

From FECYT – Spanish Foundation for Science and Technology, via “Eurekalert

Here is their press release…

“Coffee in capsules contains more furan than the rest”

Coffee in capsules contains more furan than the rest, although the levels are still within safe health limits.

“Preparing a coffee in a drip coffee maker is not the same as making one in an espresso machine or from capsules, because these give rise to differing levels of furan”, Javier Santos, a professor at the Department of Analytical Chemistry at the University of Barcelona and lead author of the study, tells SINC.  Concern has risen over recent years about the presence of this compound in foods, because of its toxic and carcinogenic effects in animals, as well as the fact that the International Agency for Research on Cancer has listed it as a possible carcinogen in humans.

“The results, published online in the Journal Food Chemistry, reveal that higher concentrations are found in espresso (43‐146 nanograms/mililitre) than in coffee made in drip coffee makers, both in the case of normal coffee (20‐78 ng/ml) and decaffeinated coffee (14‐65 ng/ml).  The levels of these toxic products were “slightly lower” (12‐35 ng/ml) in instant coffee, but a great deal higher in those made from the capsules of a well-known brand, which showed up higher levels (117‐244 ng/ml).”

“The reason for these higher levels is due to the fact that hermetically-sealed capsules prevent furan, which is highly volatile, from being released, while the coffee makers used to brew this coffee use hot water at higher pressures, which leads to the compound being extracted into the drink”, says Javier Santos. The longer that coffee is exposed to the air in cups or jugs, meanwhile, the more the furan evaporates. ”

“Different values, but not dangerous: The researcher stresses that, in all these cases, the levels of the substances found are within the limits considered to be “safe” to health. In fact, the team has estimated the amount of furan ingested as a result of coffee consumption in Barcelona, obtaining values of 0.03‐0.38 micrograms/kilogram of body weight, which is less than the maximum acceptable level (2 μg/Kg of body weight). In order for furan ingestion to exceed the maximum acceptable values, a person would have to drink at least 20 cups of capsule coffee or 30 espressos per day (for the brands with the highest furan content), or 200 instant coffees. These estimates were made on the basis of 40 ml cups and an average body weight for coffee drinkers of around 70 Kg.”

“The study also shows that furan concentrations are lower if coffee is roasted at low temperatures over a longer time (140ºC for 20 minutes) than in coffee roasted under usual conditions (200‐220ºC for 10-15 mins).”

Furan, like acrylamide, is one of a group of carcinogenic substances that can form when foods and drinks are subject to heat treatment. They are the result of a reaction, known as the Maillard reaction, between carbohydrates, unsaturated fatty acids and ascorbic acids or its derivatives.”

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M.S. Altaki, F.J. Santos and M.T. Galceran. “Occurrence of furan in coffee from Spanish market: contribution of brewing and roasting”. Food Chemistry 126 (4) 1527, June 2011 (Available online December 2010). Doi: 10.1016/j.foodchem.2010.11.134.

Molecule of the moment – butyric acid

One of the short chain fatty acids produced in lower bowel microbial fermentation. Butyric acid production in the human lower gut is promoted by the ingestion of resistant starch [RS]: that is, starch that is resistant to digestion in the preceding elements of the digestive tract via either acidic or enzymatic hydrolysis. There are different types of RS:

RS1 is starch physically occluded [hidden] by other plant anatomical structures, e.g. when consuming unmilled whole grains;

RS2 is raw granular starch of poor digestibility often with B-type amylopectin crystal structures [potato & banana starches], RS2 starch becomes digestible on cooking after gelatinization;

RS3 is most commonly based on normal, or preferably high-amylose, starch sources. The need for amylose in RS3 is the enhanced capability of amylose to quickly and strongly re-crystallize (retrograde) on cooling of a cooked starch matrix. The strong tendency of amylose to re-crystallize and the ability to grow and make the amylose crystallites more perfect during repeated heating and cooling cycles is exploited in the food industry in order to create sources of RS3 for addition to foods

Back to butyric: the higher levels of butyric acid that arise from the RS fermentation (compared to the higher amount of propionic acid fermented from non-starch fiber sources) are believed to be the genesis of the protective effects of RS against colo-rectal cancers. Butyric acid is believed to act as a cell growth regulator for the cells in the bowel epithelium, but also contributes to other more general factors that improve bowel function such as lowered fecal pH. RS appears to be fermented in the distal (descending) colon, as opposed to non-starch fibers that are fermented in the ascending and transverse colons, it extends these beneficial attributes further along the digestive tract.

More whole grains at Oregon State

I’ve been having a work “vacation” – working with Craig Ponsford at the “Ponsford’s Place”  Innovation Center [link] to fine-tune our barley bread formulations.

We uncovered some interesting processing challenges that point to the particle size of the barley flour as being a suspect.

We played with the water because barley has so much great soluble fiber as mixed linkage beta 1-3, 1-4 glucans that it soaks up water like a sponge. These breads had 50% by flour weight whole-milled barley flour and respectively left to right 90% or 100% [flour basis] water. 100% water on this basis is equal weights of flour and water, and still it made bread.

Oregon State University’s “Streaker” hull-less barley going into the mill.

Food Science [sort of] in action

Once again food gums come to the rescue of our building project.

This time – sodium alginate.

Here an I applying a slurry of a 2% (w/w) alginate solution containing peat moss, compost, and grass seeds to a newly exposed cut at the back of our driveway.

The alginate forms a gel slowly in-situ using the Ca2+ from the soil, and we found out, from the peat moss. It seems to bind the soil  and retains moisture for the seeds.

The alginates gel more strongly if there are more “G” or guluronate blocks than “M” or mannuronate blocks based on a variant of the ion-mediated “egg-box” junction zones of a similar nature to those found in low- methoxy pectins.

Other polysaccharides with ability to bind soil exist, possibly the most unusual one being the gums of  a “new” polysaccharide complex from the seeds of  “Artemisia sphaerocephala” in the family Asterceae. A sphaerocephala is thought to have pectin-like polymers with arabinogalactan side chains and the putative presence of a 4-O-Methyl glucuronoxylan which is considered to be bioactive (Batbayar et al., 2008).

In contrast Zhang et al. (2007) reported onlythe presence of arabinose, xylose, lyxose, mannose, glucose, and d-galactose but no acidic monosaccharides.

The reported ability of A sphaerocephala gum to improve chewing quality and elasticity in noodles (Xing et al., 2009) may suggest an anionic polymer with gelling capabilities similar to alginate or low-methoxy pectins. A sphaerocephala gum is reputed to be effective against diabetes and has a clinical record in animal studies to support that conjecture (e.g. (Xing et al., 2009).

Soil? A sphaerocephala gum also has the interesting property of being able to aggregate sandy soil (Batbayar et al., 2008).

BATBAYAR, N., BANZRAGCH, D., INNGJERDINGEN, K. T., NARAN, R., MICHAELSEN, T. E. & PAULSEN, B. S. 2008. Polysaccharides from  Mongolian plants and their effect on the complement system:  I.  Polysaccharides from plants of the Asteraceae family. Asian Journal of Traditional Medicines, 3, 33-41.

ZHANG, J., WU, J., LIANG, J., HU, Z., WANG, Y. & ZHANG, S. 2007. Chemical characterization of Artemisia seed polysaccharide. Carbohydrate Polymers, 67, 213-218.