/oss/taxonomy/term/1277/all en /oss/article/history-general-science/brown-isnt-always-dull <p>When an apple is cut in half, the exposed surface quickly turns brown. Do the same thing to an orange, and nothing happens. The noted Hungarian biochemist Albert Szent-Gyorgyi was intrigued by this observation because the brown colour seemed to him to be very similar to the skin pigmentation often noted in patients suffering from Addison's disease. He was studying the disease which had been described by Thomas Addison in 1855 and knew that it was characterized by an underactive adrenal gland.</p> Wed, 07 Jul 2021 18:50:43 +0000 Joe Schwarcz PhD 8779 at /oss /oss/article/videos-history/right-chemistry-william-henry-perkins-discovery-mauveine <p></p><div class="media-youtube-video media-element file-default media-youtube-1"></div> Mon, 06 May 2019 19:24:09 +0000 Joe Schwarcz PhD 7748 at /oss /oss/article/can-aspirin-help-remove-stains-and-keep-your-whites-white <p><span>The internet is </span><a href="https://www.huffingtonpost.ca/entry/remove-sweat-stains_n_1452258">full of</a><span> suggestions that Aspirin can be used to </span><a href="https://www.wikihow.com/Get-White-Clothes-White-Again">remove stains</a><span> and get </span><a href="https://www.rd.com/home/cleaning-organizing/6-secret-laundry-ingredients/">whiter whites</a><span>. These sites don’t offer any mechanism of this bleaching of course, so I had to try it myself.</span></p> Thu, 14 Jun 2018 17:00:00 +0000 Ada McVean B.Sc. 7134 at /oss /oss/article/you-asked/where-does-colour-go-when-i-bleach-my-hair <p><span>Hair naturally gets its colour from a pigment molecule called</span><a href="https://en.wikipedia.org/wiki/Melanin"> melanin</a><span>. There are 2 types of melanin:</span><a href="https://en.wikipedia.org/wiki/Melanin#Eumelanin"> eumelanin</a><span>, which gives hair and skin a brown or black hue, and</span><a href="https://en.wikipedia.org/wiki/Melanin#Pheomelanin"> pheomelanin</a><span>, which gives the red hue.</span></p> Wed, 28 Feb 2018 18:52:47 +0000 Ada McVean B.Sc. 6939 at /oss /oss/article/health-news-quackery/fearsome-yellow <p>Next time you think of welcoming someone home by tying a yellow ribbon around an old oak tree, you might want to think again. According to a widely circulating report the yellow dye could leave a toxic residue on your hands. What are we talking about? PCBs. Actually one specific PCB, namely PCB-11. Polychlorinated biphenyls have become an environmental pariah, accused of being endocrine disruptors and carcinogens. Quite a comedown for chemicals that were once revered as ideal heat transfer fluids and insulating materials in electrical equipment.</p> Mon, 24 Mar 2014 02:56:31 +0000 Joe Schwarcz PhD 2117 at /oss /oss/article/food-health/pistachios-reputed-have-some-uplifting-health-benefits <div> <p style="text-align:justify">Remember when it wasn’t hard to determine if someone had been into the pistachio bowl? They’d be caught red-handed! That’s because until artificially coloured foods became a pariah, pistachio nuts, which are actually not nuts but the seeds of a fruit, often used to be coloured red. Exactly why that was the case is a matter of some controversy.</p> <p style="text-align:justify">Some suggest that when pistachios were first imported into North America back in the 1930s, mostly from Iran, the shells tended to be blemished as a result of hand-picking. Since Americans didn’t care for blemished food, the pistachios were dyed red.</p> <p style="text-align:justify">Others suggest that the red colour was added to distinguish the newly introduced nuts from other varieties to attract attention. Another possibility is that in Iran, traditionally, the nuts were soaked in brine and then roasted in the sun which resulted in a pinkish coloured shell — and importers added red dye to achieve a uniform product.</p> <p style="text-align:justify">The fact is that nobody really knows how the tradition started, or indeed what dye was used, although some accounts make reference to a “vegetable dye,” probably beet juice. With concerns being raised about food additives, red pistachios have mostly disappeared, although a few companies still produce them for consumers mired in nostalgia. The vast majority of pistachios sold in North America now come from California, and instead of attracting consumers with colour, producers hope to attract them with science. The hook is a possible benefit in the prevention of heart disease — and believe it or not, help with erectile dysfunction.</p> <p style="text-align:justify">Nuts are low in saturated fats, high in monounsaturates and are rich in antioxidants, so it comes as no great surprise that epidemiological studies have demonstrated a link between increased nut consumption and reduced risk of cardiovascular disease. Pistachios have a chemical profile similar to nuts and have therefore been studied in terms of reducing cardiovascular risk. In one small study, subjects were asked to consume either 40 grams, 80 grams or no pistachios daily. The pistachio consumers lowered their LDL cholesterol (the “bad guy”), but interestingly, there was no difference between the 40 or 80 gram consumers. So one pistachio snack seems to be enough; more is not better.</p> <p style="text-align:justify">But does this extra consumption not lead to weight gain? Apparently not. A study in China examined the pistachio effect in some 90 subjects diagnosed with metabolic syndrome, which is a combination of disorders that increase the risk of developing cardiovascular disease and diabetes. Although there are some variations in the definition of metabolic syndrome, it basically means a high waist circumference combined with any two of elevated triglycerides, reduced HDL cholesterol (the “good guy”), raised blood pressure, raised fasting glucose, or previously diagnosed Type 2 diabetes. In the Chinese study, subjects consumed either no pistachios, or 42 grams or 70 grams for 12 weeks. There were no changes in body-mass index or waist-to-hip ratio. Curiously, there was also a slight improvement in triglyceride levels in the 42-gram group but not the others.</p> </div> <div>Pistachios have also been the subject of a study by Dr. James Painter of Eastern Illinois University who coined the term “pistachio principle,” referring to an effect by which the body is fooled into eating less by using visual cues.</div> <p><a href="http://blogs.mcgill.ca/oss/2013/11/09/pistachios-reputed-to-have-some-uplifting-health-benefits">Read more</a></p> Sun, 10 Nov 2013 00:11:22 +0000 Joe Schwarcz PhD 2031 at /oss /oss/article/food-health-history-you-asked/you-asked-it-true-some-candies-are-coloured-insect-extract <p>Yes some candies and other foods can be coloured with cochineal extract which is an approved food additive. Hernan Cortez was the first European to learn about this colourant when he became intrigued by the beautifully colored Aztec fabrics. He learned that the source of the dye was what appeared to be seeds on a cactus plant. But closer scrutiny revealed that they were not seeds at all, they were little bugs. Today we know them simply as “cochineal” and the dye they yield as “carmine.”.</p> Sun, 22 Dec 2013 01:37:48 +0000 Joe Schwarcz PhD 2050 at /oss /oss/article/health-science-science-everywhere-you-asked/why-were-red-mms-eliminated-should-i-be-concerned <p style="text-align:justify"><a href="http://blogs.mcgill.ca/oss/?p=4365"><img alt="" height="150" src="http://blogs.mcgill.ca/oss/files/2013/03/MMs-150x150.jpg" width="150" /></a> Much to the public’s dismay, the Mars and Murray Company stopped production of red M&Ms because of a health scare concerning Red Dye Number 2, which at the time was the most common red food dye in use. This dye was never used in M&Ms but the company decided to withdraw the red candies “to avoid consumer confusion and concern.” It isn’t clear exactly what confusion Mars and Murray was worried about since the Food and Drug Administration banned Red Dye Number 2 in January of 1976. So if red M&Ms had stayed on the market, it would have clearly meant that the suspect dye was not used. Perhaps the Company was concerned that people might think it was using an illegal dye. The story becomes even more bizarre when the evidence upon which Red Dye Number 2 was banned is examined. In the early 1970s there were a couple of small, poorly carried out Soviet studies that suggested the dye caused thyroid tumours in male rats and stillbirths and deformities in females. <a href="/oss/why-were-red-mms-eliminated-should-i-be-concerned/">Read more</a></p> Tue, 05 Mar 2013 18:09:17 +0000 Joe Schwarcz PhD 1887 at /oss /oss/article/general-science-history/carmine-dye-and-cochineal-insect <p>At least in a manner of speaking. When Hernan Cortez came to America in 1518 he was intrigued by the beautifully coloured Aztec fabrics, particularly the stunning reds. He asked the natives about the source of the colorant and was shown some specks on a cactus plant. Closer scrutiny revealed that the little specks were actually little bugs. Today we know them as Dactylopius coccus, or simply as cochineal. The dye that can be extracted from these insects is called carmine. Montezuma was so fond of it that he imposed a tax upon his subjects that had to be paid in dried cochineal bugs.</p> Wed, 15 Feb 2017 21:55:27 +0000 Joe Schwarcz PhD 1462 at /oss