Tag: fruit

The Chemistry of Jam-Making

What Makes Jam Set? – The Chemistry of Jam-Making

The Chemistry of Jam-Making
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If you’ve ever tried your hand at jam-making, you’ll know that it’s something of a tricky process. A number of factors need to be just right to achieve a perfectly set jam – and chemistry can help explain why. There are three key chemical entities that go into jam-making: sugar, pectin, and acids. Here, we’ll look at each in turn, and how they help jam achieve its eventual consistency.

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The Chemistry of Raspberries

Raspberries, Weight Loss, & The Galaxy – The Chemistry of Raspberries

The Chemistry of Raspberries

Raspberries, like all fruits, contain a complex mix of organic compounds. Unlike many fruits, however, raspberries have the less common distinction of lending their name to the compound that is a major contributor to their aroma – and one of the compounds that contributes to their flavour has also been detected in the centre of our galaxy. So, does the centre of the galaxy taste faintly of raspberries?

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Why avocados turn brown — and how chemistry can stop it

Infographic on avocado browning. Avocados contain compounds called phenols. Exposure to oxygen converts phenols to compounds called quinones. The enzyme polyphenol oxidase speeds up this process. The polymeric compounds causing the brown colouration are melanin pigments. Leaving the stone in the avocado or in guacamole doesn’t slow browning as it doesn’t block oxygen. Covering with clingfilm can block oxygen and delay browning. Adding lemon or lime juice, or chilling the avocado, can also delay browning, as it inhibits the activity of the polyphenol oxidase enzyme.
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Anyone who’s ever purchased an avocado will testify that, after taking several days to reach the point of perfect ripeness, they remain at that point for an incredibly short amount of time before morphing into a brown, sludgy mess. As if to confound this problem, if you do catch them at the optimum ripeness, they turn brown incredibly quickly after being cut open if not eaten straight away. As always, chemical processes at work are to blame for this occurrence.

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