When it comes to foods that pack more than the usual share of goodness, look no further than kiwifruit. Photo / 123RF
Scientists have been making incredible new discoveries – and not in foods of the future, but in those staples we eat every day. Plant and Food Research scientists share eight exciting insights.
Kiwi-grown blackcurrants are great for your brain and, as a recent study found, they also happen to help you work out.
New Zealand blackcurrants contain a combination of anthocyanins not found in other berries or blackcurrants grown elsewhere.
Studies by Plant & Food Research scientists have found that, after consuming a time-dependent 120mg dose of anthocyanins from the little dark purple berries, they can improve exercise performance and recovery.
How? They're known to manage oxidative stress, speeding the resolution of inflammation post-exercise, and improving immunity.
On top of that, scientists have found they can actually increase motivation to keep exercising.
They've already been shown to help people stay alert, reduce mental fatigue and allow us to work with greater accuracy while under stress.
Studies have pointed to increased mental performance indicators like accuracy, attention and mood.
An extract from a hop cultivar bred by Plant and Food Research and grown in New Zealand has been clinically demonstrated to regulate eating behaviour.
Known as amarasate, it works by triggering the "bitter brake" - a psychological mechanism that tells the brain to stop eating.
When specific cells in the small intestine sense the bitter compounds, they trigger a hormonal response that tells the brain to stop eating.
About one in 1000 cells on the surface of the gut is an enteroendocrine cell.
Some of these enteroendocrine cells have bitter taste receptors that detect specific bitter compounds – such as those found in amarasate.
"This isn't a silver bullet for obesity, but we have found a natural compound that is able to activate one of the body's own mechanisms for curbing appetite," Dr John Ingram says.
Scientists were working on turning amarasate extract into a supplement and functional food product.
Imagine buying your mushrooms in punnets made of… mushrooms.
Plant and Food Research has been working with Scion researchers and Kiwi business Meadow Mushrooms to turn mushroom by-products into a valuable bio-resource, in the form of bio-degradable mushroom punnets.
Dr Ben Schon explains: "Mushrooms have the ability to absorb water - and compared to other natural fibres, their fibres can stay strong when they are wet.
"There are able to absorb water from their environment without losing strength, which makes them suitable for use in packaging."
Schon says the manufacturing process for creating mushroom-based packaging is similar to the process used to make paper and card.
Researchers are also exploring how they can optimise the amount of mushroom resource used to improve packaging products - even waterproofing them.
Plant and Food Research experts have suggested avocados may be good for gut health – a previously unknown benefit of the Kiwi favourite.
They're already known for supporting cardiovascular health, regulating blood glucose, and having anti-inflammatory properties as well as being high in "good fats" and dietary fibre.
In a 2017 study, rats fed avocado metabolised the dietary fibre through fermentation to produce short-chain fatty acids (SCFAs).
These helped stimulate cells to produce antimicrobial peptides called defensins, which play an important role in immune protection.
The SCFAs were also fuel for goblet cells which produce mucus in a healthy gut- which protects gut tissue.
We might often think of them as tasteless balls of starch – but potatoes do have a range of flavours, some which consumers prefer over others.
Scientists have been investigating how consumers perceive potato flavour.
Consumers had definite differences in how acceptable they found the flavour of the 12 cultivars studied, which was related to the attributes they detected in them, Dr Marian McKenzie says.
"The findings that some attributes such as buttery, sweet and savoury are liked by consumers while green, sour and bitter are not, is not surprising."
"However, different consumers may prefer different combinations and balances of these attributes."
Even the glycoalkaloid compounds that give the unpleasant "green potato" flavour can enhance the flavour of potatoes when present at low concentrations – potatoes may even be perceived as bland and tasteless without them.
Metabolomic analyses of potato cultivars have now been used to delve further into what specific compounds are linked to these liked and disliked flavours.
"A better understanding of what flavour compounds contribute positively to flavour profiles will help breeding programmes in the future."
Wine lovers crave a perfect combination of things like aroma, taste and "mouth feel" in their vino – and striking that balance is a tricky job for winemakers.
Fortunately, there's also science to it. Using metabolic profiling, scientists found that the aromas in pinot noir are driven by a complex interaction of many compounds, rather than a few.
Further, they've learned the chemistries driving the aromas in pinot noir may be similar to those driving aromas in fruits and spices, such as blackcurrant and cinnamon.
In a PhD project, Emma Sherman analysed a large number of commercial pinot noir wines to find new ways to improve flavour.
She and colleagues went as far as making small scale wines themselves, from grapes sourced from several different vineyards around the country.
"Our findings showed that wines with strong fruity and spicy flavours - such as raspberry, blueberry, blackcurrant, cinnamon and black pepper - contained many of the same volatile compounds as the fruits and spices themselves."
This indicated that the same chemistries are likely to be responsible for the flavours in the wine and those of the fruits and spices.
"Additionally, a major driver of ripe fruity and spicy wine flavour was actually the decrease in concentrations of compounds that give wine more unripe, herbaceous and vegetal flavours, not the increase in the fruity or spicy flavoured compounds."
What happens to the remains of a fish after it's been filleted? It's long been practice to process much of it for animal feeds.
But Dr Susan Marshall sees the potential for so much more.
"If we optimise the value of all of the molecules within a whole fish, rather than just focusing on the meat, we have the potential to significantly increase returns from our wild fisheries without any increase to catch volume - as well making the most of aquaculture."
Her group has been working with the fishing industry to develop new high-tech products from fish and shellfish.
In one example, collagen extracted from hoki skin is being spun into nanofibres that are an incredible 500 times thinner than a human hair.
These are already being used in Revolution Fibre's dissolvable ActivLayr cosmetic patches.
"Thanks to the environment that hoki lives in, its skin collagen is unique," lead collagen scientist Dr Mathew Cumming says.
"We were able to use these special characteristics to develop a collagen that is perfectly suited for nanofibre production."
And, because hoki nose collagen is similar to human cartilage, it could even be used in biomaterials to treat cartilage-related illnesses like osteoarthritis.
When it comes to foods that pack more than their share of goodness, look no further than kiwifruit.
They're a high source of Vitamin C, a powerhouse of antioxidants, a great source of folate and dietary fibre, and help with everything else from digestion to sleeping.
But one recent finding by Plant & Food Research is worth singling out.
Scientists found they can also help reduce the glycaemic response when eaten with starchy foods like breakfast cereals, so long as the kiwifruit doesn't add to the overall carbohydrates in the meal.
It's likely because kiwifruit fibre behaves differently from other food fibres and boasts a low glycaemic index (GI) - making it suitable for diabetics.
In fact, the GI of kiwifruit measured in humans is less than calculated from the GI of its constituent sugars alone.
Scientists have also found kiwifruit eaten with carbohydrate can lower the blood glucose response to the carbohydrate in the meal.
"And if the kiwifruit is eaten 30 minutes before the meal the height of the blood glucose spike may be reduced by almost half," principal scientist Dr John Monro says.
"We have shown the effect for simple experimental studies and for realistic meals. There are probably several mechanisms underlying the effect, which we hope to unravel in further research."
In another surprising potential benefit, scientists are investigating how kiwifruit, like hoki skins, can be used in cosmetics.
One particular area of interest is in the possible use of kiwifruit in melanin-controlling skincare products for reducing pigmentation and enhancing the complexion.
In Asia, melanin-controlling skincare products are popular, but sometimes have undesirable side effects.
Scientists have been looking at whether there is anything in kiwifruit that could inhibit melanin, while also being safe for application.
Skin melanin acts as a natural barrier to ultraviolet light damage.
Its synthesis is catalysed by the enzyme tyrosinase. Tyrosinase inhibitors prevent melanin synthesis and lead to skin whitening - a desirable skin cosmetic attribute.
Kiwifruit, meanwhile, has previously been shown to contain natural inhibitors of tyrosinase.
In a recent study, scientists screened ten varieties of kiwifruit to give a snapshot of genetic diversity.
"We identified strong inhibitors and non-inhibitors of tyrosinase, which suggest there may be a beneficial effect from some varieties of kiwifruit on skin complexion," Dr Andrew Carroll says.
"The primary compounds that seem to be driving this are procyanidins, which may be absorbed either through food or directly through the skin."
This research may help in the creation of a new product category for the kiwifruit industries aimed at the large cosmetic market.
Based on the study findings, kiwifruit extracts will hopefully go into human trials shortly.
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