Resveratrol, a bioactive compound in fruits like grapes and cranberries, helps fight infections and reduce damage due to stress. However, when resveratrol is used to fortify food, there is poor absorption and low bioavailability.
Can encapsulating resveratrol help increase its bioavailability in fortified foods, wondered Adil Gani and Mudasir Ahmad from the University of Kashmir. They thought of encapsulating resveratrol in starch. Starch, a highly branched polymer, offers high stability and good encapsulation. So, Adil and Mudasir decided to try starch extracted from water chestnut, lotus stem and horse-chestnut, as they were easily available in Kashmir.
To encapsulate resveratrol in starch, they applied sound energy to agitate a mixture of the two. This distributes the resveratrol molecules within the starch. The mixture was then freeze-dried to a powder.
The duo then prepared wheat paste to which they added the powder. The paste was extruded under heat to prepare a snack.
To check the retention of resveratrol, the researchers powdered the fortified snack. Using spectroscopy, they found that the starch-encapsulated snacks retained almost 50 per cent of resveratrol whereas only five per cent remained without encapsulation.
The researchers found that the resveratrol-loaded snacks inhibit alpha-glucosidase, an enzyme that increases blood glucose levels by breaking down starch and disaccharides. Snacks with lotus stem starch showed the highest inhibition, suggesting its potential to reduce the risk of type-2 diabetes.
The researchers also analysed the snack’s anti-obesity properties. It inhibited enzymes involved in fat absorption and digestion. The effect was two-fold higher with the fortified snacks than with those containing free resveratrol.
Snacks fortified by lotus stem starch-encapsulated resveratrol also had strong antioxidant properties. Lipid peroxidation was inhibited by nearly 60 per cent!
Trained panelists then judged the snack’s texture, flavour and overall acceptability. They found no significant difference between fortified and non-fortified snacks, suggesting acceptability to consumers.
‘Food processing industrialists can now encapsulate resveratrol to enhance the nutraceutical properties of snacks,’ says Mudasir Ahmad, University of Kashmir.
‘Encapsulated resveratrol in food is an opportunity for young entrepreneurs and start ups in regions where lotus stem is available in plenty,’ says Adil Gani, University of Kashmir.
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