How do you eat kiwi? You probably cut it in half and extract the pulp with a teaspoon throwing away the peel ... well from today maybe you won't throw away the peel anymore, but you will eat it. Oh yes, because the kiwi peel is not only edible but also a powerful source of antioxidants in quantities significantly higher than the pulp. This emerges from a recent scientific research published in the Food and Nutrition Research journal (Alim et al, FNR, 2019).
Pulp and peel of kiwifruit, how the experiment was carried out
Kiwifruit is considered a healthy fruit, rich in substances capable of fighting free radicals, bacteria but also cellular degeneration. However, the pulp does not contain even half of these beneficial substances when compared to the peel. Precisely to understand the difference between the peel and the pulp of the kiwifruit, the researchers of the study we are talking about today developed an experiment in which they analyzed extracts of the peel and pulp of Actinidia chinensis, or golden kiwi. In particular, these extracts were subjected to measurements with the mass spectrometer, to detect the presence and type of antioxidants, and were placed in contact with bacteria of the type Escherichia coli but also Listeria monocytogenes and Staphylococcus aureus, to test their antibacterial action, and with diseased cells of the liver to evaluate anticancer properties.
Comparison between peel and pulp
What emerged is that the peel contains significantly higher quantities of antioxidants than the kiwi pulp, 12.8 mg of polyphenols and flavonoids per gram of peel compared to 2.7 mg per gram of pulp.
As for the type of antioxidants, catechins, quercetin and epigallocatechin prevailed. The antibacterial action was observed for both the peel and pulp extracts of the kiwi, however the peel proved to be more powerful in inhibiting the bacteria of the three strains tested. The antitumor action was also demonstrated in both extracts but with the difference that, in the long term, the polyphenols contained in the kiwi peel proved to be more effective in counteracting cellular degeneration.
Don't throw away the kiwi peel, conclusions
So, from today we have one more reason to eat kiwifruit, alone or added to fruit salads and yogurt. But without throwing the peel! Perhaps you can choose the variety of golden kiwi, on which the experiment was also performed, that has a more sweet-tasting and less hairy skin.