The cashew apple is a tropical pseudo fruit, with high fiber
content, high nutritional value, and therapeutic compositional profile.
Consuming cashew apples can help with several health-related problems, such as
obesity, stomach ulcers, and gastritis. It has even demonstrated anti-tumor and
anti-carcinogenic effects, and its antioxidants can help with wound-healing.
Despite such benefits, the cashew apple is frequently considered as waste
generated by cashew nut industries, since its commercial applications are
restricted by the astringency and poor storability. This astringency is
primarily due to the presence of tannins; and a lack of proper, efficient, and
economical astringency reduction strategy is accountable for major waste
generation. This review compiles pieces of information on the causes of
astringency, as well as tannin reduction methods, such as clarification,
thermal treatments, microfiltration, and fermentation. These methods aim to
either just reduce tannin content or to valorize this by-product in a
less-astringent better product. Both routes will eventually help with the
better utilization of said organic food waste, which is critical for sustainable development.