Table 5: Advantages and disadvantages of the coffee husk and pulp utilization, and further developments.

Utilization	Advantages	Disadvantages	Research
Animal feeding	Coffee husk and pulp are rich in organic components, mainly carbohydrates, proteins and minerals that are present in the mesocarp of ripe fruits. It has been used as partial substitutes of animal feed amendments such as cereal grains.	The presence of tannins and caffeine diminish the acceptability and palatability of husk by animals. Caffeine has stimulatory and diuretic effects and tannins decrease the protein availability and inhibit digestive enzymes.	Some research studies have been done to remove these anti-nutritional substances, it include biological decaffeination with microorganism and silage. Silage presents and ideal method to preserve the material and partially reduce the contents of anti-physiological compounds. Coffee husk added up to 30% improve fermentative standard for silage of good quality increasing the protein content. Several studies have been done to evaluate their use as dietary supplement for cattle, swine, sheep, chicken, horses and fish. Good results have been observed with concentrations between 5 and 40%. Il all cases a saving of 30% is estimated. Animal feeding could represent a possible-re-use.
Growth substrate for mushrooms	Coffee husk and pulp could be used for edible and medicinal fungi production without any pre-treatment. Residues after fungi cultivation could be used to feed ruminants because caffeine and tannic acids decrease while protein increase (9%).	There are not large scale application probably because the cost of sterilization.	Development of detoxification pre-treatment of the substrate would help to obtain an entirely safe mushrooms production.
Silverskin for cosmetics and dermaceutics	Aqueous extracts may be used for the production of added value products, i.e. cosmetics and dermaceutics, beacause of the presence of anti-oxydants and bioactive substances.	This re-use can help in alleviating the environmental overburden of silverskin for limited global quantities of this residue.	The acquisition of preclinical data on the nutraceutical. benefits should be accompanied by safety assessment data in order to facilitate the authorization of these products for use in humans.
Spent coffee grounds for biodiesel production	Oil extraction with isopropanol and a mixture of hexane/isopropanol (50:50, vol/vol) allowed high oil recovery (21 %) at a relatively lower cost.	The quality of the obtained biodiesel, evaluated according the NP EN 14214:2009 standard, shows that biodiesel obtained is out of the standard limits for all the evaluated parameters.	Many improvements of the process need be developed to make it both technically and economically viable.
Ethanol production	Given the high concentration of carbohydrates in the coffee husk, this residue is viewed as potential raw material for bioethanol production.	Has not been adopted on a practical scale.	Many improvements of the process need be developed to make it both technically and economically viable.
Organic Fertilizers/ green amendments	Coffee husk and coffee pulp are rich in potassium and other mineral nutrients, which results in an organic/green fertilizer or amendment.	Disposal of coffee husk and pulp residues without treatment result in severe environmental problems including the proliferation of flies, foul odours, soil infiltration and others. Correct composting technology is seldom applied.	Appropriate composting and worm-composting provide a product that can be easily handled, stored, and applied to the land without adverse effects. However the voluminous supply of husks and pulp and the composting process currently used do not guarantee the destruction of the coffee borer that may be infecting some of the coffee pulp.