2.4 Nutraceuticals
Unlike functional foods, nutraceuticals are healthy products
elaborated from foods that are formulated and consumed in
defined dosages and in a drug format (El Sohaimy 2012).
Therefore, the rich composition of wastes from the food
industry makes them suitable for the development of
nutraceuticals as an alternative to synthetic substances
(Rudra et al. 2015). To this end, many conventional and
emerging technologies are used to extract bioactive compounds from agro-industrial residues for nutraceutical
development (Galanakis 2013). This allows many food
industry residues have been selected for the development of
nutraceuticals. Examples of this can be found in pomegranate seed waste using an enzymatic green extraction
process to obtain high quality oil, food-grade proteins, and
fibre; in peel of citrus plant for flavonoid extraction by
supercritical CO 2 ; or in coffee waste residues for obtainment
of phenolic compounds using subcritical water under
semi-continuous flow conditions (Talekar et al. 2018;
Giannuzzo et al. 2003; Mayanga-Torres et al. 2017).
2.5 Cosmeceuticals
Increasing attention has also recently been devoted to a
marked trend in the cosmetic industry toward the development and manufacture of high value products from natural
sources. Likewise, ethical consumerism has reached the
cosmetic industry, raising the question of sustainable
development. In addition to that, it is known that the
excessive consumption of ingredients for solar UV damage,
like organic UV filters, is related to the environmental
impact by exhibiting hormonal activity that affects negatively to the reproduction cycle of organisms (Gordobil et al.
2020). In fact, consumers are currently aware of circular
economy and sustainability concepts, looking for “green”
products. In this sense, bioactive compounds extracted from
food by-products, such as phytonutrients, microbial
metabolites, dairy-derived actives, minerals, vitamins, or
animal proteins, may have skin benefits resulting in new
high value-added products as cosmeceuticals (Prakash, L.
and Majeed, M. Natural ingredients for anti-ageing skin
care. Househ. Pers. Care Today 2009). The most widely
reported are bioactive phenolic compounds because of their
photoprotective and antioxidant properties (Panzella 2020).
3 Green Technologies for Obtaining
Bioactive Ingredients from Agro-Industrial
by-Products
The revalorisation of agro-industrial wastes to obtain functional ingredients have had an interest growing by the
industries to achieve a circular economy decreasing the
environmental impact as well as increase the use of their
own resources. To this end, different advanced extraction
technologies that allow to use green and Generally Recognised as Safe (GRAS) solvents (water, ethanol, deep eutectic
solvents) have been developed and applied to attain a great
variety of functional ingredients, minimising the solvent, and
energy consumption and increase the effectiveness of the
extraction processes (Ameer et al. 2017). The uses of some
of these advanced extraction techniques to attain functional
ingredients from different agri-food by-products are detailed
in Table 1.
Food by-products (e.g., leaves, peels, barks, or pomaces)
are an important source of bioactive compounds. However,
the concentrations of these bioactive compounds are sometimes reduced being necessary an extraction procedure to
concentrates them. In this sense, pressurised liquid extraction (PLE) has been used to attain different phytocomplexes
which are enriched mainly in phenolic compounds from
food by-products (Herrero et al. 2015). For example, this
technique has been used to discern the effect of grape
pomace fermentation to obtain enriched extracts in anthocyanins and tannins with high antioxidant capacities
(Vergara-Salinas et al. 2013).
Additionally, PLE was compared with conventional
extraction in order to attain phenolic enriched extracts from
olive pomace. PLE revealed a high capacity to extract a wide
variety of phenolic compounds and obtain more concentrated extracts than conventional extraction (Cea Pavez et al.
2019). Despite the fact that PLE is a versatile extraction
method since it can work with a wide variety of solvents and
provide high yield, some thermolabile compounds, such as
anthocyanins, can be slightly degraded because of the
extraction conditions (Machado et al. 2015). Although PLE
has been used mainly to recover phenolic compounds, it has
demonstrated to be an useful technique to retrieve carbohydrates such as inulin and pectin, which are compounds
that belong to soluble fibre (Ruiz-Aceituno et al. 2016; Guo
et al. 2012) and, in a minor proportion, oils (Eller et al. 2010)
from agri-food by-products. In summary, PLE is a versatile
232
Á. Fernández-Ochoa et al.
Unlike functional foods, nutraceuticals are healthy products
elaborated from foods that are formulated and consumed in
defined dosages and in a drug format (El Sohaimy 2012).
Therefore, the rich composition of wastes from the food
industry makes them suitable for the development of
nutraceuticals as an alternative to synthetic substances
(Rudra et al. 2015). To this end, many conventional and
emerging technologies are used to extract bioactive compounds from agro-industrial residues for nutraceutical
development (Galanakis 2013). This allows many food
industry residues have been selected for the development of
nutraceuticals. Examples of this can be found in pomegranate seed waste using an enzymatic green extraction
process to obtain high quality oil, food-grade proteins, and
fibre; in peel of citrus plant for flavonoid extraction by
supercritical CO 2 ; or in coffee waste residues for obtainment
of phenolic compounds using subcritical water under
semi-continuous flow conditions (Talekar et al. 2018;
Giannuzzo et al. 2003; Mayanga-Torres et al. 2017).
2.5 Cosmeceuticals
Increasing attention has also recently been devoted to a
marked trend in the cosmetic industry toward the development and manufacture of high value products from natural
sources. Likewise, ethical consumerism has reached the
cosmetic industry, raising the question of sustainable
development. In addition to that, it is known that the
excessive consumption of ingredients for solar UV damage,
like organic UV filters, is related to the environmental
impact by exhibiting hormonal activity that affects negatively to the reproduction cycle of organisms (Gordobil et al.
2020). In fact, consumers are currently aware of circular
economy and sustainability concepts, looking for “green”
products. In this sense, bioactive compounds extracted from
food by-products, such as phytonutrients, microbial
metabolites, dairy-derived actives, minerals, vitamins, or
animal proteins, may have skin benefits resulting in new
high value-added products as cosmeceuticals (Prakash, L.
and Majeed, M. Natural ingredients for anti-ageing skin
care. Househ. Pers. Care Today 2009). The most widely
reported are bioactive phenolic compounds because of their
photoprotective and antioxidant properties (Panzella 2020).
3 Green Technologies for Obtaining
Bioactive Ingredients from Agro-Industrial
by-Products
The revalorisation of agro-industrial wastes to obtain functional ingredients have had an interest growing by the
industries to achieve a circular economy decreasing the
environmental impact as well as increase the use of their
own resources. To this end, different advanced extraction
technologies that allow to use green and Generally Recognised as Safe (GRAS) solvents (water, ethanol, deep eutectic
solvents) have been developed and applied to attain a great
variety of functional ingredients, minimising the solvent, and
energy consumption and increase the effectiveness of the
extraction processes (Ameer et al. 2017). The uses of some
of these advanced extraction techniques to attain functional
ingredients from different agri-food by-products are detailed
in Table 1.
Food by-products (e.g., leaves, peels, barks, or pomaces)
are an important source of bioactive compounds. However,
the concentrations of these bioactive compounds are sometimes reduced being necessary an extraction procedure to
concentrates them. In this sense, pressurised liquid extraction (PLE) has been used to attain different phytocomplexes
which are enriched mainly in phenolic compounds from
food by-products (Herrero et al. 2015). For example, this
technique has been used to discern the effect of grape
pomace fermentation to obtain enriched extracts in anthocyanins and tannins with high antioxidant capacities
(Vergara-Salinas et al. 2013).
Additionally, PLE was compared with conventional
extraction in order to attain phenolic enriched extracts from
olive pomace. PLE revealed a high capacity to extract a wide
variety of phenolic compounds and obtain more concentrated extracts than conventional extraction (Cea Pavez et al.
2019). Despite the fact that PLE is a versatile extraction
method since it can work with a wide variety of solvents and
provide high yield, some thermolabile compounds, such as
anthocyanins, can be slightly degraded because of the
extraction conditions (Machado et al. 2015). Although PLE
has been used mainly to recover phenolic compounds, it has
demonstrated to be an useful technique to retrieve carbohydrates such as inulin and pectin, which are compounds
that belong to soluble fibre (Ruiz-Aceituno et al. 2016; Guo
et al. 2012) and, in a minor proportion, oils (Eller et al. 2010)
from agri-food by-products. In summary, PLE is a versatile
232
Á. Fernández-Ochoa et al.