**4. Potential for macauba applications**

*A. aculeata*, in growing regions, is widely used by the local population, from the stem, leaves, and thorns to all parts of the fruit (epicarp, mesocarp, and endocarp) for food, medicinal, and craft purposes [90], while the medicinal applications of macauba palm as an analgesic, hypotensive, and diuretic are empirical [90]. Recently, a phytochemical study of the components of *A. totai* spines allowed the identification of eight bioactive compounds with anticancer, antiparasitic, antibacterial, and antiviral activities [91].

The macauba potential for industrial applications is due to the high productivity and quality of pulp and kernel oils and can be grouped into four industrial segments, such as pharmaceuticals, cosmetics, food, and energy [15].

Both the macauba pulp and kernel are edible and have high nutritional value, allowing their insertion into the food industry [15]. The pulp can be added directly to food or as flour [92]. Other parts of the fruit can also be used. The biomass resulting from the macauba oil extraction is pressed to form cakes as an alternative for animal feed, as they do not present toxic components [93]. The pulp cake contains 9% protein, while the kernel cake has 32% [15]. Residues from the oil extraction from the macauba endocarp have been used for the production of higher quality vegetable carbon when compared to carbon from eucalyptus, with wide application in the steel industry [5, 94].

The differential composition of macauba pulp and kernel oils concerning the fatty acid profile and minor components (tocopherols, carotenoids, antioxidants, and phenolic compounds) provides a differentiated market for both products [15]. Pulp oil has a higher content of oleic and linoleic acids, with a recognized role in disease prevention and health promotion, including the role of oleic acid in the prevention of breast cancer and linoleic acid in the cognitive abilities of the elderly [95, 96]. Additionally, the macauba pulp oil has a higher content of carotenoids and tocopherols when compared to kernel oil. Traesel et al. reported no cytotoxic, genotoxic, or mutagenic effects of macauba pulp oil in rats [97].

Studies have shown that pulp oil, both in its raw and microencapsulated form, has diuretic and anti-inflammatory potential. It was also found that the microencapsulated pulp oil maintained the stability of the active ingredient and exhibited antiedematogenic activity [98]. Recent research has suggested that macauba pulp oil can be a promising high-quality raw material for the production of functional ingredients and foods with nutraceutical properties [99].

The kernel oil presents high content of saturated fatty acids (74%) with a predominance of lauric acid (44%) [99], which can be a promising approach for use in the pharmaceutical and cosmetic industries [9]. Studies have shown the hypoglycemic effect of kernel oil in rats with type 2 diabetes when administered orally [100]. Dario et al. showed that kernel oil can be an alternative adjuvant in the development of a nanocarrier, enhancing the photoprotective activity [101]. Macauba kernel oil has also shown potential for use as a lipid ingredient in margarines and mayonnaises [102].

The macauba mesocarp oil is a promising raw material for biodiesel production due to the predominance of unsaturated fatty acids (±73%), mainly oleic acid (±52%) [14]. Biodiesel is defined as methyl esters of long-chain fatty acids derived from vegetable oils or fats [103]. As reported by Coimbra and Jorge, biodiesel derived from *A. aculeata* pulp oil is mainly composed of intermediate alkyl esters (16- and 18-carbon fatty acid chains) consisting of more than 50% monounsaturated alkyl esters, and approximately 25% palmitic acid esters [14]. This chemical composition ensures the desired thermo-oxidative stability and viscosity [104]. Currently, the industrial production of biodiesel is accomplished by alkali-catalyzed transesterification of vegetable oils in the presence of short-chain alcohol to form fatty acid esters and glycerol [105]. Meanwhile, macauba pulp oil has been used for the synthesis of ethyl esters by transesterification using both heterogeneous and homogeneous acid catalysts [106, 107]. Enzymatic transesterification reactions have also been used as a sustainable alternative to the chemical process for the production of biofuels from macauba pulp oil and ethanol [108]. Non-catalytic transesterification of macauba pulp oil in supercritical alcohols also generates quality products and environmental benefits [109]. These methodologies are more tolerant to high levels of oil acidity, which is common in macauba oil, while basic transesterification requires a maximum acidity of 0.5% (w/w) [105].

Xavier and Costa [15] performed a scientific and technological mapping on the characteristics and applications of macauba oil, showing the important contribution of Brazil in this area, and the participation of Brazilian universities in the valorization of native raw material. The technological segments most represented in this analysis of patents were energy, cosmetics, and agriculture [15].
