3.1. FA composition, TAG profile, and nutritional quality indexes
Table 1 shows the FA composition of the fats and oils analyzed by gas chromatography, as well as their atherogenicity and thrombogenicity indexes. While pracaxi, patawa, and Brazil nut oils presented high contents of monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acids, tucuma kernel oil, murumuru fat and bacuri fat presented a high content of saturated fatty acids (SFA). Due to their high SFA contents, these last three products are solid at room temperature, whereas pracaxi, patawa, and Brazil nut oils are liquid.
The particular FA composition of Amazon oils opens up possibilities for application in the food industry. For instance, the high concentration of oleic acid found in patawa oil (74.18%) is in the same range as that found in high oleic sunflower and buriti oil (Silva et al., 2009; Smith, King, & Min, 2007). Furthermore, high concentrations of this fatty acid have a beneficial effect on thermal stability, suggesting that patawa oil could be useful to the food industry as a frying oil. In addition, the high oleic and linoleic ratio (˃ 12:1) of patawa oil could increase shelf life and nutritional value of foods.
While oleic acid is the primary FA in the composition of pracaxi oil and Brazil nut oil, pracaxi oil also showed a high content of behenic acid (17.88%) and Brazil nut oil had a high content of linoleic acid (31.73%). Behenic acid has a neutral impact on serum lipid concentration because of its low bioavailability and very long chain length (Cater & Denke, 2001), suggesting that pracaxi oil can be useful in the preparation of low-calorie products. Since Brazil nut oil has a higher content of linoleic acid when compared to conventional edible nut oils, such as almond or macadamia oils (Maguire, O’Sullivan, Galvin, O’Connor, & O’Brien, 2004), it can be nutritionally beneficial as an ingredient in food products.
Tucuma kernel oil, murumuru and bacuri fats were found to be rich in SFA. Murumuru fat and tucuma kernel oil had a high content of lauric acid, meanwhile bacuri fat had a high content of palmitic acid. Tucuma kernel oil has a FA composition rather similar to coconut oil’s (Marina, Che Man, Nazimah, & Amin, 2009). Therefore, like coconut oil, it can be used in cooking and in the pharmaceutical and cosmetic industries. Lastly, the high content of palmitic acid in bacuri fat makes it a potential source of tripalmitin (PPP), a TAG used for formulating lipid nanoparticles and alternative drug delivery systems (Reddy, Sharma, Chuttani, Mishra, & Murthy, 2004). Furthermore, bacuri fat had a relatively high content of palmitoleic acid, a beneficial FA which improves insulin sensitivity (Yang, Miyahara, & Hatanaka, 2011).
Atherogenicity index (AI) and thrombogenicity index (TI) are health lipid indexes, which take into account the effects of saturated and unsaturated FA in the development of coronary heart diseases (Ulbricht & Southgate, 1991). According to Table 1, nutritional quality indicators AI and TI ranged from 0.1 to 14.6 and 0.18 to 6.69, respectively. Tucuma kernel oil and murumuru fat presented the highest values for both indicators due to their SFA contents. Thus, to improve the nutritional quality of fatty products, these lipids could be blended with healthier oils, such as patawa or pracaxi oils.