Quinoa (Chenopodium quinoa) is nutritious grain that is grown in the Andean highlands. It is an excellent example of ‘functional food’ that aims at lowering the risk of various diseases. Functional properties are given also by minerals, vitamins, fatty acids and antioxidants that can make a strong contribution to human nutrition, particularly to protect cell membranes, with proven good results in brain neuronal functions. However, several antinutritional substances, such as saponins, have been found in quinoa. A significant problem with quinoa grain is the high saponins content located mainly in the outer layers of grains. Saponins have traditionally been removed by washing the grain in alkaline water. A problem of this process is that it uses large amounts of water and causes pollution. Because of that, the aim of this work was to use the pearling technology to produce quinoa flours with low saponin content and to obtain ingredients for pasta and bakery industry. Moreover, the effect of pearling on phenolic content was also evaluated. The results indicate that an abrasion degree of 20% allows reducing the saponin levels more than 50% of initial saponin content. Besides, the phenolic content was evaluated before and after pearling. Flavonoids were the principal class of free phenolic compounds in whole and pearled samples and ranged between 94 and 96 % of total free phenolic compounds. The loss of single free phenolic compounds was in the range of 18 and 100 %, however some phenolic compound increased after pearling. Bound phenolic compounds were contained in lower quantities compared to free phenolic compounds and they were only phenolic acids. As reported for free phenolic fraction, all bound phenolic compounds, except p-coumaric acid, decreased after pearling (13-53 %). The increase of some phenolic compounds can be justified because, probably, they were contained in the internal layers of quinoa seed, because of that they are not removed during pearling.
Influence of pearling process on phenolic and saponin content in quinoa
VERARDO, VITO;CABONI, MARIA
2013
Abstract
Quinoa (Chenopodium quinoa) is nutritious grain that is grown in the Andean highlands. It is an excellent example of ‘functional food’ that aims at lowering the risk of various diseases. Functional properties are given also by minerals, vitamins, fatty acids and antioxidants that can make a strong contribution to human nutrition, particularly to protect cell membranes, with proven good results in brain neuronal functions. However, several antinutritional substances, such as saponins, have been found in quinoa. A significant problem with quinoa grain is the high saponins content located mainly in the outer layers of grains. Saponins have traditionally been removed by washing the grain in alkaline water. A problem of this process is that it uses large amounts of water and causes pollution. Because of that, the aim of this work was to use the pearling technology to produce quinoa flours with low saponin content and to obtain ingredients for pasta and bakery industry. Moreover, the effect of pearling on phenolic content was also evaluated. The results indicate that an abrasion degree of 20% allows reducing the saponin levels more than 50% of initial saponin content. Besides, the phenolic content was evaluated before and after pearling. Flavonoids were the principal class of free phenolic compounds in whole and pearled samples and ranged between 94 and 96 % of total free phenolic compounds. The loss of single free phenolic compounds was in the range of 18 and 100 %, however some phenolic compound increased after pearling. Bound phenolic compounds were contained in lower quantities compared to free phenolic compounds and they were only phenolic acids. As reported for free phenolic fraction, all bound phenolic compounds, except p-coumaric acid, decreased after pearling (13-53 %). The increase of some phenolic compounds can be justified because, probably, they were contained in the internal layers of quinoa seed, because of that they are not removed during pearling.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
