Nutritional composition and bioactive properties of the wholegrain flour obtained from maize inbred lines

Abstract

The aim of this study was to assess the chemical composition and bioactive properties of the wholegrain flour obtained from eleven maize inbred lines to identify genotypes with increased potential for the development of hybrids with high nutritional and functional value, suitable for food production. The maize inbreds, including seven standard yellow, two QPM (quality protein maize) and two lines for red kernel hybrids, were grown in the experimental field of the Maize Research Institute at the location of Zemun Polje, Serbia. Wholegrain maize flour was got by grinding the maize grain in a laboratory mill. The assessment of the chemical composition and content of certain bioactive compounds, as well as the total antioxidant capacity, was conducted using standard laboratory procedures. The highest starch content (73.73%) was determined in line L8, while line L10 had the highest protein content (12.82%). Among soluble proteins, the α-zein fraction was dominant in most of the lines, ranging from 0.92% to 3.57%. The highest content of total fibres (NDF) was determined in red kernel line L9 (15.77%). Line L8 was the richest in total carotenoids (21.08 μg βCE/g d.m.), while line L7 had the highest total antioxidant capacity (34.30 mmol Trolox/kg d.m.), which can be explained by the presence of anthocyanins in the red grain. Line L1 had the highest content of total sugars (3.36%), and line L4 had the lowest (1.44%). Most of the samples of inbred lines investigated in this study showed good quality parameters regarding chemical composition and bioactive properties. The obtained results may provide some valuable guidelines needed in the following stages of maize breeding and open up various possibilities for the utilization of wholegrain maize flour in the food industry.

Cilj ovog istraživanja bio je da se odrede hemijski sastav i bioaktivna svojstva integralnog brašna dobijenog od jedanaest inbred linija kukuruza u cilju identifikacije genotipova sa povećanim potencijalom za razvoj hibrida visoke nutritivne i funkcionalne vrednosti, pogodnih za proizvodnju hrane. Linije kukuruza, uključujući sedam standardnih žutih, dve QPM i dve linije za hibrid crvenog zrna, gajene su na oglednom polju Instituta za kukuruz na lokaciji Zemun Polje, Srbija. Integralno kukuruzno brašno dobijeno je mlevenjem u laboratorijskom mlinu. Procena hemijskog sastava i sadržaja pojedinih bioaktivnih jedinjenja, kao i ukupnog antioksidativnog kapaciteta, sprovedena je primenom standardnih laboratorijskih procedura. Najviši sadržaj skroba (73,73%) utvrđen je u liniji L8, dok je linija L10 imala najveći sadržaj proteina (12,82%). Među rastvorljivim proteinima, frakcija α-zeina bila je dominantna u većini linija, u rasponu od 0,92% do 3,57%. Najveći sadržaj ukupnih vlakana (NDF) utvrđen je u zrnu crvene boje Linije 9 (15,77%). Linija L8 je bila najbogatija ukupnim karotenoidima (21,08 mg βCE/g s.m.), dok je linija L7 imala najveći ukupni antioksidativni kapacitet (34,30 mmol Trolox/kg d.m.), što se može objasniti prisustvom antocijana u crvenom zrnu. Linija L1 je imala najveći sadržaj ukupnih šećera (3,36%), a linija L4 imala je najmanji (1,44%). Svi uzorci novih inbred linija ispitivani u ovoj studiji pokazali su dobre parametre kvaliteta u pogledu hemijskog sastava i bioaktivnih svojstava. Dobijeni rezultati mogu dati neke dragocene smernice potrebne u narednim fazama oplemenjivanja kukuruza, kao i otvoriti različite mogućnosti za korišćenje integralnog kukuruznog brašna u prehrambenoj industriji.